JPS6112310A - Compression molding method and apparatus therefor - Google Patents

Abstract

PURPOSE:To prevent molding defect such as seizure generated at the rib part of a molded product, in clamping a movable mold and a fixed mold to each other, by positively exhausting air filling a rib hole to the open air. CONSTITUTION:When a movable mold 13 is clamped together to a fixed mold 1, the molding protruded part formed to the fixed mold 1 is embedded in the molding recessed part 13 formed to the movable mold 11. By this constitution, the molding surface 13 a of the movable mold 11 is contacted with a molding material M and, as pressure is applied, the molding material M is softened and begins to flow. At this time, a part of the molding material M flows to be flowed in a rib hole 5 but a cylinder 8 is operated to retract a movable pin 7 and a first piercing hole 6 is communicated with a second piercing hole 9 and air filling the rib hole 5 is exhausted to the open air through the second piercing hole 9 by operating a vacuum pump 10. Because air does not remain in the rib hole at the time of compression molding, the molding defect such as seizure generated at the rib part of a molded product can be completely sliminated.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a compression molding method for a molding material made of a sheet molding compound and a molding apparatus therefor.

[Prior art]

Conventionally, parts such as over fenders and fender garnishes that are attached to automobile fenders have been used as seats and
When molding with a molding material made of a molding compound, a compression molding apparatus as shown in the schematic cross-sectional view of FIG. 1 is widely used.

In FIG. 1, 51 is a fixed type, and this fixed type 5
A fixed guide plate 52 is provided on the lower surface of 1.
A convex molded portion 53 is formed on the upper surface, and a flat surface 54 is formed around the molded portion 53 . Also, fixed type 5
A rib hole 55 facing toward the fixed guide plate 52 is formed in the first molded portion 53 . Further, a movable mold 56 is disposed at a portion facing the fixed mold 51, and a movable gouging plate 57 is provided on the upper surface thereof.

Further, a concave molding surface 58 that opens toward the fixed mold 51 is formed on the lower surface of the movable mold 56, and a flat surface 59 is formed around the concave molding surface 58. When the movable mold 56 is closed to the fixed mold 51, the convex molded part 53 formed in the fixed mold 51 is fitted into the concave molded part 58 formed in the movable mold 56, and both A molding space is formed by the molds 51 and 56.

When compression molding parts such as over fenders and fender garnishes, a fixed mold 51 and a movable mold 56 are used.
Preheat to 140℃ to 160℃,
Next, a molding material M of a sheet molding compound made of glass fiber, calcium carbonate, unsaturated polyester resin, etc. is charged onto the surface of the molding part 53 formed in the fixed mold 51. Thereafter, the movable mold 56 is closed to the fixed mold 51, and compression molding is performed while heating the molding material M with both molds 51 and 56. At this time, a part of the fluidized molding material M gradually flows into the rib holes 55, and is filled and hardened while discharging the air filling the rib holes 55 into the molding space.

However, in such a compression molding device, the air filling the rib holes 55 is discharged into the molding space by some of the fluidized molding material flowing in, so the ribs are removed during compression molding. It may not be possible to completely evacuate the air in the holes 55. For this reason, the rib hole 5
Due to the heat insulating and compressing effects of the air remaining in step 5, there is a problem in that molding defects such as burning occur in the rib portions of the molded product.

[Purpose of the invention]

The present invention was made to solve the above-mentioned problems, and its purpose is to actively exhaust the air filling the rib holes to the atmosphere when the movable mold is closed to the fixed mold. An object of the present invention is to provide a compression molding method and a molding device for the same, which can prevent molding defects such as cracks occurring in the rib portions of the compressor.

[Structure of the invention]

In order to achieve the above object, the composition of the compression molding method according to the present invention is such that a sheet is formed on a molding surface formed in a fixed mold.
When charging a molding compound consisting of a molding compound and compressing the movable mold by closing the movable mold to the fixed mold, when the movable mold is closed to the fixed mold and both molds come into contact, it communicates with the molding surface of the fixed mold. The molding process is carried out while actively exhausting the air filling the rib holes formed in the mold to the atmosphere.

Furthermore, the configuration of the compression molding apparatus according to the present invention is such that the fixed mold has a molding surface for charging a molding material made of sheet molding compound, and a concave rib hole is formed in communication with the molding surface. A compression molding apparatus is provided with a movable mold having a molding surface that fits with the molding surface of the fixed mold in opposing parts, the fixed mold having one end open to the atmosphere and the other end. is connected to the vicinity of the tip of the rib hole.
a second through hole having one end open to the atmosphere and the other end communicating with the vicinity of the tip of the first through hole; A movable pin that is on the same plane is provided so that it can move forward and backward.

The movable pin provided in the first through hole closes the second through hole in the advanced state, and is located on the same plane as the side wall surface of the rib hole, and becomes a part of the wall surface of the rib hole. Further, in a state where the rib hole is retracted from the side wall surface, at least the first through hole and the second through hole are in communication with each other. As a result, when the molding material is fluidized and flows into the rib hole, the movable pin retreats and the first through hole and the second through hole communicate with each other.
Air filling the rib holes passes through the second through holes and is exhausted to the atmosphere. In addition, when the fluidized molding material flows into the vicinity of the tip of the rib hole, the movable pin moves forward and closes the second through hole, and the tip becomes flush with the side surface of the rib hole, so that the movable pin moves forward and closes the second through hole. A rib portion is formed.

〔Example〕

Hereinafter, one embodiment of the present invention will be described in detail based on the drawings.

Fig. 2 is a schematic sectional view of the compression molding apparatus according to the present invention;
This figure and FIG. 4 are enlarged sectional views illustrating the action within the ellipse of section A in FIG. 2.

In FIGS. 2 to 4, 1 is a fixed mold, and a fixed die plate 2 is provided on the lower surface of the fixed mold 1. Further, a molding convex portion 3 extending upward is formed at the center of the upper surface of the fixed mold 1, and the surface thereof is a molding surface 3a formed flat. Then, the forming convex portion 3
A flat surface 4 is formed around the periphery.

Further, a concave rib hole 5 extending from the molding surface 3a toward the fixed die plate 2 is formed in one side of the fixed die 1, and in the lateral direction of the fixed die 1, a first through hole 5 whose inner diameter becomes larger from the middle is formed. A hole 6 is formed. One end of the first through hole 6 is open to the atmosphere, and the other end is open near the tip of the rib hole 5. Moreover, a movable pin 7 is provided inside the first through hole 6 so as to be slidable and fit into the inner diameter of the first through hole 6, and the movable pin 7 is slidably provided at the outer end thereof. A rod 8a of a cylinder 8 is connected to the cylinder 8. This allows the movable pin 7 to move to the first position of the fixed mold 1.
It is movable forward and backward with respect to the through hole 6, and when the cylinder 8 is actuated and the movable pin 7 moves forward, its tip becomes flush with the side surface of the rib hole 5.

The fixed mold 1 also has a second through hole 9 parallel to the first through hole 6.
is formed, one end of which rises in the direction of the first through hole 6 and is open near the tip, and the other end is open to the atmosphere. For example, a vacuum pump 10 is provided at the open end of the second through hole 9, and when the movable pin 7, which is provided in the first through hole 6 so as to be movable back and forth, is moved back by the operation of the cylinder 8, First through hole 6 and second through hole 9
The rib holes 5 of the fixed mold 1 are communicated with each other so that the air filling the rib holes 5 of the fixed mold 1 is discharged to the atmosphere.

In addition, there is a movable mold 1 on the upper part, which is the part facing the fixed mold 1.
1 is arranged, and a movable die plate 1 is disposed on the top surface of the movable die plate 1.
2 is provided, and a molding recess 13 that opens downward is formed in the center of the lower surface, and the upper part thereof becomes a molding surface 13a.

Further, a flat surface 14 is formed around this molded recess.

Then, when the movable mold 11 is closed to the fixed mold 1,
3 molding protrusions formed on the fixed mold 1 are fitted into molding recesses 13 formed on the movable mold 11, and both molds 1.11
The molding space wall is formed by this.

Incidentally, M is a molding material for sheet molding compound wood made of glass fiber, calcium carbonate, unsaturated polyester resin, etc. charged on the molding surface 3a of the fixed mold 1.

A method for compression molding parts such as over fenders and fender garnishes using the compression molding apparatus configured as described above will be explained with reference to FIGS. 3 and 4. FIG.

Further, the fixed mold 1 and the movable mold 11 are preheated to 140° C. Iz'L160° C. by a heating means such as a heater (not shown), and in that state, the molding surface 3a formed on the fixed mold 1 is molded. Charge material M.

Next, the movable mold 13 is closed to the fixed mold 1.

At this time, the molding protrusions 134 formed on the fixed mold 1 are fitted into the molding recesses 134 formed on the movable mold 11. As a result, the molding surface 13a of the movable mold 11 is exposed to the molding material M.
As pressure is applied, the molding material M softens and begins to fluidize.

At that time, a part of the molding material M is fluidized and flows into the first through hole 5, but the cylinder 8 is actuated and the movable pin 7 retreats, so that the first through hole 6 and the second through hole 9 (communicate). The air filling the rib hole 5 passes through the second through hole 9 and is discharged to the atmosphere by the operation of the neucum pump 10.

When the fluidized molding material M flows into the vicinity of the tip of the rib hole 5, the cylinder 8 moves backwards and the movable pin 7 moves forward to forcefully close the second through hole 9. The tip portion is flush with the side surface of the rib hole 5, and a rib portion Mb of the molding surface Ma is formed.

Then, the molding material M is compression-molded while being heated, begins to gel, is compression-molded into the shape of the molded article Ma, and is completely cured. Thereafter, the movable mold 11 is released from the fixed mold 1 to release the molded product Ma, and the molded product Ma is removed from the molding surface 3a of the fixed mold 1.

〔Effect of the invention〕

As explained above, according to the compression molding method and the molding apparatus according to the present invention, when closing the movable mold to the fixed mold, air filling the rib holes formed in the fixed mold is actively exhausted. Since no air remains in the lip holes during compression molding, molding defects such as smudges occurring in the rib portions of the molded product can be completely eliminated.

Furthermore, the present invention has the effect of significantly improving the yield of molded products during compression molding by preventing the occurrence of molding defects.

[Brief explanation of the drawing]

FIG. 1 is a schematic cross-sectional view of a conventional compression molding apparatus. FIG. 2 is a schematic sectional view of a compression molding apparatus according to the present invention. 3 and 4 are enlarged sectional views illustrating the action within the ellipse of section A in FIG. 2. 1----------Fixed mold 2--------Fixed guide plate 3-------1 Molded convex portion 3 a-----1 Molded surface 4---- -・Flat surface 5・・・・Rip hole 6・・First through hole 7・・・・Movable pin 8・・・−・Cylinder 8a・・・・・Rin 9・-・-Second through hole 10--Vacuum pump 11--Movable mold 12--Movable plate 13--Molding recess 13a-- Molding surface 14 --- Flat surface M --- Molding material M a --- Molded product Mb --- Rib portion 141 Figure Beam 2 Figure

Claims (2)

[Claims] (1) The molding surface formed on the fixed mold is charged with a molding material consisting of sheet molding compound, and the movable mold is closed to the fixed mold for compression molding. When the molds come into contact,
A compression molding method characterized in that molding is carried out while actively exhausting air filling rib holes formed in communication with the molding surface of the fixed mold to the atmosphere. (2) A concave rib hole is formed in communication with the molding surface on which the molding material made of sheet molding compound is charged on the fixed mold, and the molding surface of the fixed mold is formed in a portion facing the fixed mold. A compression molding apparatus is provided with a movable mold having a molding surface that fits with the fixed mold, one end of which is open to the atmosphere, and the other end of which communicates with the vicinity of the tip of the rib hole. A first through hole and a second through hole are formed, one end of which is open to the atmosphere and the other end of which communicates with the vicinity of the tip of the first through hole, and further, the first through hole has a tip that is connected to the rib hole. A compression molding device characterized by having a movable pin on the side surface that is movable in the same plane so as to be able to move forward and backward.