JPH0636319Y2 - Elastic strainer for submersible motor pump - Google Patents

Description

[Detailed Description of the Invention] [Industrial application] The present invention relates to a suction strainer to be attached to a suction port of a submersible motor pump, and more particularly to a seamless ring-shaped elastic strainer integrally molded by a mold. Regarding

[Conventional technology]

Conventionally, as shown in FIGS. 6 (a) and 6 (b), a strainer attached to the lower end of a submersible motor pump is made of a strip-shaped steel plate having a large number of holes 102 made of stainless steel or plated steel plate. After cutting the punching metal 101 to a length slightly longer than the circumferential length of the mounting portion of the pump casing, a step portion 103 is press-molded at one end edge, and the punching metal 101 is formed as shown in FIG. It was formed into a cylindrical shape, and the other end edge 101a was superposed on the stepped portion 103 at the one end edge, and then the end portion was welded 104 to form a structure.

[Problems to be solved by the device]

A conventional strainer molded and welded as described above,
Since it is manufactured from steel plate, the material cost and processing cost are high, and there is a large storage space for stocking parts when storing the strainer that has been formed into a cylindrical shape and welded, while the shape of the strainer hole is large. In addition, since the sizes are the same and uniform, there is a problem in that it is difficult to form the shape of the hole according to each application such as the type of foreign matter contained in the fluid and the accumulation state.

Compared with the above-mentioned conventional punching metal strainer, the present invention has a lower material cost and machining cost, and has a very small storage space when parts are in stock, while the strainer hole has a planar shape and a cross-sectional shape. An object is to provide an elastic body strainer for a submersible motor pump that can be freely selected.

[Means for Solving the Problems]

In order to achieve the above object, the present invention comprises a strainer, which is attached to the suction port of a submersible motor pump, made of an elastic material such as rubber, and has a circumferential length in a free state before being attached and used. It is characterized in that it is constituted by a flat ring-shaped body that is substantially the same as when it is attached, and a large number of holes in the long sides of the ring-shaped body facing each other are opened.

The large number of holes can be formed so that the diameter is gradually reduced in the height direction, and can be formed in an oblong shape elongated in the circumferential direction.

[Action]

Since the suction strainer of the present invention is configured as described above in a free state before being attached and used, when the strainer is attached to the suction port portion of the submersible motor pump, the strainer having a flat ring shape made of an elastic body is used. Is deformed into a circular shape and slightly extended in the circumferential direction, and is fitted into the suction port of the submersible motor pump from the lower end. As a result, it is attached to the suction port portion while being elastically pulled slightly, so that it is held tightly.

Moreover, since a large number of holes are provided on the opposite long sides, the effective passage area does not become insufficient.

Also, in the long side portions facing each other of the ring-shaped body, in which a large number of holes whose diameters are gradually reduced downward in the height (width) direction are opened, the submersible motor pump is used as a civil engineering drainage pump,
When used for drainage of accumulated water with sand or gravel accumulated on the bottom, stones with a large diameter accumulated below are prevented from being sucked in by a strainer hole at the bottom with a small diameter. It is possible to prevent damage to the impeller and the like due to. The foreign matter sucked from the upper strainer hole having a normal diameter is sand or the like having a small diameter, so that it is drained together with the flow without obstruction.

Further, in the case where a large number of oblong elliptical holes elongated in the circumferential direction are opened in the opposing long sides of the ring-shaped body, this corresponds to the short diameter of the oblong elliptical holes rather than the diameter of the conventional strainer. Since the passage gap of foreign matter can be made small, it is possible to prevent passage of solid matter and prevent entrapment due to it without reducing the effective passage area of the strainer.

The shape of the large number of holes as described above is easily formed by the elastic strainer molding.

〔Example〕

 Next, an embodiment of the present invention will be described with reference to the drawings.

1 (a) and 1 (b) are plan views seen from the long side of the strainer in a free state before use, showing an embodiment of the present invention, and a cross section taken along line I-I of FIG. 1 (a). It is a figure.

In the figure, the strainer 1 is made of an elastic body such as rubber, and is formed in a flat ring shape in a free state before use, that is, before attachment, and the flat shape faces each other. A large number of round holes 2 are opened in the long side portions 1a, 1a such that the center lines of these holes are orthogonal to the long side portion peripheral surface.

4 (a), (b) and (c) are explanatory views showing a manufacturing process of the elastic strainer according to the present invention. In FIG. 4 (a), the upper die 5, the lower die 6 and the middle die 7 are stacked. A sectional view showing the combined state, a sectional view (b) showing the three molds 5, 6 and 7 separately, and a sectional view (c) showing the molded product 1.

When the elastic strainer 1 is molded, a flat middle mold (core) 7 having a large number of projections 7a corresponding to holes protruding vertically is formed on the peripheral surface of the elastic strainer 1. The lower mold 6 is brought into contact (the condition shown in FIG. 4 (a)), both side surfaces are sealed and tightened by an external force, and molten rubber (vulcanized rubber) is injected from an injection port provided in the upper portion (not shown). When injected, the above-mentioned molten rubber is filled in the space surrounded by the upper mold 5, the middle mold 7, and the lower mold 6 in FIG.

After the above-mentioned filling, after cooling, the upper mold 5 and the lower mold 6 are removed, and the rubber flat ring-shaped body fitted in each projection 7a of the middle mold 7 is pulled out from the projection 7a in the vertical direction. When it is taken out from the middle mold 7, a molded body of the suction strainer 1 which is a flat ring-shaped body in which porous holes 2 are opened in the opposite long side portions 1a, 1a is obtained.

According to this embodiment, since the suction strainer 1 is made of an elastic body and is constituted by a flat ring-shaped body having a circumferential length substantially equal to that at the time of mounting in a free state before mounting and using, It can be easily manufactured by molding using an elastic body such as rubber, and burrs during molding can be less likely to occur. As a result, the following advantages over conventional punched metal products Occurs.

(I) Material costs and processing costs can be reduced.

(Ii) The storage space when parts are in stock can be extremely small.

(Iii) The strainer hole can be freely selected in plan and sectional shapes by changing the shape to the projection 7a of the middle mold 7 during molding. Therefore, it becomes possible to form an optimum shape and non-uniformly, as described below, depending on the use such as the type of foreign matter and the deposition state.

FIG. 2 is a plan view of a strainer showing a second embodiment of the present invention, and the same reference numerals as those shown in FIG. 1 (a) indicate the same or similar parts.

In this embodiment, the diameter of the hole 2a is gradually reduced in the height (width) direction of the strainer.

According to this embodiment, when the submersible motor pump is used as a drainage pump for civil engineering and is used for drainage of accumulated water in which sand or gravel is deposited on the bottom, a large-diameter stone that is deposited downward is Since suction is blocked by the strainer holes, damage to the impeller and the like due to biting of hard foreign matter such as stones can be prevented. The foreign matter sucked from the upper strainer hole having a normal diameter is sand or the like having a small diameter, so that it is drained together with the flow without obstruction.

FIG. 3 is a plan view of a strainer showing a third embodiment of the present invention, and the same reference numerals as those shown in FIG. 1 (a) indicate the same or similar parts.

In this embodiment, a large number of oblong holes 2b elongated in the circumferential direction are opened.

According to this embodiment, rather than the diameter of the conventional strainer,
The passage gap of foreign matter corresponding to the minor diameter of the oblong hole can be made small, so it is possible to prevent passage of solid matter and prevent entrapment due to it without reducing the effective passage area of the strainer. Becomes

FIG. 5 is a longitudinal sectional view showing an example of the submersible motor pump in which the elastic strainer 1 of the present invention is attached to the suction port portion.

In the figure, the pump casing portion 11a and the outer shell 11b are integrally formed of an elastic body 11 such as rubber, and the upper surface of the pump casing portion 11a is covered with an intermediate casing 12, and an impeller 13 is provided inside. Is built in.

A bottom plate 15 made of a rigid body is abutted (pressed) on the lower surface of the pump casing portion 11a made of the elastic body, with a fluid passage 14 for sucking a liquid therebetween, and the intermediate casing 12
From the intermediate casing 12 and the bottom plate 15 with the bolt 16 that is screwed with the inner threaded portion of the tubular body 12a that extends downward integrally from and penetrates into the pump casing portion 11a. Further, the upper end 11c of the elastic outer case 11b has a motor head cover 19
It is fitted so as to fit into the lower end portion 19a of the.

In addition, a plurality of strainer reinforcement ribs 17 are provided at intervals on the outer peripheral portion of the fluid passage 14 in the pump casing portion 11a.
The strainer 1 is integrally provided on the lower surface of the bottom plate 15 and is inserted from below the ring-shaped body 15a integrated with the bottom plate 15 so as to expand the strainer 1 in a circular shape against the elasticity. The strainer 1 is fitted so as to contact the outer surface. In the figure, 20 is an annular passage between the outer body 11b and the outer surface of the motor, 21 is a suction port of the pump casing,
22 is a casing discharge port.

When the pump is operating, the fluid passes through the strainer 1 as shown by the arrow a, and the bottom surface of the pump casing portion 11a and the bottom plate 15a.
Through a passage 14 formed between the inlet and the outlet, and flows from the pump casing suction port 21 into the casing, that is, into the pump chamber. At this time, foreign matter contained in the fluid is removed by the strainer 1.

The fluid that has flowed into the pump casing portion 11a is
Is discharged from the casing discharge port 22, and is discharged from the pump discharge port 18 while cooling the motor outer skin while passing through the annular passage 20 surrounded by the motor outer periphery and the outer body portion 11b.

In the above-described embodiment, the strainer 1 has the same shape as the circular hole 2 having the same diameter (FIG. 1 (a)), the circular hole 2a having different diameters (FIG. 2), and the oblong hole 2b (FIG. 3). As described above, these are merely examples, and the shape of the hole of the strainer 1 can be changed to an arbitrary shape by forming the protrusion 7a (FIG. 4 (b)) of the molding medium die 7 in an arbitrary cross-sectional shape. It is also possible to form and to form an inclined surface in the cross-sectional shape of the protrusion 7a and therefore the holes 2, 2a, 2b so that the elastic strainer 1 can be easily removed from the middle mold 7.

[Effect of device]

As described above, according to the present invention, the suction strainer is made of an elastic body, and has a flat ring-shaped body that is substantially the same in circumference length as that at the time of mounting in a free state before mounting and using. By forming a large number of holes in the long side portion, it can be easily manufactured by molding using an elastic body such as rubber, and burrs at the time of molding can be less likely to occur. As a result, the following advantages are produced as compared with the conventional punched metal products.

(I) Material costs and processing costs can be reduced.

(Ii) The storage space when parts are in stock can be extremely small.

(Iii) By changing the plane shape and the cross-sectional shape of the strainer hole by changing the shape of the protrusion of the middle mold during the mold molding,
It is freely selectable as in the embodiment or the third embodiment. Therefore, it is possible to form an optimum shape and non-uniformly according to the use such as the type of foreign matter and the deposition state.

[Brief description of drawings]

FIGS. 1 (a) and 1 (b) are a plan view and a sectional view taken along line I-I of an elastic strainer in a free state before mounting, showing a first embodiment of the present invention, FIGS. Similar plan views showing the second and third embodiments of the present invention, and FIG. 4 (a) is a sectional view showing a coupled state of a mold used in manufacturing the elastic strainer of the present invention. b) is a sectional view showing the same disassembled state, FIG. 5c is a sectional view of the molded strainer, and FIG. 5 is a longitudinal sectional view showing an example of an underwater motor pump to which the elastic strainer of the present invention is attached. 6 (a) and 6 (b) are a side view and a sectional view taken along line VI-VI of a strainer showing a conventional example. 1 ... Strainer, 1a ... Long side part, 2, 2a, 2b ... Hole, 5 ... Upper mold, 6 ... Lower mold, 7 ... Medium mold.

Claims (3)

[Scope of utility model registration request] 1. A strainer to be attached to a suction port of a submersible motor pump, wherein the strainer is made of an elastic material such as rubber, and its circumference is substantially equal to that at the time of attachment in a free state before attachment and use. An elastic strainer for a submersible motor pump, which comprises a flat ring-shaped body and has a large number of holes formed in opposing long sides of the ring-shaped body. 2. An elastic body for a submersible motor pump according to claim 1, characterized in that a large number of holes whose diameters are gradually reduced in the height direction are opened at the opposite long sides of the ring-shaped body. strainer. 3. The elastic strainer for a submersible motor pump according to claim 1, wherein a large number of elliptical holes elongated in the circumferential direction are opened in the opposed long sides of the ring-shaped body.