JP3380635B2 - Mold for center core of water governor - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a molding die for a center core of a water governor (simple flow rate limiting device).

[0002]

2. Description of the Related Art The basic structure of a conventional water governor and its problems will be described with reference to FIGS. This water governor aims to always supply a substantially constant flow rate regardless of the pressure level on the upstream side, and it regulates the maximum flow rate of faucets in centralized boilers, tankless flush toilets, hotels, etc. It is being used for other purposes. The basic form was proposed in Japanese Examined Patent Publication No. 51-23059. This water governor includes a casing 10, a center core 20, and an O-ring (elastic member) 30. Center core 20
Has a columnar core portion 20A and a flange portion 20B, and the core portion 20A is formed with a plurality of convex portions 21 extending in the radial direction on the outer surface thereof and a concave portion 22 between these convex portions 21. Has been done. The ridge lines of the convex portion 21 and the concave portion 22 are inclined with respect to the axis of the core portion 20A. O-ring 3
0 is fitted on the outer periphery of the core portion 20A of the center core 20, and forms a flow path 23 between the core portion 20A and the recess 22. A plurality of through holes 24 are formed between the core portion 20A and the flange portion 20B of the center core 20, except for the bridge portion 25. The casing 10 supports the combined body of the center core 20 and the O-ring 30, and has a stepwise cross section for receiving the flange portion 20B of the center core 20.
In the casing 10, the center core 20 is pressed against the casing 10 by the pressure on the upstream side,
For example, it is fixed in the water pipe 11.

According to this water governor, the fluid on the upstream side (referred to as water) flows into the O-ring 30 side from the through hole 24, passes through the flow path 23 between the O-ring 30 and the concave portion 22, and reaches the downstream side. Flowing to the side. At this time, the O-ring 30 elastically deforms inward according to the flow velocity of the water passing through the flow path 23 to change the area of the flow path 23. An example of the position of the O-ring 30 after elastic deformation is shown by reference numeral 30 'in FIG. That is, as the flow velocity is faster, the O-ring 30 is elastically deformed inward and the flow path 2
Since the channel 3 is throttled, a substantially constant flow rate can always be taken out to the downstream side regardless of the pressure on the upstream side.

The center core 20 of this conventional water governor
In a mass-produced product, is formed by molding a resin material.
However, the molding die has the following problems. In this type of molding die, conventionally, a molding electrode of a similar shape slightly smaller than the center core shape was created, and the mold blank was subjected to electric discharge machining to form a bottomed hole corresponding to the center core shape. Is configured. Therefore, every time the shape, the number, the inclination, etc. of the convex portions 21 and the concave portions 22 of the core portion 20A of the center core 20 are changed, the entire molded electrode is processed,
The entire molding die must be machined from the beginning using the molding electrode. In other words, the manufacturing cost is high and much time is required because the entire molding electrode and molding die must be rebuilt even with a slight design change. Further, if a bottomed mold is formed with a single molding electrode, it is difficult to finely control the irregularities of the molding electrode, and therefore the degree of freedom in setting the shapes of the convex portion 21 and the concave portion 22 of the center core 20 is high. It was limited.

[0005]

It is an object of the present invention to easily form a center core of a water governor based on the above-mentioned awareness of the problems of the conventional water governor molding die, and at a low cost even when the shape of the center core is changed. The purpose is to obtain a molding die that can be manufactured in a short time.

[0006]

SUMMARY OF THE INVENTION According to the present invention, a molding die is composed of a master die having a bottom surface corresponding to one end face of a center core and a cavity die which can be attached to and detached from the master die. For example, most of the shape changes of the center core are made only by changing the cavity mold.

That is, the mold for molding the center core of the water governor of the present invention includes a center core having a plurality of radially extending projections and recesses located between these projections; and a center core fitted to the outer circumference of the center core. , An elastic ring that forms a flow path between the recess and the recess; and a casing that supports the center core and the elastic ring and causes a fluid to flow in the flow path.
A projecting portion having a diameter smaller than that of the core portion and a flange portion having a diameter larger than that of the core portion having a plurality of through holes, respectively, at one and the other end portions in the axial direction of the core portion having the plurality of protrusions and recesses The molding die has a concave portion corresponding to the protruding portion of the center core, and a bottomed concave portion concentric with the concave portion, the bottom surface of the bottomed concave portion between the core portion of the center core and the protruding portion. A master mold for regulating the end face of the step portion; and a cavity mold that can be inserted into and removed from the bottomed recess of the master mold; the cavity mold is connected to the recess of the master mold. A center recess having a molding recess corresponding to the projection and the recess of the core portion of the center core, and a through molding hole having a molding projection; and an annular molding recess corresponding to the flange of the center core having the through hole. It has a feature. According to this molding die, the contour surface of the molding concave portion and the molding convex portion of the cavity mold can be easily machined into a non-tapered surface parallel to the axis of the center core by, for example, a wire cut electric discharge machine.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. 1 and 2 show examples of the shape of a water governor having a center core molded by a molding die according to the present invention. This water governor includes a casing 10, a center core 200, and an O-ring (elastic member) 30, as in the conventional product. The center core 200 includes a columnar core portion 20A, a flange portion 20B at one end portion in the axial direction of the core portion 20A, and a small diameter protruding portion 2 at the other end portion.
It has 0C. On the outer surface of the core portion 20A, a plurality of protrusions 121 extending in the radial direction and the protrusions 12 are provided.
1 and the concave portion 122 between the core portion 20A
A step portion 27 is formed at the boundary between the protrusion 20C and the protrusion 20C. Unlike the conventional product, the ridgelines (outer surface contour surfaces) of the convex portion 121 and the concave portion 122 on the outer periphery of the core portion 20A are configured as non-tapered surfaces parallel to the axis of the core portion 20A. The O-ring 30 is fitted on the outer periphery of the core portion 20A of the center core 200, and forms the flow path 23 with the recess 122. A plurality of through holes 24 are formed between the core portion 20A and the flange portion 20B of the center core 200 except for the bridge portion 25. The casing 10 is the center core 20.
It supports the combined body of the 0 and the O-ring 30, and has a stepwise cross section for receiving the flange portion 20B of the center core 200. The casing 10 is fixed in, for example, the water pipe 11 in a direction in which the center core 200 is pressed against the casing 10 by the pressure on the upstream side.

The above water governor differs from the conventional example shown in FIGS. 8 and 9 in that the convex portion 121 and the concave portion 122 of the center core 200 are provided.
The outer surface (contour surface) of is parallel to the axis O of the center core,
It is composed of a non-tapered surface. In FIG. 1, the convex portion 121
Draw an extension line 121 ′ that passes through the apex of and a extension line 122 ′ that passes through the bottom of the recess 122, which are parallel to the axis O. When the contour surfaces of the concave portion and the convex portion are composed of non-tapered surfaces parallel to the axis in this way, the working of the molding die becomes easy.

Next, an embodiment of a molding die suitable for molding the above center core 200 will be described. In this embodiment, the present invention is applied to a molding die for forming the center core 200 whose plane shape is shown in FIG. Figure 3
5 to FIG. 5 show the entire structure of the molding die 100 of the present invention, and show the combined state of the master die 40 and the cavity die 50. The master mold 40 has a circular recess (cavity) 41 formed at the center of one end face thereof, and the planar circular cavity mold 50 is inserted into the circular bottomed recess 41. . Master mold 4
In addition, a concave portion 43 concentric with the circular bottomed concave portion 41 is formed at 0. The recess 43 corresponds to the protrusion 20C of the center core 200. The cavity mold 50 inserted into the circular bottomed recess 41 is fixed to the circular bottomed recess 41 by a fixing bolt 42 inserted from the other end surface of the master mold 40. The central portion of the circular bottomed recessed portion 41 constitutes a bottom surface 27F corresponding to the step portion 27 (FIG. 1) between the core portion 20A and the protruding portion 20C of the center core 200.

FIG. 6 and FIG. 7 show details of a single unit of the cavity mold 50. The cavity mold 50 has an annular molding recess 20BF corresponding to the flange portion 20B of the center core 200 on the outer end surface thereof, and a through molding hole 20AF corresponding to the core portion 20A at the center thereof. In FIG. 6, this through-molding hole 20AF is hatched for easy understanding. The protrusion 121 of the center core 200 is formed around the through molding hole 20AF.
The convex-formed concave portions 121F corresponding to the concave portions and the concave-shaped convex portions 122F corresponding to the concave portions 122 are alternately formed.
The inner surface (contour surface) of each of the convex portion forming concave portion 121F and the concave portion forming convex portion 122F is a non-tapered surface parallel to the axis O. Further, in the cavity mold 50, a hole forming leg 24F corresponding to the through hole 24 and a bridge molding portion 25F corresponding to the bridge portion 25 are simultaneously formed.

The above cavity mold 50 can be processed separately from the master mold 40, and after processing, the cavity mold 50 is inserted into the circular bottomed recess 41 of the master mold 40 and fixed. The molding die 100 can be used. Projection portion 20C and step portion 2 of the center core 200
The shape of No. 7 hardly affects the performance of the water governor, and the performance of the water governor is affected by the planar shapes of the projections 121 and the recesses 122, the intervals, the size of the through holes 24, and the like. , When changing these, cavity mold 5
The change can be dealt with by replacing only 0.

Further, the cavity die 50 has a core portion 2
There is a through molding hole 20AF corresponding to 0A, and the convex molding concave portion 121F and the concave molding convex portion 1 are formed on the periphery of the through molding hole 20AF.
22F are formed, these molding recesses 121F,
A wire cut electric discharge machine can be used to process the forming convex portion 122F, and thus a more precise shape can be easily processed. In particular, the cavity mold 50
Convex shaped concave portion 121F and concave shaped convex portion 1 which penetrate through
22F can be easily machined by a wire cut electric discharge machine by making it a non-tapered surface.

In the resin molding using the main molding die 100, as shown in FIG. 7, the open end surface of the cavity die 50 is closed by another die 60 according to a conventional method, and then the resin of the die 60 is molded. Resin is injected into the cavity mold 50 through the injection port 61.

[0015]

As described above, the center core molding die of the present invention is composed of the master die and the cavity die. Therefore, when changing the shape of the main part of the center core, only the cavity die is used. It can be manufactured and replaced. Therefore, the manufacturing cost of the center core molding die can be reduced, and the manufacturing time can be shortened. In particular, a center core cavity mold having a non-tapered surface can be easily manufactured by a wire cut electric discharge machine.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view showing an example of a water governor having a center core molded by a molding die according to the present invention.

2 is a plan view of the center core used in the water governor of FIG. 1 taken along arrow A in FIG.

FIG. 3 is a front view showing an embodiment of a molding die for a center core of a water governor according to the present invention.

FIG. 4 is a sectional view taken along line IV-IV in FIG.

FIG. 5 is a rear view of FIG.

FIG. 6 is a front view of a single cavity mold.

7 is a sectional view taken along line VII-VII in FIG.

FIG. 8 is a vertical cross-sectional view showing an example of a conventional water governor.

9 is a plan view of the center core alone used in the water governor of FIG. 8 as viewed in the direction of arrow A in FIG.

[Explanation of symbols]

10 casing 200 center core 20A core part 20B Flange part 20C protrusion 121 Radial convex 122 recess 23 channel 24 through holes 30 O-ring (elastic member) 40 master mold 41 Circular bottomed recess 42 fixing bolt 43 recess 50 cavity mold 20AF Through molding hole 20BF annular molding recess 121F Convex molding concave 122F Concave molding convex 24F Hole forming leg 25F bridge molding part 100 Mold

Continuation of the front page (56) References Actually open Sho-58-137166 (JP, U) Actual-open Sho-58-172188 (JP, U) Actual-open Hei 5-54875 (JP, U) Japanese Patent Sho-51-23059 (JP , B1) (58) Fields investigated (Int.Cl. ⁷ , DB name) F16K 17/22 F16K 17/34

Claims (2)

(57) [Claims] 1. A center core having a plurality of radially extending projections on its outer periphery and recesses located between these projections;
The center core of the water governor including an elastic ring fitted to the outer periphery of the center core and forming a flow path between the center core and the recess; The center core has a plurality of protrusions and recesses at one end and the other end in the axial direction of the core, the protrusion having a diameter smaller than the core, and the plurality of through holes. And a flange portion having a diameter larger than that of the core portion, and the molding die has a concave portion corresponding to the protruding portion of the center core and a bottomed concave portion concentric with the concave portion. The bottom mold includes a master mold that regulates a step end face between the core part and the protrusion of the center core; and a cavity mold that can be inserted into and removed from the bottomed recess of the master mold. The mold is the concave of the master mold A through-molded hole having a molding recess and a molding projection corresponding to the convex portion and the concave portion of the core portion of the center core, and an annular molding recess corresponding to the flange portion having the through hole of the center core. Mold for center core of water governor. 2. A center core molding die for a water governor according to claim 1, wherein the contoured surfaces of the cavity concave portion and the molding convex portion of the cavity die are formed by non-tapered surfaces parallel to the axis of the center core. Mold for center core of water governor.