JPH0786355B2 - Manufacturing method of self-priming centrifugal pump - Google Patents

Description

The present invention relates to a method for manufacturing a centrifugal pump having a self-priming structure.

(Prior Art) Among the centrifugal pumps most often used for liquid delivery, there has been a type in which the inside of the pump and the impeller (rotating blades, etc.) are formed or lined with rubber or resin. This is because this type of centrifugal pump is designed to prevent the metal component, which is the forming material thereof, from being attacked by the liquid to be transported and, conversely, the component composition of the liquid to be transported from being damaged by the metal component. In addition,
As the liquid to be transported that requires such a centrifugal pump, the raw material slurry of the pottery that requires a rare value due to the color-developing properties peculiar to the production area, the raw material slurry of insulating porcelain that is strongly disliked to be magnetized, and the high purity Examples include chemicals where importance is placed on importance, and liquids for drinks that are inevitable for hygiene.

By the way, generally, the centrifugal pump is roughly classified into a self-priming type and other types depending on whether or not priming is required when the operation is restarted (or whether or not equipment for vacuuming the liquid to be transported is required). . In the centrifugal pumps other than the self-priming type, since the internal shape (passage structure of the liquid to be transported) is relatively simple, the entire lining inside the pump can be realized relatively easily. However, in a self-priming centrifugal pump, a liquid pool must be maintained in the pump in order to generate a negative pressure for suction, and a self-priming chamber for maintaining this pool is complicated. It had a simple structure. Therefore, it was extremely difficult to line the entire surface of the pump.

FIG. 5 is a side sectional view of a self-priming centrifugal pump, which was previously developed by the applicant of the present application and filed for utility model registration (Japanese Utility Model No. 62-162392). The centrifugal pump has a self-priming structure, but is capable of lining the entire inner surface of the pump. This will be briefly described below. In the figure, reference numeral 1 is a pump body, 2 is a suction port portion, 3 is a suction side self-suction chamber, 4 is an impeller,
Reference numeral 5 is a spiral chamber, 6 is a discharge side self-priming chamber, and 7 is a discharge port. Further, the pump body 1 has a suction port 2
The check valve 8 provided so as to partition the suction side self-suction chamber 3 and the suction side self-suction chamber 3 maintains a liquid pool inside the suction side self-suction chamber 3 to the discharge side self-suction chamber 6. Was becoming. In this centrifugal pump, the most characteristic structure for enabling the lining is a spiral inductor 9 (see the partially cutaway perspective view shown in FIG. 6) for forming the spiral chamber 5. The point was that the pump body 1 could be disassembled. That is, if the spiral guide 9 is removed from the pump body 1 together with the impeller transmission unit 10, the suction side joint 11, the inspection lid 12, all the inner surfaces of the pump body 1 can be inserted. Was becoming. Therefore, in the lining work, the pump body 1 is heated to about 350 ° C., and the lining material (for example, powdery, jelly-shaped or plate-shaped rubber material) is manually pumped before the temperature is cooled. It was supposed to be painted on the inside.

(Problems to be Solved by the Invention) As described above, the conventional lining work relies entirely on manual work. Therefore, as a matter of course, the work efficiency was poor. In addition, since the coating of the lining material had to be completed before the temperature of the pump body 1 had cooled, the average wall thickness of the lining was
The limit was about 2 mm, and it was impossible to exceed it. Moreover, in the interior of the pump body 1, it is extremely difficult to secure or hold a wall thickness of 2 mm at an acute-angled portion that is an inner corner or an outer corner or a portion having a small radius of curvature. Therefore, even a person with considerable skill has a wide variation in the lining wall thickness (1.6 to 2.1 m).
m). Furthermore, those involved in such lining work are routinely exposed to the risk of burns.

The present invention has been made in view of the above circumstances, and enables a lining work of a pump main body to be performed easily and efficiently, so that the entire centrifugal pump can be easily and efficiently manufactured. It is an object of the present invention to provide a method of manufacturing a self-priming centrifugal pump (hereinafter, referred to as "method of the present invention").

(Means for Solving the Problems) The gist of the present invention is to provide a forming recess for an impeller storage chamber, which has a widest opening edge portion, on one side of a partition wall of a pump body, and to form the partition wall. A self-priming type with a self-priming chamber with a widest opening edge on the other side of the wall and a lining made of rubber or synthetic resin on the entire surface of the pump body that can come into contact with the liquid to be transported. In the method of manufacturing a centrifugal pump, when performing the lining, a pressurizing mold having a shape corresponding to at least the formation recess for the impeller storage chamber and the formation recess for the self-priming chamber in the pump body is opposed from both sides of the partition wall of the pump body. The point is to arrange and inject the lining material in a heat-melted state along the pressing surface of each pressure die.

(Operation) In the method of the present invention, since the shape recesses on both sides of the partition wall of the pump body are shaped so that the respective opening edges are the widest mouths, the formation recesses on both sides are applied from the respective open sides. The pressure die can be taken in and out, and the lining work can be mechanized.

Furthermore, in the method of the present invention, each pressure die is inserted into each forming recess in the pump body from both sides of the partition wall, and the lining material is injected along the pressing surface of the pressure die. Can be in a heat-melted state before being injected into the pressure mold, or can be brought into a heat-melted state by heating with the pressure mold. Then, after the lining material is injected, a predetermined pressure reduction of each pressure mold is applied to wait for the lining material to cure. The obtained pump body has a desired surface lined.

(Example) The following will describe the present invention with reference to the drawings illustrating an example thereof.

FIG. 1 is a side sectional view showing an embodiment of a self-priming centrifugal pump obtained by the method of the present invention, and FIG. 2 is an exploded view thereof. As is clear from FIG. 2, the self-priming centrifugal pump comprises a pump body 15, a suction side closing plate 16, a spiral guide 17, and an impeller 20 side closing plate 18. Further, in the present embodiment, the joint portion 19 on the discharge side can also be separated from the pump body 15. Further, reference numeral 21 in FIG. 2 is an impeller transmission, 22 is a check valve, and 23 is a drain lid.

The pump body 15 is provided with a partition wall 24 in the center of the inside thereof, and one side of the partition wall 24 is provided with a forming recess 25 for an impeller storage chamber, and the other side thereof is for a self-priming chamber. Forming recess 26 is provided. The self-suction chamber forming recess 26 is on the suction side, and the discharge-side self-suction chamber is provided on the lower side thereof (see reference numeral 27). Further, the pump main body 15 has an egg shape as a whole as shown in FIG. 3 as viewed from the side of the forming recess 25 for the impeller storage chamber. As is clear from FIG. 2, the forming recesses 25 and 26 of the pump body 15 are formed such that their opening edges are the widest.
That is, the forming recess 25 for the impeller storage chamber is provided with a gradient such that the inner diameter gradually increases toward the opening edge. Further, even in the forming recess 26 for the self-priming chamber, a similar gradient is provided although it is minute. Further, any of the forming recesses 25, 26 is devised so that none of the recesses 25, 26 projecting radially outward from their respective opening peripheral portions. The reason will be described later.

The self-suction side closing board 16 is bolted to the pump body 15 so as to close the self-suction chamber forming recess 26, and a check valve 22 is provided between the two. As a result, the formed recess 26 serves as the suction side self-suction chamber 30 (see FIG. 1). A suction side joint 28 is integrally formed on the suction side closing board 16 so as to be used for connection with an appropriate external pipe.

The spiral inducer 17 is attached to the pump body 15 described above in the forming recess 25 for the impeller storage chamber (see FIG. 1). The outer shape of the spiral derivative 17 is substantially the same as that of the conventional one (see FIG. 6), and the liquid to be transported is guided along the rotation of the impeller 20 (see the direction of the white arrow in FIG. 6). This is to facilitate the flow. The spiral guide 17 is positioned by being fitted and held in a central hole 29 (see FIGS. 1 and 3) provided in the partition wall 24 of the pump body 15.

An impeller transmission section 21 is bolted to one surface side of the impeller-side closing board 18, and an impeller 20 is held by an output end 21a of the impeller transmission section 21 on the other surface side. As shown in FIG. 1, the impeller-side closing plate 18 is
The pump body 15 is bolted so as to close the impeller storage chamber forming recess 25. Therefore, the spiral inductor mounted in the forming recess 25
The impeller 20 is positioned so as to face the impeller 17, and at the same time, the spiral inductor 17 is firmly pressed and fixed to the pump body 15. Further, as a result, the impeller storage chamber forming recess 25 of the pump body 15 is formed.
Is partitioned into a discharge side self-priming chamber 31 and a spiral chamber 32.

In addition, the discharge side joint portion 19 and the drain lid 23 described above are also bolted to the pump body 15.

The self-priming volute pump constructed in this manner is such that the entire surface of each of the pump body 15, the suction side closing plate 16, the spiral guide 17, and the impeller side closing plate 18 that can come into contact with the liquid to be transported is rubber or synthetic resin. It is lined by etc. Of course, the same applies to the impeller 20, the discharge side joint portion 19, the check valve 22 and the drain lid 23. Therefore, the suction side joint
Even if the liquid to be transported is passed from the suction side self-priming chamber 30, the central hole 29, the swirl chamber 32, and the discharge side self-priming chamber 31 to the discharge-side coupling portion 19 on the upper side, the transport-target liquid causes the metal to flow. The components are not attacked, and on the contrary, the component composition of the liquid to be transported is not damaged by the metal component. Moreover, the pump main body 15 and each component (16, 22, 23, 17,
Between the mounting surfaces of (20,18,19), the linings are overlapped with each other so that complete liquid leakage can be prevented.

Next, the method of the present invention will be described. In the method of the present invention, when the inner surface of the pump body 15 is entirely lined, it can be mechanized. That is, as shown in FIG. 2, the forming recesses 25 and 26 in the pump body 15 are formed so that the opening edge portions thereof have the widest openings, and the pressurizing mold can be easily inserted into the forming recesses 25 and 26. Make it accessible. FIG. 4 is a side sectional view showing a combined relationship between the pump body 15 and the pressurizing molds 33, 34. As shown in the figure, the pump body 15 is in a sideways posture such that the self-suction chamber forming recess 26 faces downward. The reason is as follows. Pressurized type
In the mechanical lining work using 33, 34, the pressure die 3
Positioning of the 3, 34 and the pump body 15 and their holding are extremely important. However, as is clear from FIG.
Since the pump main body 15 requires a lining on most of its inner and outer peripheral surfaces, it is very difficult to directly contact the pressure molds 33 and 34. Therefore, the present inventor, after trial and error, has come to the idea that a surface (~ in FIG. 4) that does not require lining can be formed around the opening of the self-priming chamber forming recess 26. . That is, the and parts of the pump main body 15 are horizontally supported by the (1) and (4) parts of the lower pressurizing mold 34, and the and parts of the pump main body 15 are (2) and They were supported so that they would fit together at the part (3). As a result, the pump body 15 can be accurately positioned and firmly held with respect to the pressurizing die 34. Therefore, in this state, the upper pressure die 33 may be processed and set in the formation recess 25 for the impeller storage chamber in the pump body 15 in a predetermined arrangement. In this embodiment, since the discharge side joint portion 19 (see FIG. 2) can be separated from the pump body 15, the connection hole 35 for that purpose must be formed in the pump body 15. I have to. So, the side pressure type
36 was also made to mold at a predetermined position. When the press dies 33, 34, 36 are combined with the pump body 15 in this way, a lining material (for example, a powdery or jelly-like rubber material) is injected along the respective pressing surfaces. The lining material can be in a heat-melted state (about 70 ° C. for a rubber material) before the injection, or after injecting an unmelted material, it is heated by a pressure die 33, 34, 36 (for example,
It may be heat-melted at about 160 ° C). As still another method, a plate-shaped lining material (rubber material or the like) is adhered to a required portion of the pump body 15 before the pressure dies 33, 34, 36 are combined, and then the pressure dies 33, 34, 36, 36 may be combined. After such combination, each pressure mold 33, 34, 36
Apply a predetermined reduction to wait for the lining material to cure. In this example, a pressing pressure of 500 t was used to obtain a rubber lining having a wall thickness of 4 mm or 5 mm. After the lining material is hardened, the pressure molds 33, 34, 36 are demolded to remove burrs generated in the lining material.

The suction side closing plate 16, the spiral guide 17, the impeller side closing plate 18, as well as the impeller 20, the discharge side joint 1
With respect to the drain cover 23 and the like, the lining work can be mechanized by a method substantially similar to that of the pump body 15. For these parts, a press pressure of 100 t was sufficient to make the lining wall thickness 4 mm or 5 mm, which is the same as the pump body 15.

(Study of another mode) By the way, the reason for lining the pump body 15 and the like is
This is not limited to the case where the dissolution of the metal component as described above is regarded as a problem. For example, when using a slurry (suspension) containing high hardness particles as the liquid to be transported, the pump body
There are also 15 reasons to try to protect against internal wear.

The embodiment shown in FIGS. 1 to 4 is only one specific example, and the outer shapes of all parts including the pump body 15 are dependent on the pump performance, application, type of liquid to be transported, etc. It can be changed appropriately. Further, it is needless to say that the pressurizing dies 33, 34, 36 used in the method of the present invention can be changed in positional relationship with the pump main body 15, the number of divisions, the shape, etc., if necessary. Furthermore, the thickness of the lining can be manipulated as desired. As described above, the shape and configuration of the self-priming centrifugal pump and the detailed configuration of the method of the present invention can be appropriately changed according to the embodiment.

(Effects of the Invention) As is clear from the above description, according to the method for manufacturing a self-priming centrifugal pump according to the present invention, the two forming recesses in the pump body are given a predetermined shape. It became possible to mechanize the lining work of the main body. Therefore, naturally, the work of lining each component can be performed easily and efficiently, and the manufacture of the entire centrifugal pump is also easy and efficient. To give a specific example, the work of lining the pump body is more than 50 times the work efficiency of the conventional product, which is truly epoch-making. Of course, the person who is involved in the lining work does not need the skilled technique and is not at risk of being burned.

And by being able to mechanize the lining work in this way, it has become possible to make linings of 2 mm or more, which was previously impossible. Not only does the lining have a uniform wall thickness throughout all parts and all forming points, but it is also possible to pursue geometrical and dimensional accuracy by applying pressure, and further smooth the lining surface. It can be anything. Therefore, for example, the clearance generated between the impeller and the spiral inductor facing each other can be made minute, and the flow path resistance at each part can be minimized, resulting in a dramatic increase in pump performance. It will be done. Furthermore, what is noteworthy here is that the existing concept of the pump body and other parts has been changed because the lining can be formed thick and accurately as described above. In other words, since the lining itself can be pursued in terms of shape and dimensions, the pump body itself does not need to have such high dimensional accuracy, and the pump body, etc. in the end is a "core material" for maintaining a rough shape. It can be understood as "". That is, this core material has an advantage that it can be formed in a smaller size than the size to be completed. In particular,
In the past, the inner surface of the pump body (mostly the casting surface) was manually polished to a smooth surface, and then the lining material was applied to this smooth surface.
According to the present invention, in addition to removing burrs and dust, this kind of polishing work can be completely eliminated. Therefore, when the manufacturing efficiency of the pump main body and the like is compared with the conventional one based on such a viewpoint, it is possible to obtain the manufacturing efficiency which is slightly more than double. However, in the present invention, since it is possible to apply a pressure reduction by a pressurizing mold when performing the lining work, the adhesion of the lining material can be obtained even if the inner surface of the pump body is the casting surface. is there. On the contrary, this has many excellent advantages such as an effect of improving the adhesiveness of the lining material.

[Brief description of drawings]

FIG. 1 is a side sectional view showing an embodiment of a self-priming centrifugal pump obtained by the method of the present invention, FIG. 2 is an exploded view thereof, and FIG. 3 is a state in which the pump body is viewed from the impeller storage chamber side. FIG. 4 is a side sectional view showing a state in which the pump main body is mechanically lined (the method of the present invention), and FIG. 5 is disclosed in Japanese Utility Model Publication No. 62-162392. FIG. 6 is a side sectional view showing a conventional self-priming centrifugal pump, and FIG. 6 is a perspective view showing a conventional spiral inductor with a part thereof cut away. 15 …… Pump body 25 …… Forming recess for impeller storage chamber 26 …… Forming recess for self-priming chamber 33,34 …… Pressurized type

Claims (1)

[Claims] 1. A pump body is provided with a concave portion for forming an impeller storage chamber having a widest opening edge on one side of the partition wall, and the opening edge is widest on the other side of the partition wall. In the method of manufacturing a self-priming spiral pump, the shape-forming recess for the self-priming chamber is provided, and the entire surface of the pump body that can come into contact with the liquid to be transported is lined with rubber, synthetic resin, or the like. A pressure die having a shape corresponding to at least the formation recess for the impeller storage chamber and the formation recess for the self-priming chamber in the pump main body is arranged facing both sides of the partition wall of the pump main body, and along the pressing surface of each pressurization die. A method of manufacturing a self-priming centrifugal pump, comprising injecting a lining material in a heat-melted state.