JP2717119B2 - Manufacturing method of end plate of filter element - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for manufacturing an end plate of a filter element mainly made of a synthetic resin.

(Prior art) Used, for example, for the production of electronic equipment parts (semiconductor substrates such as ICs and LSIs) and for the treatment of chemical liquids and gas bodies used in the production of various pharmaceuticals or pure water used in the food industry. An example of a filter element is shown in Fig. 3, in which all members are made of synthetic resin having chemical resistance, heat resistance, and elution resistance, such as fluorine resin and polypropylene, and are made of porous material. A material 1 in which a mesh cloth is layered on both sides or one side on the inner side of the thin film is formed into a chrysanthemum flower-shaped tube, and porous tubes 2a and 2b are inserted inside and outside the tube, and a blind end is provided at the upper end thereof. While the plate 3 is covered, a lower end is provided with a dished end plate 4 having legs formed of a cylindrical portion 4a having a processing fluid outlet hole 4c and a disk portion 4b, and their butted portions are fused and integrated. A plurality of annular grooves 4d are provided on the outer periphery of the central cylindrical portion 4a of the lower end plate 4. The seal ring 5 is embedded in the groove 4d, the exit holes 4c are fitted with metal rings 6 such as stainless steel, adapter A for the fluid and out the tubular portion 4a of the lower end plate 4
This prevents the seal ring 5 from being compressed and deformed, and also prevents fluid leakage due to distortion of the cylindrical portion 4a due to the influence of temperature during steam sterilization and hot water sterilization.

However, in this case, since the metal ring 6 is completely exposed inside the outlet hole 4c, it comes into contact with the fluid passing through the outlet hole 4c, and the metal is eluted in the fluid or rust is generated. From this, the applicant of the present application has improved a structure in which a metal ring 6 for reinforcement is embedded in the central cylindrical portion 4a of the lower end plate 4 and is surrounded by the above synthetic resin as shown in FIG.
-329474.

(Problems to be Solved by the Invention) By the way, in the above-mentioned prior art, when forming the lower end plate 4 in which the metal ring 6 is embedded in the central cylindrical portion 4a, first, FIG. Place the metal ring 6 to the end plate disk portion forming recess a metal ring holding the annular ridge b of the provided first-order lower die D ₁ of the on annular ridge b as, the lower mold D ₁ thereof On top of the,
Covered with a upper mold D ₂ having a cylindrical portion for forming recesses d around the core c for forming the outlet hole, a metal ring in the cylindrical portion in by injecting molten resin into the cavity between the upper and lower molds to form a 6 primary end plate 4 which is partially embedded in ', then the lid type D ₄ thereon with fitting which is inverted the secondary lower mold D ₃ as Ha view the
To fill the annular space e on the ring 6 with molten resin and surround the metal ring 6 with the resin. In order to improve the fixability of the metal ring 6, as shown in FIG. keep in providing a rectangular parallelepiped-shaped recess b ₁ to several locations of the primary lower die D ₁ of the annular ridge b, the annular space e that can be on top of the metal ring 6 in this Figure 5 at the primary molding as In some places, a resin bridge 4e is made. However, at the intermediate position of the bridging portion 4e, the end face of the metal ring 6 is slightly exposed, and the gate at the time of the second molding for filling the annular space e with resin becomes the intermediate position of the bridging portion 4e. Therefore, the injection pressure of the molten resin is directly applied to the exposed portion of the metal ring 6, and the molten resin enters the buried portion of the metal ring 6 as shown in FIG. This may result in defective products.

SUMMARY OF THE INVENTION It is an object of the present invention to reliably prevent the above-mentioned problem in manufacturing a lower end plate of a filter element.

(Means for Solving the Problems) In order to achieve the above-mentioned object, the invention provides a filter element end comprising a disk portion made of synthetic resin and a central cylindrical portion, wherein a reinforcing metal ring is embedded in the central cylindrical portion. As a method of manufacturing a plate, a plurality of resin bridges and a plurality of recesses are alternately formed on the top of a metal ring, and at the same time, a curved base portion reaching the upper end surface of the ring is formed on both sides of each bridge. Embedded in the central cylindrical portion, and then the injection port is located on the curved base portion, and the molten resin is injected toward the curved base portion to fill each recess. .

(Embodiment) An embodiment of the present invention will be described below with reference to FIG. 1 and FIG.

Reference numeral 10 in FIG. 1A denotes a primary lower mold for forming the dish-shaped lower end plate 4 with legs of the filter element, and a circular recess for forming an end plate disk portion in the same manner as described above. Place 11
However, a plurality of arc-shaped projections 12 having a required thickness and height are formed on the circumference of a certain radius at the center portion at a certain interval 13 ′ serving as a bridging portion 13 of resin, and each arc-shaped projection is formed. At the top of 12, a shallow flat groove 12a for preventing the metal ring from slipping is provided.

Then, the reinforcing metal ring 6 is placed on each of the arc-shaped projections 12 of the lower die 10 while being fitted into the flat groove 12a, and the lower die 10 is provided with a core 21 for forming an outlet hole and the periphery thereof. Cover the upper mold 20 provided with the annular recess 22 for forming the cylindrical portion, and
The molten resin of the synthetic resin having the above-mentioned chemical resistance, heat resistance and elution resistance is injected and injected into the space formed at 0,20.

Then, a primary end plate 4 'in which the metal ring 6 is buried in the central cylindrical portion as shown in FIG. 1C is formed. In this case, the primary end plate 4' shown in FIG. Above the metal ring 6, a plurality of resin bridges 13 formed by the above-mentioned gaps and a plurality of recesses 14 formed by the arc-shaped projections 12 forming a curved base 13a on both sides are formed alternately. A portion of the upper end surface of the ring 6 adjacent to each bridging portion 13 is covered by the curved skirt portion 13a.

Next, the primary end plate 4 'is inverted and fitted into a secondary lower mold 30 having a central core 31 and a stepped recess 32 around it as shown in FIG. 2A, and a lid mold 40 is placed thereon. The resin injection port (gate) g is positioned on one of the right and left curved bases 13a adjacent to each bridging portion 13 as shown by the solid arrow in FIG. Injection filling with molten resin
As shown in FIG. 2B, the lower end plate 4 in which the metal ring 6 is surrounded by a synthetic resin and embedded in the central cylindrical portion 4a is formed. that time,
Since the molten resin is injected toward the curved base 13a,
The resin is introduced into the recess 14 without the injection pressure being applied directly to the metal ring 6, and does not enter the embedded portion of the ring 6.

(Effects of the Invention) As described above, according to the present invention, when embedding a metal ring for reinforcement in a central cylindrical portion of an end plate of a synthetic resin filter element, a plurality of resin bridging portions are provided on an upper portion of the metal ring. A plurality of recesses are alternately formed, and at the same time, a curved skirt portion is formed on both sides of each bridge portion to reach the upper end surface of the ring. Injection pressure is injected into each recess so that the injection pressure of the molten resin can be dispersed without directly applying to the metal ring during secondary molding in which the upper part of the metal ring is wrapped with resin. To the central part and the bulging of the central cylinder part can be reliably prevented.
Since the molten resin enters the recess through the curved base portion, the resin flow is good and the filling operation is smooth.

[Brief description of the drawings]

FIG. 1A is a partially cut-away side view showing a primary molding state of the present invention. FIG. 2B is a perspective view of a part of the primary lower mold. FIG. 3C is a downward sectional view of the primary end plate. FIG. 2D is a perspective view of a part of the cylindrical portion of the primary end plate. FIG. 2A is a sectional view showing a state of secondary molding. FIG. 2B is a cross-sectional view of the end plate. FIG. 3 is a sectional view of a filter element using a conventional end plate. FIG. 4 is a cross-sectional view of a part of a filter element using the end plate of the prior application. FIG. 5A is a side view of the end plate of the prior application at the time of primary molding. FIG. 2B is a perspective view of a part of the ridge portion of the primary lower die. FIG. 3C is a sectional view at the time of the secondary molding. Fig. 2D is a partial perspective view showing a state where the central cylindrical portion is inflated. In the drawing, 4 ... end plate, 4 '... primary end plate 4a ... central tubular part, 4b ... disk part 4c ... outlet hole, 6 ... metal ring 10 ... primary lower die, 11 … Circular recess 12… Arc-shaped projection, 13… Bridged section 13 ′… Spacing, 13 a… Bent base 14… Recess, 20… Upper mold 30… Secondary lower mold, 40… … Lid type

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code Agency reference number FI Technical display location B29L 31:14

Claims (1)

(57) [Claims] 1. A synthetic resin disk portion and a central cylindrical portion,
In a method of manufacturing a filter element end plate in which a reinforcing metal ring is embedded in a central cylindrical portion, a plurality of resin cross-links and a plurality of recesses are alternately formed on the upper portion of the metal ring, and at the same time, each cross-link portion is formed. Forming a curved base portion extending to the upper end surface of the ring on both sides, embedding the metal ring in the central cylindrical portion, then positioning an injection port on the curved base portion, injecting the molten resin toward the curved base portion. A method of manufacturing an end plate of a filter element, wherein each recess is filled.