JP2003056711A - Plug - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a plug having superior corrosion resistance. SOLUTION: This plug is so formed that a hollow part 10 recessed inward is formed in the tip surface of a plug body 7, a fitting insertion part 17 capable of press-fitted inside the hollow part 10 is formed in a packing 15, an annular groove 11 is formed in one of the inside of the hollow part or the outside of the fitting insertion part 17, an annular rib 18 is formed in the other, and the fitting insertion part 17 is press-fitted inside the hollow part 10 till the annular groove 11 and the annular rib 18 are fitted to each other so that the packing 15 is joined with the tip part of the plug body 7. The adoption of this constitution can firmly join the packing 15 to the tip surface of the plug body 7 by synergistic effect of a pushing force caused by the elastic deformation of the fitting insertion part 17 and a regulating force caused by the annular groove 11 and the annular rib 18 without using corrosive components.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plug used to close a plug hole.

[0002]

2. Description of the Related Art In a pump that requires priming, the pump operation is started after the priming is introduced from a priming hole (plug hole) formed in the pump.

In recent years, in an automatic water supply system using such a pump, it has been considered to pump a special liquid such as seawater in addition to fresh water.

Therefore, a rustproof structure that is resistant to seawater has been studied. Of course, the plugs that close the priming holes (parts that close the priming holes except when starting) are also being considered for rust prevention.

Usually, the priming water plug has a structure in which, for example, a rubber packing is attached to the tip of the plug body which can be inserted into and removed from the priming hole. Then, when the plug body is attached to the priming hole, the packing at the tip is pressed against the step surface formed on the inner surface of the priming hole to seal the portion.

In the plug for priming water, a plug body made of synthetic resin is generally used for rust prevention, and a structure in which a packing is fixed to a tip end surface of the plug body with a stainless screw member such as a bolt is adopted. There is.

[0007]

However, since the head portion of the bolt is exposed to the outside from the tip end surface of the packing, the head portion of the bolt comes into contact with the liquid in the pump in the priming hole.

Therefore, when the plug is applied to seawater, the phenomenon of corrosion of the bolt is unavoidable, water may leak through the bolt, and the conventional rust preventive means cannot withstand it.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a plug having excellent corrosion resistance.

[0010]

In order to achieve the above-mentioned object, the invention described in claim 1 forms a cavity portion which is recessed inward from the tip surface of the plug body, and the packing has an interior cavity portion. A press-fitting insertable portion is formed on the inner surface of the cavity, and a groove extending along the circumferential direction is formed on one of the inner surface of the cavity and the outer surface of the inserting insert, and the other extends along the circumferential direction that can be inserted into the groove. The protrusion is formed, and the packing is joined to the tip of the plug body by press-fitting the fitting insertion portion into the cavity until the groove and the protrusion fit together.

As a result, the fitting insertion portion is elastically contacted with the inner surface of the cavity portion and is accommodated in the cavity portion, and the circumferentially extending groove portion and the projecting portion are elastically fitted to each other and the direction in which they are pulled out is restricted.

That is, the packing is firmly joined to the front end surface of the plug body by the synergistic effect of the pressing force generated by the elastic deformation of the fitting portion and the restriction force generated by the groove and the protrusion.

Therefore, the packing is assembled to the plug body without using a component that causes corrosion, so that a plug having excellent corrosion resistance suitable for a special liquid can be provided.

Moreover, by forming the packing with the fitting portion by using a material suitable for the special liquid, it becomes possible to easily manufacture a plug that can be applied to other special liquids by combining it with the plug body.

In addition to the above object, the invention as set forth in claim 2 further comprises: at least one of the inner surface of the cavity and the outer surface of the fitting portion, so that the packing is further firmly bonded to the plug body. The second ridge extending along the axial direction is formed so as to increase the joining force of the fitting insertion portion.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described below based on an embodiment shown in FIGS.

FIG. 1 shows, for example, a part of a water supply pump of an automatic water supply system. In FIG. 1, reference numeral 1 has a discharge port 1a (partially shown) in the upper part and a suction port (not shown) in the front. It is the pump section. The pump unit 1 has a spiral chamber (not shown) accommodating the impeller, and when the impeller rotates, it sucks a special liquid such as seawater from the suction port and discharges it from the discharge port 1a to obtain a desired liquid. Pump up to the point.

As shown in FIGS. 1 and 2, a tubular mouth body 2 projects upward from the outer peripheral wall on the upper stage side of the casing 1b of the pump portion 1, and the inside of the pump portion 1 is located at the same portion. Is formed with a priming hole 3 (plug hole). The priming hole 3 is used to introduce necessary priming water into the pump unit 1 from the outside when starting the pump operation. Usually, a step surface 4 having a larger diameter on the opening side than the casing 1b side is formed on the inner surface of the priming hole 3, and the hole portion on the opening side from the step surface 4 serves as a plug insertion port 5. Also, on the inner surface of the plug insertion port 5, a female screw portion 5
a is formed. A priming plug 6 is attached to the plug insertion port 5 to close the priming hole 3.

As shown in FIG. 3, the plug 6 has a plug body 7 formed of a material having excellent corrosion resistance, for example, a synthetic resin member, and the corrosion resistance of the plug body 7 to be attached to the end surface of the plug body 7 is excellent. A structure in which two parts, which are a material, for example, a packing 15 formed of a rubber member, are combined is used.

More specifically, as shown in FIG. 4 (a), the plug body 7 has a disk-shaped operating portion 8 with a knob 8a.
And the insertion portion 9 protruding from the center of the inner surface of the operation portion 8 are integrally formed. The insertion portion 9 has an outer shape (columnar shape) corresponding to the plug insertion opening 5. And
A male screw portion 9a is formed on the outer peripheral surface of the insertion portion 9a so that the male screw portion 9a can be screwed into the plug insertion port 5. The tip surface of the insertion portion 9 is recessed in a cylindrical shape from the center toward the inner side, and the cylindrical cavity portion 10 is provided inside the insertion portion 9.
Is formed. Further, as shown in FIG. 4C, on the inner surface on the opening side of the cavity portion 10, a groove portion extending in the circumferential direction,
For example, an annular groove 11 is formed over the entire circumference. Further, as shown in FIG. 4B, vertical ribs 12 extending in the axial direction are provided on the inner surface of the cavity 10 at regular intervals in the circumferential direction, for example.
(Corresponding to the second ridge) is formed. Specifically, the vertical ribs 12 are formed, for example, by ribs extending from the open end of the cavity 10 to a deep portion, and these are arranged at four locations in the circumferential direction of the cavity 10. The vertical ribs 12 are the same as the detents used when the plug body 7 having the male thread 9a is injection-molded and removed from the mold.

The packing 15 includes a disk-shaped packing main body 16 and the packing main body 16 as shown in FIG.
And a fitting insertion portion 17 protruding from the center of the side surface of the. The fitting portion 17 has a cylindrical shape that fits in the cavity 10. Specifically, the fitting / inserting portion 17 includes the cavity portion 10.
It is formed in a columnar shape having an outer shape slightly larger than the inner diameter of (1) so that the entire fitting insertion portion 17 can be pressed into the cavity 10 by press fitting (fitting). Further, a protrusion extending in the circumferential direction, for example, an annular rib 18 extending over the entire circumference is formed at the root portion of the fitting insertion portion 17 corresponding to the annular groove 11.
The annular rib 18 and the annular groove 11 of the cavity 10 are formed so as to be fitted to each other so that the fitting insertion portion 17 press-fitted into the cavity 10 does not come out.

With such a press-fitting structure and a retaining structure,
The packing 15 is attached to the front end surface of the plug body 7.

That is, when the packing 15 is assembled, as shown in FIG. 4A, the cavity portion 1 of the plug body 7 is
The fitting insertion portion 17 is pushed in from the opening of 0 from the circular tip.

At this time, since the fitting insertion portion 17 is formed of a rubber material whose outer diameter is slightly larger than the inner diameter of the cavity portion 10 and is hard to slip with respect to the synthetic resin material, the fitting insertion portion 17 is elastically deformed from the tip side. While being accompanied by, it is gradually press-fitted into the inner side of the cavity 10. Of course, the vertical ribs 12 emphasize the elastic deformation of the fitting portion 17.

Then, when the annular rib 18 and the annular groove 11 are inserted until they are fitted to each other, the packing 15 is attached to the tip of the insertion portion 9 as shown in FIG. That is, the fitting insertion portion 17 makes elastic contact with the inner surface, and further, while the annular groove 11 and the annular rib 18 are elastically fitted to each other, the cavity portion 10 is formed.
When it fits inside.

Then, the outer peripheral surface of the fitting insertion portion 17 has the cavity 10
In addition to making strong frictional contact with the inner surface of the, the fitting of the annular rib 18 and the annular groove 11 limits the direction in which the annular rib 18 comes out.

As a result, the packing 15 has the fitting insertion portion 17
Force caused by deformation of the annular rib 18 and the annular groove 1
With the synergistic effect of the restriction force of 1 and 1, a strong bond is made to the tip surface of the plug body 7.

Therefore, the packing 15 is attached to the tip of the plug 6 without using any part that causes corrosion. This is because the fitting portion 17 is made of a rubber material and the plug body 7 is made of a material such as a synthetic resin material that does not easily slip with each other.

Then, as shown in FIGS. 1 and 2, when the plug 6 is screwed into the priming hole 3 from the plug insertion port 5 until the packing 15 at the tip comes into contact with the step surface 4, the inside of the pump portion 1 is reached. The priming hole 3 is closed while sealing with the packing 15 without exposing the parts that cause corrosion.

Therefore, the plug 6 is excellent in corrosion resistance, and even in a place exposed to seawater (special liquid) where a corrosion phenomenon is likely to occur, water leakage does not occur and the sealing effect can be maintained sufficiently. Moreover, the annular groove 11 and the annular rib 18
Since a high joining force is generated by the retaining force caused by and, even if the liquid enters between the fitting insertion portion 17 and the cavity portion 10, it does not escape. In particular, when the vertical rib 12 is formed on the inner surface of the cavity portion 10, the pressing force is increased, so that the fitting insertion portion 17 can be further firmly joined to the plug body 7.

Moreover, since the plug 6 is composed of two parts, the plug body 7 and the packing 15, as long as the packing 10 with the fitting insertion portion 17 is formed with a material adapted to the special liquid, the packing 10 can be formed. The plug 6 that can be applied to other special liquids can be easily manufactured only by combining it with the plug body 7. In particular, it is suitable for the priming plug 6 of a pump, which tends to use various liquids.

The present invention is not limited to the above-described embodiment, and various modifications may be made without departing from the gist of the present invention. For example, in the above-described one embodiment, the one-row annular rib and the annular groove are used, but a plurality of annular ribs and the annular groove may be used. In addition, in one embodiment, the example in which the vertical rib is formed on the inner surface of the cavity is not limited to this, but even if the vertical rib is formed only on the outer surface of the fitting insertion portion, the inner surface of the cavity and the fitting insertion portion may be formed. Vertical ribs may be formed on both outer surfaces of the section. Further, although the present invention is applied to a plug fixed by screwing in one embodiment, the present invention is not limited to this, and the present invention may be applied to a plug fixed by other means. Of course, the present invention may be applied not only to the plug that closes the plug hole of the priming water but also to the plug used in other systems, devices, devices, and the like.

[0033]

As described above, according to the first aspect of the present invention, the packing has a combination of the pressing force generated by the elastic deformation of the fitting insertion portion and the regulating force generated by the groove and the protrusion.
It can be firmly joined to the tip surface of the plug body.

Therefore, it is possible to join the packing to the plug body without using a component that causes corrosion, and it is possible to provide a plug having excellent corrosion resistance suitable for a special liquid.

Moreover, since the plug is composed of two parts, the plug body and the packing, it is possible to easily change it to another special liquid simply by combining the plug body with a packing having a fitting insertion part made of a material adapted to the special liquid. Applicable plugs can be manufactured.

According to the second aspect of the invention, in addition to the above effects, the packing can be further firmly bonded to the plug body.

[Brief description of drawings]

FIG. 1 is a perspective view showing a plug according to an embodiment of the present invention together with a plug hole of a pump in which the plug is mounted.

FIG. 2 is a sectional view taken along line AA in FIG.

FIG. 3 is a sectional view of a plug.

FIG. 4 is a view showing a structure of each part of the plug.

[Explanation of symbols]

3… Primary water hole (plug hole) 6 ... Plug 7 ... Plug body 8 ... Operation part 9 ... insertion part 10 ... cavity 11 ... Annular groove (groove part) 12 ... Vertical ribs (second protrusion) 15 ... packing 17 ... Fitting part 18 ... Annular rib (projection).

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) F04D 29/08 F04D 29/42 E 29/42 F04B 21/00 Z (72) Inventor Masahiko Tashiro Okazaki, Aichi Prefecture No. 1 Goryota, Ichihashime-cho Stock Company Shakawamoto Factory Okazaki Plant F-term (reference) 3H022 AA01 BA07 CA21 CA48 CA51 CA56 DA13 DA14 3H034 AA01 AA04 AA11 BB01 BB06 BB11 CC07 DD24 DD26 DD28 DD30 EE11 3H071 AA01 CC26 DD11 CC11 DD51 3J040 AA02 AA11 EA03 HA07

Claims (2)

[Claims] 1. A plug main body having a plug body detachable from a plug hole, and a packing disposed on a front end surface of the plug main body to seal the plug hole according to mounting of the plug main body. A cavity portion that is recessed inward from the tip surface is formed in the packing, and a fitting insertion portion that can be press-fitted into the cavity portion is formed in the packing, and the inner surface of the cavity portion and the outer surface of the fitting insertion portion are formed. A groove extending along the circumferential direction is formed on one side, and a protrusion extending along the circumferential direction that can be fitted into the groove is formed on the other side, and the packing is formed by fitting the groove and the protrusion. A plug, characterized in that it is joined to the front end of the plug body by press-fitting the fitting insertion portion into the cavity until the whole. 2. The second protrusion extending along the axial direction is formed on at least one of the inner surface of the cavity and the outer surface of the fitting portion. The described plug.