JPH0467913A - Different hardness bare headrest and manufacture thereof - Google Patents

Abstract

PURPOSE:To manufacture a different hardness bare headrest capable of reducing a feeling of physical disorder in a boundary part changed in hardness by forming a recessed part to an elastomer in a shape enlarged from the bottom surface thereof toward the opening end thereof and fixing a different hardness member to the inner surface of the recessed part in a closely bonded state. CONSTITUTION:A foaming mold 50 is composed of a split mold and has a cavity 52 having the pillow shape of a headrest therein. A bank 55 is vertically provided to the surface 54 of the cavity 52 at a predetermained position and a cavity surface 54a forming the head contact part of the headrest is surrounded by the bank 55. A different hardness member 34 composed of a foamed body having predetermined hardness is arranged to the cavity surface 54a surrounded by the bank 55 within the foaming mold 50 and a liquid foamable raw material 32a forming a foamed body harder than the different hardness member 34 on the cavity surface is injected in the cavity 52 of the foaming mold 50. As the liquid foamable raw material 32a, a polyurethane raw material forming soft polyurethane foam is pref.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a bare headrest with different hardness in which the hardness of the surface is partially different, and a method for manufacturing the same.

(Prior Art) The above-mentioned bare headrest with different hardness is used as a headrest for an automobile in a state where the pillow part is covered with an outer skin.

A conventional bare headrest with different hardness includes a pillow-shaped elastic body 1 made of foam having a predetermined hardness, as shown in the cross-sectional view of FIG.
A concave portion 12 is formed in a predetermined portion of the surface of the elastic body 10, and a different hardness member 14 made of a foam having a hardness different from that of the elastic body 10 is fixed to the concave portion 12.

As shown in FIG. 9, a simple manufacturing method for the bare headrest with different hardness is as shown in FIG. A variable hardness member 24 made of a foam having a predetermined hardness is installed on the cavity surface 22 surrounded by the embankment 20, and a foam having a hardness different from that of the variable hardness member 24 is installed in the remainder of the cavity 26. There is a method of injecting a liquid foaming material to be formed and foam-molding a pillow-shaped elastic body integrally with the variable hardness member 24 on the cavity surface.

(Problem to be Solved by the Invention) However, in the bare headrest with different hardness, since the boundary 13 of the hardness change on the surface is clear,
There is a problem in that the boundary portion 13 causes a sense of discomfort. Particularly in the case of automobile headrests, the change in hardness appears on the surface of the headrest in contact with the head, so the sense of discomfort at the boundary 13 where the hardness changes has a large impact on the user that cannot be ignored. It is something.

On the other hand, in the method for manufacturing the bare headrest with different hardness, the obtained bare headrest with different hardness causes a sense of discomfort at the boundary where the hardness changes as described above, and there are also the following problems. One of them is the cavity surface 22 surrounded by the embankment.
The different hardness member 24 installed in the cavity 26 is likely to come off from the cavity surface 22 during injection and foaming of the liquid foaming raw material into the cavity 26, and the bare headrest with different hardness is likely to be a defective product. The second reason is that the liquid foaming raw material easily enters between the different hardness member 24 and the embankment 20 on the cavity surface and forms an impregnated and hardened part around the different hardness member 24, and the resulting different hardness bare headrest is The problem is that the impregnated and hardened portion causes a sense of discomfort. Thirdly, as shown in the partial sectional view of FIG. 10, the different hardness member 24 of the obtained different hardness bare headrest
A gap 28 is formed by the embankment 20 on the cavity surface between the elastic body 26 and the gap 28, and an unsightly line 29 in the form of a depression is generated due to the gap 28 on the skin 27 that is then applied to the bare headrest surface of different hardness. That's true.

Therefore, in view of the above points, this invention provides a bare headrest with different hardness that can reduce the discomfort at the boundary where the hardness changes;
It is an object of the present invention to provide a method for manufacturing bare headrests with different hardness without causing the above-mentioned problems.

(Means for Solving the Problems) The gist of the present invention regarding a bare headrest with different hardness is that a pillow-like elastic body made of a foam with a predetermined hardness has a recess in a predetermined portion of the surface of the foam with a hardness different from that of the foam. In the bare headrest of different hardness to which a member of different hardness made of foam is fixed, the recess of the elastic body is expanded from the bottom surface toward the open end, and the member of different hardness is fixed to the inner surface of the recess. The bare headrest is characterized by different hardness.

In addition, the gist of the present invention regarding a method for manufacturing bare headrests with different hardness is that a bank is erected on the cavity surface of a foam mold to surround a predetermined portion of the cavity surface, and a foam of a predetermined hardness is formed on the cavity surface surrounded by the bank. A liquid foaming material is injected into the cavity, and a pillow-like elastic body made of a foam whose hardness is different from that of the different hardness member on the cavity surface is installed. In a method for manufacturing a bare headrest of different hardness that is integrally foam-molded, a cavity surrounded by a bank is made into a shape that becomes smaller as it goes away from the cavity surface, and a member of different hardness is formed whose periphery is larger than the cavity surface surrounded by the bank. A method for producing a bare headrest with different hardness, characterized in that the device is installed on a cavity surface surrounded by a bank, and the liquid foaming raw material is injected and foamed while the peripheral edge of the member of different hardness is pressed and compressed by the bank. It is in.

(Function) In the bare headrest with different hardness of the present invention, the recess on the surface of the elastic body has a shape that expands from the bottom toward the open end, and the member with different hardness is housed and fixed in close contact with the recess. The thickness of the hardness member becomes thinner toward the periphery of the different hardness member, and the change in hardness at the boundary between the different hardness member and the elastic body becomes gentler.

On the other hand, in the manufacturing method of the present invention, a cavity surrounded by an embankment erected on the cavity surface is formed into a shape that becomes smaller as it moves away from the cavity surface (in other words, a shape that expands toward the cavity surface), and the enclosed cavity is A member of different hardness larger than the surface is installed on the cavity surface surrounded by the bank, and the liquid foaming raw material is injected and foamed while the periphery of the member of different hardness is pressed and compressed by the bank. Due to the concave shape of the cavity surrounded by the embankment and the pressure bond between the periphery of the different hardness member and the embankment wall surface, the different hardness member is securely fixed to the cavity surface, and the different hardness member is firmly fixed to the cavity surface during injection of liquid foaming raw material and foaming. It does not lift up or come off from the surface, and since the periphery of the different hardness member is pressed against the embankment wall surface, liquid foaming raw material is prevented from entering between the periphery of the different hardness member and the embankment, Formation of an impregnated hardened portion on the periphery of the member of different hardness is prevented. Furthermore, in the manufacturing method, the periphery of the member of different hardness, which had been pressed and compressed by the bank in the cavity, is restored outward by demolding the bare headrest of different hardness. The gap once formed between the hardness member and the elastic body is closed by the restoration of the periphery of the different hardness member.

(Example) Examples of the present invention will be described below.

FIG. 1 shows a bare headrest with different hardness according to an embodiment of the present invention used as an automobile headrest.
FIG. 2 is a perspective view with a portion thereof removed.

The bare headrest 30 with different hardness is composed of an elastic body 32 and a member 34 with different hardness.

The elastic body 32 is made of polyurethane foam having a predetermined hardness and has a pillow shape of a headrest, and has a recess 36 formed on the surface that comes into contact with the head. The recess 36 on the head contact surface is inclined so as to gradually open outward as the peripheral wall 36a approaches the recess opening end 36b, and the recess 36 as a whole expands from the bottom surface 36c toward the opening end 36b. ing.

The different hardness member 34 is made of a soft polyurethane foam that is lower in hardness (softer) than the polyurethane foam constituting the elastic body 32 , and is made of a soft polyurethane foam that is softer than the polyurethane foam that constitutes the elastic body 32 .
It is firmly attached to the Recessed portion 36 of the elastic body 32
The different hardness member 34 fixed to the recess 36 has a substantially trapezoidal cross-sectional shape matching the enlarged shape of the recess 36, and the thickness of the peripheral edge 34a becomes thinner toward the edge.

The hardness of the elastic body 32 and the different hardness member 34 is as follows:
It is determined by the shock absorption properties and softness of the head contact surface required for automobile headrests.

Further, a reinforcing body 37 and a part of a stay 38 for attachment, which is integrated with the reinforcing body 37, are buried in the elastic body 32.

A bag-like skin 39 made of fabric, plastic leather, or the like is adhered to the surface of the bare headrest 30 with different hardness, thereby constructing a headrest for an automobile.

In the automobile headrest using the bare headrest 30 with different hardness, the peripheral edge 34a of the different hardness member on the head contact surface is
Since the surface of the elastic body 32 gradually becomes thinner as it approaches the boundary, the change in hardness at that part is gradual, and the discomfort felt on the head is minimized. Furthermore, this feeling of discomfort can be seen in Figure 2, which shows an enlarged cross section of part A.
By making the peripheral edge 34a of the member of different hardness into a thin fin shape and by making the wall surface 36a of the recess 36 of the elastic body into an arc shape that bulges outward, the layer can be made inconspicuous.

Next, an embodiment of the method for manufacturing a bare headrest with different hardness according to the present invention will be described.

Figures 3 to 6 relate to the method for manufacturing bare headrests of different hardness, of which Figure 3 is a cross-sectional view of a foam molding die showing the device for different hardness members, etc., and Figure 4 is a cross-sectional view of the foam molding die. One plan view, Figure 5 is a sectional view of the foam mold during foam molding, Figure 6 is a sectional view of the bare headrest with different hardness after demolding, and Figure 7 is a partial sectional view of the other foam mold. , is a sectional view taken at the same position as section B in FIG. 3. This will be explained below using those figures.

Note that the same numbers are used for the same members as in the description of the bare headrest with different hardness.

The foaming mold 50 is made of a split mold and has a cavity 52 in the shape of a headrest pillow inside. A cavity surface 54 constituting the cavity 52 has a bank 5 at a predetermined position.
5 is erected, and the cavity surface 54a forming the head contact portion of the headrest is surrounded by the embankment 55. The embankment 55 has a height of about 10 to 30 W, and is inclined at a predetermined angle toward the cavity 52a surrounded by the embankment 55, and sinks as the cavity 52a surrounded by the embankment 55 moves away from the cavity surface 54a. It is shaped like this.

Note that the angle a between the embankment 55 and the cavity surface 54a surrounded by the embankment is 90" or less, preferably 30" or less.
Approximately 60" is preferable.

Furthermore, a stay insertion recess 51 communicating with the cavity 52 is formed in the mold matching surface 50a of the foaming mold 50.

A variable hardness member 34 made of a foam having a predetermined hardness is provided on the cavity surface 54a surrounded by the bank 55 in the foam mold 50.
equipment. The different hardness member 34 has a peripheral edge 34a that is similar to the bank 5.
5 and the cavity surface 54a, and the size of the peripheral edge 34a is about 5 to 15 mm larger than the cavity surface 54a on which the different hardness member 34 is installed, and the soft foam A slab cut out into a predetermined shape is preferably used. The device of the different hardness member 34 to the cavity surface 54a is that the different hardness member 34 is larger than the cavity surface 54a, so that the peripheral edge 34
a is pressed and compressed by the wall surface of the embankment 55. And the member 3 of different hardness is installed on the cavity surface 54a.
4 is pressed and compressed by the wall surface of the bank 55 on the peripheral edge 34a of the member of different hardness, so that it comes into close contact with the wall surface of the bank 55 without any gaps. However, the different hardness member 34 has a cavity 52a in which the different hardness member 34 is installed, which becomes smaller as the distance from the cavity surface 54a increases.
It will be securely fixed within a.

Further, in addition to the different hardness member 34, an insert consisting of a reinforcing body 37 and a stay 38 is also installed in the cavity 52 of the foaming mold 50.

Next, as in the fifth (2I), a liquid foaming raw material 32a that forms a foam harder than the variable hardness member 34 on the cavity surface is injected into the cavity 52 of the foaming mold 50.

As the liquid foaming raw material 32a, a polyurethane raw material that forms a flexible polyurethane foam is suitable.

Then, the liquid foaming raw material 32a injected into the cavity is foamed to form an elastic body integrated with the variable hardness member 34 on the cavity surface. During injection and foaming of the liquid foaming raw material, the periphery of the different hardness member 34 is in close contact with the wall surface of the embankment 55, so the liquid foaming raw material 32a does not enter between the embankment 55 and the different hardness member 34, and the periphery of the different hardness member 34 In addition, since the different hardness member 34 is securely fixed to the cavity surface 54a surrounded by the embankment 55 as described above, it will not form an impregnated hardened part during injection of the liquid foaming raw material and foaming. It does not float or come off from the cavity surface 54a.

After that, if the molded product is taken out from the foaming mold 50, the sixth
As shown in the figure, a bare headrest 30 with different hardness is obtained in which a soft different hardness member 34 and a harder elastic body 32 are integrated. Note that in the bare headrest 30 of different hardness obtained by demolding, the bank 50 in the foaming mold should have become a gap 51 and remain between the elastic body 32 and the member 34 of different hardness. In this invention, the periphery 34a of the member of different hardness, which was pressed and compressed by the wall surface of the embankment 55 during foam molding of the elastic body, is restored to the outside by demolding the bare headrest 30 of different hardness. It becomes something without.

Further, as shown in FIG. 7, the periphery of the cavity surface 54a surrounded by the embankment 55 is formed into a substantially V-shaped cross section 7454b along the embankment 55, and the peripheral edge of the member of different hardness is shaped to fit into the groove 54b. If the elastic body is foam-molded, the resulting bare headrest with different hardness will have a thin fin-like shape at the periphery of the elastic body, which overlaps the surface of the elastic body. The change in hardness at the boundary becomes more gradual, and the uncomfortable feeling in the measurement area is further reduced.

In addition, in each of the above embodiments, the different hardness member was made to have a lower hardness (softer) than the elastic body, but depending on the use, design, etc. of the different hardness bare headrest, contrary to the above embodiments, the different hardness member may be used. The member may be made harder than the elastic body.

(Effect) Since the bare headrest with different hardness of the present invention has the above-described structure, the change in hardness becomes gradual near the boundary where the hardness changes, and it has the effect of reducing the discomfort caused by the change in hardness. .

Further, the method for manufacturing the bare headrest with different hardness of the present invention includes:
Since the headrest has the configuration described in +iir, it is possible to easily obtain a bare headrest with different hardness that causes little discomfort, and also has the following effects. In other words, the manufacturing method of the present invention allows the different hardness members to be placed on the cavity surface correctly and reliably, so that the different hardness members do not float or come off from the cavity surface during injection of liquid foaming raw material and foaming. This has the effect of making it possible to obtain a bare headrest with different hardness in which the members are in the correct position. Further, in the manufacturing method of the present invention, the peripheral edge of the different hardness member installed on the cavity surface is in close contact with the embankment wall surface, almost no liquid foaming raw material enters between the different hardness member peripheral edge and the embankment, and the different hardness member periphery Since almost no hardened portions are impregnated with the liquid foaming raw material, it is possible to reduce the discomfort that conventionally occurs on the bare headrest surface of different hardness due to the impregnated hardened portions. In addition, in the manufacturing method of the present invention, the peripheral edge of the member of different hardness, which had been pressed and compressed by the bank in the cavity, is restored by demolding the bare headrest of different hardness, and the bank in the cavity makes the peripheral edge of the member of different hardness elastic. When covering the obtained bare headrest surface with different hardness with a skin to close the gap once formed between the bodies, there is also the effect of eliminating unsightly lines that conventionally occur due to the gap.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway perspective view showing a bare headrest with different hardness according to an embodiment of the present invention, FIG. 2 is an enlarged sectional view of section A in FIG. 1, and FIGS. 3 to 6 are This relates to an embodiment of the method for manufacturing a bare headrest with different hardness of the present invention, in which FIG. 3 is a sectional view of a foam molding die showing when a member of different hardness is installed, and FIG. 4 is a plan view of one of the foam molding molds. Figure 5 is a cross-sectional view of a foam mold during foam molding of liquid foam raw material, Figure 6 is a cross-sectional view of a bare headrest with different hardness after demolding, and Figure 7 is a cross-sectional view of a bare headrest with different hardness according to the present invention.・This is a partial cross-sectional view of another foam mold used in the manufacturing method of Ndrest.
8 is a sectional view showing the conventional bare headrest with different hardness, FIG. 9 is a sectional view showing the conventional manufacturing method of the bare headrest with different hardness, and FIG. 10 is a sectional view showing the same part as part B in the figure. FIG. 2 is a partial cross-sectional view of a bare headrest with different hardness obtained by a conventional manufacturing method. 32: Elastic body, 34: Different hardness member, 36: Recess, 5-discharge foaming mold, 52: Cavity, 52a: Cavity surrounded by bank, 54: Cavity surface, 54a: Cavity surface surrounded by bank, 55 : Tsutsumi,
32a: Liquid foaming raw material Figure 1 Factor 2

Claims (2)

[Claims] (1) Different-hardness bare headrest in which a different-hardness member made of a foam having a different hardness than the foam is fixed to a recess formed in a predetermined part of the surface of a pillow-like elastic body made of a foam with a predetermined hardness. A bare headrest with different hardness, characterized in that the recessed portion of the elastic body has a shape that expands from the bottom surface toward the open end, and a member of different hardness is fixed in close contact with the inner surface of the recessed portion. (2) A bank is erected on the cavity surface of the foam mold to surround a predetermined part of the cavity surface, and a member of different hardness made of foam of a predetermined hardness is installed on the cavity surface surrounded by the bank, and the inside of the cavity is Manufacture of a bare headrest with different hardness by injecting liquid foaming raw material into the material and foam-molding a pillow-like elastic body made of a foam having a hardness different from that of the different hardness member on the cavity surface, integrally with the different hardness member on the cavity surface. In this method, a cavity surrounded by an embankment is made into a shape that becomes smaller as it goes away from the cavity surface, and a member of different hardness whose periphery is larger than the cavity surface surrounded by the embankment is installed on the cavity surface surrounded by the embankment. A method for producing a bare headrest with different hardness, characterized in that the liquid foaming raw material is injected and foamed while the peripheral edge of the different hardness member is pressed and compressed by the embankment wall surface.