JPS6220392B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a mortar casing for a screw pump trough, in which a mortar casing is created on the inner surface of the trough by utilizing the rotation of a screw having a spacer attached to its outer periphery.

As shown in Figures 1 and 2, screw pump equipment usually has one or more (three in the figure) screw blades 2 spirally arranged around a hollow shaft 1.
A screw 3 having a structure is disposed in an inclined trough 10 having a U-shaped cross section and a mortar casing 7 on its inner surface, supported by an upper bearing 4 and a lower bearing 5, and connected to a drive motor 6. 6 is driven, water is pumped from the pump well 8 to the discharge well 9. 16 is a cover for preventing water from overflowing on the upper side of the screw 3.

When constructing the above screw pump trough,
The gap between the screw blade 2 and the mortar casing 7 not only affects pumping efficiency, but also may lead to an accident if the mortar casing 7 and the screw blade 2 come into contact during actual operation. 7 is required to be uniform.

Furthermore, the length of the screw 3 is long, ranging from several meters to more than 10 meters, and it is subject to relatively large deflection due to its own weight. It is necessary to match the cross-sectional shape of the casing 7 parallel to the axis with the deflection curve of the screw 3.

For this reason, conventionally, as shown in Figure 3 (cited in Figure 3 of Japanese Patent Application Laid-Open No. 52-142314), a spacer 11 such as a flat steel or round bar is temporarily fixed approximately parallel to the outer peripheral edge of the screw blade 2. , a method of creating a mortar casing 7 by arranging the screw in a trough to which unsolidified mortar is adhered to the inner surface, and then rotating the screw by a drive motor 6 to scrape off the surface of the unsolidified mortar. was commonly practiced.

However, during construction, welding is employed as a method for temporarily fixing the spacer 11, such as a flat steel or round bar, to the outer peripheral edge of the screw blade 2, so it is not easy to attach or detach the spacer 11. That is, during installation, it takes time and effort to weld the outer periphery of the spacer 11 and the screw blade 2, and the spacer 1 is difficult to weld after installation.
1 has the disadvantage that it takes time and effort to separate the welded parts. Another disadvantage is that the welded portion of the screw blade 2 must be repainted and repaired. Furthermore, since the spacer 11 is fixed to the outer edge of the screw blade 2, the moment of inertia of the entire screw 2 including the spacer 11 becomes large, and the cross-sectional shape of the mortar casing after installation is similar to that of the screw 3 with the spacer 11 removed. This had the disadvantage that it did not match the deflection curve and the gap became non-uniform.

As a conventional example different from the above conventional example,
There are methods for manufacturing mortar casings for screw pumps described in Japanese Patent Application Laid-open No. 30987 and JP-A-52-142314, but in both conventional methods for manufacturing mortar for screw pumps described in these publications, the outer periphery of the screw blade is It is characterized by the fact that a spacer such as a round bar is continuously provided in a spiral shape along the wall, and has the disadvantage that it is not easy to attach and detach during construction. That is, during installation, it takes time and effort to weld the spacer to the outer peripheral edge of the screw blade 2, and when the spacer is removed after installation, it takes time and effort to separate the welded portion. Another drawback is that the welded parts of the screw blades must be repainted to repair them.

Furthermore, since the spacer is fixed to the screw blade, the deflection curve of the screw during construction will not match the deflection curve of the screw when the spacer is removed after construction, resulting in an uneven gap between the mortar casing and the screw. be.

The present invention provides a method for constructing a mortar casing for a screw pump trough that solves these drawbacks when attaching and detaching a spacer to a screw, equalizes the gap between the screw blades and the mortar casing, and improves workability. The gist of the system is to provide locking portions at both ends of the screw shaft or at both ends and the center, and to attach both ends of a rope-shaped spacer to these locking portions so that they can be removed and freely locked. The screw, in which the intermediate part of the rope-shaped spacer is stretched under tension so as to make point contact with the outer peripheral edge of the screw blade, is placed in a trough with unsolidified mortar adhered to the inner surface, and then This is a method for creating a mortar casing for a screw pump trough, in which a mortar casing for a screw pump trough is created by rotating the screw to shape the unsolidified mortar surface with the spacer.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment embodying the present invention will be described below with reference to the accompanying drawings to provide an understanding of the present invention.

FIG. 4 is a schematic side view of a screw with a spacer attached thereto, which can be used in a method for constructing a mortar casing for a screw pump trough according to an embodiment of the present invention.

Hereinafter, the present invention will be described based on this figure, using the same reference numerals for elements common to those used in the conventional example shown in FIGS. 1 and 2.

In the figure, a screw 3 consisting of a hollow shaft 1 and screw blades 2 is provided at both ends with an upper locking portion 12 and a lower locking portion 13 comprising eye bolts, locking holes, or the like. The upper engaging part 12 and the lower engaging part 13 are provided with one or two threads made of wire rope or the like.
Both ends of a rope-shaped spacer 15 of more than one strip (three strips in this embodiment) are removably locked. The rope-shaped spacer 15 has a tensioning device 14 made of a spring or a tightener spring near its lower end, contacts the outer circumferential edge of the screw blade 2 from the upper part of the screw 3 in a point-like manner, and tensions the lower part of the screw 3. has been done.

When constructing a mortar casing, the screw 3 to which the spacer 15 is attached is placed in a trough 10 with unsolidified mortar adhered to the inner surface.
The screw 3 is supported by an upper bearing 4 and a lower bearing 5 in the same position as in the actual operating state, and the screw 3 is rotationally driven by a drive motor 6. Since the spacer 15 is sufficiently tensioned by the tensioning device, as the screw 3 rotates, the unsolidified mortar inside the outermost rotation locus of the spacer 15 is scraped off by the spacer 15, and the trough is scraped off by the spacer 15. being carried outside. In this way, a mortar casing 7 having a cross-sectional shape that matches the deflection curve of the screw 3 is created.

In addition, in the method for constructing the mortar casing of the screw pump trough according to the embodiment of the present invention, since no welding is performed, installation and removal are easy, and there is no need to repaint the screw 3. Therefore, all construction can be done on-site. In particular, since the tensioning device 14 is provided, it is extremely easy to attach and detach the spacer 15. Furthermore, since the tension of the spacer 15 can be adjusted by the tension device 14, the tension of the spacer 15 can be adjusted due to hardening of mortar during construction.
It can be adjusted in response to changes in the external force applied to it, and construction can be carried out without being affected by it. Of course, it is also possible to adjust the tension of the spacer 15 by the tension of the rope-shaped spacer 15 itself without providing a special tensioning device 14.

Furthermore, since the spacer 15 is only in point contact with the screw blade 2 and is not fixed, it has little effect on the moment of inertia of the screw 3, and the change in the deflection curve of the screw 3 due to attachment and detachment of the spacer 15 is small. rare. Therefore, unevenness in the gap between the created mortar casing and the screw blade can be prevented.

Furthermore, in the method for constructing a motor casing for a screw pump trough according to the embodiment of the present invention, the attachment parts 12 and 13 of the rope-shaped spacer 15 are provided in the vicinity of the shaft end of the hollow shaft 1. It is also possible to provide the spacer 15 and also provide the engaging portion at the center of the hollow shaft 1, with the rope-shaped spacer 15 stretched between them.

As described above, the present invention provides locking portions at both ends of the screw shaft or at both ends and the center, and both ends of the rope-shaped spacer can be removed and freely locked in both of the locking portions. Then, the screw, in which the intermediate part of the rope-shaped spacer is stretched so as to be in point contact with the outer periphery of the screw blade, is placed in a trough with unsolidified mortar adhered to the inner surface, and then Since this is a method for creating a mortar casing for a screw pump trough, in which the mortar surface in an unsolidified state is formed by the spacer by rotating the screw, and a mortar casing for the screw pump trough is created, the spacer can be easily attached and detached. Compared to the conventional method, the construction period for the mortar casing of the screw pump trough can be shortened, and the spacer can be removed without damaging it, and there is no permanent deformation of the spacer, so the spacer can be used multiple times. It can be done, and there is no need to repaint the screw after removal. Therefore, this can reduce construction costs.

Furthermore, since the spacer is not directly fixed to the screw blade itself, the moment of inertia of the area of the screw as a whole does not increase, and therefore a mortar casing having a cross-sectional shape that matches the deflection curve of the screw can be created. Furthermore, even if the mortar during construction hardens, no excessive force is applied to the mortar casing, making it possible to create a uniform mortar layer.

[Brief explanation of the drawing]

Fig. 1 is a side sectional view of a general screw pump equipment, Fig. 2 is a sectional view taken along the line A-A in Fig. 1,
FIG. 3 is a partial side view for explaining the mounting situation of a spacer according to a conventional example, and FIG. 4 is a spacer that can be used in a method for creating a mortar casing for a screw pump trough according to an embodiment of the present invention. A schematic side sectional view of the screw with the screw attached thereto is shown. (Explanation of symbols), 1... Screw shaft, 2... Screw blade, 7... Mortar casing, 10...
...Trough, 14...Tension device, 15...Spacer.

Claims (1)

[Claims] 1. In a method of creating a mortar casing by rotating a screw to which a spacer is attached and molding unsolidified mortar with the spacer, the screw is attached to both ends of the screw shaft or to both ends and the center of the screw shaft, respectively. At the same time, both ends of a rope-shaped spacer are detachably and freely locked in both of the anchoring parts, and the intermediate part of the rope-shaped spacer is tensioned so as to come into point-like contact with the outer peripheral edge of the screw blade. The stretched screw is placed in a trough with unsolidified mortar adhered to the inner surface, and then the screw is rotated to shape the unsolidified mortar surface with the spacer,
A method for creating a mortar casing for a screw pump trough. 2. A method for constructing a mortar casing for a screw pump trough according to claim 1, wherein a tensioning device is attached to a portion near the end of the rope-shaped spacer.