JPS6157958B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method of manufacturing a synthetic resin pump.

[Background of the invention]

In conventional vortex-flow pumps, the main parts such as the casing, impeller, and casing cover, which constitute the water pumping function, are generally made of copper alloy casting or the like. Due to the characteristics of a vortex pump, the gap between the impeller and the liner of the casing or casing cover must be kept as small as 0.05 mm to ensure pumping performance. Therefore, these parts require highly accurate machining and finishing, which has been an obstacle to improving productivity. In addition, the pumping of water caused corrosion in the liner, etc., and the performance deteriorated in a short period of time due to the enlargement of the minute gaps.

In order to solve this drawback, it may be possible to use synthetic resin for the above-mentioned parts, but especially in well pumps, sand is often mixed in and sucked up from the pumped water during the initial stage of installation in a well. It was confirmed in the prototype that the impeller and the liner surface that faces the impeller, which maintains a small gap, wear out prematurely due to sand, resulting in a significant drop in pumping performance over short periods of operation. In order to solve this problem,
As shown in Publication No. 45109, an attempt was made to integrally mold a corrosion-resistant and wear-resistant metal liner such as stainless steel into the liner part.

[Problem that the invention seeks to solve]

However, due to differences in the shrinkage rates of the synthetic resins, the liner moved or deformed within the mold during injection molding, making it impossible to obtain sufficient dimensional accuracy in the prototype.

Further, in order to solve this problem, it was necessary to prevent water leakage during use of the pump and a reduction in manufacturing efficiency.

[Means for solving problems]

The present invention was made in order to solve such problems, and the liners 20 and 22 are mounted in close contact with the side surfaces inside the first mold 24, and the liners 20 and
22 is made of a material with high corrosion resistance and abrasion resistance, and the liners 20 and 22 are positioned at a portion facing the disc-shaped impeller 8 with a small gap therebetween.
is equipped with a plurality of pressing pins 26A, and this pressing pin 2
6A is made to extend parallel to the direction in which the second mold 26 and the casing members 2 and 4 are separated, and the first mold 24 and the second mold 26 are aligned to perform injection molding including the liner 22. A synthetic resin is injected into the injection molding space 35 while pressing the press pin 26A at a plurality of locations at the center of the back surface of the runners 20, 22, and integrated with the liners 20, 22. After the injection molding is completed, the first mold 24, the second mold 26 and the pressing pin 26A are separated from the casing members 2, 4, and the pressing pin 26A is separated from the casing members 2, 4. A plug 30 is inserted into the opening 4C of the hole 4B of the casing members 2, 4 caused by
This is a method for manufacturing a casing member for a swirl pump, which is watertightly mounted.

[Effect]

In this method of manufacturing a casing member for a swirl pump, the liners 20 and 22 are attached in close contact with the side surfaces inside the first mold 24, and multiple locations at the center of the back surface of the runner 22 are pressed with the press pins 26A. In this state, synthetic resin is injected into the injection molding space 35 to mold the casing members 2 and 4 integrally with the liner 22, and after this injection molding is completed, the first mold 24, the second mold 26 and the press pin Since the casing members 2 and 4 are removed from 26A, the side surfaces inside the first mold 24 are aligned with the liners 20 and 22.
The liners 20 and 22 will not move or deform even if there is a difference in the shrinkage rate of the synthetic resin, and this reference surface will be maintained until the injection molding of the casing members 2 and 4 is completed. maintained.

Further, a pressing pin 26A is provided in the second mold 26,
Since this pressing pin 26A is made to extend parallel to the direction in which the second mold 26 and the casing members 2, 4 are separated, the casing members 2, 4 and the second mold 26 can be pressed by simply separating them. pin 26A
can be easily separated without being disturbed.

Furthermore, since the plug body 30 is watertightly attached to the opening 4C of the hole 4B of the casing members 2 and 4, which is formed by the pressing pin 26A that presses the runner 22,
Even if water should seep out from between the liners 20, 22 and the casing members 2, 4 and reach the hole 4B,
The plug body 30 prevents leakage to the outside.

Moreover, the hole 4B created by the pressing pin 26A
not only saves material costs for the casing members 2 and 4, but also has the function of absorbing the expansion portion in the wall thickness direction when the casing members 2 and 4 expand due to temperature rise. Therefore, changes in the minute gap between the impeller 8 and the liners 20, 22 can be absorbed accordingly.

〔Example〕

Hereinafter, one embodiment of the present invention will be described based on the drawings.

FIG. 1 is a sectional view of a pump head of a vortex pump showing an embodiment of the present invention.

A pump chamber 6 is provided by a casing 2 and a casing cover 4 made of synthetic resin.
A disc-shaped impeller 8 is rotated by a motor shaft 10 to perform a water pumping action. The casing 2 and the casing cover 4 constitute a casing member. A plurality of substantially quarter-arc-shaped vortex chambers 12 are formed at the outer edge of the impeller 8, and as the vortex chambers 12 rotate at high speed in the vortex flow channel 14 from the forcing side toward the discharge side, centrifugal Water is pumped up by the interaction of force and fluid friction. Further, in order to prevent pumped water from leaking to the outside from the central opening 16 of the casing 2, a shaft sealing device 18 is installed between the motor shaft 10 and the casing 2. In addition, liners 20 and 22 made of a corrosion-resistant material such as stainless steel are integrally molded with synthetic resin on the liner surfaces 2A and 4A of the casing 2 and casing cover 4 that face the side surface of the impeller 8. The structure is such that the gap between the two is kept very small.

As shown in FIG. 2, the liner 22 has a lid shape with a hole 22A in the center, and an outer peripheral edge 22
The end portion 22C of B is formed to expand outward.

FIG. 3 shows the casing cover 4 shown in FIG. 1 in a synthetic resin molded state.

First, the liner 22 is mounted in close contact with the side surface inside the first mold 24. This first mold 24 is a fixed mold. The second mold 26 has a plurality of pressing pins 2.
6A, and this second mold 26 is a movable mold. This pressing pin 26A is attached to the second mold 26
In other words, it extends parallel to the direction in which the second mold 26 and the casing cover 4 are separated. Therefore, the first mold 2
4 with the second mold 26 and the runner 22
At the same time, a plurality of locations at the center of the back surface of the runner 22 are pressed by the pressing pin 26A. In this state, high-pressure molten synthetic resin is injected into the injection molding space 35 from the gate 24B provided in the first mold 24 to form the liner 2.
The casing cover 4 is molded integrally with the casing cover 2.
After this injection molding is completed, the second mold 26 and the pressing pin 26A are moved to the right and separated from the casing cover 4. Opening 4C of the hole 4B of the casing cover 4 created by the pressing pin 26A
The plug body 30 is attached in a watertight manner.

A method of attaching this plug 30 will be explained with reference to FIGS. 4 and 5. First, as shown in FIG.
The casing cover 4 and the plug body 30 are held and pressed between the vibration transmitting body 34 and the vibration transmitting body 34, and ultrasonic vibrations of about 20 KHz are applied. Then, the opening 4C of the casing cover 4 and the plug body 30 are fused together by the vibrational frictional heat generated between them, so that they are welded together as shown in FIG. 5, and the hole 4B is made watertight. Closed.

In this method of manufacturing a casing member for a swirl pump, the liner 22 is attached in close contact with the side surface inside the first mold 24, and a plurality of locations at the center of the back of the runner 22 are pressed with the press pins 26A. Then, a synthetic resin is injected into the injection molding space 35 to mold the casing cover 4 integrally with the liner 22.
After this injection molding is completed, the casing cover 4 is removed from the first mold 24, second mold 26 and press pin 26A, so the side surface inside the first mold 24 functions as a reference surface for the liner 22. However, even if there is a difference in the shrinkage rate of the synthetic resin, the liner 22
This reference plane is reliably maintained without moving or deforming until the injection molding of the casing cover 4 is completed.

Further, a pressing pin 26A is provided in the second mold 26,
Since the press pin 26A is made to extend parallel to the direction in which the second mold 26 and the casing cover 4 are separated, simply separating the casing cover 4 and the second mold 26 will interfere with the press pin 26A. It can be easily separated without being damaged.

Furthermore, since the plug 30 is watertightly attached to the opening 4C of the hole 4B of the casing cover 4, which is created by the pressing pin 26A that presses the runner 22, in the unlikely event that there is a leak from between the liner 22 and the casing cover 4. , even if water seeps out and reaches the hole 4B, the plug body 30
to prevent leakage to the outside.

Moreover, the hole 4B created by the pressing pin 26A
not only saves the material cost of the casing cover 4, but also has the function of absorbing the expansion in the wall thickness direction when the casing cover 4 expands due to a rise in temperature. 8 and Raina 2
It is possible to absorb the change in the minute gap with 2.

〔Effect of the invention〕

According to the present invention, the following effects are achieved.

The side surface inside the first mold 24 is liner 20, 22.
casing members 2 and 4.
Even if there is a difference in yield rate between the liners 20 and 22, this reference plane is reliably maintained as the injection molding of the casing members 2 and 4 is completed without the liners 20 and 22 moving or deforming. Therefore, the dimensional accuracy of the liners 20 and 22 is improved, and a minute gap with the impeller 8 can be formed with high precision. This allows the performance of the vortex pump to be significantly improved.

By simply separating the casing members 2, 4 and the second mold 26, they can be easily separated without being interfered with by the pressing pins 26A. Never.

Even if water should seep out from between the liners 20, 22 and the casing members 2, 4 and reach the hole 4B, the plug body 30 can prevent the leakage to the outside, and the pressure pin 26A can prevent water from leaking to the outside. Hole 4B not only saves material costs, but also
Due to the function of B to absorb the expansion of the casing members 2 and 4, a minute gap between the impeller 8 and the liners 20 and 22 can be secured. This also makes it possible to improve the performance of the vortex pump.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of the swirl pump according to the present invention, Fig. 2 is a perspective view of the liner, Fig. 3 is a sectional view of the casing cover immediately before molding, and Figs. 4 and 5 are the casing. FIG. 6 is a cross-sectional view of each step showing ultrasonic welding of the cover. 2...Casing (casing member), 4...
Casing cover (casing member), 8... impeller, 20, 22... liner, 24... first mold, 26... second mold, 26A... press pin,
30...Bung body.

Claims (1)

[Claims] 1. The liners 20, 22 are attached in close contact with the side surfaces inside the first mold 24, and the liners 20, 22 are made of a material with high corrosion resistance and wear resistance.
0 and 22 are located at a portion facing the disc-shaped impeller 8 with a minute gap, the second mold 26 is provided with a plurality of pressing pins 26A, and the pressing pins 26A
, the second mold 26 and the casing members 2, 4
and extending parallel to the direction of separation from the first
The mold 24 and the second mold 26 are aligned to form an injection molding space 35 including the runner 22,
The casing members 2, 4 are injected into the injection molding space 35 while a plurality of locations on the central portions of the back surfaces of the runners 20, 22 are pressed by the press pins 26A to form the casing members 2, 4 integrally with the liners 20, 22. After this injection molding is completed, the first mold 24, the second mold 26 and the press pin 26A are
and the casing members 2, 4 are separated, and a plug 30 is watertightly attached to the opening 4C of the hole 4B of the casing member 2, 4 created by the pressing pin 26A. Method for manufacturing a casing member.