JP2016070059A - Steel pipe pile - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a steel pipe pile capable of improving a ground supporting force at a low cost by simple means without impairing workability.SOLUTION: A steel pipe pile 1 has a shaft part 2 made of a steel pipe. A circular end face plate 3 with a diameter D larger enough than a diameter d of the shaft part 2 is welded on an apical surface of the shaft part 2. The steel pipe pile has a flange part 4 protruding outward beyond the shaft part diameter of the end face plate. The flange part has a cutout part 5 in a direction from a circumference of the end face plate to a center. Inclined face parts 6 and 7, which are inclined in vertically opposite directions to each other, are formed at both sides in a circumferential direction of the end face plate of the cutout part 5. A concavity 8, which is dented toward the pile head side, is formed on a central part of the end face plate 3.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a steel pipe pile used for a rotary press-fitting method in which a steel pipe which is a pile main body is inserted into the ground by rotary press-fitting.

  There are various types of steel pipe piles of this type. For example, there is an expanded steel pipe pile of Patent Document 1. This steel pipe pile is formed by welding and fixing a circular enlarged disk to the tip of the steel pipe, and the disk is formed at two locations where a cut from the periphery toward the center and a cut along the periphery of the steel pipe are opposed to each other. The configuration is such that downward and upward blades are formed by folding downward and upward along a diametrical fold line along a notch from the periphery toward the center.

  Further, Patent Document 2 is intended to obtain a steel pipe pile that can be easily screwed even in a hard ground, and has a plate-like blade portion 2 having a larger outer shape than the cylindrical shaft portion 11 at the distal end portion 12. This is a steel pipe pile 1. And the groove-shaped cut | notch parts 13 and 13 cut | disconnected diagonally from the front end surface 12a in the cylindrical outer shell of a front-end | tip part are formed in two places, and two blades which form a blade | wing part in those cut | notch parts 21 and 21 are fixed in the inserted state, and the remaining portion 141 is bent toward the center C in the plan view of the shaft portion to form a tip convex portion 14 having a curved surface portion 14a (reference numeral Is a code in Patent Document 2).

  Further, Patent Document 3 is intended to obtain a rotating penetrating pile that is easy to process, has a large supporting force, and has an excellent penetration efficiency. A steel blade 3 formed by bending a flat plate is used as a tip of a steel pipe. A rotary penetrating steel pipe pile fixed to a surface at a right angle to the pipe axis direction of the steel pipe 5, wherein the steel blade 3 is provided with a cut 7 in a predetermined range along the outer periphery of the tip of the steel pipe 5. 7 is cut out into a fan shape to form a cut portion 9, and one of the portions where the cut 7 is provided with the extension line of the line connecting each end 7 a of the cut 7 and the center of the pile as a fold line 11. The upward inclined surface portion 13 is formed by bending upward, the other of the portions provided with the cuts 7 is bent downward to form the downward inclined surface portion 15, and the upward inclined surface portion 13 and the downward inclined surface portion 15 are cut. The intersection of the inclined part and the non-inclined part in the joint is joined by welding It is to (the code is a code in Patent Document 3).

JP 2006-9354 A JP2008-45338 JP 2010-281205

  Each of the conventional steel pipe piles has an effect, but since the function of the pile is in the ground supporting force, it is desired that the supporting force of the cast steel pipe pile is as high as possible. In that case, it is desired that high supporting force can be obtained efficiently in various aspects, that is, by simple means at low cost and without impairing workability.

  The present invention has been made to solve the above-described conventional problems, and provides a steel pipe pile capable of improving the ground supporting force at a low cost and without impairing workability by simple means. With the goal.

  The steel pipe pile of the invention of claim 1 which solves the above-mentioned problem is a pile at the tip surface of the shaft portion made of steel pipe, the diameter D being sufficiently larger than the diameter d of the shaft portion and at the center portion when viewed from the lower surface side. A circular end face plate formed with a concave portion formed on the head side is fixed by welding, and the diameter of the concave portion is larger than the diameter of the shaft portion, and the flange portion protruding outward from the concave portion in the end face plate, It has a notch part which goes to the center from the peripheral edge of the end face plate, and inclined face parts which are inclined in the upside down direction are formed on both sides of the end face plate in the circumferential direction of the notch part.

  According to a second aspect of the present invention, in the steel pipe pile of the first aspect, the end face plate is formed by welding or bolting a plurality of steel plates.

  According to a third aspect of the present invention, in the steel pipe pile according to the first or second aspect, a plate-shaped excavation blade is vertically fixed to a lower surface of the concave portion of the end face plate, and a semicircular inclined blade is fixed to a side surface of the excavation blade. It is characterized by that.

  The steel pipe pile according to any one of claims 1 to 3, wherein the steel pipe pile has a wing portion having substantially the same shape as the wing portion of the end face plate at a position above the end face plate of the shaft portion. A circular auxiliary wing larger than the end face plate is welded and fixed in such a manner as to penetrate the shaft portion.

According to a fifth aspect of the present invention, in the steel pipe pile according to the fourth aspect, the auxiliary wing has a concave portion indented on a pile front end side when viewed from the upper surface side opposite to the concave portion of the end face plate. .

According to a sixth aspect of the present invention, in the steel pipe pile according to the fourth aspect, the auxiliary wing has a recessed portion that is recessed toward the pile head side when viewed from the lower surface side, similar to the recessed portion of the end face plate.

  According to a seventh aspect of the present invention, in the steel pipe pile according to the sixth aspect, a second auxiliary wing having the same shape as the auxiliary wing and a larger outer diameter is provided further above the auxiliary wing.

  According to the invention of claim 1, an end having a structure (inclined surface portions inclined in the upside down direction formed on the flange portion) on the front end surface of the steel pipe which is a pile main body, which bites into the ground at the time of rotational press-fitting and increases the propulsive force. Supporting piles at a low cost and without sacrificing workability by forming a recess (convex when viewed from the top surface) in the center of the face plate that is recessed toward the pile head as viewed from the bottom surface side It becomes possible to increase power.

  Since a large load acts on the end face plate at the time of pile construction, it is necessary to make it a large plate thickness, and in order to press the concave portion of the end face plate of this large plate thickness, a heavy load press machine is required. According to the steel pipe pile of claim 2, which can be manufactured by welding three thin plate thicknesses, an end plate with a large plate thickness can be manufactured without requiring a heavy load press.

In the steel pipe pile of claim 3, since the plate-shaped excavation blade fixed perpendicularly to the lower surface of the concave portion of the end face plate stirs the soil, the force required for press-fitting the pile body (steel pipe) can be reduced, The pile body can penetrate smoothly.
Furthermore, since the semicircular inclined blade is provided on the side surface of the vertical excavating blade, the propulsive force can be increased by the inclined blade.
In addition, the structure of having a semicircular inclined blade on the side of the vertical excavating blade has a synergistic effect on improving the propulsive force, and can efficiently increase the propulsive force. Propulsive force can also be improved efficiently by producing a synergistic effect with the propulsive action of the outer peripheral edge side portion having the inclined surface part that is inclined in the reverse direction of the flange.

In the steel pipe pile according to claim 4, the auxiliary wing having an outer diameter larger than that of the end face plate and provided at a position higher than the end face plate performs a propulsion action in the same manner as the propulsion blade portion of the end face plate, thereby increasing the propulsive force.
Moreover, it can respond to the pulling force (tensile force) generated when the building is shaken by an earthquake.
In addition, the presence of the auxiliary wing disperses the ground support force, and the ground support force as a whole pile improves.

  In the steel pipe pile according to claim 5, the auxiliary wing having a concave portion (convex when viewed from the lower surface side) that is recessed toward the tip side of the pile when viewed from the upper surface side opposite to the concave portion of the end face plate, The action of pulling force and ground support force work effectively.

In claim 6, the structure having a concave portion similar to the concave portion of the end face plate at a position above the end face plate and having an auxiliary wing having a diameter larger than that of the end face plate is a structure in which the end face plate and the auxiliary wing exhibit a screw action. Increase power.
According to the structure having the second auxiliary wing above the auxiliary wing as in claim 7, the end face plate, the auxiliary wing and the second auxiliary wing have a structure having a screw action, and further propulsion. Increase power. Further, if a plurality of additional auxiliary wings having a larger diameter are provided at the upper position of the second auxiliary wing, the propulsive force is further increased.

It is a front view of the steel pipe pile of one Example of this invention. 1 is a cross-sectional view taken along a line AA in FIG. 1, (B) is a front view of (A), (C) is a cross-sectional view taken along a line BB in (A), (D) is a supplementary explanatory diagram about the cross-sectional shape of the concave portion of the end face plate. It is a figure explaining the point which manufactures the end surface board of FIG. It is a front view of the steel pipe pile of the other Example of this invention. 4A and 4B are diagrams illustrating an end face plate in which FIG. 4A is a DD cross-sectional view of FIG. 4, FIG. 4B is a front view of FIG. 4B, and FIG. 4C is a cross-sectional view of FIG. It is a figure explaining the point which manufactures the end surface board of FIG. It is a figure which shows the modification of the steel pipe pile of FIG. It is a figure explaining an example of the aspect which constructs the steel pipe pile of this invention as a foundation pile of a house. The steel pipe pile of the further another Example of this invention is shown, and is a figure equivalent to FIG. FIG. 10 is a perspective view of FIG. 9B viewed from below. (A) is a plan view of the end face plate of the embodiment when two end face plates are manufactured by lap welding, and (B) is a plan view of the reinforcing plate in the end face plate of (A). FIG. 13 is an enlarged DD cut end view of FIG. 12. The Example which provided the auxiliary wing is shown, and it is a front view of the lower part of a steel pipe pile. It shows the other Example which provided the auxiliary wing, and is a front view of the lower part of a steel pipe pile. The further another Example which provided the auxiliary wing is shown, It is a front view of the lower part of a steel pipe pile.

  Hereinafter, the form for implementing the steel pipe pile of this invention is demonstrated with reference to drawings.

FIG. 1 is a front view of a steel pipe pile 1 according to an embodiment of the present invention, FIG. 2 illustrates an end face plate in FIG. 1, (A) is a cross-sectional view taken along the line AA in FIG. (C) is a cross-sectional view taken along the line BB of (b).
The steel pipe pile 1 is formed by welding and fixing a circular end face plate 3 having a diameter D sufficiently larger than the diameter d of the shaft part 2 to the tip surface of the shaft part 2 made of a steel pipe.
The end face plate 3 has a notch portion 5 extending from the periphery of the end face plate toward the center in the flange portion 4 projecting outward from the diameter of the shaft portion (steel pipe) 2, and the end face plate circumferential direction of the notch portion 5 On both sides, inclined surface portions 6 and 7 that are inclined in the opposite directions are formed. And the recessed part 8 dented in the pile head side is formed in the center part of the end surface board 3 further. The outer part of the recess 8 is indicated by 8 '. A circular contour viewed from above the concave outer portion 8 ′ is indicated by S.
The axial part (steel pipe) of the steel pipe pile 1 of an Example is board thickness t = 4.5mm, diameter d = 114.3mm, and material STK400.
The end face plate 3 has a plate thickness T = 12 mm, a diameter D = 500 mm, and a height H of the recess 8 = 60 mm. The diameter of the circular contour S of the concave outer portion 8 ′ is approximately 280 mm and the material SS400 or SS490.
The shape of the concave portion 8 is a spherical concave portion (in the cross section, an arc shape) in the drawing, but in particular, when the plate thickness is thick, the shape is generally a gentle shape as shown in FIG. Become.

The method of manufacturing the end face plate 3 is not particularly limited, but the inclined surface portions 6 and 7 may be formed after forming the concave portion 8 in the flat disk of the steel plate, or the inclined surface portion 6 may be formed in the flat disk. , 7 may be formed and then the recess 8 may be formed. It is also conceivable to form a concave portion after forming an inclined surface portion by cutting into a flat disk.
FIG. 3 shows the case where the inclined surface portion is formed after the concave portion (8 ′) is formed in the disk. In the figure, the end face plate at the stage before the inclined surface portion is formed is indicated by 3 ', and the portions that become the inclined surface portions 6 and 7 are indicated by 6' and 7 '.
In the illustrated example, an arc-shaped cut m is made at the position of the substantially circular contour S of the concave outer portion 8 ′, and after the cut n extending radially outward from the center position of the arc-shaped cut m is inserted, the cut n 2 are inclined in the upside down direction to form the inclined surface portions 6 and 7 in the upside down direction as shown in FIG. In the figure, a valley fold when forming the inclined surface portions 6 and 7 is indicated by a one-dot chain line, and a mountain fold is indicated by a two-dot chain line.
The arc-shaped cut m is preferably slightly outside the circular contour S.

When the steel pipe pile 1 described above is driven into the ground, the pile is penetrated into the ground by rotary press-fitting with a pile driving machine having a rotary press-fit drive unit. In this case, the end face plate 3 at the tip exhibits a driving force in such a manner that the inclined surface portions 6 and 7 bite into the soil. And in the state which the end surface board 3 reached | attained the support layer, it becomes a thing with high support power because the recessed part 8 exists in a lower surface.
FIG. 8 illustrates an example of an embodiment in which the above-described steel pipe pile 1 is constructed as a foundation pile of a building such as a house. The steel pipe pile 1 is installed on the ground in a form that supports the foundation concrete 20 of the building. . According to the steel pipe pile 1, since the ground supporting force is improved, a desired supporting force can be ensured with fewer piles than in the past.

4 to 6 show a steel pipe pile 11 according to another embodiment. 4 is a front view of the steel pipe pile 11, FIG. 5 is a diagram for explaining the end face plate 13 in FIG. 4, (A) is a DD sectional view of FIG. 4, (B) is a front view of (A), (C) is a cross-sectional view taken along line EE in (a).
This steel pipe pile 11 is the same as the embodiment of FIGS. 1 to 3 except for the inclined surface portion of the end face plate 13. That is, the shaft portion (steel pipe) 12 is the same size and material as the embodiment of FIGS. The plate thickness T and diameter D of the end face plate 13 and the height H of the recess 8 are also the same size and material as the embodiment of FIGS. The diameter of the circular contour S of the concave outer portion 8 ′ is also substantially the same.

The inclined surface portions 16 and 17 of the end face plate 13 of the steel pipe pile 11 of this embodiment are not linear in the end edges, and have a square shape.
FIG. 6 shows the end face plate 13 ′ before the inclined surface portion is formed, and the portions that become the inclined surface portions 6 and 7 are indicated by 16 ′ and 17 ′.
In the illustrated example, an arc-shaped cut N is made at a position of a substantially circular contour S of the concave outer portion 18 ′, and a short cut M ₁ extending radially outward from a position deviated from the center of the arc-shaped cut N to one side. and after notched M ₂ extending to the outer peripheral edge from the tip bent at an angle of 55 °, it is inclined in the circumferential direction on both sides of the incision M ₁ · M ₂ each upside down, as shown in FIG. 5 The inclined surface portions 16 and 17 that are opposite to each other are formed. In the figure, a valley fold when forming the inclined surface portions 16 and 17 is indicated by a one-dot chain line, and a mountain fold is indicated by a two-dot chain line.
The inclined surface portions 16 and 17 in the end face plate 13 of this embodiment are improved in the propulsive force when the steel pipe pile 11 is pushed in while penetrating into the ground because the circumferential edge is bent. To do.

FIG. 7 shows another embodiment of the present invention.
The steel pipe pile 1A of this embodiment has the shaft portion (steel pipe) 2 and the end face plate 3 itself that are the same as those of the embodiment of FIGS. It is fixed by welding.
According to the steel pipe pile 1A of this embodiment, the height position of the inclined surface pairs 6 and 7 on both sides in the diametrical direction of the end face plate 3 is relatively changed with rotation, so that the action of stirring the soil is enhanced. It is also possible to increase the driving force.

9 and 10 show a steel pipe pile 11A of another embodiment.
The end face plate portion structure of the steel pipe pile 11A of this embodiment is the same as the end face plate 13 shown in FIGS. 4 and 5 at the lower end face plate 13 itself. The excavation blade 31 is welded and fixed vertically, and a semicircular inclined blade 32 is welded and fixed to the side surface of the excavation blade 31.
The excavation blade 31 has a pointed triangular tip, and a base is welded and fixed in a shape that follows the concave surface of the recess 18.

In this steel pipe pile 11A, since the excavating blade 31 fixed perpendicularly to the lower surface of the concave portion 18 of the end face plate 13 stirs the soil, the force required for press-fitting the pile main body (steel pipe) can be reduced. Can penetrate smoothly.
Further, since the semicircular inclined blade 32 is provided on the side surface of the vertical excavating blade 31, the inclined blade 32 can increase the propulsive force.
Further, the structure having the semicircular inclined blades 32 on the side surface of the vertical excavating blade 31 has a synergistic effect for improving the propulsive force, and can efficiently increase the propulsive force. Propulsive force can also be improved efficiently by exerting a synergistic effect with the propulsion effect of the propulsion blade portion (the flange portion 14 having the inclined surfaces 16 and 17 inclined in the upside down direction).

When the plate thickness of the end face plate is thick and processing to form a recess is difficult, or when it is difficult to form a simple recess by requiring a large facility, processing to form a recess in a thin disc, A plurality of thin circular plates that have been processed with recesses can be welded to form a thick end face plate having a multi-layered structure.
In this case, a method of forming an inclined surface portion on a thick end face plate having a plurality of concave portions formed by welding, or an inclined surface portion is formed at the stage of a thin disk that has been processed into a concave portion, and the concave portion has been processed and inclined. One thick end face plate can be formed by welding and joining a plurality of thin end face plates with the face portions already formed. In this case, SM490 may be used as the material steel plate.

11 and 12 show an end face plate 13A having a two-layer structure. FIG. 11A is a plan view of the end face plate 13A, and FIG. 12 is a GG cut end view of FIG.
The end face plate 13A, as shown in FIG. 12, a structure obtained by bonding the shaft portion (steel pipe) 12 is slightly thinner reinforcing end plates 13 ₂ in the lower surface of the welded fixed main end sheet 13 ₁ in the lower end of the.
The reinforcing end plates 13 ₂ has a recess along the main end sheet 13 ₁ in the recess 18, as shown in FIG. 11 (b), lack cut portion of the inclined surface 16, 17 in the main end sheet 13 ₁ (Notch part is shown by 31). The outer peripheral edge is a range indicated by M in FIG.
As a joining means of both, welding joining can be adopted. For example, welding joining can be performed on the outer peripheral end faces of both. Further, a hole at a plurality of strength for the end plate 13 _2, can also be joined by a plug weld to weld the main end surface plate 13 ₁ and the reinforcing end plates 13 ₂ in the hole portion.
In the illustrated example, a two-layer structure is used, but a three-layer structure may be used. In this case, it is possible to further bond the second reinforcing end plates on the lower surface of the reinforcing end plates 13 ₂ in FIG. 12.
Can also be bonded to the upper surface of the main end plates 13 ₁ in FIG. 12, the second reinforcing end plates with holes through which the shaft portion 12.

It is also possible to bolt joining the reinforcing end plates 13 ₂ and the main end surface plate 13 _1.

FIG. 13 shows a steel pipe pile 11B of still another embodiment.
This steel pipe pile 11B has the same shape as the flange portion 14 (the flange portion 14 with the inclined surface portions 16 and 17 inclined in the upside down direction) of the end surface plate 13 above the end surface plate 13 at the lower end of the shaft portion (steel pipe) 12. In this configuration, a circular auxiliary wing 34 having an outer diameter 14 larger than that of the end face plate 13 is welded and fixed in such a manner as to penetrate the shaft portion 12.
For example, the outer diameter of the collar portion 14 of the auxiliary wing 34 is set to about 600 mm with respect to the outer shape 500 mm of the end face plate 13.
Further, the auxiliary wing 34 in the illustrated example has a concave portion 38 (a convex portion 38 ′ when viewed from the lower surface side) that is recessed toward the tip of the pile as viewed from the upper surface side opposite to the concave portion 18 of the end face plate 13. The auxiliary wing 34 having an outer diameter larger than that of the end face plate 13 and provided at a position above the end face plate 13 performs a propelling action in the same manner as the propulsion blade portion of the end face plate 13 to increase the propulsive force.
In addition, the auxiliary wing 34 having the recessed portion 38 that is recessed toward the top end of the pile as viewed from the upper surface side can cope with a pulling force (tensile force) generated when the building is shaken by an earthquake.
Further, the presence of the auxiliary wings 34 at a position separated from the end face plate 13 disperses the ground supporting force, and the ground supporting force as a whole pile is improved.

FIG. 14 shows a steel pipe pile 11C of still another embodiment. In this example,
In this steel pipe pile 11C, the auxiliary wing 44 fixed at a position above the end face plate 13 at the lower end of the shaft portion (steel pipe) 12 has a flat plate shape.
When the flat auxiliary wing 44 is fixed to the shaft portion 12 by welding, the auxiliary wing 44 may be fixed by welding using a reinforcing tip above and below the auxiliary wing 44.
In the illustrated example, a short reinforcing rod (reinforcing tip) 35 disposed so as to sandwich the auxiliary wing 44 from above and below the auxiliary wing 44 is welded to the shaft portion 12 and the end of the reinforcing rod 35 is connected to the auxiliary wing 44. It is fixed by welding.

FIG. 15 shows a steel pipe pile 11D of still another embodiment.
In the steel pipe pile 11D, a first auxiliary wing 54 is welded and fixed to the shaft portion 12 at an upper position of the end face plate 13, and a second auxiliary wing 64 at an upper position thereof is fixed by welding.
The relationship between the end face plate 13 and the first auxiliary wing 54 is the same as the relationship between the end face plate 13 and the auxiliary wing 34 described with reference to FIG. 13, and the outer diameter of the first auxiliary wing 54 is greater than the outer diameter of the end face plate 13. Although it is large, the outer diameter of the second auxiliary wing 64 is larger than the outer diameter of the first auxiliary wing 54.
As the end face plate 13, the first auxiliary wing 54, and the second auxiliary wing 64 have a structure in which the outer diameter of the wing portion becomes larger as the upper one is fixed with a vertical spacing, the screw action is achieved. It becomes the structure which plays, and increases propulsive force.

1, 1A, 11, 11A, 11B, 11C, 11D Steel pipe pile 2, 12 Shaft (steel pipe)
3, 13, 13A End face plate 13 ₁ Main end face plate 13 ₂ Reinforcement end face plate 3 ′, 13 ′ End face plate 4, 14 before the inclined surface portion is formed Edge portion 5, 15 Notch portion 6, 16 Upward Inclined surface portion 6 ', 16' Inclined surface portion 7, 17 Downwardly inclined surface portion 7 ', 17' Inclined downward surface portion 8, 18, 38 Recessed portion 8 ', 18', 38 ' Outer portion 31 Excavation blade 32 Semi-circular inclined blade 34 Auxiliary wing 35 Reinforcing rod 44 Flat auxiliary wing 54 First auxiliary wing 64 Second auxiliary wing S Circular contour T (outside plate of the end plate) ) Plate thickness t (Shaft (steel pipe)) thickness d Shaft (steel pipe) diameter D End plate diameter H Recess height

Claims (7)

  Circular end face plate in which the diameter D is sufficiently larger than the diameter d of the shaft portion, and a concave portion is formed in the center portion on the side of the pile head when viewed from the lower surface side. Is fixed by welding, the diameter of the concave portion is larger than the diameter of the shaft portion, and has a notch portion extending from the peripheral edge of the end face plate to the center on the flange portion protruding outward from the concave portion in the end face plate, The steel pipe pile characterized by the inclined surface part inclined in the up-and-down reverse direction mutually being formed in the end surface board circumferential direction both sides of the said notch part.   The steel pipe pile according to claim 1, wherein the end face plate is formed by welding or bolting a plurality of steel plates.   The steel pipe pile according to claim 1 or 2, wherein a plate-shaped excavation blade is fixed vertically to a lower surface of the concave portion of the end face plate, and a semicircular inclined blade is fixed to a side surface of the excavation blade.   In a mode in which the shaft portion has a wing portion having substantially the same shape as the wing portion of the end face plate at a position above the end face plate of the shaft portion, and a circular auxiliary wing having an outer diameter larger than that of the end face plate is passed through the shaft portion. The steel pipe pile according to any one of claims 1 to 3, wherein the steel pipe pile is fixed by welding.   5. The steel pipe pile according to claim 4, wherein the auxiliary wing has a concave portion indented on a tip end side of the auxiliary wing as viewed from the upper surface side opposite to the concave portion of the end face plate.   5. The steel pipe pile according to claim 4, wherein the auxiliary wing has a recessed portion that is recessed toward the pile head side when viewed from the lower surface side, similarly to the recessed portion of the end face plate. The steel pipe pile according to claim 6, wherein a second auxiliary wing having the same shape as the auxiliary wing and having a larger outer diameter is provided at a position further above the auxiliary wing.

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