JP7666313B2 - Slush molding device and method for producing skin material - Google Patents

Description

The present invention relates to a slush molding device and a method for manufacturing skin materials.

Slush molding is known as a molding method for skin materials that make up instrument panels, which are interior parts of automobiles. Slush molding uses a slush molding device that includes a mold with a molding surface that matches the surface shape of the skin material to be molded, and a reservoir tank with an opening on the top surface and a storage section that stores powdered resin material.

In slush molding, a heated mold is first attached to the reservoir tank with its molding surface facing the powdered resin material contained in the reservoir tank, so as to close the opening of the reservoir tank. By clamping the mold and the reservoir tank together, the mold and the reservoir tank form an integrated internal space that includes the storage space of the storage section of the reservoir tank. This internal space becomes the movement space for the powdered resin material.

Then, by rotating the mold and reservoir tank in the clamped state, the powdered resin material in the reservoir tank is moved to the molding surface side of the mold. As a result, the powdered resin material in contact with the molding surface of the mold is melted by the heat of the mold and adheres to the molding surface. The mold and reservoir tank are then rotated to return to their original state, and the excess powdered resin material is moved into the storage section of the reservoir tank. The mold is then cooled, and the molten resin material is hardened to obtain the skin material.

Patent Document 1 discloses a molding device that uses slush molding to mold a skin material that has partially thick portions. In Patent Document 1, an airbag is provided in the storage section so as to correspond to the thick portions of the skin material to be molded. By using the airbag to pressurize a portion of the powdered resin material against the molding surface of the mold, a skin material that has partially thick portions can be molded.

JP 2006-095794 A

In this type of slush molding, when the clamped molding die and the reservoir tank are rotated, the powdered resin material may leak from the internal space to the outside. To prevent this, a seal member that seals the internal space is provided at the contact area (abutment area) between the molding die and the reservoir tank. When a seal member is provided at the contact area between the molding die and the reservoir tank, the outer periphery of the resulting molded product is defined by the seal member.

However, the molded product defined by the sealing member may end up with excess material formed around the skin material to be molded. For example, if the R-shaped portion of the sealing member cannot follow the shape of the skin material to be formed due to the bending process limit of the sealing member, unnecessary excess material will be formed on the skin material at a position corresponding to the R-shape of the sealing member. This excess material must be removed and discarded in a later process, resulting in problems such as poor work efficiency and reduced yield.

The present invention was made in consideration of these problems, and the object of the present invention is to provide a slush molding device and a method for manufacturing a skin material that can prevent excess material from being formed around the skin material.

The slush molding device according to one aspect of the present invention comprises a mold having a molding surface, a reservoir tank that contains a powdered resin material and that, when clamped to the mold, forms a movement space for the powdered resin material together with the mold, a seal member provided in the reservoir tank that comes into close contact with the mold when the mold and the reservoir tank are clamped to seal the movement space, and an elastic member provided on the movement space side of the seal member that defines the outer shape of the skin material.

In a slush molding device according to one aspect of the present invention, the elastic member includes a first elastic body that is provided in contact with the movement space side of the sealing member.

In a slush molding device according to one aspect of the present invention, the elastic member is provided to correspond to the R-shaped portion of the sealing member.

The slush molding device according to one embodiment of the present invention further includes a frame extending from the reservoir tank, and the elastic member is provided away from the sealing member and includes a second elastic body supported by the frame.

In a slush molding device according to one aspect of the present invention, the second elastic body forms a thin-walled portion and/or a cutout portion in the skin material.

A method for manufacturing a skin material according to one aspect of the present invention includes clamping a mold having a molding surface and a reservoir tank that contains a powdered resin material to form a movement space for the powdered resin material between the mold and the reservoir tank, bringing a seal member provided on the reservoir tank into close contact with the mold when the mold and the reservoir tank are clamped to seal the movement space, rotating the mold and the reservoir tank together to attach the powdered resin material to the molding surface, and defining the outer shape of the skin material with an elastic member provided on the movement space side of the seal member.

In one aspect of the method for manufacturing a skin material according to the present invention, the elastic member includes a first elastic body that is in contact with the movement space side of the sealing member.

In one aspect of the method for manufacturing a skin material according to the present invention, the elastic member is provided to correspond to the R-shaped portion of the sealing member.

In one embodiment of the method for manufacturing a skin material according to the present invention, the elastic member includes a second elastic body that is provided away from the sealing member and is supported by a frame extending from the reservoir tank.

In one aspect of the method for manufacturing a skin material according to the present invention, the second elastic body is used to form a thin-walled portion and/or a cutout portion in the skin material.

The present invention makes it possible to prevent excess material from forming around the skin material.

FIG. 1 is a schematic diagram showing a configuration of a slush molding apparatus according to a first embodiment. FIG. 2 is a view of the reservoir tank of FIG. 1 as seen from the opening side. 2 is a diagram showing a configuration of an R-shaped portion of the seal member of FIG. 1 ; FIG. 2 is a diagram showing a portion of a skin material produced using the slush molding apparatus according to the first embodiment. FIG. 5 is a schematic diagram showing the configuration of a slush molding apparatus according to a second embodiment. FIG. 11 is a diagram showing a part of a skin material produced by using a slush molding apparatus according to a second embodiment. FIG. 2 is a schematic diagram showing the configuration of a slush molding apparatus of a comparative example. 8 is a diagram showing a configuration of an R-shaped portion of the seal member of FIG. 7 . FIG. 13 is a diagram showing a portion of a skin material produced using a slush molding apparatus of a comparative example. FIG. 1 is a diagram showing an entire skin material produced using a slush molding apparatus of a comparative example.

Below, an embodiment of the present invention will be described with reference to the drawings. For clarity of explanation, the following description and drawings have been omitted and simplified as appropriate. In addition, in each drawing, the same elements are given the same reference numerals, and duplicate explanations have been omitted as necessary.

The present invention relates to a technique for manufacturing molded products by powder slush molding using a powdered resin material as a raw material. In the following embodiment, an example of a molded product by slush molding will be described using a skin material that constitutes an instrument panel, which is an interior part of an automobile.

The instrument panel has a three-layer structure consisting of a base material formed by injection molding using synthetic resin such as PP (polypropylene), a skin material formed by slush molding, and a foam body placed between the base material and the skin material and foamed using a foaming resin material such as polyurethane. The skin material forms the design surface of the instrument panel with its outer surface.

The present invention is not limited to the use of skin materials for instrument panels, but can be widely applied to molded products that are formed by slush molding using powdered resin materials as raw materials, such as skin materials for automobile door trims.

Embodiment 1.
Fig. 1 is a schematic diagram showing the configuration of a slush molding apparatus 1 according to embodiment 1. Fig. 2 is a diagram showing the reservoir tank of Fig. 1 as viewed from the opening side. Fig. 3 is a diagram showing the configuration of the R-shaped portion of the seal member of Fig. 1.

As shown in FIG. 1, the slush molding device 1 includes a reservoir tank 10 and a molding die 20. The molding die 20 is a member having a molding surface 21 with a three-dimensional uneven shape that corresponds to the surface shape of the skin material to be molded. For example, a nickel mold with excellent heat conductivity can be used as the molding die 20.

The powdered resin material 30 that is the raw material for the skin is a material that is commonly used in slush molding, such as polyvinyl chloride resin powder, olefin-based thermoplastic elastomer (TPO) resin powder, polyurethane-based thermoplastic elastomer (TPU) resin powder, etc.

The reservoir tank 10 has a tank body 11, a sealing member 12, and an elastic member 13. The tank body 11 is a member that includes a box-shaped storage section 14 having an opening 15. The tank body 11 is formed of a material such as aluminum or epoxy resin. The storage section 14 stores powdered resin material 30, which is the raw material for the skin material. The opening 15 is configured to fit within the range of the molding surface 21 of the mold 20 in a plan view.

The mold 20 is attached to the reservoir tank 10 so as to close the opening 15, with its molding surface 21 facing the powdered resin material 30 contained in the storage section 14 of the reservoir tank 10. In other words, the reservoir tank 10 and the mold 20 are clamped together with the molding surface 21 facing the opening 15.

By clamping the reservoir tank 10 and the mold 20 together, the reservoir tank 10 and the mold 20 form an integrated internal space including the storage space of the storage section 14. This internal space becomes the movement space for the powdered resin material 30. The powdered resin material 30 can pass through the opening 15 and move toward the molding surface 21. When clamped together, the reservoir tank 10 and the mold 20 can be rotated around a predetermined rotation axis by a rotating means (not shown) using a motor or the like.

The reservoir tank 10 is provided with a seal member 12. The seal member 12 is made of an elastic material such as silicone rubber that has excellent heat resistance. The seal member 12 prevents the powder resin material 30 from leaking to the outside when the reservoir tank 10 and the mold 20 are rotated in a clamped state. The seal member 12 is provided on the portion of the reservoir tank 10 that comes into contact with the mold 20 (the abutting portion). In the first embodiment, as shown in FIG. 1, the seal member 12 is arranged so as to cover the top of the side wall portion 16 erected from the periphery of the opening 15.

The sealing member 12 is provided in a ring shape that conforms to the uneven shape of the molding die 20 and conforms to the outer shape of the molding surface 21 (the outer shape of the skin material 2) in a plan view. In other words, the sealing member 12 is in close contact with the molding die 20 to seal the movement space of the powder resin material 30.

As shown in Figures 1 and 2, an elastic member 13 is provided on the movement space side of the sealing member 12. An elastomer having excellent heat resistance and rubber elasticity, such as silicone rubber, can be used as the elastic member 13. The sealing member 12 and the elastic member 13 define the outer shape of the skin material 2 to be molded. That is, in the first embodiment, the sealing member 12 and the elastic member 13 form the boundary between the molding area of the skin material 2 and its external area on the molding surface 21 of the mold 20.

Now, a comparative example will be described with reference to Figures 7 to 9. Figure 7 is a schematic diagram showing the configuration of a slush molding device of the comparative example. Figure 8 is a diagram showing the configuration of the R-shaped portion of the sealing member of Figure 7. Figure 9 is a diagram showing a portion of a skin material produced using the slush molding device of the comparative example, and Figure 10 is a diagram showing the entirety of the same.

As shown in Figures 7 and 8, in the comparative example, the elastic member 13 is not provided, and the sealing member 12 defines the outer shape of the skin material 2 to be molded. In other words, the sealing member 12 forms the boundary between the molding area of the skin material 2 and its outer area on the molding surface 21 of the mold 20.

The limit of the R-shape that the sealing member 12 can take (minimum bending radius) is determined by the bending process limit. In other words, the R-shaped portion 4 of the sealing member 12 cannot take a radius smaller than the minimum bending radius. For this reason, there are cases where the R-shaped portion 4 of the sealing member 12 cannot follow the shape of the skin material 2 to be formed.

In this case, as shown in FIG. 9, a molded product is obtained in which unnecessary excess material 3A is formed around the skin material 2 at a position corresponding to the R-shaped portion 4 of the sealing member 12. This excess material 3A must be removed and discarded in a later process, resulting in problems such as poor work efficiency and reduced yield.

Since the sealing member 12 is disposed on the side wall 16, it is not limited to a position corresponding to the R-shape of the sealing member 12, and there may be some locations where the excess material 3B is formed depending on the shape of the side wall 16 of the reservoir tank 10 (see FIG. 10, for example). In this case, in order to improve yield, it is necessary to change the shape of the side wall 16 of the reservoir tank 10 in order to bring the position of the sealing member 12 closer to the external shape of the skin material 2 to be molded, and an additional process of machining the reservoir tank 10, such as sheet metal or welding, is required.

As described above, in the first embodiment, the elastic member 13 is provided on the movement space side of the seal member 12. The elastic member 13 can be provided in contact with the movement space side of the seal member 12. In this case, the elastic member 13 is supported by the seal member 12. The elastic member 13 has a shape that matches the outer shape of the skin material 2 to be molded. This makes it possible to manufacture a skin material 2 molded into a desired shape in a location where excess material would be formed if only the seal member 12 was used, as in the comparative example.

Figure 3 shows an enlarged view of the reservoir tank where the elastic member is formed. As shown in Figure 3, it is preferable that the elastic member 13 is provided in particular to correspond to the R-shaped portion 4 of the seal member 12. Figure 4 is a diagram showing a part of a skin material manufactured using the slush molding device of the first embodiment. In Figure 4, a part of the skin material 2 corresponding to the R-shaped portion 4 in Figure 3 is shown. As shown in Figure 4, in the molded product, it is possible to obtain a skin material 2 molded into a finer desired shape in the R-shaped portion 4 where excess material 3A would be formed if only the seal member 12 was used.

Next, a method for manufacturing the skin material 2 will be described. First, the reservoir tank 10 is arranged so that the opening 15 faces upward with the powdered resin material 30 contained in the container 14. An elastic member 13 is provided on the movement space side of the seal member 12.

Then, the mold 20 is heated to a temperature of, for example, about 230°C using a heating means such as a heating furnace. The heated mold 20 is attached to the reservoir tank 10 so that its molding surface 21 faces the powder resin material 30 contained in the storage section 14 of the reservoir tank 10 and closes the upper opening 15, and then the mold is clamped.

Then, the reservoir tank 10 and the mold 20 in the clamped state are rotated upside down using a rotating means (not shown). This causes the powdered resin material 30 in the storage section 14 to move within the movement space and pass through the storage section 14 toward the mold 20. The powdered resin material 30 that comes into contact with the molding surface 21 is melted by the heat of the mold 20, and adheres to and is molded along the shape of the molding surface 21. At this time, the elastic member 13 provided on the movement space side of the seal member 12 allows the desired shape to be molded in areas where excess material would be formed with only the seal member 12, as in the comparative example.

Then, the reservoir tank 10 and the mold 20 are rotated to return them to their original state, thereby moving the excess powdered resin material 30 into the storage section 14. The mold 20 is then removed from the reservoir tank 10 and cooled, for example, by immersing it in a water tank (not shown). This allows the molten resin material to harden, and a skin material 2 without excess material can be obtained.

Embodiment 2.
Fig. 5 is a schematic diagram showing the configuration of a slush molding apparatus 1A according to embodiment 2. In Fig. 5, the same components as those in Fig. 1 are given the same reference numerals, and their explanations will be omitted. The difference between embodiment 2 and embodiment 1 is that an elastic member 13A is provided at a position separated from the seal member 12.

As shown in FIG. 5, the slush molding apparatus 1A further includes a frame 17. The frame 17 may be formed of the same material as the tank body 11, such as aluminum or epoxy resin. An elastic member 13A is provided at the tip of the frame 17. The elastic member 13A is provided away from the seal member 12 on the movement space side of the seal member 12. The elastic member 13A is supported by the frame 17. Note that the shape, number, arrangement, etc. of the frame 17 are not particularly limited as long as the strength required to support the elastic member 13A is ensured.

The elastic member 13A is used to form thin-walled portions and/or cutout portions in the skin material 2 by adjusting its shape and position. For example, as shown in FIG. 5, when an elastic member 13A thicker than the skin material 2 to be molded is placed in contact with the molding surface 21 of the mold 20, the powder resin material 30 does not adhere to the portion of the molding surface 21 where the elastic member 13A contacts. Therefore, as shown in FIG. 6, a cutout portion 2A is formed in the skin material 2 manufactured using this slush molding device 1A.

If the distance between the bottom surface of the elastic member 13A and the molding surface 21 of the mold 20 is smaller than the thickness of the skin material 2 to be molded, a thin-walled portion will be formed in the skin material 2. In this way, the cutout portion 2A and the thin-walled portion can be formed simultaneously with molding of the skin material 2, which makes it possible to simplify the manufacturing process.

As described above, in the slush molding device according to the embodiment, by providing an elastic member 13 on the moving section side of the sealing member 12, it is possible to prevent excess material from being formed and to obtain the skin material 2 in the desired shape.

The present invention is not limited to the above embodiment, and can be modified as appropriate without departing from the spirit and scope of the invention.

REFERENCE SIGNS LIST 1, 1A slush molding device 2 skin material 2A cutout portion 3A, 3B excess material portion 4 R-shaped portion 10 reservoir tank 11 tank body 12 sealing member 13, 13A elastic member 14 storage portion 15 opening 16 side wall portion 17 frame 20 molding die 21 molding surface 30 powdered resin material

Claims (10)

A mold having a molding surface;
a reservoir tank that contains a powdered resin material and that, when clamped to the molding die, forms a movement space for the powdered resin material together with the molding die;
a seal member provided in the reservoir tank, the seal member being in close contact with the mold when the mold and the reservoir tank are clamped to seal the movement space;
an elastic member provided on the movement space side of the seal member and defining an outer shape of a skin material;
Equipped with
Slush molding equipment. The elastic member includes a first elastic body provided in contact with the seal member on the side of the movement space.
The slush molding apparatus of claim 1. The elastic member is provided in correspondence with the R-shaped portion of the seal member.
The slush molding apparatus of claim 2. The reservoir tank further includes a frame extending from the reservoir tank.
the elastic member includes a second elastic body provided apart from the seal member and supported by the frame;
The slush molding apparatus according to any one of claims 1 to 3. The second elastic body forms a thin portion and/or a hollow portion in the skin material.
The slush molding apparatus according to claim 4. a molding die having a molding surface and a reservoir tank for accommodating a powdered resin material are clamped together to form a movement space for the powdered resin material by the molding die and the reservoir tank;
a seal member provided on the reservoir tank is brought into close contact with the mold when the mold and the reservoir tank are clamped to seal the movement space;
Rotating the molding die and the reservoir tank together to cause the powdered resin material to adhere to the molding surface;
An outer shape of the skin material is defined by an elastic member provided on the movement space side of the seal member.
A method for manufacturing a skin material. The elastic member includes a first elastic body provided in contact with the seal member on the side of the movement space.
A method for producing the skin material according to claim 6. The elastic member is provided in correspondence with the R-shaped portion of the seal member.
A method for producing the skin material according to claim 7. The elastic member includes a second elastic body that is provided apart from the seal member and is supported by a frame extending from the reservoir tank.
A method for producing the skin material according to any one of claims 6 to 8. forming a thin portion and/or a hollow portion in the skin material by the second elastic body;
A method for producing the skin material according to claim 9.

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