JP2004034356A - Manufacturing apparatus for foamed molded object - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enhance the durability of a seal material in a mold in the vacuum foam molding of foam such as a pad or the like for a seat of a car. <P>SOLUTION: In a manufacturing apparatus 10 for a foamed molded object equipped with a mold 14 operable between a horizontal posture and an inclined posture inclined by a predetermined angle (θ), a vacuum pump 16 sucking air in a mold cavity 12 to set the cavity to a vacuum state and an injection device 18 for injecting a foamable raw material U in the cavity 12, the seal material 34 comprising an elastic tube is arranged to the flange part 36 of the lower mold 20 around a mold splitting surface 24 and filled with air by an air supply device 54. The seal material 34 filled with air is held between the flange part 40 of an upper mold 22 and the flange part 36 at mold clamping to seal the space of the seal material 34. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
TECHNICAL FIELD The present invention relates to an apparatus for producing a foam molded article for foam-forming a foam raw material in a vacuum.
[0002]
Problems to be solved by the prior art and the invention
2. Description of the Related Art In general, a synthetic resin foam molded article such as a flexible polyurethane foam having high elasticity is used for a seat pad and a cushion for furniture of a vehicle such as an automobile. With respect to such seat pads, low-density and lightweight ones have been demanded in accordance with recent demands for weight reduction and cost reduction of automobiles. Therefore, in order to reduce the density and weight of the foamed molded article and to secure the moldability of a complex shaped product, there are various vacuum foaming molding methods for foaming and foaming a foamed material under a pressure lower than the atmospheric pressure. Proposed.
[0003]
In such vacuum foaming molding, it is necessary to hermetically seal the inside of the mold to make it vacuum. Conventionally, an elastic sealing material 100 such as rubber having a circular cross section as shown in FIG. 7 has been used as a sealing material for sealing the inside of a mold. However, in such a conventional sealing material 100, there is a problem in that the rubber is likely to be set by long-term use, and thus sufficient durability cannot be secured.
[0004]
An object of the present invention is to improve a seal structure in a molding die in vacuum foam molding, and an object of the present invention is to provide a manufacturing apparatus of a foam molded article having a seal structure having excellent durability.
[0005]
[Means for Solving the Problems]
An apparatus for manufacturing a foamed molded article according to the present invention includes a first mold and a second mold each having a flange portion on an outer periphery of a mold surface, and forming a cavity inside the mold surface by closing both molds. A mold, a vacuum pump for sucking gas in the cavity to create a vacuum, an injection device for injecting a foaming material into the cavity, and the mold split on one of the first and second mold flanges. A sealing material that is disposed along the outer periphery of the surface and is formed of an elastic tube that seals an inner space by being sandwiched between the other flange portion when the mold is closed, and a gas supplied and filled into the sealing material. And a gas supply device. In use, the foaming material is injected into the cavity by the injection device, the gas in the cavity is sucked by the vacuum pump, and the inside of the cavity is evacuated, and the foaming material is foamed and molded in the cavity in this vacuum state.
[0006]
In the manufacturing apparatus according to the present invention, the gas is filled and sealed inside the sealing material formed of the elastic tube by the gas supply device, and the flange is sealed between the two flange portions when the mold is closed by the sealing material filled with the gas. Since the elastic tube is used as the sealing material as described above, by appropriately filling the gas into the tube, it is possible to exhibit a stable sealing property for a long period without a problem of sag. In addition, since the elastic modulus of the sealing material can be arbitrarily changed by adjusting the gas filling amount in the tube, it is possible to exhibit optimal sealing properties according to manufacturing conditions and the like.
[0007]
In the manufacturing apparatus of the present invention, one end and the other end of the sealing material surrounding the entire outer periphery of the mold surface are arranged in an inner and outer double, and one end or both ends of the sealing material is You may make it draw out from a flange part and connect to a gas supply apparatus. The sealing material may be formed in a loop shape in advance.However, in the present invention, the sealing material is formed of an elastic tube that can be filled with gas, and the connection portion with the gas supply device is also required. In the case of the shape, the cost increases. For this reason, it is more advantageous to use a string-shaped sealing material, and by arranging the inner and outer double portions at both ends as described above, it is possible to ensure sealing performance over the entire circumference at low cost. it can. In addition, by drawing one end or both ends of the flange from the flange and connecting it to the gas supply device, a gas supply path to the sealant can be secured.
[0008]
In the manufacturing apparatus of the present invention, the molding die includes a lower die as a first die and an upper die as a second die, and the sealing material is disposed on a flange portion of the lower die. , Is operable between a horizontal position and an inclined position inclined at a predetermined angle with respect to the horizontal position, and includes a chamber portion sealed by a seal material on an outer periphery of the mold surface, and the mold surface includes An exhaust groove communicating the cavity and the chamber portion is formed in the upper portion in the inclined posture, and a vacuum pump is connected to the chamber portion, and the cavity through the exhaust groove is formed by sucking gas in the chamber portion. In some cases, a vacuum is drawn by sucking the gas inside. In this case, the foaming material can be uniformly and smoothly foam-filled in the cavity by performing foam molding in a state where the mold is inclined in the inclined posture.
[0009]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to the drawings. The present embodiment relates to an apparatus for manufacturing an automobile seat pad made of a flexible polyurethane foam.
[0010]
As shown in FIGS. 1 and 2, a manufacturing apparatus 10 according to the present embodiment includes a mold 14 that forms a cavity 12 sealed inside, and a gas inside the cavity 12 that is suctioned to reduce the pressure inside the cavity 12 from atmospheric pressure. The vacuum pump 16 is also provided with a vacuum having a low atmospheric pressure, and an injection device 18 for injecting the polyurethane foam raw material U into the cavity 12.
[0011]
The mold 14 includes a lower mold 20 that opens upward, and an upper mold 22 that opens and closes an upper surface opening of the lower mold 20. By closing both the molds 20 and 22, the mold surface (PL portion) 24 is formed. A cavity 12 is formed which is sealed inside. The lower mold 20 is a mold for molding the front side of the seat pad, and has a concave portion corresponding thereto. The upper mold 22 is a mold for molding the back side of the seat pad, and forms a cavity 12 which is a foaming space corresponding to the shape of the seat pad between the upper mold 22 and the lower mold 20 by closing the recess. The lower mold 20 and the upper mold 22 are provided with outer peripheral flange portions 36 and 40 facing each other in parallel with each other on the outer periphery of the mold surface 24.
[0012]
The upper mold 22 is provided with an inlet 26 so that the foam material U can be injected into the cavity 12 with the lower mold 20 and the upper mold 22 closed, and the inlet 26 is opened and closed by a lid 30 having a driving device 28. It is supposed to be. Then, with the lid 30 opened, the nozzle 32 of the injection device 18 is inserted into the injection port 26, and the foam material U is injected into the cavity 12 from the nozzle 32.
[0013]
The mold 14 is moved by a rotating mechanism (not shown) between a horizontal position (a position where the upper surface of the lower die 20 (the outer peripheral flange 36) is horizontal) and an inclined position inclined by a predetermined angle θ with respect to the horizontal position. It is configured to be operable. The angle (inclination angle) θ in the inclined posture with respect to the horizontal posture is preferably about 15 ° to 30 °. If the inclination angle θ is too large, the expansion of the foam in the vertical direction of the mold (direction toward the exhaust groove 44) is suppressed, which may adversely affect the moldability at the end.
[0014]
The entire outer periphery of the mold surface 24 is surrounded by a seal member 34 made of an elastic tube such as a silicone rubber tube (see FIG. 3). The sealing material 34 is fitted into a sealing groove 38 provided in the outer peripheral flange portion 36 of the lower die 20, and seals the gap between the outer peripheral flange portion 40 of the upper die 22 and the outer peripheral surface of the mold split surface 24. A closed annular chamber portion 42 is formed.
[0015]
As shown in FIG. 3, the seal member 34 is arranged so as to be double-wrapped inside and outside at a part in the circumferential direction. In detail, a string-shaped extruded product is used as the sealing material 34, and when the extruded product is attached to the lower mold 20 so as to surround the outer periphery of the mold surface 24, the both end portions 34a and 34b are overlapped inside and outside. Is arranged.
[0016]
The sealing material 34 is connected to a gas supply device 54 such as a pump, and the gas supply device 54 fills and seals a gas (for example, air) inside the tube. Specifically, as shown in FIGS. 4 and 5, both end portions 34 a and 34 b of the sealing material 34 wrapped inside and outside are arranged so as to penetrate the outer peripheral flange portion 36 on the bottom surface of the concave groove 38. The holes 56, 56 are drawn to the back side. The drawn-out both ends 34 a and 34 b are connected to a branch member 60 provided on a pipe 58 from the gas supply device 54.
[0017]
An exhaust groove 44 that connects the cavity 12 and the chamber portion 42 is provided on the mold splitting surface 24 between the lower die 20 and the upper die 22. The mold splitting surface 24 is configured so that the lower die 20 and the upper die 22 come into close contact with each other except for the portion of the exhaust groove 44, which has zero contact, that is, has no minute gap for exhaust.
[0018]
As shown in FIG. 3, the exhaust grooves 44 are provided at two locations in the circumferential direction of the loop-shaped parting surface 24. In detail, one side of the cavity 12 having a substantially rectangular shape is provided at each corner at both ends. One side of the cavity 12 is an upper side, that is, a side higher than the opposite side when the mold 14 is in the inclined posture. For this reason, the exhaust groove 44 is provided at a position that is on the upper side in the inclined posture on the mold split surface 24.
[0019]
In this embodiment, the vacuum pump 16 includes an ejector 46, which is a vacuum generator, and a compressor 48 that supplies compressed air to the ejector 46. The suction side of the ejector 46 is connected to the chamber part 42 of the mold 14 via a pipe 50, and the compressor 48 is operated to suck the gas in the chamber part 42 via the pipe 50. The pipe 50 is connected to an exhaust port 52 provided on the outer peripheral flange portion 40 of the upper mold 22 and opening to the chamber portion 42.
[0020]
In the manufacturing apparatus 10 described above, a predetermined amount of gas is supplied to the inside of the sealing material 38 by the gas supply device 54 and filled and sealed before the molding. Thereby, the sealing material 38 is given a sufficient elasticity to ensure the sealing property, and the sealing property is exhibited by being sandwiched between the two flange portions 36 and 40 when the mold is closed.
[0021]
When molding the seat pad, first, as shown in FIG. 1, the lower mold 20 and the upper mold 22 of the mold 14 are closed to be in the inclined position, and the cover material of the injection port 26 of the upper mold 22 is formed. Open 30. Next, the compressor 48 is operated, and the exhaust from the chamber portion 42 by the ejector 46 is started. The polyurethane foam raw material U is injected into the cavity 12 by inserting the nozzle portion 32 of the injection device 18 into the injection port 26. Then, the injected foam raw material U spreads over a wide area while flowing downward due to the appropriate inclination of the lower mold 20. In the present embodiment, the foam raw material U is injected in the inclined posture. Alternatively, the foam raw material U may be injected in the horizontal posture, and the inclined posture after the injection.
[0022]
When the injection port 26 is closed with the lid 30 after the injection of the foam raw material U, the inside of the cavity 12 is thereby closed, so that the gas in the cavity 12 is sucked through the exhaust groove 44 by the action of the ejector 46 and the pressure of the air is reduced. The decline begins. Since the mold 14 is inclined as described above, the foam material U is sequentially filled from the end opposite to the exhaust groove 44 in the cavity 12 as shown in FIG. The area near 44 is finally filled. Therefore, urethane can be foamed while exhausting the gas through the exhaust groove 44 until the filling of the cavity 12 is completed.
[0023]
After the cavity 12 is filled with the urethane foam, the supply of the compressed air from the compressor 48 to the ejector 46 is stopped to end the exhaust. Thereafter, the mold 14 is opened and the molded seat pad is released.
[0024]
According to the manufacturing apparatus 10 of the present embodiment described above, since the gas can be appropriately filled and sealed in the inside by using the sealing material 34 made of an elastic tube, it is possible to secure a stable sealing performance over a long period of time. Can be. Further, the elastic modulus of the seal member 34 can be arbitrarily changed by adjusting the gas filling amount in the tube. Further, since the both ends 34a and 34b of the seal member 34 are wrapped and arranged inside and outside, sealing performance over the entire periphery can be realized at low cost, and the gas supply path to the seal member 34 can be reduced. Can be secured.
[0025]
In addition, since the mold 14 is inclined at a gentle angle and foam molding is performed while exhausting the inside of the cavity 12 from the exhaust groove 44 at the upper part, the urethane stock solution U spread on the bottom of the lower mold 20 is uniformly distributed in the cavity 12. And it can be filled smoothly. Furthermore, since the mold splitting surface 24 of the mold 14 has zero contact except for the exhaust groove 44, the number of steps in the post-process such as the work of removing burrs is reduced, and the mold 14 is excellent in maintainability.
[0026]
As described above, according to the present embodiment, it is possible to stably produce a seat pad which is about 10 to 30% lighter than normal molding and has excellent moldability without voids or underfill for a long period of time. it can.
[0027]
In addition, the gas supply device 54 can be configured to be detachable from the sealant 34. In this case, the gas supply device 54 is separated from the sealant 34 during foam molding, and is connected to the sealant 34 every predetermined molding cycle. Alternatively, the gas may be supplied and charged.
[0028]
FIG. 6 shows a seal structure according to another embodiment. As shown in the figure, in this case, as the sealing material, a first sealing material 62 made of sponge rubber having a substantially trapezoidal cross section and a second sealing material 64 made of an elastic tube disposed outside thereof are used in combination. I have. The first seal member 62 is mounted in a concave groove 66 on the inner peripheral side of the flange portion 36, and the second seal member 64 is mounted in a concave groove 68 provided on the outer peripheral side thereof. Here, the second sealing material 64 is connected to the gas supply device like the sealing material 34 of the above-described embodiment, and is configured so that the inside thereof can be filled with gas.
[0029]
On the other hand, the bottom surface corresponding to the long side of the trapezoid is placed on the bottom surface of the concave groove 66 so that the first sealing material 62 is compressed in the height direction of the trapezoid by the flange portion 40 of the upper mold 22 when the mold is closed. It is arranged to be placed. Such a sealing member 62 having a trapezoidal cross section is harder to set than a sealing member having a circular cross section, and is therefore excellent in durability. In addition, the concave groove 66 is formed in a substantially trapezoidal cross-section having a width narrower toward the opening side in correspondence with the cross-sectional shape of the first sealing material 62, and therefore, the sealing material 62 is hard to come off.
[0030]
As in the other embodiments, the sealing material 64 made of an elastic tube and the sealing material 62 made of ordinary sponge rubber can be used together to further improve the sealing performance.
[0031]
【The invention's effect】
ADVANTAGE OF THE INVENTION According to the manufacturing apparatus of the foaming molded body of this invention, the sealing material for sealing the inside of a shaping | molding die can exhibit the stable sealing performance for a long period of time.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a foam molding apparatus according to an embodiment when a foam material is injected.
FIG. 2 is a cross-sectional view of the same device during foam molding.
FIG. 3 is a plan view of a lower die in the same device.
FIG. 4 is an enlarged sectional view of a seal structure in the device.
FIG. 5 is a perspective view of a main part of a seal structure in the device.
FIG. 6 is an enlarged sectional view of a seal structure according to another embodiment.
FIG. 7 is an enlarged sectional view of a seal structure in a conventional manufacturing apparatus.
[Explanation of symbols]
10 foam molding apparatus 12 cavity 14 mold 16 vacuum pump 18 injection apparatus 20 lower mold 22 upper mold 24 mold splitting surface 34 sealing materials 36 and 40 … Flange part 42… Chamber part 44… Exhaust groove 54… Gas supply device

Claims (3)

A mold having a first mold and a second mold having a flange portion on the outer periphery of the mold surface, and forming a cavity inside the mold surface by closing both molds;
A vacuum pump that sucks gas in the cavity to create a vacuum;
An injection device for injecting a foaming material into the cavity,
An elastic tube disposed on one flange portion of the first mold and the second mold along the outer periphery of the mold split surface, and sandwiched between the other flange portion when the mold is closed to seal an inner space. And a sealing material comprising
A gas supply device that supplies and fills gas inside the sealing material,
The manufacturing apparatus of a foaming molding provided with. One end and the other end of the sealing material surrounding the entire circumference of the mold surface are arranged so as to be overlapped inside and outside, and one or both ends of the sealing material are pulled out from the flange portion to supply the gas. The apparatus for producing a foamed molded article according to claim 1, wherein the apparatus is connected to an apparatus. The molding die includes a lower die as the first die and an upper die as the second die, and is a molding die in which the sealing material is disposed on a flange portion of the lower die. It is operable between an inclined posture inclined at a predetermined angle with respect to the horizontal posture, and includes a chamber portion sealed by the seal material on an outer periphery of the mold surface, and the inclined surface is provided on the mold surface. An exhaust groove communicating with the cavity and the chamber portion is formed in an upper portion at
2. The vacuum pump is connected to the chamber, and sucks gas in the chamber to suck gas in the cavity through the exhaust groove to make a vacuum. Or the manufacturing apparatus of the foaming molded article of Claim 2.

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