JP2001271346A - Underground anchor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an underground anchor in which no excessive force is applied to the root portion of the stay rod. SOLUTION: At the underground anchor supporting a predetermined structure such as a stay for an electric pole, an architectural structure or the like through a stay rod provided at the head portion of an underground anchor main body portion embedded underground, the stay rod is connected to the head portion of the anchor main body by using a flexible joint.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an underground anchor for supporting a predetermined structure such as a branch line of a utility pole or a building structure in the ground.

[0002]

2. Description of the Related Art The present applicant has previously filed Japanese Patent Application No. 10-166.
No. 757 and the like propose a rod-shaped underground anchor having a spiral excavation blade on the tip side.

[0003] The underground anchor according to the above proposal has a sharply formed side and outer periphery of a spiral excavating blade provided on the tip end side of the underground anchor main body and which enters the ground. Since the drill portion formed of the cutting blade is formed at the tip of the main body, it has features such that the ground can be easily excavated and buried.

The underground anchor according to the above proposal is buried in a vertical direction with respect to the ground by a rotating machine such as an auger of an excavator, and a branch line connected to the head of the buried underground anchor body. The structure is configured to be supported via the rod.

[0005]

However, in the above-mentioned conventional underground anchor, the underground anchor main body is disposed perpendicular to the ground, whereas the underground anchor main body is connected to the head of the underground anchor main body. The supporting rod is at a predetermined angle with respect to the ground, for example, 6 degrees.
Since the structure is supported at 0 °, when the support rod is tightened, excessive excessive force may be applied to the root of the support rod connected to the head of the underground anchor body, and the support rod may be damaged. was there.

More specifically, when the underground anchor is buried, the head of the underground anchor body is also buried to some extent in the ground. In this state, when the branch rod is tightened by a turnbuckle or the like, the branch rod is Rotates around the connection part of the head of the underground anchor body, but if this rotation is not performed smoothly, an excessive load is applied to the root of the branch rod and the branch rod is damaged. There was a fear.

Accordingly, the present invention has been made to solve the above-mentioned drawbacks, and an object of the present invention is to provide an underground anchor in which an excessive force is not generated at a root portion of a branch rod. is there.

[0008]

According to the present invention, there is provided an underground anchor in which a predetermined structure such as a branch of a utility pole or a building structure is buried underground to achieve the above object. In the underground anchor supported via a branch rod provided on the head of the underwater anchor, the branch rod is connected to the head of the underground anchor body using a universal joint.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1A is a front view of an underground anchor according to an embodiment, and FIG. 1B is a right side view of an upper portion thereof.

The underground anchor main body 1 has a rod-like shape in its entirety, and a plurality of the underground anchors 1 are intermittently provided at the tip (the lower end in FIG. 1A) buried in the ground. In the example of 4
) Spiral digging blades 2a to 2d are integrally provided. The spiral digging blades 2a to 2d move upward, that is, 2b more than the spiral digging blade 2a, and 2
It is configured such that 2c has a larger diameter than b.
The side and outer periphery of the spiral excavating blades 2a to 2d that enter the ground are sharply formed. Further, a tip portion of the underground anchor main body 1 is formed in a drill portion having a cutting blade 3 similarly to a known drill.

The underground anchor main body 1 is buried in the ground on the side opposite to the tip of the underground anchor main body 1, that is, on the upper end side opposite to the side on which the spiral digging blades 2a to 2d are provided. A brim portion 4 having a diameter slightly larger than the diameter of the underground anchor main body 1 is provided on the ground side at the time, and an upper end portion of the brim portion 4 is formed in a square pillar portion 5 formed of a square pillar. The underground anchor main body 1 is configured to be fitted to a rotating machine described later so that the underground anchor main body 1 can be rotated by the rotating machine. In FIG. 1A, reference numeral 5a denotes a hole provided in the prism 5 and is a hole to which a later-described branch rod a is attached.

As shown in FIG. 1A, the underground anchor main body 1 is formed in a spindle shape in which a central portion in the longitudinal direction is expanded. As described above, when the underground anchor main body 1 is formed in a spindle shape, the strength of the underground anchor main body 1 can be increased. The applicant has separately proposed this spindle-shaped underground anchor.

In FIG. 1A, reference numeral 6 denotes an auxiliary spiral excavating blade, which is formed integrally with the underground anchor main body 1 like the spiral excavating blades 2a to 2d, and has a brim. The diameter is formed almost at the middle between the portion 4 and the spiral digging blade 2d and slightly larger than the diameter of the flange portion 4 and the helical digging blade 2d. The auxiliary spiral digging blade 6 has a sharply formed side and outer periphery that enter the ground, similarly to the spiral digging blades 2a to 2d described above.

The underground anchor having the above structure is used when the underground anchor body 1 is buried in the ground by being rotated by a rotating machine.
Since the lower part of the collar part 4 is excavated by the auxiliary spiral excavation blade 6, the resistance of the collar part 4 is reduced, and the underground anchor main body 1 can be easily buried deep underground.

In addition, between the brim portion 4 and the auxiliary spiral excavating blade 6, the spiral excavating blades 2a to 2d provided on the tip side of the underground anchor main body 1 are formed. Since a similar compacted mass is formed, the bearing capacity of the underground anchor can be increased.

The helical excavation blades 2a to 2d and the periphery of the auxiliary helical excavation blade 6 are quenched by induction hardening. The cutting blade 3 of the drill portion at the tip of the underground anchor main body 1 is also hardened by induction hardening.

When the quenching process is performed as described above, the hardness of the helical digging blades 2a to 2d, the auxiliary helical digging blade 6, and the cutting blade 3 of the drill portion is increased. Underground anchor body 1
But, for example, in the case of cast iron FC400, pre quenching treatment is its H _B (Brinell hardness) is 220 to 230, H _B after quenching processing is 350-400. The quenching process is not limited to induction quenching, but induction quenching has the advantage that partial quenching can be easily performed and the quenching process can be performed at low cost. The quenched portions were the spiral digging blades 2a to 2d, the peripheral portion of the auxiliary helical digging blade 6, and the portion of the cutting blade 3 of the drill, but the helical digging blades 2a to 2d and the auxiliary helical digging The entire blade 6 and the drill portion or the entire underground anchor body 1 may be quenched. However, as described above, if a part is subjected to a quenching process, it can be implemented at low cost. In any case, when such quenching is performed, the underground anchor main body can be rotated with a relatively small torque, and the rotating machine can be downsized.

In the drawing, reference numeral 10 denotes a universal joint as a characteristic component of the present invention.
And includes a ring member 11 and a connecting portion 12.

The ring member 11 is rotatably provided by being inserted into the hole 5a of the prism 5 and has a connecting portion 12 fixed to the opposite side of the hole 5a by welding. When the ring member 11 is positioned in the axial direction of the underground anchor main body 1 (see FIGS. 1A and 1B), the connecting portion 12 is provided with a screw hole 12a that is in the same direction as the axial direction. ing.
The screw rod a 'provided at the lower end of the support rod a is screwed into the screw hole 12a. Therefore, the feeder rod a screwed into the connection portion 12
As shown by the arrow in FIG. 1A, can be rotated around the hole 5 a of the prism 5, that is, by the universal joint 10.

FIG. 2 is an exploded perspective view showing a construction state when the underground anchor main body 1 having the above configuration is buried by the auger b of the rotary machine provided on the digging and construction column car.

In FIG. 2, c is a construction tool used in the burying work, which is composed of one rod-like body 20 and has one end (the lower end in the example of FIG. 2) of the underground anchor 1 attached thereto. Prism 5
A rectangular hole 21 is provided in which a rectangular hole 21 is provided so as to be removably fitted, and a prism inserted into a prism-shaped insertion opening b 'provided in the auger b at the other end (upper end in FIG. 2). Is formed on the mounting portion 22. And the rod 20
Is provided with a space 23 having a sufficient volume for accommodating the branch rod a opened in the square hole 21.

In order to bury the underground anchor main body 1 in the ground using the construction tool c having the above structure, first,
Is inserted into the insertion opening b 'of the auger b. Then, a bolt B is inserted into a through hole b ″ provided at the tip of the auger b and a through hole 22a provided in the mounting portion 22 and fixed with a nut N to prevent the auger b from dropping.

Next, a branch rod a is inserted into the space 23 of the rod 20.
Is inserted, and the prism 5 of the underground anchor main body 1 is fitted into the square hole 21. At this time, the underground anchor body 1
The pin P is inserted into a through hole 20a provided in the lower part of the rod-shaped body 20 so as not to fall off. That is, the rod P and the underground anchor main body 1 are maintained in a connected state by allowing the pin P to penetrate the ring member 11 of the branch rod b.

The pin P inserted into the rod 20 is removed when the tip (drill portion) of the underground anchor body 1 contacts the ground by the auger b and the underground anchor body 1 is kept pressed. Can be

When the underground anchor main body 1 is rotated while keeping the pressed state after the pin P is removed from the rod-shaped body 20, the underground anchor main body 1 is rotated by the spiral excavating blades 2a to 2d and the auxiliary spiral excavating blades. 6 is buried vertically in the ground by the action of 6. When the auger b is moved upward after the underground anchor main body 1 is buried at a predetermined depth, the rod-shaped body 20 is moved.
Is detached from the underground anchor main body 1 and the underground anchor main body 1 and the branch rod a are maintained in a state buried underground. afterwards,
A wire (not shown) is attached to the support rod a to support a structure such as a utility pole.

That is, when the wire attached to the tip of the line-of-sight bar a is tightened by a turnbuckle or the like, a force at a predetermined angle (for example, 60 °) acts on the branch bar a with respect to the ground. The universal joint 10 can prevent an excessive force from being applied to the root portion of the branch rod a according to the angle. Therefore, breakage of the branch rod a can be effectively prevented.

FIGS. 3 (a) and 3 (b) show another embodiment of the present invention.
(B) is a right side view of the upper part of FIG.

The universal joint 10 'shown here is characterized by having a double ring configuration. That is, in the universal joint 10 ′ shown here, the auxiliary ring member 13 is provided in the hole 5 a of the prism 5, and the ring member 11 having the above-described connecting portion 12 is provided in the auxiliary ring member 13.

As described above, when the ring members (11, 13) are doubled, there is a feature that the rotation of the branch rod a can be more easily performed.

FIG. 4 shows still another embodiment of the present invention, and is a front view showing a part of an upper portion of the underground anchor main body 1 in a cross section.

The universal joint 10 "shown here has a structure in which a ball a" is provided at the lower end of a branch rod a, and this is rotatably supported by a prism 5. That is, a concave portion 5a 'for inserting a ball a "is provided at the upper end of a tip portion 5a integrated with the underground anchor body 1 of the prism portion 5, and the ball a" inserted into the concave portion 5a' is provided. It is composed of a cap member 5b that is screwed to the tip 5a for holding. Therefore, the branch rod a can rotate with the ball a ″ as a fulcrum.

[0032]

The underground anchor according to the present invention is constructed such that a predetermined structure such as a branch line of a utility pole or a building structure is connected to a ground rod provided on a head of an underground anchor body buried underground. In the underground anchor to be supported, the branch rod is connected to the head of the body of the underground anchor using a universal joint, so that no excessive force is applied to the root of the branch rod. It can be prevented beforehand.

[Brief description of the drawings]

FIG. 1A is a front view of an underground anchor according to an embodiment of the present invention, and FIG. 1B is a right side view of an upper portion thereof.

FIG. 2 is an exploded perspective view when the underground anchor according to one embodiment of the present invention is buried.

FIG. 3A is a front view of an upper portion of an underground anchor according to another embodiment of the present invention, and FIG. 3B is a right side view thereof.

FIG. 4 is a front view showing a cross section of a part of an upper portion of an underground anchor according to still another embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Underground anchor main body 2a-2d Helical drilling blade 3 Cutting blade (drill part) 4 Collar part 5 Square column part 6 Auxiliary spiral drilling blade 10, 10 ', 10 "Universal joint 11 Ring member 12 Connection part 13 Auxiliary ring Member a Branch wire rod a 'Screw rod a "sphere c Construction tool 20 Rod body 21 Square hole 22 Mounting part b Auger (rotary machine)

Claims (1)

[Claims] An underground anchor for supporting a predetermined structure such as a branch line of a telephone pole or a building structure via a branch rod provided at a head of an underground anchor body buried underground. An underground anchor, wherein the rod is connected to a head of the underground anchor body using a universal joint.