JPS63176115A - Mold assembly for compression molding of thermosetting resin - Google Patents

Abstract

PURPOSE:To evacuate surely air in a mold space and gas in a molding material and to obtain a molding having a smooth surface and a good quality, by fixing airtightly a bellows surrounding outer circumferences of both top and bottom forces and setting a seal member at the apex part of the projection of the bellows which can shield airtightly the space of the circumferences of the molds from the outside when it contacts with the other supporting member. CONSTITUTION:A bellows 15 being protruding expandably and contractably downward is set on a supporting member 2 of a top force 4 and a seal member 19 which is press-contacted with an outer cylinder 17 of the bottom force 5 side through a pressing ring 16 is also set at an apex part of the projection of this bellows 15. The space of the outer circumference 20 and the molding space 9 of a mold assembly 1 can be thereby airtightly shielded from outside without any limitation in the fitting timing of both top and bottom forces 4 and 5. Moreover, as the projected length downward of this bellows 15 is expandable and contractable, the shielding timing of the space 20 and the molding space 9 can be freely adjustable. Therefore, the molding space can be shifted to a low pressure space at an earlier time before starting the compres sion of the molding space 9, namely before a molding material A to be compressed in the molding space 9 is gelated.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is a method of kneading a thermosetting resin or a reinforcing material with a thermosetting resin, or compression molding a prepreg material formed into a sheet 1. Regarding mold equipment for.

[Prior art]

In this type of mold, when the molding space between the upper mold and the lower mold is filled with molding material and compression molding is performed, the air in the molding space and the gas contained in the molding material are released during mold clamping. Until completion, the flow of molding material forces it out of the molding space.

However, if this air or gas does not spread properly, compression molding will be completed with this gas still sealed inside the molding material, resulting in many small holes and bulges on the surface of the molded product. There was a problem that surface defects such as

For this reason, conventionally, for example, "Jikko 52-35
975, from the start of compression to the final stage of compression, the molding space is airtightly shut off from the outside, and the inside of this molding space is evacuated by r)1 air device, and the molding space is closed. A mold is known that prevents the occurrence of surface defects by forcibly removing air and gas inside the mold.

[Problem that the invention seeks to solve]

However, in this conventional mold, the molding space is hermetically sealed only when the upper mold and the lower mold fit together, so the timing to make this molding space airtight is independent of the timing at which compression of the molding material starts. Therefore, it is difficult to set the molding space to a low pressure space, and the transition of this molding space to a low pressure space is naturally restricted after the compression of the molding material starts. therefore,
By the time the inside of the molding space transitions to a low-pressure space, gelation of the molding material has already progressed, and the gas in the molding material may not be completely removed.

In addition, the exhaust port for exhausting the inside of this molding space is opened at the bottom of the molding space into which molding material with air and gas flows during the compression process, so the exhaust port is closed by the flowing molding material. Sometimes it got blocked.

Therefore, it is not possible to completely eliminate the air in the molding space and the gas in the molding material until the final stage of compression, and there is still room for improvement in preventing surface defects. It had been.

The present invention was made based on these circumstances, and
The purpose of the present invention is to provide a mold device for compression molding a thermosetting resin, which can reliably exclude air in a molding space and gas in a molding material, and can yield a high-quality molded product with a smooth surface.

[Means for solving problems]

Therefore, in the present invention, compression molding molds are attached facing each other to a pair of supporting members that are movable in tangent directions, and a thermosetting resin molding material is compression molded between these molds. In addition to forming a molding space, a bellows is airtightly fixed to one of the supporting members so as to extend and contract toward the other supporting member and surround the outer periphery of both molds. An adjustment means is provided for adjusting the length of the protrusion along the axial direction of the bellows, and the space around the mold surrounded by the bellows is evacuated by an exhaust device. In this case, a sealing member is provided to airtightly isolate the space around the mold from the outside.

(Function) According to this configuration, the bellows airtightly shuts off the atmosphere around the mold including the molding space without being restricted by the fitting timing of the mold, so by adjusting the protruding length of the bellows, Even if you change the mold, you can freely change the timing to airtightly shut off the atmosphere around the mold depending on the mold.For this reason, the molding space can be closed at an early stage before the compression starts, that is, when the molding material has gelled. It is possible to move to a low-pressure space even before

Moreover, since the outer periphery of the mold is airtightly sealed for exhaust air, there is no need to provide an exhaust port at the bottom of the molding space as in the past, and this exhaust port will not be blocked by molding material. .

Therefore, air in the molding space and gas contained in the molding material can be reliably eliminated until the final stage of compression.

〔Example〕

The present invention will be explained below based on an embodiment shown in the drawings.

The mold apparatus for compression molding indicated by reference numeral 1 in the figure is equipped with an upper mold 4 serving as a female mold and a lower mold 5 serving as a male mold on opposing surfaces of upper and lower support members 2.3. In this example, the upper support member 2 is connected to a ram 6 of a press and is moved up and down.

A recess 7 is formed on the lower surface of the upper mold 4, and a protrusion 8 is formed on the upper surface of the lower mold 5, and the outer peripheral surfaces of the recess 7 and the protrusion 8 are , are finished with smooth mold surfaces 7a and 8a, respectively. Then, the molding material A produced in the form of a sheet or block by kneading a thermosetting resin or this thermosetting resin and a reinforcing material is set on the top of the convex portion 8, and the above-mentioned Recess 7
A molding space 9 for compression molding the molding material A is provided between and the convex portion 8 .

Further, a fitting step 10 that fits into the lower end opening of the recess 7 is formed on the outer circumference of the lower end of the projection 8. Between the fitting step 10 and the recess 7, the projection 8 fits into the recess Z and the mold device 1 closes! At this time, a minute gap 11 of, for example, about 0.1 to 0.4M is formed that continues below the molding space 9.

Note that inside the upper mold 4 and the lower mold 5, there is a mold surface 7a.

A steam flow path 12 is formed for heating the molding material 8a to melt and harden the molding material A.

By the way, a support ring 1 is provided on the lower surface of the upper support member 2.
3 is airtightly fixed via an O-ring 14, and the base end of a metal bellows 15 is hermetically welded to the lower surface of this support ring 13. This bellows 15 protrudes downward in an expandable and contractable manner and coaxially surrounds the outer periphery of the upper mold 4I3 and the lower mold 5, and a pressure ring 1G is hermetically welded to the lower end, which is the protruding tip. ing. Further, on the upper surface of the lower support member 3, an outer cylinder 1 surrounding the outer periphery of the lower mold 5 is provided.
7 is airtightly attached via an O-ring 18, and a press ring 16 is opposed to the upper surface of this outer cylinder 11 so as to be able to come into contact with and separate from it. A sealing member 19 made of, for example, an O-ring is attached to the surface of the pressing ring 16 facing the outer W117, and this sealing member 19 comes into pressure contact with the upper surface of the outer cylinder 17 when the supporting member 2 is lowered. The space 20 surrounded by the bellows 15 and the outer cylinder 17 is hermetically sealed from the outside.

A plurality of flange portions 21.22 are provided on the outer peripheral surfaces of the support ring 13 and the pressure ring 16, respectively, at intervals in the circumferential direction, and an adjustment rod 23 is provided between these flange portions 21.22. The rack has been handed over. A threaded portion 24 is formed in the lower half of the adjustment rod 23.
4 is tightened and fixed to the flange portion 21 of the press ring 16 via a nut 25, and the upper end portion of the adjustment rod 23 without the threaded portion 24 is slidable on the flange portion 21 of the support ring 13. I have sent one. A spring receiver 26 is attached to the threaded portion 24 via a nut 27 so that its position can be adjusted in the vertical direction.
A coil spring 28 is stretched between the flange portion 21 and the flange portion 21 .

Therefore, when the spring receiver 26 is moved upward and the coil spring 28 is compressed, the reaction force causes the adjustment rod 23 to
The pressure ring 16 is pressed downward through the coil springs 2, causing the bellows 15 to expand.
8, the spring receiver 26 and the adjustment rod 23 are attached to the bellows 15
It constitutes an adjusting means for adjusting the protruding length of the. In the case of this embodiment, the protruding length of the bellows 15 is adjusted so that the seal member 19 comes into pressure contact with the upper surface of the outer cylinder 17 before the mold surface 7a of the upper mold 4 comes into contact with the molding material A. There is.

Further, a plurality of exhaust ports 30 are opened on the side surface of the outer cylinder 17 and are connected to the space 20 around the upper and lower molds 4 and 5. It is connected to an external exhaust device 31. As shown in FIG. 1, the exhaust device 31 of this embodiment includes an exhaust port 30 and a rotary pump 3.
A booster pump 33, a first electromagnetic valve 34, a surge tank 35, and a second electromagnetic valve 36 are installed in the two exhaust pipes connecting the rotary pump 32, and from downstream of the second electromagnetic valve 36. An exhaust valve 38 is provided in the branched exhaust branch pipe 37, and the interior of the surge tank 35 is always pulled to a vacuum state by the rotary pump 32, regardless of whether the space 20 is in a sealed state or not. It is maintained.

Note that the reference numeral 39 in the figure indicates a pressure relief valve.

Next, the process of compression molding the molding material A will be explained.

First, the upper mold 4 is raised to form the molding space 9 and the space portion 2.
0 is opened and the molding material A is set on the top of the convex portion 8.

Next, the press machine is operated, and the upper die 4 together with the support member 2 is
descend. Then, as shown in FIG. 1, before the mold surface 7a of the upper mold 4 comes into contact with the molding material A, the sealing member 19 at the tip of the bellows 15 comes into pressure contact with the upper surface of the outer cylinder 17, and the bellows 15 and the outer cylinder 17 The space portion 20 surrounded by is hermetically sealed off from the outside. At this stage, since the concave portion 7 and the convex portion 8 are not completely fitted, the molding space 9 is communicated with the space portion 20 through between the molds 4.5, and therefore the molding space 9 is also hermetically sealed from the outside.

Note that, after the seal member 19 comes into pressure contact with the outer cylinder 17, the bellows 15 sequentially contracts in the axial direction in accordance with the lowering of the upper mold 4.

On the other hand, when the seal member 19 comes into pressure contact with the outer cylinder 17, the second N magnetic piece 36 is opened in synchronization with this, and the surge tank 35 is opened.
The space portion 20 and the molding space 9 are communicated with each other. In this case, since the inside of the surge tank 35 is already in a vacuum state, the air in the space 20 and the molding space 9 is removed from the exhaust port 30.
As a result, the atmosphere around the upper and lower molds 4.5, including the molding space 9, instantly shifts to a low-pressure space.

Thereafter, as the compression progresses, when the mold surface 7a of the upper mold 4 comes into contact with the molding material A, the molding material A will contact the mold surfaces 7a, 8a.
The air in the molding space 9 and the gas contained in the molding material A begin to flow toward the bottom of the molding space 9, and this pushed out air and gas flow through the exhaust port. Coupled with the suction action from 30 . . . , it is discharged all at once from the molding space 9 into the space 20 around the outer periphery of the mold device 1 .

As the molding material A is pressurized, the molding material A is filled into every corner of the molding space 9, and the excess material in the molding space 9 is disposed of in the gap between the concave part 7 and the convex part 8. 11
Flow inside. Since this gap 11 is as small as 0.1 to 0.4 m, the excess molding material A turns into particles and is eaten away at this gap 11. When the upper mold 4 is completely lowered and mold clamping is completed, the molding material A is densely filled in the molding space 9 and becomes pressurized, and the second electromagnetic valve 36 closes and the exhaust valve 38 closes accordingly. opens, and the space 20 returns to atmospheric pressure.

Then, the pressurized molding material A is heated by the steam flowing through the flow passages 12 in each mold 4.5, causes a polymerization reaction in the molding space 9, and is hardened. The molded product B obtained by this curing is taken out by opening the mold device 1 after a certain curing time has elapsed, thereby completing a series of compression molding.

According to such an embodiment of the present invention, the bellows 15 is provided on the support member 2 of the upper mold 4 and extends and retractably protrudes downward.
At the same time, a sealing member 19 is provided at the protruding tip of the bellows 15 to press against the outer cylinder 17 on the lower mold 5 side via the press ring 16. The space 9 is hermetically sealed off from the outside without being restricted by the timing of fitting the molds 4 and 5. Furthermore, since the bellows 15 can extend and contract in its downward projecting length, the timing at which the space portion 20 and the molding space 9 are hermetically sealed can be freely adjusted.

Therefore, the molding space 9 can be shifted to a low-pressure space early before the start of compression, that is, before the molding material A compressed in the molding space 9 gels.

In addition, since the outer peripheral atmosphere of the mold device 1 is airtightly shut off and exhausted, there is no need to provide an exhaust port 30 for air suction in the lower part of the molding space 9 into which the molding material A flows. The opening 30 will not be blocked by the molding material A.

Therefore, the air in the molding space 9 and the gas in the molding material A can be reliably eliminated until the final stage of compression.
The inclusion of air bubbles that cause small pores and swelling can be suppressed, and a high-quality molded product B with a smooth surface can be obtained.

Further, according to this configuration, the sealing member 19
Since the sealing member 19 is provided outside of the mold, it is not necessary to directly measure the thermal influence of the steam for heating the mold, and accordingly,
Thermal deterioration of the seal member 19 is reduced, resulting in a longer life.

At the same time, there is no need to provide an exhaust port 30, a seal member 19, etc. in the upper mold 4 and lower mold 5, so the degree of freedom in mold shape increases, and the internal structure of the mold can be simplified, resulting in mold cost. It is possible to reduce the

In addition, in the above-mentioned embodiment, the upper mold is moved up and down, but the present invention is not limited to this, and the lower mold may be moved up and down.

〔Effect of the invention〕

According to the present invention described in detail above, the inside of the molding space can be airtightly shut off and evacuated from an early stage before compression of the molding material starts, that is, before the molding material gels. The opening is not blocked by the flowing molding material, and air in the molding space and gas contained in the molding material can be reliably expelled until the R final stage of compression. Therefore, a high-quality molded product with a smooth surface can be obtained without trapping small pores or bubbles that cause swelling in the molding material.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, and FIG. 1 is a cross-sectional view of the outer periphery of the mold device and the molding space in a state where the molding space is hermetically sealed;
FIG. 2 is a cross-sectional view of a state in which mold clamping is completed, and FIG. 3 is a side view of the mold apparatus. 1...Mold 8' placement, 2.3...Supporting member, 4,5...
... Mold (upper mold, lower mold), 9... Molding space, 15...
Bellows, 19... Seal member, 23.26.28.
・Adjustment means (adjustment rod, spring receiver, coil spring),
31... Exhaust device, A... Molding material. Applicant's agent Patent attorney Takehiko Suzue Figure 3

Claims (1)

[Claims] Compression molding molds are mounted facing each other on a pair of support members movable toward and away from each other, and a molding space is formed between these molds for compression molding a thermosetting resin molding material, A bellows is airtightly fixed to one of the supporting members so as to extend and contract toward the other supporting member and surround the outer periphery of both molds, and the bellows has a projecting length along the axial direction of the bellows. The space surrounding the mold is evacuated by an exhaust device, and the projecting tip of the bellows is provided with an adjusting means for adjusting the expansion and contraction of the bellows. A mold device for compression molding thermosetting resin, characterized in that it is provided with a sealing member that airtightly blocks a space from the outside.