JP6872977B2 - A molding die for resin foam molding and a method for manufacturing a vehicle seat pad using the molding die. - Google Patents

Description

The present invention relates to a molding die used in a manufacturing process of a resin foam molded product in which an insert member is integrally molded, and in particular, an insert having a magnetic portion set in the cavity by a permanent magnet attached to the surface of the cavity. The present invention relates to a molding mold in which the fixing force of a member can be improved.

Conventionally, polyurethane foam molded products used as cushioning materials for vehicle seats and the like have been molded to prevent abnormal noise due to contact with metal springs, prevent urethane resin from seeping out, or reinforce the foam molded products. After arranging an insert member made of a cloth such as a woven fabric or a non-woven fabric inside, a liquid urethane resin is injected and foam molded to integrally mold the insert member and the polyurethane foam molded body (that is, the insert member is integrally formed). To obtain a molded polyurethane foam molded article) is performed. In the production of a resin foam molded product in which such an insert member is integrally molded, it is necessary that the insert member set in the cavity of the molding mold is fixed in the cavity without moving in the process of foam molding of the resin. is there. For this reason, normally, a permanent magnet is attached to the surface of the cavity of the molding die, while a magnetic portion is provided in the insert member, and when the insert member is set in the cavity, the magnetism of the insert member is caused by the magnetic effect of the permanent magnet. A method is adopted in which the insert member is fixed by sucking the portion. As a method of providing the magnetic portion on the insert member, for example, there is a method of attaching a plate-shaped magnetic material piece to a desired portion of the insert member with double-sided adhesive tape (Patent Document 1).

Japanese Unexamined Patent Publication No. 2001-252930

The present invention has been made in view of the above circumstances, and an object of the present invention is that the magnetic effect (adhesive force) acting on the magnetic part of the insert member by a plurality of permanent magnets attached to the surface of the cavity is higher than before. It is an object of the present invention to provide a molding die for resin foam molding which can be greatly improved.

As a result of diligent research to solve the above problems, the present inventors have made a plurality of permanent magnets attached to the surface of the cavity, the first magnet having the end face of the S pole facing the cavity side, and the end face of the N pole thereof. Is composed of a second magnet facing the cavity side, and in particular, when the first magnet and the second magnet are alternately and repeatedly arranged, a magnetic effect (adhesive force) acting on the magnetic part of the insert member by a plurality of permanent magnets. ) Was found to be greatly improved. The present invention is based on such findings, and its features are as follows.

[1] A molding die for resin foam molding used in the manufacturing process of a resin foam molded product in which an insert member is integrally molded.
A plurality of permanent magnets for attracting the magnetic part of the insert member are attached to the surface of the cavity of the molding die.
The plurality of permanent magnets are a molding die for resin foam molding, comprising a first magnet having its S pole end face facing the cavity side and a second magnet having its N pole end face facing the cavity side. ..
[2] The molding die according to the above [1], wherein the first magnet and the second magnet are alternately and repeatedly arranged.
[3] The molding die according to the above [2], wherein the adjacent first magnet and the second magnet are separated from each other.
[4] The molding die according to the above [2], wherein the adjacent first magnet and second magnet are in contact with each other on their side surfaces.
[5] The molding die according to any one of the above [1] to [4], wherein the total number of the plurality of permanent magnets is 4 or more.
[6] The molding die according to any one of the above [1] to [5], wherein each of the plurality of permanent magnets is a neodymium magnet.
[7] The molding die according to any one of the above [1] to [6], wherein a plurality of permanent magnets are attached to the inner surface of the cavity of the upper die of the molding die.
[8] The insert member is any one or two selected from the group consisting of a cloth, a urethane slab sheet, a urethane chip, a plastic film, a molded body of a wood stock material, and a molded body of a wood plastic material. The molding die according to any one of the above [1] to [7], which is the above-mentioned composite.
[9] An insert member having a magnetic portion is set in the cavity of the molding mold according to any one of the above [1] to [8], and the magnetic portion of the insert member is attracted by the magnetic effect of a plurality of permanent magnets. The process of fixing the insert member,
A step of injecting urethane foam resin into the cavity of the molding mold and foaming it to obtain a polyurethane foam molded product integrally molded with the insert member, and molding the polyurethane foam molded product integrally molded with the insert member. A method for manufacturing a vehicle seat pad, which comprises a step of removing a mold from a mold.

According to the molding die for resin foam molding of the present invention, the magnetic effect (adhesive force) acting on the magnetic portion of the insert member by the plurality of permanent magnets attached to the surface of the cavity is greatly improved as compared with the conventional case. Therefore, the number of magnetic parts provided on the insert member (for example, the number of magnetic material pieces attached to the insert member) required to prevent the insert member from moving in the resin foam molding process can be reduced as compared with the conventional case. , It is possible to reduce the manufacturing cost of the resin foam molded product in which the insert member is integrally molded.

Further, in addition to the magnetic part, the pin and the hole part are locked with respect to the insert member which conventionally needs to form a hole part to which the pin erected on the surface of the cavity is locked and fix the pin part. The structure is not necessarily required, and the insert member can be fixed only by the attractive force acting on the magnetic portion formed on the insert member. Therefore, the work of arranging the insert member in the cavity of the worker at the manufacturing site becomes easy, and the manufacturing efficiency of the resin foam molded product in which the insert member is integrally molded is improved.

It is a schematic cross-sectional view of the 1st example of the molding die for resin foam molding of this invention. It is a schematic cross-sectional view of the upper mold of the 2nd example of the molding mold for resin foam molding of this invention. It is a schematic cross-sectional view of the upper mold of the 3rd example of the molding mold for resin foam molding of this invention, and shows the state in which the magnetic part of an insert member is attracted to the permanent magnet attached to the surface of a cavity. It is a schematic cross-sectional view of the upper mold of the conventional molding mold for resin foam molding. It is a schematic perspective view of the insert member which formed the magnetic part in the urethane chip.

Hereinafter, the present invention will be described in more detail in line with its preferred embodiment.
FIG. 1 is a diagram schematically showing a cross section of a molding mold for resin foam molding (hereinafter, also simply abbreviated as “molding mold”) of the first example of the present invention. In the figure, 1A-1 is an upper mold. 1B is a lower mold, 2 is a permanent magnet, 3 is a cavity, and 10 is a molding mold. Note that FIG. 1 shows only the gate immediately before the cavity 3 among the spool, runner and gate which are the flow paths of the foamed resin in the molding die, and the spool, runner and the like are omitted.

FIG. 2 is a diagram schematically showing a cross section of the upper mold of the molding die of the second example of the present invention, and in the figure, the same reference numerals as those in FIG. 1 indicate the same or corresponding portions. Since the lower mold of the molding mold 11 of the second example is the same as that of the first example, the illustration is omitted and only the upper mold 1A-2 is shown.

The molding die for resin foam molding of the present invention is a molding die used when manufacturing a resin foam molded body integrally molded with an insert member, and is used in the molding dies 10 and 11 of the first and second examples. As shown, a plurality of permanent magnets 2 attached to the surface of the cavity 3 (that is, the wall surface partitioning the cavity) are the first magnet 2A and its N with the end surface of its S pole directed toward the cavity 3. It is characterized in that it is composed of a second magnet 2B with the end face of the pole facing the cavity 3 side.

Usually, the plurality of permanent magnets 2 are arranged in which the first magnet 2A and the second magnet 2B are alternately repeated as shown in FIGS. 1 and 2. That is, the configuration is such that different poles in parallel (N pole-S pole) are repeated.

FIG. 4 is a diagram schematically showing a cross section of an upper mold of a conventional molding die, and the same reference numerals as those in FIG. 1 indicate the same or corresponding portions. Since the lower mold of the conventional molding mold 20 is the same as that of the molding mold 10 (FIG. 1) of the first example of the present invention, the illustration is omitted and only the upper mold 21 is shown. The upper mold 21 is provided with the same number of permanent magnets 2 as the upper mold 1A-1 of the molding mold 10 of FIG. 1 on the surface of the cavity 3, but all the permanent magnets 2 have the end faces of the S poles on the cavity 3 side. (That is, the plurality of permanent magnets 2 are arranged in parallel with the same pole (S pole-S pole)). When a plurality of permanent magnets 2 are arranged in parallel with the same pole, the attractive force acting on the magnetic part of the insert member is the same even if the end face of the magnet facing the cavity 3 side is the north pole and the south pole. Is.

As is clear from the evaluation test described later, in the molding dies 10 and 11 of the present invention shown in FIGS. 1 and 2, a plurality of permanent magnets 2 (2A, 2B) attached to the surface of the cavity 3 are arranged in different poles in parallel. Since the configuration is a repetition of (N pole-S pole), a plurality of permanent magnets 2 attached to the surface of the cavity 3 as in the molding mold 20 of FIG. 4 are in parallel with the same pole (S pole-S pole). Compared to the arranged molding mold, the magnetic effect (adhesive force) acting on the magnetic portion of the insert member by the plurality of permanent magnets 2 is increased. The reason why this magnetic effect (adhesive force) increases is not clear, but when two permanent magnets are placed in parallel with different poles, a high-density magnetic flux distribution from the parallel north pole to the south pole is obtained, and the different poles are parallel (N). By repeating the pole-S pole), a high-density magnetic flux distribution becomes continuous, and it is presumed that this state contributes to the improvement of the attractive force of the insert member to the magnetic part.

In the molding die of the present invention, the total number of the plurality of permanent magnets 2 (2A, 2B) attached to the surface of the cavity 3 is usually four or more in order to obtain a high magnetic effect (adhesive force). On the other hand, the upper limit of the total number of permanent magnets 2 (2A, 2B) is not particularly limited, and is appropriately determined in consideration of the size of the cavity, the size of the insert member set in the cavity, the weight of the insert member, and the like. The number is not limited, but is usually about 20.

Type of permanent magnet 2 (the first magnet 2A and the second magnet 2B) is not particularly limited, for example, neodymium c arm magnet, samarium cobalt magnet, but a ferrite magnet or the like is available, the most force is large upfield neodymium c arm magnets capable of generating is preferred. The shape of the permanent magnet 2 (2A, 2B) is not particularly limited, but is usually a columnar object such as a prism, a cylinder, or an elliptical column, and the relationship between the height of the columnar object and the length of the cross section (cross-sectional diameter). Is not particularly limited, and the height may be larger or smaller than the length of the cross section (cross-sectional diameter), but the height is the length of the cross section from the viewpoint of ease of attachment and the like. It is preferably larger than the ellipse (cross-sectional diameter).

In the molding dies 10 and 11 of FIGS. 1 and 2, the end face of the S pole of the permanent magnet 2 (first magnet 2A) and the end face of the north pole of the permanent magnet 2 (second magnet 2B) are the faces of the cavity 3. The permanent magnet 2 is embedded in the upper mold 1-A so that it is located in the same plane, but the end face of the S pole of the first magnet 2A and the end face of the N pole of the second magnet 2B are located in the same plane. If so, the end face of the S pole of the first magnet 2A and the end face of the N pole of the second magnet 2B may protrude from the surface of the cavity 3.

Further, in the molding die 10 of FIG. 1, the first magnet 2A and the second magnet 2B adjacent to each other in parallel with different poles are separated from each other, but as shown in the molding die 11 of FIG. 2, they are adjacent to each other in parallel with different poles. The first magnet 2A and the second magnet 2B may be in a state where the side surfaces of the first magnet 2A and the second magnet 2B are in contact with each other. The width of one permanent magnet 2 (the width of each of the adjacent first magnet 2A and the second magnet 2B in parallel with different poles) is not particularly limited, but for example, when the permanent magnet is a columnar object, the width thereof. (The length of the cross section (cross-sectional diameter)) is preferably about 8 to 20 mm from the viewpoint of the stability of the attached magnet. When the adjacent first magnet 2A and the second magnet 2B in parallel with different poles are separated from each other, the separation distance is preferably 20 mm or less, more preferably 10 mm or less, and particularly preferably 5 mm or less. If the separation distance exceeds 20 mm, it becomes difficult to obtain the effect of increasing the magnetic effect (adsorption force) acting on the magnetic portion of the insert member by repeating the different pole parallel (N pole-S pole) and the different pole parallel.

FIG. 3 is a diagram schematically showing a cross section of an upper mold of a molding die of a third example of the present invention, and also shows an insert member in which a magnetic portion is attracted to a permanent magnet. In the figure, the same reference numerals as those in FIG. 1 indicate the same or corresponding parts, 5 is an insert member, 5A is a non-woven fabric, 5B is a urethane chip, 6 is a magnetic part (magnetic material piece attached to the insert member), and 12 is molding. Indicates the type. Since the lower mold of the molding mold 12 of the third example is the same as that of the first example, the illustration is omitted and only the upper mold 1A-3 is shown.

In the molding die 12 of the third example, magnet arrays 2-1 in which the first magnet 2A and the second magnet 2B are alternately and repeatedly arranged in a state where the side surfaces of the first magnet 2A and the second magnet 2B are in contact with each other are attached to two places on the surface of the cavity. doing. That is, in the molding mold of the present invention, the magnet arrangements 2-1 in which the first magnet 2A and the second magnet 2B are alternately and repeatedly arranged in a state where the side surfaces of the first magnet 2A and the second magnet 2B are in contact with each other may be provided at a plurality of locations on the surface of the cavity. it can.

In the molding die of the present invention, a plurality of permanent magnets 2 are usually attached to the surface of the cavity of the upper die of the molding die. In this method, the insert member is usually set in the upper die cavity (upper mold space in the cavity), and the foamed resin for obtaining the resin foam molded product flows into the lower mold cavity (lower mold space in the cavity). This is for foam molding. As for the "upper mold" and the "lower mold", the mold positioned on the upper side in the vertical direction is the "upper mold", and the mold positioned on the lower side is the "lower mold".

The material of the molding mold (upper mold and lower mold) is not particularly limited, and an aluminum or casting mold similar to a general molding mold for resin foam molding may be used.

When an insert member having a magnetic portion is set in the cavity of the molding mold of the present invention, a strong attractive force acts on the magnetic portion of the insert member by a plurality of permanent magnets, and the insert member is firmly fixed in the molding mold. .. Then, in a state where the insert member is firmly fixed, for example, urethane foam resin is injected into the cavity and foamed to obtain a polyurethane foam molded product integrally molded with the insert member, which is integrated with the insert member. A seat pad for a vehicle is manufactured by removing a polyurethane foam molded product molded into a mold from a molding mold.

In the molding die of the present invention, the insert member integrally molded with the resin foam molded body is, for example, integrally molded with the polyurethane foam molded body which is a cushioning material for a vehicle seat, and is formed on the back surface of the polyurethane foam molded body. Examples thereof include fabrics (fiber-based materials) such as non-woven fabrics and woven fabrics to be joined. Further, a solid molded body formed into a three-dimensional shape such as a rectangular body made of plastic such as polyurethane, polypropylene (PP), polyethylene (PE), or a polyhedron such as a cube, which is joined to the non-designed surface of the polyurethane foam molded body. Urethane chips; Solid molded bodies molded into three-dimensional shapes such as rectangular bodies made of wood stock materials and wood plastic materials, polyhedrons such as cubes; porous or non-porous plastic films (eg, polyester film, polyolefin film, etc.) Polypropylene film, polyvinyl chloride film, polystyrene film, urethane slab sheet, etc.) and the like can be mentioned. Moreover, two or more kinds of complexes selected from the above-exemplified ones can be mentioned. The "urethane chip" refers to a material obtained by compacting a waste material of a polyurethane foam (polyurethane foam), and the "urethane slab sheet" refers to a film (sheet) of a polyurethane foam sliced.

The magnetic portion may be formed on the insert member by a conventionally known method. For example, (a) a method of attaching a magnetic material piece with a double-sided adhesive tape, (b) a thermoplastic resin containing a thermoplastic resin and a magnetic material, or a curable binder impregnated with a magnetic material in which magnetic material powder is dispersed. Examples thereof include a method of solidifying (curing). In addition, a commercially available magnetic paint is atomized and sprayed onto the surface of the insert member and air-dried by using a means such as an air-type spray gun that atomizes and sprays a liquid substance to adhere and solidify the magnetic paint. Examples thereof include a method of forming a magnetic portion made of an object. With this method, a magnetic portion can be easily formed on the surface of a non-porous member or a porous member having relatively few voids (high density).

When the molding die of the present invention is used, the magnetic effect (adhesive force) acting on the magnetic portion of the insert member by the plurality of permanent magnets attached to the surface of the cavity is greatly improved as compared with the conventional case. Therefore, for example, the number of magnetic parts provided on the insert member (for example, the number of magnetic material pieces attached to the insert member) required to prevent the insert member from moving in the resin foam molding process should be reduced as compared with the conventional case. It is possible to reduce the manufacturing cost of the resin foam molded product in which the insert member is integrally molded.

Further, in the past, in addition to the magnetic part, it was necessary to form and fix a hole part in which a pin erected on the surface of the cavity was locked, such as a urethane chip or a woodstock molded body. Even with a heavy member, the insert member can be fixed in the mold only by the attractive force acting on the magnetic portion formed on the insert member. Therefore, when the worker at the manufacturing site arranges the insert member in the mold, the work of inserting the pin erected on the inner surface of the mold into the hole formed in the insert member becomes unnecessary, and the worker inserts. The work of arranging the members in the mold can be performed easily and in a short time.

Further, the locking structure of the pin and the hole portion is not always required, and the insert member can be fixed only by the attractive force acting on the magnetic portion formed on the insert member. Therefore, the work of arranging the insert member in the molding cavity of the worker at the manufacturing site becomes easy, and the manufacturing efficiency of the resin foam molded product in which the insert member is integrally molded is improved.

The molding die of the present invention can be particularly suitably used for manufacturing a vehicle seat pad.
That is, the present invention is a step of setting an insert member having a magnetic portion in the above-mentioned molding cavity, and the magnetic portion of the insert member is attracted by the magnetic effect of a plurality of permanent magnets to fix the insert member.
The process of injecting urethane foam resin into the cavity of the mold and foaming it to obtain a polyurethane foam molded product integrally molded with the insert member, and removing the polyurethane foam molded product integrally molded with the insert member from the mold. Also provided is a method of manufacturing a vehicle seat pad, including the process of performing.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited by the following Examples, and appropriate modifications are made to the extent that the above and the following objectives can be met. Of course, it is also possible to carry out the above, and all of them are included in the technical scope of the present invention.

[Example 1]
Prepare one plastic plate with a rectangular flat shape (short side 200 mm, long side 350 mm, thickness 8 mm) and five cylindrical neodymium magnets with a cross-sectional diameter of 8 mm and a height of 10 mm. Five columnar neodymium magnets parallel to the long side are placed in the middle position on one side in the lateral direction, and magnets with the north pole facing up and magnets with the south pole facing up alternate. Further, the magnets were placed side by side in a state where the side surfaces of the adjacent magnets were in contact with each other as an example, and the upper mold model A, which was a model of the upper mold 1A-2 of the molding mold 11 of FIG. 2, was assembled.

[Comparative Example 1]
Using the same plate material and 5 columnar neodymium magnets as above, place all 5 columnar neodymium magnets in the direction parallel to the long side at the middle position in the lateral direction on one side of the plate material with the north pole up. The upper mold model B, which is a model of the upper mold 21 of the molding mold 20 of FIG. 4, was assembled by arranging them side by side at intervals of 8 mm.

[Reference example 1]
Using the same plate material and 5 columnar neodymium magnets as above, place 5 columnar neodymium magnets in the direction parallel to the long side at the middle position in the lateral direction on one side of the plate material with the north pole facing up. The upper model C was assembled by arranging the magnets with the oriented magnets and the magnets with the S poles facing up alternately and placing the adjacent magnets at a distance of 30 mm as an example.

[Evaluation test]
(Manufacturing of insert member with magnetic part)
A means for preparing a rectangular (W × H × D = 150 mm × 10 mm × 45 mm) shaped urethane chip (density: 118.5 kg / m ³ ) 50 as an insert member and spraying the magnetic paint in a mist form. Using an air-type spray gun, apply magnetic paint ("Magnet Paint" (manufactured by Turner Color Co., Ltd.)) to the main surface of the urethane chip (W x D = 150 mm x 45 mm) while moving the air-type spray gun. A magnetic part of a line pattern with a line width of about 39 mm and a total length of 150 mm, which consists of deposits of magnetic paint (solidified material) after being sprayed and dried (total amount of solidified material of magnetic paint: 1650 mg, unit area ( Adhesion amount of solidified magnetic paint per 1 mm ^{2 ): 0.314 mg / mm 2} ) 51 was formed to prepare an insert member 52 with a magnetic portion.

(Adsorption evaluation)
For each of the upper model A of Example 1, the upper model B of Comparative Example 1, and the upper model C of Reference Example 1, the magnetic part of the line pattern of the insert member with the magnetic part produced above was arranged in the neodymium magnet arrangement. When the adhesiveness of the insert member with the magnetic part was evaluated by contacting the insert member, all of the upper models A to C attracted the insert member with the magnetic part, and the attracted state was maintained.

For the upper mold models A to C in which the insert member with the magnetic part is in the suction state, the upper mold model is held upright on the work table (the long axis of the plate material is perpendicular to the work table surface) and then spontaneously falls. When the impact load test was performed, the insert member with the magnetic part remained adsorbed on the upper model A, but the insert member with the magnetic part was detached from the upper model B and the upper model C. ..

From this result, the plurality of permanent magnets attached to the surface of the cavity of the molding die are repeatedly arranged in parallel with different poles, and the two magnets in parallel with different poles are from the north pole of one magnet to the S of the other magnet. It is clear that the magnetic effect (adhesive force) acting on the magnetic part of the insert member increases due to the proximity state in which the magnetic flux distribution toward the pole is formed.

1A-1, 1A-2, 1A-3 Upper mold 1B Lower mold 2 Permanent magnet 2A 1st magnet 2B 2nd magnet 3 Cavity 5 Insert member 6 Magnetic part 10, 11, 12, 20 Molding mold

Claims (5)

A molding die for resin foam molding used in the manufacturing process of a resin foam molded product in which an insert member is integrally molded.
A plurality of permanent magnets for attracting the magnetic part of the insert member are attached to the surface of the cavity of the molding die.
The plurality of permanent magnets, Ri Do from the first magnet towards the end faces of the S pole on the cavity side and the second magnet towards the end face of the N pole to the cavity side,
And the total number of the plurality of permanent magnets 4 or more, the first magnet and a second magnet adjacent in contact with side surfaces of each other, a resin foam molding mold characterized that you have been repeatedly arranged alternately .. Each of the plurality of permanent magnets are neodymium magnets claim 1 Symbol mounting mold. The molding die according to claim 1 or 2 , wherein a plurality of permanent magnets are attached to the surface of the cavity of the upper die of the molding die. The insert member is any one selected from the group consisting of a cloth, a urethane slab sheet, a urethane chip, a plastic film, a molded body of a wood stock material, and a molded body of a wood plastic material, or a composite of two or more kinds. The molding die according to any one of claims 1 to 3 , which is a body. An insert member having a magnetic portion is set in the cavity of the molding die according to any one of claims 1 to 4 , and the magnetic portion of the insert member is attracted by the magnetic effect of a plurality of permanent magnets to fix the insert member. Process to be done,
A step of injecting urethane foam resin into the cavity of the molding mold and foaming it to obtain a polyurethane foam molded product integrally molded with the insert member, and molding the polyurethane foam molded product integrally molded with the insert member. A method for manufacturing a vehicle seat pad, which comprises a step of removing a mold from a mold.

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