JP2001096613A - Mold - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a mold which can change a mold surface freely. SOLUTION: A shape-changing mold 16 is composed of a plurality of expansion/contraction support means 25 having support heads 26 and housed tightly longitudinally/laterally in a vacuum-formed container 15 with the support head turned upward. The support head is formed from elastic silicone rubber and installed freely rotatably in the upper end part of the support means through a universal joint. In the mold 16, the height of each support head 26 is adjusted individually by a head height adjusting robot 17 to be parallel with the three- dimensional surface of a mod surface to be set up in advance. In this way, the mold 16 with the mold surface molded is moved to a vacuum molding part B, an overheated/softened molding material 5 covered with silicone rubber sheets 6, 7 is mounted on the mold surface and evacuated to be vacuum-formed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a mold for vacuum forming.

[0002]

2. Description of the Related Art In recent years, as a core material of a sandwich structure, a foamed plastic core (hereinafter, abbreviated as a foamed core) has been attracting attention instead of a honeycomb core. It is used as a material. Such a foamed core has excellent characteristics such as isotropic properties, excellent impact resistance, and moldability into a complicated shape.

[0003] As a molding method of the foamed core, there is a vacuum molding method (stretch molding method). In the vacuum molding method, a material to be molded, which is a foamed plastic, is heated and softened, and the softened material to be molded is placed on a mold, covered with a stretch rubber, and evacuated. Then, the molding material softened by the stretch rubber is pressed against the molding die, and the shape of the mold surface is faithfully reproduced on the molding material. After that, it is cooled and hardened, and trimming is performed.

[0004]

As described above, the vacuum molding method requires a mold, but a new mold must be manufactured each time a core having a different shape is manufactured. As a result, the number of processing steps increases, and the manufacturing cost also increases. Under such circumstances, there is a demand for a molding die that can freely change only the shape of the mold surface, instead of manufacturing a molding die for each foam core having a different shape from scratch. An object of the present invention is to provide a mold capable of changing the shape of a mold surface.

[0005]

According to the first aspect of the present invention, a plurality of telescopic support means which are extendable and contractible and have a support head attached to an end thereof are densely arranged vertically and horizontally in parallel with each other. A shape-changing mold for forming a mold surface by expanding and contracting each of the expansion and contraction support means so that the support surface of the support head facing the other side is arranged along a three-dimensional curved surface of a preset mold surface; The shape-changing mold is accommodated in the container such that the support head is on the opening side, and a plate-shaped molding material made of a thermoplastic synthetic resin is heated and softened so as to be on each support head. The container is placed in a container, and the inside of the container is evacuated to form a vacuum.

According to the present invention, the mold has a plurality of telescopic support means, and a support head facing outward is attached to an end of each telescopic support means. The expansion and contraction support means is housed vertically and horizontally in an airtight container, and the surface connecting the support surfaces of the support heads facing outward forms a mold surface. Therefore, the mold surface can be determined by individually expanding and contracting the expansion and contraction support means so that the support surface of each support head is arranged along the three-dimensional aspect of the set mold surface.

After the mold surface is determined, the heat-softened material to be molded is placed on each supporting head, and further covered with, for example, a stretch rubber to form a sealed space, and then vacuum-formed to perform vacuum forming. Do.

As described above, since the mold surface of the mold of the present invention is formed by expanding and contracting the expansion and contraction support means, the mold surface can be easily changed. In other words, it is not necessary to manufacture a new molding die each time a core having a different shape is manufactured. It is possible to prevent the thickness of the molding material from being uneven, and to significantly reduce the number of processing steps and manufacturing costs.

[0009] The support head according to the second aspect of the present invention,
It is characterized in that it is attached to the telescopic support means in a rotatable or fixed state.

When the material to be molded is placed and pressed on each support head, the material that has been heated and softened is spread. At this time, when the support heads are rotatably supported, each support head is rotated and positioned so that the support surfaces are smoothly connected. In this manner, the support surface of the support head is automatically positioned so as to follow the set three-dimensional curved surface, so to speak, and the mold surface can be formed with high precision.

If the support head does not necessarily move in the direction in which it is desired to rotate and cannot be formed into a good shape by making it rotatable, the support head is fixed to the telescopic support means.

According to a third aspect of the present invention, the support head is replaceable with a support head capable of holding a material to be formed.

At the time of vacuum forming, as described later, the material is covered with a silicon rubber sheet and the material to be molded is held using the silicon rubber sheet. However, when trimming the material to be molded, the silicon rubber sheet is removed and the material to be molded is removed. Is set in the mold and trimmed. At this time, the molding material cannot be held by using the silicon rubber sheet. However, in the present invention, the molding head can be replaced with a supporting head capable of holding the molding material. By holding the molding material, the trimming can be performed accurately.

According to a fourth aspect of the present invention, the support head has elasticity.

According to the present invention, since the supporting head has elasticity, a portion where a large force is applied when the material to be molded is pressed, such as a corner, is dented, and the mold surface is smoothly connected to form the mold with high precision. A surface can be formed.

[0016]

FIG. 1 is a sectional view showing a schematic configuration of a vacuum forming apparatus 1 using a shape changing mold 16 according to an embodiment of the present invention. The vacuum forming device 1 forms a foamed core having a sandwich structure.

The vacuum forming apparatus 1 is mainly composed of a heating section A, a vacuum forming section B, and a mold forming trim section C. A heating device 2 is disposed in the heating section A, and a foamed core 5 which is a molding material made of a thermoplastic foam synthetic resin is heated and softened here.

In the mold forming trim portion C, a shape changing mold 16 is provided.
Are arranged, where a mold for vacuum forming is formed. That is, here, the molding die 16 depends on the shape of the foam core to be manufactured.
Change the shape of the mold surface.

There is a vacuum forming section B between the heating section A and the mold forming trim section C. The forming die 16 formed by the mold forming trim section C moves to the vacuum forming section B and is heated by the heating section A. The foamed core 5 is conveyed to the forming die 16 of the vacuum forming part B, and the vacuum forming part B performs vacuum forming.

The foam core 5 is a rectangular plate-shaped foam synthetic resin, and is covered with a pair of silicone rubber sheets 6 and 7. The silicone rubber sheet 6 covering the upper surface of the foam core 5 has a rectangular outer frame 8. Similarly, the silicone rubber sheet 7 covering the lower surface of the foam core 5 also has a rectangular outer frame 9. Therefore, the foamed core 5 is placed on the lower silicone rubber sheet 7, the upper silicone rubber sheet 6 is covered thereon, and the lower outer frame 9 and the upper outer frame 8 are overlapped and sandwiched, so that The rubber sheets 6 and 7 are hermetically joined. Further, a plurality of through holes 10 are formed in the lower silicon rubber sheet 7.

The heating device 2 of this embodiment has an upper panel 11 and a lower panel 12, and the upper panel 11 and the lower panel 12 each have a built-in heater. Also, the upper panel 11
Can be moved up and down by a top plate elevating motor 13. Therefore, the foam core 5 covered with the silicone rubber sheets 6 and 7 is moved to the lower plate 12 while the upper plate 11 is raised.
The foam core 5 can be softened by lowering the upper panel 11 to set the foam core 5 in a heating device, and heating the set foam core 5 for a predetermined time.

In the present embodiment, the foam core 5 heated in the heating section A is transported to the vacuum forming section B by the transport means 3.
The conveying means 3 has a horizontal conveying section for conveying from the heating section A to the vacuum forming section B, and an elevating / lowering conveying section for lowering the foam core 5 conveyed on the forming die 16 to the forming die 16. Since the foamed core 5 is covered by the silicone rubber sheets 6 and 7 during the conveyance, it is possible to prevent the temperature of the heated and softened foamed core 5 from rapidly decreasing during the conveyance. Further, in the transfer operation, the outer cores 8, 9 of the silicone rubber sheets 6, 7 are gripped and transferred without holding the foam core 5, so that the deformation and displacement of the foam core 5 during the transfer can be prevented. .

The shape changing mold 16 is composed of a large number of elastic supporting means 25. The telescopic support means 25 is composed of a cylinder which can be vertically extended and contracted, and a support head 26 is rotatably attached to the upper end by a universal joint. The plurality of expansion / contraction support means 26 is
Thus, a three-dimensional curved surface which is closely housed vertically and horizontally in parallel with each other and which connects the support surfaces 26a of the support heads 26 facing upward becomes the mold surface of the molding die 16. Therefore, the shape of the mold surface can be changed by adjusting the height of each support head 26. For this purpose, a head height adjusting robot 17 is provided in the mold forming trim section C. In addition, the molded foam core 5
A trim robot 18 for trimming is also provided in the molding trim section C.

FIG. 2 is a perspective view showing the structure of the mold forming trim portion C. A frame 36 is provided in the mold forming trim portion C, and the shape changing mold 16 is disposed below the frame 36. An XY table 35 is provided on the frame 36, and the head height adjusting robot 17 and the trim robot 18 are movably supported on the XY table 35 in a horizontal plane.

The head height adjusting robot 17 is, for example, a robot that can expand and contract vertically, and has a hand 20 at its lower end.
The height of the support head 26 is adjusted by gripping the support head 26 with the hand 20 and pulling it upward, pushing it down, or rotating the support head 26 to move it up and down. Can be. Since the head height adjusting robot 17 is provided so as to be movable on the XY table 35 as described above, it is possible to adjust the height of all the support heads 26 of the molding die 16.

The trim robot 18 is an articulated robot and has an ultrasonic cutter 21 on the wrist. Trimming is performed by removing the silicone rubber sheets 6, 7 from the molded foam core 5.
Is removed and placed on the mold 16 again, and the ultrasonic cutter 21
By moving the trim robot 18 with the XY table 35 while cutting the foam core, the foam core 5 can be cut into a predetermined shape and trimming can be performed.

As another method of the trimming operation, a rotary cutting blade such as an end mill may be provided on the wrist of the trim robot 18 in place of the ultrasonic cutter to perform the trimming operation.

FIG. 3 is a front view showing the structure of the telescopic support means 25. In the present embodiment, the telescopic support means 25 is configured such that a support head 26 is rotatably attached to the upper end of a telescopic cylinder 27 via a universal joint 28.

In this embodiment, the support head 28 is rotatably attached to the telescopic cylinder 27. However, depending on the molding case, for example, the support head 2 is limited only in a limited axial direction.
8 may be supported so as to be angularly displaceable, or may be completely fixed to the telescopic cylinder 27.

In this embodiment, the telescopic cylinder 27 is provided with a lock mechanism (not shown) for preventing the telescopic cylinder 27 from expanding and contracting. Therefore, the support head 2 is moved by the head height adjusting robot 17 with the lock mechanism released.
After the height position of the support head 26 is adjusted by raising and lowering 6, the height position of the support head 26 is determined by operating the lock mechanism. In the present embodiment,
The amount of expansion and contraction of the expansion and contraction support means 25 is, for example, 0 to 300 mm.
It is.

As described above, the support head 26 is rotatably mounted on the upper end of the telescopic cylinder 27 via the universal joint 28. In the present embodiment, as an example, the support head 26 is rotatably mounted within a range of ± 45 °. In addition, the support head 26
As an example, it is made of a plate-like silicon rubber having a diameter of about 80 mm and a thickness of 20 mm and has elasticity. The support surface 26a of the support head 26 forming the mold surface forms a part of a spherical surface having a radius of curvature of about 400 mm as an example.
In the present embodiment, the telescopic support means 25 having such a support head having a diameter of 80 mm is uniformly erected on the entire surface of the vacuum forming container 15 at intervals of 100 mm vertically and horizontally and accommodated. In addition, the size of the vacuum forming container 15 of this embodiment is 3000 mm in length and 1550 mm in width as an example.

The support head 26 according to the present embodiment, which is rotatably mounted, is biased by a spring so as to return to a neutral position, for example, within a range of ± 10 ° from a horizontal state when no external force is applied. Is done.

As described above, the height of the support head 26 is adjusted by setting the support surface 2 of each support head on the three-dimensional curved surface of the mold surface to be set.
Adjust so that the center of 6a is arranged. When the foam core 5 is pressed on each support head 26 in this state, the support head 26 is rotated so that the support surfaces 26a of the support heads are smoothly connected, and a smooth mold surface is formed. In addition, since the support head 26 has elasticity, if there is a corner or the like, the corner is dented, and the mold surface is also smoothly formed by this.

FIG. 4 is a sectional view showing the structure of the vacuum forming container 15. The vacuum forming container 15 is in the form of an airtight square box with an open top, and a support 40 is laid at the bottom. The support base 40 is disposed apart from the bottom wall 43, and supports each telescopic support means 25 by standing vertically.

Further, a plurality of through holes 45 are formed in the support base 40. The support 40 and the bottom wall 4 of the vacuum forming container 15
The vacuum hose connection port 42 is attached to the side wall 44 of the vacuum forming container 15 so as to face the space between the vacuum hose 3 and the vacuum hose. With such a configuration, the evacuation can be performed efficiently.

At the upper end of the side wall 44 of the vacuum forming container 15, a sealing material 19 is provided over the entire circumference. When the foam core 5 is set in the vacuum forming container 15, the sealing material 19 comes into airtight contact with the outer frame 9 on the lower side of the silicone rubber sheets 6 and 7 covering the foam core 5. Thereby, a closed space can be formed in the vacuum forming container 15.

A moving means 41 is attached to the lower part of the vacuum forming container 15, so that the vacuum forming container 15
Between the molding portion B and the mold forming trim portion C.

Next, a method of manufacturing the foam core 5 by the vacuum forming apparatus 1 will be described with reference to a flowchart shown in FIG.

First, in step a1, the mold surface of the shape changing mold 16 is formed based on the three-dimensional curved surface of the mold surface set in the vacuum forming apparatus 1. That is, the heights of all the support heads 26 are individually adjusted using the head height adjustment robot 17.

Next, the molding die 16 whose mold is determined in step a2 is moved to the vacuum molding section B together with the vacuum molding container 15 and set at a predetermined position, and the vacuum hose 48 of the vacuum pump 47 is connected to the vacuum hose connection port 42. Connecting.

In parallel with the mold forming operation in step a1, the foamed core 5 is sandwiched between the silicone rubber sheets 6 and 7 in step a3, and this is set in the heating device 2, and then in step a4.
Then, the upper panel 11 of the heating device 2 is moved down to heat it to a predetermined temperature. After the temperature reaches a predetermined temperature, the temperature is held for a certain time to soften the foam core 5 made of thermoplastic foam synthetic resin.

As described above, in the present embodiment, the time-consuming mold forming operation and the heating operation can be performed at the same time, which is efficient.

In the next step a5, after the heating is completed, the upper surface plate 11 is raised, and the foam core 5 is moved to the vacuum forming section B by the horizontal transfer section of the transfer means 3. In this movement, the outer frames 9, 10 of the silicone rubber sheets 6, 7 are held and transported. By not holding the foam core 5 in this way,
This prevents the softened foam core 5 from being deformed during movement.

In the next step a6, the foamed core 5 is lowered by the lifting / lowering transport section of the transport means 3, and the core is set in a molding die. At this time, the core 5 is made of silicon rubber sheets 6 and 7
Since it is covered with and held by, the positioning can be performed with high accuracy without displacement. Also,
As described above, the outer frame 9 is made of the sealing material 1 of the vacuum forming container 15.
9 to form a sealed space in the vacuum forming container. Thereafter, the vacuum pump 47 is driven to start evacuation, and vacuum forming is performed. Since a plurality of through holes 10 are formed in the lower rubber sheet 7 covering the foam core 5, the upper silicon rubber sheet 6 is formed during the vacuum forming.
As a result, the foam core 5 is pressed against the mold surface and is brought into close contact therewith. At this time, since the core 5 is covered and movably held in the silicone rubber sheets 6 and 7, if a large tensile force is applied at the time of molding due to the shape of the mold surface, the core 5 in the sheets 6 and 7. Is moved, whereby the thickness of the core 5 can be made substantially uniform.

In the next step a7, evacuation is continued until the surface temperature of the silicon rubber sheets 6, 7 is cooled to 60 ° C. or less. After cooling, stop evacuation, release to atmosphere,
The foamed core 5 after molding is lifted by the lifting / lowering transport section of the transport means 3 using the sheet outer frames 8 and 9.

In the next step a8, the upper silicon rubber sheet 6 is first removed, the foam core 5 is once removed, and then the lower silicon rubber sheet 7 is removed.

In the next step a9, the mold 16 is moved to the mold forming trim portion C again and set at a predetermined position. Next, several support heads 26 are replaced with support heads (not shown) capable of holding the foam core 5. In the present embodiment, the support head capable of holding the foam core has a needle projecting above the support head, and the formed foam core 5 is pierced into the needle to hold the foam core 5.

In this manner, the foamed core 5 is fixed by the plurality of exchanged support heads, and the silicone rubber sheets 6 and 7 are fixed.
Is set in the molding die 16. Thereafter, the core excess portion is trimmed using the trim robot 18.

In the next step a10, the trimmed foam core 5 is carefully lifted from the needle, and the portion not completely trimmed is manually cut to complete the foam core 5.

Then, on both surfaces of the completed foam core 5,
A plurality of semi-cured prepregs impregnated with a resin are adhered to the reinforcing fibers 24, and the prepregs are further inserted into an autoclave to heat and cure the resin, thereby completing a sandwich structure having a foam core.

In the above-described embodiment, the heating device 2 is used for heating, and the conveying device 3 is used to convey the sheet to the molding die 16. However, the present invention is not limited to such an embodiment, and other embodiments shown in FIG. As in the embodiment, a configuration using a movable heating device 2a and a mold 16a that can move up and down may be adopted.

The heating device 2a is disposed above the molding die 16a in the vacuum forming section B, and vertically sandwiches the foam core 5 covered with the silicone rubber sheets 6 and 7, and is heated and softened by a heater. When the foam core 5 softens, the foam core 5 is
At 0, the upper and lower heaters of the heating device 2a are detached vertically and retracted in the horizontal direction. Then, mold 1
6a is raised, the foam core 5 is pressed against the molding die 16a, and the sealing material 19 and the outer frame 9 are brought into close contact with each other to set the foam core 5 in the molding die 16. Thereafter, vacuum evacuation is performed in the same manner as described above, and vacuum forming is performed.

In this way, instead of transporting the heat-softened foam core 5 by the transport device 3, the foam core 5 is not moved, and the heating device 2a and the molding die 16a are moved to remove the heat-softened foam core 5. By setting the core in the molding die 16a, it is possible to further suppress a decrease in the temperature of the foamed core 5 from heating and softening to setting in the molding die 16a.

In this embodiment, the height of the support heads 26 is adjusted one by one by the head height adjustment robot 17, but the present invention is not limited to such a form. The means 25 may be constituted by a hydraulic cylinder, and the height of the support head 26 may be adjusted by controlling each hydraulic cylinder. Thereby, the head height can be adjusted at the same time, and the mold can be formed quickly.

Although the vacuum forming apparatus of the present embodiment has been described as a vacuum forming apparatus for a foamed core having a sandwich structure, the present invention is not limited to this, and can be applied to vacuum forming of a thermoplastic synthetic resin.

[0056]

As described above, since the mold surface of the present invention can be freely changed by using a plurality of expansion and contraction support means having a support head, the mold is manufactured each time the foam core has a different shape. There is no need, and for example, in the above-described embodiment, the cost of the molding die can be significantly reduced in the number of man-hours for core processing and the total time.

Further, since the support head is rotatably attached to the expansion and contraction support means and the support head has elasticity, the molding accuracy is improved.

Further, since the support head can be replaced with a support head capable of holding the workpiece, the trim can be accurately trimmed by holding the workpiece with the support head capable of holding during trimming. .

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing an overall configuration of a vacuum forming apparatus 1 using a shape changing mold 16 according to one embodiment of the present invention.

FIG. 2 is a perspective view showing a configuration of a mold forming trim portion C.

FIG. 3 is a front view showing a telescopic support means 25.

FIG. 4 is a sectional view showing a vacuum forming container 15.

FIG. 5 is a flowchart showing a manufacturing process of the foam core 5 by the vacuum forming device 1.

FIG. 6 is a cross-sectional view showing a heating device 2a and a molding die 16a used in another embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Vacuum forming device 2, 2a Heating device 3 Conveying device 5 Foam core 6,7 Silicon rubber sheet 8,9,30 Outer frame 15 Vacuum forming container 16,16a Shape change molding die 17 Head height adjusting robot 18 Trim robot 25 Telescopic Supporting means 26 Supporting head

Claims (4)

[Claims] A plurality of telescopic support means which are extendable and contractable and have a support head attached to an end thereof are densely arranged vertically and horizontally in parallel with each other, and a support surface of the support head facing outward is preset. A shape-changing mold for forming a mold surface by expanding and contracting each of the elastic supporting means so as to be arranged along a three-dimensional curved surface of the mold surface, and an airtight container having one opening, wherein the support head has an opening. The shape-change molding die is housed in a container so as to be on the side, a plate-like molding material made of a thermoplastic synthetic resin is heated and softened and placed on each support head, and the inside of the container is evacuated to vacuum. A molding die characterized by being molded. 2. The molding die according to claim 1, wherein the support head is attached to the telescopic support means in a rotatable or fixed state. 3. The molding die according to claim 1, wherein the support head is replaceable with a support head capable of holding a material to be molded. 4. The mold according to claim 1, wherein the support head has elasticity.