JPH089177B2 - Molding method for fiber-reinforced plastic valve body - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for molding a fiber reinforced plastic valve body in which an insert is embedded and reinforced inside.

(Prior art and its problems) In Japanese Patent Laid-Open No. 58-124609, a disk-shaped cavity is formed by a cylindrical upper / lower mold and a side mold, and the inserts arranged in the cavity are arranged above and below. There has been proposed a valve body molding apparatus in which a glass fiber mat impregnated with a thermosetting resin is loaded and the mat is compression-molded by an upper mold and a lower mold.

However, when the mats laminated on the upper and lower sides of the insert are compression-molded by the upper and lower molds, the laminated surfaces of the respective mats are merely joined by the thermosetting resin without the glass fibers being entangled with each other. For this reason, there is a problem that the mat peels off on the laminated surface when a twisting force when the valve body is opened or closed or a fluid pressure acts on the insert.

The present invention solves such a problem, and even when a twisting force when opening and closing a valve body or a fluid pressure acts, a laminated surface of a glass fiber mat impregnated with a thermosetting resin is used. It is intended to provide a method for molding a valve body without peeling.

(Means for Solving Problems) According to the present invention, a disk-shaped cavity is formed by a cylindrical upper / lower mold and a side mold having a half-split structure. When the shaft rod is projected and the insert is supported at the tip of the shaft rod, and the glass fiber mat impregnated with the thermosetting resin is loaded into the cavity to mold the valve element, the side surface of the opened side mold is opposed to each other. A shaft rod is projected from the end, and a small piece mat of glass fiber impregnated with a thermosetting resin is inserted into the end of the shaft rod. Next, the side mold is closed by supporting the insert at the tip of each shaft rod, and glass fiber mats impregnated with a thermosetting resin are loaded on the upper and lower sides of the insert, and then the upper mold and the lower mold It is characterized in that it is compression molded by.

Hereinafter, a specific configuration of the present invention will be described in detail based on examples.

(Examples) FIG. 1 is a vertical cross-sectional view of a molding process showing an embodiment of the present invention, FIG. 2 is a vertical cross-sectional view of a main part when a mold is opened, and FIG.
FIG. 4 is a perspective view of a valve body obtained by the present invention, and FIG. 4 is a cross-sectional view of an essential part showing an example of a usage state in which a valve shaft is inserted into the valve body, and reference numerals 1a and 1b in the drawing are cylinders. Upper and lower molds with a shape, 2
a and 2b are a pair of left and right side molds having a half structure.

The upper die 1a and the lower die 1b are connected to a cylinder device (not shown) and are movable in the vertical direction. Also, the side wall 2a,
Like the upper and lower molds, 2b is connected to a cylinder device (not shown) so as to be movable in the left-right direction. The inner peripheral surface of the cylinder has an outer peripheral edge portion of the valve body 7 shown in FIG. An annular groove 22 forming 72 is provided. A boss molding portion 21 that forms the boss portion 71 of the valve body 7 is provided at a position opposite to the annular groove 22, and the shaft rods 3 are provided so as to penetrate the molding portion 21. The insert 4 can be supported at the tip end portion by projecting the shaft rods 3 from the inner die surfaces of the side dies 2a and 2b.

In the mold closed state shown in FIG. 1, the upper and lower molds 1a and 1b are housed in the side molds 2a and 2b having a cylindrical inner mold surface, and these upper and lower molds 1a and 1b and the side mold 2a, A disk-shaped cavity 5 is formed by 2b.

In the present invention, the upper mold 1a and the lower mold 1b are moved in the vertical direction, and the side molds 2a, 2b are moved left and right to close the mold. Therefore, as shown in FIG. 2, the shaft rods 3, 3 are attached to the side mold 2a,
A small piece mat 61 of glass fiber, which is projected from the inner mold surface of 2b and whose end is impregnated with a thermosetting resin, is inserted. The small piece mat 61 used at this time is cut into a circular shape, an elliptical shape, a rectangular shape, or any other suitable shape slightly larger than the outer diameter of the end portion 41 of the insert 4, and the small piece mat 61 has a hole through which the shaft 3 can be inserted. After drilling, they are inserted into the ends of the respective shaft rods 3. Then, the shaft rod 3 is inserted into the shaft hole 42 of the heated insert 4.
The side molds 2a and 2b are closed by inserting the tip end of the mold.

Next, a glass fiber mat 62 impregnated with a thermosetting resin is loaded on the upper and lower sides of the insert 4 and the upper and lower dies 1a and 1b are loaded with the glass fiber mat 62.
Compression molding with. At this time, the upper and lower molds 1a, 1b and the side molds 2a, 2b are preferably heated to a predetermined temperature by a heat medium such as heating oil circulating in the mold wall, and the resin impregnated in the fiber mat is When you open the mold while curing it,
The valve body 7 shown in FIG. 3 is obtained.

In the present invention, a fiber mat in which glass fibers are crossed and intertwined with each other is impregnated with a thermosetting resin such as polyester resin, and a fiber mat 61 covering the end surface of the boss portion 71 of the valve body 61 is used. It is preferable to use one having a higher glass fiber content than the fiber mat 62 loaded above and below the insert 4.

Further, as shown in FIG. 4, when the valve shaft 8 is used by being inserted into the valve body 7, the valve shaft 8 having a diameter substantially the same as the shaft hole 42 of the insert 4 is used.
If the gap 9 is formed between the fiber mat 61 and the valve shaft 8 by using, it is possible to more reliably prevent the boss portion 71 from being cracked.

(Operation and Effect of the Invention) As described in detail above, according to the present invention, a disk-shaped cavity is formed by the upper and lower molds and the side mold, and the thermosetting resin is impregnated above and below the insert supported in the cavity. When loading a glass fiber mat and compressing it with the upper and lower molds,
Since a small piece mat made of glass fiber impregnated with thermosetting resin is inserted into the shaft rod that supports the insert in advance, the boss part that inserts the valve shaft is reinforced with fiber reinforced plastic in which glass fibers are entwined with each other. It

Therefore, even when a twisting force, a fluid pressure, or the like when the valve body is opened or closed acts on the insert, peeling does not occur on the laminated surface of the glass fiber mats laminated above and below the insert.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of a molding step showing an embodiment of the present invention,
FIG. 2 is a longitudinal sectional view of a main part when the mold is opened, FIG. 3 is a perspective view of a valve body obtained by the present invention, and FIG. It is a principal part sectional view which shows an example. 1a …… upper mold, 1b …… lower mold 2a, 2b …… side wall, 3 …… axis rod 4 …… insert, 5 …… cavity 6 (61, 62) …… glass fiber mat 7 …… valve body, 8 ...... Valve shaft

Claims (1)

[Claims] 1. A disk-shaped cavity is formed by a cylindrical upper / lower die and a side die having a half-split structure, and an axial rod is projected into the cavity from opposing die surfaces of the side die. When the insert is supported and the cavity is loaded with a glass fiber mat impregnated with a thermosetting resin, the shaft rod is projected from the inner mold surface of the opened side mold when the valve body is molded. Insert a small piece of glass fiber impregnated with thermosetting resin into its end, then support the insert at the tip of the shaft to close the side mold, and set the thermosetting resin above and below the insert. A method of molding a fiber reinforced plastic valve body, comprising: loading a resin-impregnated glass fiber mat and then compression-molding the upper mold and the lower mold.