JPH03209B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for molding a thermosetting resin, and particularly to a method for molding a thermosetting resin.
This invention relates to a method for forming sheet-like raw materials such as SMC materials.

One method for molding a sheet-like raw material of thermosetting resin is to heat and press it using a mold. This is a method in which a sheet-like raw material is placed on the molding surface of a lower mold, then pressed together with an upper mold, and molded by heating and pressure.

However, in conventional molding methods, when material is put into a heated mold, the material immediately begins to gel at the contact area with the mold, so it is necessary to close the mold as quickly as possible or to use a material that gels slowly. It is necessary to use it. If a material that is partially gelled is heated and pressed to be molded, defects such as agglomeration, rough skin, and swelling are likely to occur on the surface of the product. For this reason, when performing molding where the material stays in the mold for a long time, treatments such as the use of materials that gel very slowly are taken, which lengthens the compression molding time and lowers productivity. Ta.

Further, when conventional sheet-like raw materials are charged using an automatic charge machine, a gravity drop type charge machine is often used when the shape of the molded part is simple. However, when the shape of the molded part becomes complex, such a charge machine cannot sufficiently charge a limited position, which causes molding defects. In addition, it is possible to use a charger that clamps around the raw material and removes the clamp after the material comes into contact with the surface of the lower mold, but there is a problem that the surface of the mold may be damaged by the clamping jig, etc. There is. For this reason, when the shape of the molded part is complicated, charging is carried out by an operator, resulting in poor productivity. As another conventional example, JP-A-56-
Techniques disclosed in JP-A No. 121752 and JP-A-49-74747 are cited. In the former, a retractable pin is provided on the molding surface of the lower mold, and the molding material is deposited in the pin, and the process of placing a sheet-shaped thermosetting resin material on the pin is required. It is different from the present invention, which will be described later, in that it does not include the above. The latter method also differs in structure from the present invention in that it does not include the step of making the ejecta pin appear and disappear.

Furthermore, when loading materials, press forming, and taking out products in the press equipment, the time required for material input, press forming, and product taking out becomes the production cycle time.
Due to the problems described above, the production cycle time was extremely long, making the molding method unsuitable for molding mass-produced parts.

It is an object of the present invention to provide a method for molding a thermosetting resin that eliminates the problems of the prior art, provides an excellent product finish, and is highly productive.

The present invention provides a thermosetting resin molding method in which a sheet-shaped thermosetting resin material, which is a sheet-shaped raw material, is placed on a heated lower mold, and then an upper mold is pressed together. A retractable ejector pin is disposed on the molding surface of the lower mold, and before placing the sheet-like raw material, the lever pin is made to protrude from the molding surface, and the sheet-like raw material is placed on the pin. After placing the sheet material on the molding surface of the lower mold, the pin is lowered to place the sheet material on the molding surface of the lower mold and press it.

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a side view of an apparatus for carrying out the present invention, in which reference numeral 1 is a press machine, and the lower part of the press machine is provided with a bolster 2 to which a mold can be transferred. A lower mold 3 is mounted on the bolster 2, and an upper mold 5 is disposed above this with a platen 4 interposed therebetween. Further, an ejector pin 7 is provided on the molding surface 6 of the lower die 3 so as to be retractable and ejector pin 7 is retractable. ing. Reference numeral 10 denotes an automatic charge machine to which a jig 11 is attached. The molding surface 6 of the lower mold 3 is generally U-shaped, as shown in a plan view in FIG.

A molding method using the apparatus configured as described above will be described next. First, as shown in Figure 1,
A lower mold 3 and an upper mold 5 heated to a predetermined temperature are kept open with a certain distance maintained between them. Next, the plurality of pins 7 of the lower mold 3 are made to protrude from the molding surface 6 by driving the hydraulic cylinder 8. A charge machine 10 that clamps a sheet-like raw material 12 made of a sheet-like thermosetting resin material with a jig 11 is moved above the plurality of protruding pins 7, and the sheet-like raw material 12 is charged until it comes into contact with the pins 7. machine 10
lower. After the descent is completed, the sheet-like raw material 12 clamped on the jig 11 is released and the pin 7
Put it on top. After that, the charge machine 10 is raised,
Furthermore, it is removed from the press machine 1. Next, the platen 4 is lowered and the pin 7 is also lowered in synchronization with the lower mold 3 to perform compression molding with the upper mold 5.
After the molding is completed, the platen 4 is raised and the molded product is taken out of the mold using a take-out machine (not shown). It is possible to continue molding by repeating such a cycle.

In this embodiment, since the sheet-like raw material is charged onto the protruding pins 7, the surface of the mold is not damaged by the clamp jig 11 or the like during charging. In addition, since the sheet-like raw material is held on the pins 7 immediately before pressing, the finished product is excellent. Furthermore, from the point where it is charged using an automatic charge machine,
Even for products with complex molded shapes, the finished product is excellent and productivity is improved.

FIG. 3 is a side view showing a different embodiment of the present invention;
FIG. 4 is an enlarged view showing the state in which the mold is transferred to the press machine in FIG. 3. In FIG. 3, mold opening/closing machines 13, 13' are arranged on the left and right sides of a press machine 1', and a movable bolster 14 that can move left and right is provided between the press machine 1' and the mold opening/closing machines 13, 13'. . The rest of the configuration is similar to that of the device shown in FIG. In order to carry out molding using the apparatus shown in FIG. The sheet-like raw material 12' is charged and held. Next, the upper movable part 15 of the mold opening/closing machine 13 is lowered and the upper mold 5' is placed on the stopper pin 17 (see FIG. 4) which has been raised by the hydraulic servo mechanism 16. ’ is removed.
At this time, the sheet-like raw material is compression-molded in the other molds 3'' and 5'' on the bolster 14. Next, the platen 4' is raised, the movable bolster 14 is moved to the left, and the molds 3' and 5' are introduced into the press machine 1'. Next, the platen 4' of the press 1' is lowered, and after clamping the upper die 5', the stopper pin 17 is lowered. Next, the platen 4' is lowered and the pin 7' is lowered, and after the sheet-like raw material 12' is placed on the molding surface 6',
Compression molding is performed. At this time, the molds 3'' and 5'' are opened by a mold opening/closing machine 13', and the molded product is taken out. Next, a sheet-like raw material is placed on this lower mold 3'' in the same manner as described above, and then transferred to the press machine 1' and molded.

Also in this embodiment, since the sheet-like raw material 12' is held on the pin 7' until just before pressing,
The finished product will be of excellent quality. In particular, in this example, two sets of molds are used,
During compression molding with one mold, the molded product is removed from the other mold and raw materials are input, which has the effect of significantly shortening the production cycle time. Furthermore, since the sheet-shaped raw material does not come into direct contact with the mold during transportation, the pregel phenomenon in which the surface of the raw material hardens before compression molding does not occur, and a product with excellent surface quality can be obtained.

In the above embodiment, the pins 7 and 7' are used to hold the sheet-like raw material, but they can also be replaced with ejector pins for releasing and taking out the product. .

As described above, in the thermosetting resin molding method of the present invention, prior to placing the sheet-like raw material on the lower mold, pins are made to protrude onto the molding surface of the lower mold, and the sheet-like raw material is placed on the pins. After placing the mold, the pin is lowered to place the sheet-like raw material on the molding surface of the lower mold, resulting in an extremely excellent finished product. Furthermore, even for molded products with complex shapes, raw materials can be easily charged, and productivity is significantly improved.

[Brief explanation of drawings]

FIG. 1 is a side view of an apparatus for carrying out the present invention, FIG. 2 is a plan view of the lower die shown in FIG. 1, FIG. 3 is a side view of an apparatus according to another embodiment of the present invention, and FIG. The figure is an enlarged view of FIG. 3 during transfer of the mold. 1...Press machine, 3...Lower die, 5...Upper die, 7
... Pin, 10 ... Automatic charge machine, 12 ... Sheet-like raw material, 13 ... Mold opening and closing machine, 14 ... Movable bolster, 17 ... Stopper pin.

Claims (1)

[Scope of Claims] 1. A thermosetting resin molding method in which a sheet-like thermosetting resin material is placed on a heated lower mold, and then the upper mold is pressed together. A retractable ejector pin is disposed on the molding surface of the mold, and before placing the sheet-shaped thermosetting resin material on the pin, the ejector pin is made to protrude from the molding surface, and the ejector pin is placed on the molding surface. After placing a sheet of thermosetting resin material on the
A method for molding a thermosetting resin, which comprises lowering the ejector pin, placing the sheet-like thermosetting resin material on a molding surface of a lower mold, and press-molding it using a press device. 2. After placing the sheet-like thermosetting resin material on the ejector pin of the lower mold outside the press device, lowering the upper mold to a position close to the sheet-like thermosetting resin material so that it does not come into contact with the sheet-like thermosetting resin material. 2. The method of molding a thermosetting resin according to claim 1, wherein the lower mold and the upper mold are transferred into a press machine and press-molded.