JP2017025769A - Method for adjusting outer diameter of blade of screw pump - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for adjusting an outer diameter of a blade of screw pump in which an axis of a screw blade and an axis of a screw shaft can be easily agreed, and that can easily adjust the outer diameter of the screw blade to a predetermined dimension.SOLUTION: The present invention includes the steps of: supporting a screw shaft in such a manner that a horizontally-placed screw shaft 6 is rotatably supported at both end thereof; and cutting an edge part of a blade by a cutting machine 46 so that an outer diameter of the edge part of the screw blade 7 is in a predetermined dimension while rotating the screw shaft 6, which is supported at both ends, around an axis thereof and while traveling the cutting machine 46 on a rail 45 disposed in parallel with a longitudinal direction of the screw shaft 6.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a blade pump blade outer diameter adjusting method for adjusting the outer diameter of a screw blade attached to the outer peripheral surface of a screw shaft to a predetermined size.

  The screw pump is an open-type pump that pumps water with a rotating screw, and is used, for example, as a pump in a rainwater pumping station, a pump facility in a sewage treatment plant, or the like. This screw pump is installed in a trough having a concave cross section inclined obliquely with respect to the horizontal direction. Here, the main body (main part) of the screw pump is a screw shaft having helical screw blades attached to the outer peripheral surface, and in the state installed in the trough, the tip part (outer peripheral edge part) of the screw blades. The gap between the trough and the trough must be a specified gap in order to ensure a desired pumping amount (pump performance). Therefore, the inner surface finish of the trough is also important, but it is desirable that the outer diameter of the screw blade is as accurate as possible, and the axis of the screw blade and the axis of the screw shaft match as much as possible. It is desirable. In another aspect, the pumping efficiency is improved by increasing the accuracy of the outer diameter of the screw blade and the matching accuracy between the axis of the screw blade and the axis of the screw shaft.

  As a conventional document describing a technique related to the manufacture of a screw pump, there is Patent Document 1 below. Regarding the setting of the outer diameter of the screw blade to a predetermined size, the paragraph 0048 includes “Confirm and adjust that the outer diameter of the blade is within the tolerance in the entire length in the rotation axis direction”. There is no more specific description. With regard to adjusting the blade outer diameter of the screw pump, the inventors investigated what kind of prior art is in the technical field of screw pumps, but could not find any more.

  Although it is not related to the screw pump and does not adjust the blade outer diameter of the screw blade, an invention called a ribbon blade manufacturing device for a screw conveyor is described in Patent Document 2 below. In this conventional technology, a cylindrical material is rotated at a constant speed, and at the same time, a gas cutter is moved at a constant speed in parallel with the longitudinal direction of the cylindrical material to gas-cut a spiral ribbon blade from the cylindrical material. It is to make by.

Japanese Patent Laying-Open No. 2015-40529 Japanese Utility Model Publication No. 64-33376

  As described above, regarding making the outer diameter of the screw blade of the screw pump a predetermined size, Patent Document 1 states that “the blade outer diameter is within the tolerance in the entire length in the rotational axis direction, There is only a description “adjust”, and there is no more specific description.

  In addition, as described above, the cylindrical material is rotated at a constant speed, and at the same time, the gas cutter is moved at a constant speed in parallel with the longitudinal direction of the cylindrical material so that the spiral ribbon blade is removed from the cylindrical material. There is a technique of manufacturing by gas cutting. However, this technique is a technique for manufacturing the blades of the screw conveyor itself, and is not a technique related to the screw pump or a technique for adjusting the blade outer diameter of the screw blades.

  The present invention has been made in view of the above circumstances, and the object thereof is to easily align the axis of the screw blade and the axis of the screw shaft, and to easily set the outer diameter of the screw blade to a predetermined size. It is providing the blade | wing outer diameter adjustment method of a screw pump which can be adjusted to.

  The present invention is a blade pump blade outer diameter adjusting method for making the outer diameter of a screw blade attached to the outer peripheral surface of a screw shaft a predetermined size. This adjustment method includes a screw shaft support step for rotatably supporting the screw shaft that is laid sideways by supporting both ends thereof, while rotating the screw shaft supported at both ends around its axis, A blade tip that cuts the tip of the screw blade with the cutting machine so that the outer diameter of the screw blade is a predetermined size while running the cutting machine on a rail arranged parallel to the longitudinal direction. A partial cutting step.

  According to the present invention, while rotating the screw shaft around its axis and running the cutting machine parallel to the longitudinal direction of the screw shaft, the outer diameter of the tip of the screw blade is a predetermined dimension. By cutting so as to become, the axis of the screw blade and the axis of the screw shaft can be easily matched, and the outer diameter of the screw blade can be easily adjusted to a predetermined size.

It is a side view of a screw pump. It is a figure which shows the blade | wing attachment process of the manufacturing processes of a screw main body. It is a figure which shows the upper-and-lower endplate attachment process among the manufacturing processes of a screw main body. It is a figure which shows the blade outer diameter adjustment process in the manufacturing process of a screw main body. It is a detailed structure figure of the D section of Drawing 4. It is a detailed structure figure of the E section of Drawing 4.

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.

(Configuration of screw pump)
As shown in FIG. 1, the screw pump 100 includes a screw body 1 installed in a trough 50 inclined obliquely with respect to the horizontal direction, and an upper bearing 4 and a lower bearing 2 that support the screw body 1. Yes. An upper spindle 3 is attached to the upper end of the screw body 1, and the screw body 1 is supported by being suspended by the upper bearing 4 through the upper spindle 3. A driving device (not shown) such as an engine or an electric motor that rotates the screw main body 1 transmits a rotational driving force to the screw main body 1 via the gear coupling 5.

  The screw body 1 has a cylindrical screw shaft 6 and a helical screw blade 7 attached to the outer peripheral surface thereof, and a conical cylinder 8 is attached to one end (lower side) of the screw body 1. Is attached with a lower end plate 9. The upper end plate 10 is attached to the other (upper) end.

  The inner surface of the trough 50 is finished in an arc shape along the rotating screw blades 7, and in order to secure a desired pumping amount, the clearance S between the tip portion (outer peripheral edge portion) of the screw blades 7 and the inner surface of the trough 50 is For example, it is adjusted to 7 mm to 13 mm. The screw shaft 6 is made of, for example, STPY (arc welded steel pipe), and the screw blades 7 are made of, for example, SS. The total length of the screw shaft 6 is determined from the pump head, the inclination angle, and the like, and is, for example, about 6 m to 12 m. The shaft diameter is, for example, about 0.6 m to 1.8 m. The outer diameter of the screw blade 7 is, for example, about 1.2 m to 3.6 m, and the thickness of the blade is, for example, about 6 mm to 10 mm.

(Manufacturing procedure of screw body)
The manufacturing procedure of the screw body 1 will be described with reference to FIGS. 2 to 6 as appropriate.

<Screw shaft forming process>
First, the screw shaft 6 is formed by joining pipes 6a to 6f (cylindrical members) formed by bending and welding steel plates by welding. The number of pipes to be connected is determined by the length of the screw shaft to be manufactured.

<Bane installation process>
Next, as shown in FIG. 2, a screw blade 7 formed by bending a steel plate is welded and fixed to the outer peripheral surface of the screw shaft 6. At this time, the screw shaft 6 is placed on the mount 40 on which the roller 40a is disposed at the upper end, and the screw blades 7 are attached by welding while rotating the screw shaft 6 in a timely manner.

<Upper and lower end plate mounting process>
Thereafter, as shown in FIG. 3, the conical cylinder 8 is attached to one end of the screw shaft 6, and the lower end plate 9 is attached to the end of the conical cylinder 8. The upper end plate 10 is attached to the other end of the screw shaft 6. Thereby, the screw main body 1 is formed.

<Bane outer diameter adjustment process>
Subsequently, the outer diameter adjustment of the blade | wing for making the outer diameter size of the screw blade | wing 7 into a predetermined dimension is performed. The outer diameter adjustment of the blade is performed by a screw shaft support step for rotatably supporting the horizontal (leveled) screw shaft 6 by supporting both ends thereof, a subsequent blade tip cutting step, and a subsequent blade outer portion. It is divided into a diameter finishing process.

[Screw shaft support process]
As shown in FIG. 4, the gantry that supports the screw body 1 is changed from the gantry 40 to the gantry 41. The screw shaft 6 (screw body 1) is supported so that both ends of the screw shaft 6 are sandwiched between the rotating jigs 47 and 48 provided on the gantry 41. The rotating jigs 47 and 48 are rotatably attached to the gantry 41.

  A support structure (D portion in FIG. 4) of the upper end portion of the screw shaft 6 will be described with reference to FIG. A hole 10a is formed in the center portion of the upper end plate 10, and a disc-shaped jig plate 11 is fitted into the hole 10a with a structure of marking. The structure of the marking solder is to make the axis of the upper end plate 10 coincide with the axis of the jig plate 11. A jig insertion hole 11 a having a shape that extends outward in the longitudinal direction of the screw shaft 6 is provided in the shaft core portion of the jig plate 11. The jig insertion hole 11a of the present embodiment has a truncated cone shape.

  The rotating jig 47 is a jig whose tip 47a is tapered. The tip 47a of the rotating jig 47 of the present embodiment has a conical shape. The jig insertion hole 11 a described above has a truncated cone shape corresponding to the tip portion 47 a of the rotating jig 47.

  The support structure (E part of FIG. 4) of the lower end part of the screw shaft 6 will be described with reference to FIG. A jig insertion hole 9 a having a shape that extends outward in the longitudinal direction of the screw shaft 6 is provided in the center portion (axial core portion) of the lower end plate 9. The jig insertion hole 9a of the present embodiment has a truncated cone shape.

  The rotating jig 48 is a jig whose tip 48 a is tapered like the rotating jig 47. The tip 48a of the rotating jig 48 of this embodiment has a conical shape. The jig insertion hole 9 a described above has a truncated cone shape corresponding to the tip 48 a of the rotating jig 48.

  The distal end portion 47a of the rotating jig 47 is inserted into the jig insertion hole 11a, and the outer peripheral surface of the distal end portion 47a is brought into surface contact with the inclined inner peripheral surface of the jig inserting hole 11a. 48a is inserted into the jig insertion hole 9a, and the outer peripheral surface of the tip 48a is brought into surface contact with the inclined inner peripheral surface of the jig insertion hole 9a. Thereby, the screw shaft 6 (screw main body 1) is rotatably supported by a pair of mounts 41 with both ends supported.

[Blade tip cutting process]
A belt 42 is hung on the outer peripheral surface of the screw shaft 6, and the belt 42 is rotated by a belt driving device 43, whereby the screw main body 1 is rotated around its axis. A rail 45 supported by a plurality of legs 44 is disposed on the side of the screw body 1 in parallel to the longitudinal direction of the screw shaft 6 (screw body 1). 46 (for example, a gas cutter having a gas torch) travels.

  The cutting machine 46 is run while rotating the screw shaft 6 (screw body 1) around its axis, and the tip of the screw blade 7 is cut by the cutting machine 46, and the outer diameter dimension of the screw blade 7 is set to a predetermined value. And the same outer diameter.

  Here, the screw shaft 6 is rotated so that the peripheral speed of the tip (outer peripheral edge) of the screw blade 7 is, for example, 2 mm / second or more and 5 mm / second or less. With respect to the cutting machine 46, cutting is performed at a traveling speed determined from the peripheral speed of the screw blade 7 tip and the lead of the screw blade 7 so that the tip of the rotating screw blade 7 is continuously cut by the cutting machine 46. The machine 46 is run (the rotational speed (circumferential speed) of the tip of the screw blade 7 is synchronized with the running speed of the cutting machine 46).

  In addition, as shown in FIG. 4, it is preferable to cut | disconnect the part P where the virtual line L extended from the center part of the screw shaft 6 and the front-end | tip part of the screw blade | wing 7 cross | intersect with the cutting machine 46. As shown in FIG.

[Bane outer diameter finishing process]
Although illustration is omitted, a piano wire (thread-like member) is then stretched parallel to the longitudinal direction of the screw shaft 6 (screw body 1), and the outer diameter of the screw blade 7 is ± on the basis of the piano wire. The blade tips are finished with a grinder or the like so that the tolerance is 6 mm.
In addition, you may use thread-like members, such as a wire and a thread | yarn, instead of a piano wire. Further, laser light may be used instead of the thread-like member.

<Coating process>
Finally, the screw body 1 is painted.

(Modification)

  The shape of the jig insertion holes 9a and 11a may be a truncated pyramid instead of the truncated cone. In other words, any hole having a shape that expands outward in the longitudinal direction of the screw shaft 6 may be used. Similarly, the shape of the tip portions 47a and 48a of the rotating jigs 47 and 48 may be a pyramid instead of a cone. That is, the shape of the tip of the rotating jig may be a tapered shape corresponding to the jig insertion hole (having an outer peripheral surface in surface contact with the inclined inner peripheral surface of the jig insertion hole).

  Instead of making the jig plate 11 separate from the upper end plate 10, the jig plate 11 may be integrated with the upper end plate 10.

  It is a preferable example that the peripheral speed of the tip end portion (outer peripheral edge portion) of the screw blade 7 is 2 mm / second or more and 5 mm / second or less, and the screw blade 7 (screw shaft 6) is rotated at a peripheral speed other than the above. It may be rotated.

  Examples of the cutting machine 46 other than the gas cutting machine having a gas torch include a cutting machine having a plasma torch.

  The cutting position of the rotating blade end of the screw blade 7 by the cutting machine 46 is not limited to the portion P where the imaginary line L extending in the horizontal direction from the center portion of the screw shaft 6 intersects the tip portion of the screw blade 7. .

  When the tip of the screw blade 7 can be cut into a predetermined dimension without a rough surface by the cutting machine 46, the above-described blade outer diameter finishing step may be omitted.

(Action / Effect)
According to the present invention, while rotating the screw shaft 6 around its axis and running the cutting machine 46 parallel to the longitudinal direction of the screw shaft 6, the tip end portion of the screw blade 7 has its outer diameter dimension. By cutting so as to have a predetermined dimension, the axis of the screw blade 7 and the axis of the screw shaft 6 can be easily matched, and the outer diameter of the screw blade 7 can be easily adjusted to the predetermined dimension. be able to.

  In the present invention, it is preferable to rotate the screw shaft 6 so that the peripheral speed at the tip of the screw blade 7 is 2 mm / second or more and 5 mm / second or less. By rotating the screw blade 7 at a peripheral speed of 2 mm / second or more, it is possible to prevent the tip portion of the screw blade 7 from becoming rough due to fusing. Further, by setting the peripheral speed to 5 mm / second or less, the tip of the screw blade 7 can be more reliably cut without leaving a cut.

  Further, in the present invention, it is preferable that the cutting machine 46 cuts a portion P where the imaginary line L extending in the horizontal direction from the center of the screw shaft 6 and the tip of the screw blade 7 intersect. The screw shaft 6 laid sideways bends not a little by its own weight. The amount of deflection can be predicted by calculation, but there is a difference in the amount of deflection between the calculation and the actual value. Here, the direction in which the screw shaft 6 bends is vertically downward. If the cutting machine 46 cuts the portion P where the imaginary line L extending in the horizontal direction from the center of the screw shaft 6 and the tip of the screw blade 7 intersect, the screw shaft 6 is slightly bent. However, compared with the case where other parts are cut, the cut part (cut portion) is less likely to be displaced. That is, according to this configuration, the outer diameter dimension of the screw blade 7 can be made more accurate.

  In the present invention, jig insertion holes 11a and 9a each having a shape that expands outward in the longitudinal direction of the screw shaft 6 are provided in the shaft core portions at both ends of the screw shaft 6, respectively. , The rotatable jigs 47 and 48 whose tip portions 47a and 48a are tapered are inserted into the jig insertion holes 11a and 9a so that the outer peripheral surfaces are in surface contact with the inclined inner peripheral surfaces of the jig insertion holes 11a and 9a. It is preferable that the screw shaft 6 is inserted into the end portions 47a and 48a and the screw shaft 6 is rotatably supported by supporting both ends of the screw shaft 6 so as to sandwich the both ends of the screw shaft 6.

According to this configuration, the screw shaft 6 is pressed by the tip portions 47a and 48a of the rotating jigs 47 and 48 from both sides in the axial direction. When the shaft core portion of the screw shaft 6 is pressed in the axial direction from both sides by inserting the tapered tip portions 47a and 48a into the jig insertion holes 11a and 9a having a shape extending outward in the longitudinal direction, the shaft is pressed by the pressing force. The core is automatically adjusted, and a slight error that may occur between the axis of the screw shaft 6 and the actual center of rotation of the screw shaft 6 can be easily corrected.
In addition, when the screw shaft 6 and the jig are connected by bolts or the like to support both ends of the screw shaft 6, the shaft core tends to be displaced at the connecting portion. Since the screw shaft 6 is supported at both ends by surface contact between the inclined inner peripheral surface of the hole provided and the tip portions 47a and 48a of the rotating jigs 47 and 48, the shaft core is hardly displaced.
Further, since the surface contact occurs on an oblique surface with respect to the pressing direction (axial direction) of the screw shaft 6, a strong coupling force is obtained by a frictional force generated in the surface contact portion due to a so-called wedge effect. And the rotating jigs 47 and 48 are easily rotated together, and the jig insertion holes 11a and 9a are worn by rubbing each other, and the tip portions 47a and 48a of the rotating jigs 47 and 48 are worn. Is prevented. By these, according to the said structure, it is easy to rotate the screw shaft 6 with the axial center.

  In the present invention, the jig plate 11 is preferably separated from the upper end plate 10. When the jig plate 11 is integrated with the upper end plate 10, the jig insertion hole 11 a is provided in the upper end plate having a large diameter by machining, which is difficult to process. is there. Further, since a relatively large axial pressing force acts on the jig insertion hole 11a, if the pressing force is large, the upper end plate 10 can be separated from the upper end plate 10 if the jig plate 11 is separated from the upper end plate 10. This can be dealt with by slightly increasing the thickness of only the film. On the lower end plate 9 side, a tapered conical cylinder 8 is provided to reduce the resistance to water flow, and the lower end plate 9 is attached to this end. Therefore, since the diameter of the lower end plate 9 is made smaller than the diameter of the upper end plate 10, there is a problem that the jig insertion hole 9a is directly provided in the lower end plate 9 with respect to processing and strength. No.

In the present invention, a thread-like member is stretched parallel to the longitudinal direction of the screw shaft 6 or laser light is irradiated, and the outer diameter of the screw blade 7 is ± 6 mm based on the thread-like member or the laser light. It is preferable to further include a blade outer diameter finishing step for finishing the wafer so as to be within the dimensional tolerance.
According to this structure, the outer diameter dimension of the screw blade 7 can be matched with a predetermined dimension with high accuracy, and the pumping efficiency of the screw pump 100 can be further improved.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications can be made as long as they are described in the claims. .

1: Screw body 2: Lower bearing 3: Upper spindle 4: Upper bearing 5: Gear coupling 6: Screw shaft 7: Screw blade 8: Cone 9: Lower end plate 9a: Jig insertion hole 10: Upper end plate 11 : Jig plate 11a: Jig insertion hole 45: Rail 46: Cutting machine 47, 48: Rotating jig 47a, 48a: Rotating jig tip 100: Screw pump L: Virtual line P: Virtual line L and screw blade Section where the tip of 7 intersects

Claims (5)

A screw pump blade outer diameter adjusting method for setting the outer diameter of a screw blade attached to the outer peripheral surface of the screw shaft to a predetermined size,
A screw shaft support step for rotatably supporting the screw shaft that has been laid down at both ends thereof;
While rotating the screw shaft supported at both ends around its axis and running a cutting machine on a rail arranged parallel to the longitudinal direction of the screw shaft, the tip of the screw blade is A blade tip cutting step for cutting with the cutting machine such that the outer diameter dimension is a predetermined dimension;
The blade outer diameter adjustment method of a screw pump characterized by comprising. In the screw pump blade outer diameter adjustment method according to claim 1,
In the blade tip cutting step, the screw shaft is rotated so that the peripheral speed of the tip of the screw blade is 2 mm / second or more and 5 mm / second or less. Diameter adjustment method. In the blade pump outside diameter adjustment method of the screw pump according to claim 1 or 2,
In the blade tip portion cutting step, the cutting machine cuts a portion where a virtual line extending in the horizontal direction from the center portion of the screw shaft and the tip portion of the screw blade intersects. Pump blade outer diameter adjustment method. In the blade pump blade outer diameter adjustment method according to any one of claims 1 to 3,
Each of the shaft core portions at both ends of the screw shaft is provided with jig insertion holes each having a shape that extends outward in the longitudinal direction of the screw shaft,
In the screw shaft support step, a rotatable rotating jig with a tapered tip is inserted into the jig insertion hole from the tip so that the outer peripheral surface is in surface contact with the inclined inner peripheral surface of the jig insertion hole. Then, the screw shaft blade outer diameter adjusting method, wherein the screw shaft is rotatably supported by the both ends of the screw shaft so as to sandwich both ends of the screw shaft. In the screw pump blade outer diameter adjustment method according to any one of claims 1 to 4,
A thread-like member is stretched parallel to the longitudinal direction of the screw shaft, or laser light is irradiated, and the outer diameter of the screw blade is within a tolerance of ± 6 mm with respect to the thread-like member or laser light. A blade outer diameter adjusting method for a screw pump, further comprising a blade outer diameter finishing step for finishing the blade.

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