JP2015200092A - Connection structure of excavation member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent sediment from flowing in from a joint between an excavation member and a pipe body part in excavation work.SOLUTION: An excavation member 1 comprises a cylindrical base body 2 closed at the lower end, and a rotary blade 3 for excavating soil by rotating around the axis together with this base body 2 provided on an outer peripheral surface of this base body 2. A columnar projection part 4 is also provided on the outer peripheral surface while projecting outward in its radial direction. A pipe body part 5 comprises a cylindrical pipe body 6, and a downward projecting abutting part 7 provided in a lower end part of this pipe body 6. This abutting part 7 is constituted of a first extending part 8a and a second extending part 8b forming an L shape by mutually crossing, and an abutting surface 9 having an oblique upward plane normal line is formed in an internal angle constituted by crossing both the extending parts 8a and 8b. The projection part 4 is allowed to abut on this abutting surface 9 to make abutting force act, the excavation member 1 is thereby pressed to the pipe body part 5, and a clearance g is generated in a joint between the excavation member 1 and the pipe body part 5, thereby preventing sediment from flowing in from this clearance g.

Description

  The present invention relates to a connection structure between a drilling member that is used at the tip of a foundation pile and functions as a foundation of a building, and a tubular body part that is connected to the upper end of the drilling member.

  Foundation piles are used when building buildings such as houses and buildings. By stably supporting the building with this foundation pile, problems such as unsettled settlement are prevented from occurring in this building. For example, if the foundation pile disclosed by patent document 1 is illustrated and demonstrated, this foundation pile (steel pipe pile) will have two rotary blades (blade blades) in parallel with each other at the tip of the pile body and in the axial direction. Is inclined by a predetermined angle. When this pile main body is rotated around the axis, the rotary blades are embedded in the ground and buried deep in the ground. Reliable support stability can be obtained by embedding rotary blades larger in diameter than the pile body.

  In the configuration according to Patent Document 1, it is necessary to embed rotating blades up to a hard supporting ground that is preferably deeper than the surface ground. When this supporting ground is located deep in the ground, a long steel pipe It is necessary to use a pile body consisting of However, with the recent increase in the price of steel materials, the construction method using a long steel pipe has a problem that the cost tends to increase.

  Therefore, in order to reduce this cost, the inventors of the present application, as shown in Patent Document 2, are connected to a drilling member having a rotary blade and an upper part of the drilling member, and rotate the drilling member around an axis. The pipe section made of steel pipe is constructed so that it can be freely connected and separated, and after the excavation member and the pipe section are buried to a predetermined depth, a paper tube is inserted into the pipe section until it reaches the excavation member. Invented the method of pulling out only the tube body part from the ground after inserting the paper tube. The inside of the paper tube is filled with a filler (for example, cement), and when the filler is hardened, a foundation pile having a drilling member at the lowermost portion and having a predetermined strength is completed. The pipe section pulled out from the ground is reused to install other foundation piles. Since the price of the paper tube and the filler embedded in the ground is low compared with the price of the tube portion made of steel pipe, the material cost can be greatly reduced.

  As the excavation member 1 and the tubular body portion 5, for example, a configuration shown in FIG. 4 is adopted. The excavation member 1 is provided on a cylindrical base body 2 whose lower end is closed, an outer peripheral surface of the base body 2, a rotary blade 3 that rotates around the axis together with the base body 2 to excavate the ground, and the outer peripheral surface thereof. And a protrusion 4 provided to protrude outward in the radial direction. The tube body portion 5 includes a tubular tube body 6 and a contact portion 7 that protrudes downward from the lower end portion of the tube body 6 and engages the protrusion portion 4 (FIG. 4 ( a)). When the lower end of the tubular body portion 5 is inserted into the upper end of the excavating member 1 and the tubular body portion 5 is relatively rotated around the axis in the excavating direction, the protruding portion 4 is engaged with the L-shaped contact portion 7, and the tube The retaining action of the excavation member 1 from the body part 5 is exerted (see FIG. 4B). When the tubular body portion 5 is relatively rotated in the direction opposite to the above, the contact portion 7 and the projection portion 4 are disengaged, and the tubular body portion 5 can be pulled out from the excavation member 1.

JP 2008-291523 A Japanese Patent Application No. 2013-209827 (unpublished)

In the configuration according to FIG. 4, a slight play is provided between the protruding portion 4 and the contact portion 7 so that the tube portion 5 can be smoothly inserted into the excavating member 1. It is designed to move slightly in the insertion direction. If this excavation member 1 and the pipe body part 5 are connected, and the pipe body part 5 is propelled downward at a speed v while rotating around the axis at a predetermined rotational speed r, if the ground is somewhat hard, FIG. As shown in a), the excavation member 1 receives an upward resistance force _Fres by this ground, and the excavation member 1 is pressed against the tubular body portion 5 to ensure a close state.

On the other hand, when the ground is soft, a gap g may be generated between the excavation member 1 and the tubular body portion 5. This is because the rotating blade 3 formed on the excavating member 1 easily sinks into the ground when the tubular body portion 5 is propelled downward at a speed v while rotating around the axis at a predetermined rotational speed r, and the inclination of the rotating blade 3 Depending on the angle, as shown in FIG. 5 (b), a downward propulsive force F _pro for propelling the excavating member 1 at a speed higher than the speed v for propelling the tubular body portion 5 is applied to the excavating member 1. It is because it may act. As a result of the propulsive force F _pro acting on the excavating member 1 in this way, a gap g corresponding to the amount of play is generated.

  When the gap g is generated, surrounding earth and sand or mud flows into the inside of the excavating member 1 through the gap during the excavation work (see arrow f in FIG. 5B). As described above, when soil or the like flows into the excavation member 1, the soil or the like becomes an obstacle when the paper tube is inserted into the tubular body portion 5 after excavation as shown in Patent Document 2, for example, a paper tube In the configuration in which the paper tube is inserted, the paper tube cannot be inserted smoothly. For this reason, the work which removes the earth and sand etc. which flowed in excavation member 1 is needed, and there is a problem which raises work cost.

  Therefore, an object of the present invention is to prevent earth and sand from flowing in from the joint between the excavation member and the pipe body during excavation work.

  In order to solve the above-described problems, the present invention includes a cylindrical base having a closed lower end, a rotary blade provided on an outer peripheral surface of the base and rotating around an axis together with the base to excavate the ground, and the outer periphery A digging member provided on the surface and projecting radially outward, a tubular pipe body, the digging member connected to the pipe body, and the pipe body about the axis in the digging direction A tube body portion provided with an abutting portion provided to protrude downward from a lower end portion of the tube main body, which is brought into contact with the projecting portion and rotates toward the tube main body side when rotated. A connection structure for excavation members was constructed.

  In this way, the abutting portion and the projecting portion are brought into contact with each other, and the excavation member is pulled toward the tubular body portion by the abutting force, so that the excavation member and the pipe can be used even when the ground is hard as well as when the ground is hard. The body part is in close contact with each other, and a gap is formed between them, so that it is possible to prevent sediment and muddy water from flowing into the gap. For this reason, for example, when inserting a paper tube into a tube part, the insertion can be performed smoothly.

  In the above-described configuration, the contact portion includes a first extending portion and a second extending portion that intersect with each other, and an abutting surface having an obliquely upward surface normal at an inner angle formed by intersecting both extending portions. A surface is formed, and it is preferable that the protrusion is in contact with the contact surface.

  By abutting the abutment surface having the inclined surface normal and the projection as described above, during a digging operation (while the tube body portion is rotating around the axis), the abutment force between them is always used. The excavation member can be brought into close contact with the pipe body portion, and inflow of earth and sand from the gap can be reliably prevented.

  The present invention includes a cylindrical base body whose lower end is closed, a rotary blade provided on the outer peripheral surface of the base body and rotating around an axis together with the base body to excavate the ground, and radially outward on the outer peripheral surface. A projecting part provided projectingly, a tubular pipe body, and the projecting part when the drilling member is connected to the pipe body and the pipe body is rotated about the axis in the drilling direction. And a tube portion provided with a contact portion that protrudes downward from the lower end portion of the tube main body and draws the protruding portion toward the tube main body side. . Thus, by contacting the projecting portion formed on the excavating member and the abutting portion formed on the tube portion, and bringing the excavating member and the tube portion in close contact with each other by the contact force, from the joint between both, It is possible to prevent earth and sand from flowing into the excavation member. For this reason, for example, when inserting a paper tube into the inside of a tubular-body part, the operation | work can be performed smoothly and the suppression of work cost can be aimed at.

It is a perspective view which shows 1st embodiment of the connection structure of the excavation member which concerns on this invention, Comprising: (a) is the state which isolate | separated the excavation member and the pipe part, (b) connected the excavation member and the pipe part. State The side view which shows the connection structure of the excavation member shown in FIG. The side view which shows 2nd embodiment of the connection structure of the excavation member which concerns on this invention It is a perspective view which shows the connection structure of the excavation member which concerns on a prior art, (a) is the state which isolate | separated the excavation member and the pipe part, (b) is the state which connected the excavation member and the pipe part It is a side view which shows the connection structure of the excavation member shown in FIG. 4, Comprising: (a) when the ground is hard, (b) is when the ground is soft

  1 and 2 show a first embodiment of a connecting structure for excavation members according to the present invention. The excavation member 1 has a cylindrical base body 2 whose lower end is closed. On the outer peripheral surface of the base body 2, rotating blades 3 that rotate around the axis together with the base body 2 to excavate the ground are provided. In addition, a cylindrical protrusion 4 is provided on the outer peripheral surface so as to protrude outward in the radial direction (see FIG. 1A). The tube body portion 5 has a tubular tube body 6, and a contact portion 7 that protrudes downward is provided at a lower end portion of the tube body 6. The abutting portion 7 is composed of a first extending portion 8a and a second extending portion 8b that intersect with each other to form an L-shape, and is an obliquely upward surface at an inner angle formed by intersecting the extending portions 8a and 8b. A contact surface 9 having a normal line is formed (see FIG. 1A).

  When the lower end of the tubular body portion 5 is inserted into the upper end of the excavating member 1 (see the downward arrow in FIG. 1A) and the tubular body portion 5 is relatively rotated around the axis in the excavating direction (in FIG. 1B) The protrusion 4 is engaged with the L-shaped abutting portion 7 so that the excavation member 1 is prevented from coming off from the tubular body portion 5 (see FIG. 1B). At this time, the protruding portion 4 provided on the excavating member 1 contacts the contact surface 9 of the contact portion 7. When the tubular body portion 5 is relatively rotated in the opposite direction, the engagement between the contact portion 7 and the projection portion 4 is easily released, and the tubular body portion 5 can be pulled out from the excavation member 1.

Abutting force F the protrusion 4 receives from the abutment surface 9 can be decomposed into a component force F _H on the component force F _V and a horizontal direction in the vertical direction (upward) (see FIG. 2). When the ground is hard to some extent, the excavation member 1 receives an upward resistance force _Fres by this ground. The excavation member 1 is pressed against the tubular body portion 5 by the resistance force F _res and the component force F _{V in the} vertical direction, and a state where both are in close contact is ensured. For this reason, earth and sand and muddy water can be prevented from flowing in from the joint between the excavation member 1 and the pipe body part 5.

On the other hand, when the ground is soft, the rotating blade 3 formed on the excavating member 1 is easily sunk into the ground when the tube portion 5 is propelled downward at a speed v while rotating at a predetermined rotational speed r. Depending on the inclination angle of the blade 3, a downward driving force F _pro that tries to propel the excavating member 1 at a speed larger than the speed v of the tube body part 5 may act on the excavating member 1. Even if the downward propulsion force F _pro is applied in this way, the vertical upward component force F _V is applied at the same time, so the magnitude of the component force F _{V and} the magnitude of the propulsion force F _pro are compared. If direction of the force F _V is large, similarly to the above, the drilling member 1 is pressed against the tube part 5, both close state is ensured. The inclination angle of the contact surface 9, the predetermined rotational speed r, and the speed v of the tube part are determined so that this pressing action is exhibited.

  In this way, the seam between the excavation member 1 and the pipe body portion 5 is brought into close contact with each other so that dirt and the like do not flow into the excavation member 1. For example, the excavation member 1 passes through the inside of the pipe body portion 5. When inserting a member such as a paper tube (refer to FIG. 2 of Patent Document 2) leading to the above, it is not necessary to remove the earth and sand that has flowed into the excavating member 1, improving the speed of the work, Cost can be reduced.

FIG. 3 shows a second embodiment of the connection structure for the excavating member 1 according to the present invention. The basic configuration of the excavation member 1 and the tubular body portion 5 is the same as the configuration according to the first embodiment, but is different in that the shape of the protrusion 4 formed on the excavation member 1 is a prismatic shape. Thus, the pressing force of the excavation member 1 against the tubular body portion 5 is exerted by the contact force F (vertical component force F _V ) generated between the contact surface 9 of the contact portion 7 and the projection portion 4. As long as it is exhibited, the shape of the protrusion 4 may be changed as appropriate.

  Each of the above embodiments is merely an example, and as long as the problem of preventing inflow of earth and sand from the joint between the excavation member 1 and the tubular body portion 5 during excavation work can be solved. It is allowed to change the shape of each component as appropriate.

DESCRIPTION OF SYMBOLS 1 Excavation member 2 Base | substrate 3 Rotary blade 4 Protrusion part 5 Tube part 6 Pipe main body 7 Contact part 8a First extending part 8b Second extending part 9 Contact surface

Claims (2)

A cylindrical base body (2) whose lower end is closed, a rotary blade (3) provided on the outer peripheral surface of the base body (2) and rotating around the axis together with the base body (2) to excavate the ground, and the outer periphery A digging member (1) comprising a projection (4) provided on the surface to project outward in the radial direction;
When the tubular main body (6) and the excavating member (1) are connected to the main pipe (6) and the main pipe (6) is rotated about the axis in the excavating direction, the protrusion (4 And a projecting portion (7) provided to project downward from the lower end of the tube main body (6). Part (5),
A connection structure for a drilling member.   The abutting part (7) is composed of a first extending part (8a) and a second extending part (8b) intersecting each other, and is slanted to an inner angle formed by intersecting both extending parts (8a, 8b). The excavation member connection structure according to claim 1, wherein an abutting surface (9) having an upward surface normal is formed, and the protrusion (4) abuts on the abutting surface (9). .

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