WO2019240566A1 - Phc pile connector - Google Patents

Abstract

The present invention relates to a PHC pile connector which can be constructed by a simple process in which a shear fixing pin is inserted into a fixing hole formed in a space obtained after bearing connection plates on joint surfaces of neighboring PHC piles are arranged such that a wing plate and a space portion are misaligned from each other, the bearing connection plates having the same shapes and sizes. Therefore, the PHC pile connector is configured to have a small thickness, and thus is economical and convenient to manufacture and has excellent constructability and safety.

Description

PHC file connector

The present invention constructs a PHC file connector by a simple process of inserting a shear fixing pin into a fixing hole formed between a wing plate and a space part of the acupressure connecting plate of the same shape and standard on the joint surface of a neighboring PHC pile. It is possible to construct a thin PHC pile connector, economical and convenient to manufacture, construction and safety excellent PHC pile connector.

In the recent concrete pile method, PHC pile (pretensioned spun high strength concrete pile), which is a high-strength concrete pile manufactured by centrifugal force by a pretension method, is widely used.

Since these PHC files are limited in length for manufacturing and transportation, multiple files may be connected and used in the field.

Conventional PHC piles use many welded joints to join in the field. However, field welding is heavily influenced by operator skill and on-site weather conditions. Therefore, it is difficult to expect a homogeneous welding quality, it takes a lot of welding time, there is a great risk of safety accidents due to high voltage electricity and welding sparks. In addition, there is a problem that the cost increases because the weldable steel sheet for welding must be separately installed at the pile end.

In recent years, as shown in FIG. 1, the proportion of mechanical joints for fastening the separate connector 6 to the upper and lower piles 1a and 1b with bolts has increased (Registration Utility Model No. 20-0345924, etc.).

However, the bolt fastening method requires a predetermined space for fastening the bolt by inserting a tool, thereby increasing the size of the connector 6, which is uneconomical due to the considerable amount of steel requirements. In addition, since the bolt must be fastened in a narrow space between the vertical reinforcing plate 61 of the connector 6, it is difficult to secure a uniform fastening force because it can only rely on tightening the bolt manually. In addition, since the bolt head is exposed in the connector 6, there is a disadvantage that the bolt can be released by vibration, such as driving.

In addition, recently, the strength of the PHC pile body has been greatly increased by using high-strength concrete. However, the vertical reinforcement plate 61 of the existing connector 6 has a limit to increase in thickness, so that the vertical reinforcement plate 61 of the connector 6 causes buckling before reaching the maximum supporting force that the PHC pile body can support. Inevitably, economical design is inevitable.

In addition, the conventional connector 6 is a compressive stress is mainly transmitted by the vertical reinforcing plate (61). Therefore, since stress concentration occurs around the vertical reinforcing plate 61 and the pressure stress is unevenly distributed at the end of the pile connection, it is not structurally preferable, and bending deformation may occur in the upper and lower connecting plates 62 and 63. Furthermore, in order to distribute the acupressure stress evenly, the upper and lower connecting plates 62 and 63 should be formed thickly, in which case the amount of steel in the connector 6 increases, which is uneconomical.

In order to solve the problems described above, the present invention is to provide a PHC file connector excellent in economics and file joint construction and stability while reducing the amount of steel required by minimizing the size of the connector when connecting the neighboring PHC file up and down.

The present invention is to provide a PHC pile connector that can be secured to the bolt connection of the connector in the pile joint and convenient and uniform fastening force.

The present invention is to provide a PHC pile connector that can be firmly coupled to the bolt head is not exposed to the outside does not lower the tightening force of the bolt due to vibration, such as driving.

The present invention according to a preferred embodiment relates to a PHC file connector consisting of a pair of acupressure connecting plate is fixed to each other and fixed to the end of one side PHC file and the other side PHC file to interconnect the PHC file, The plate has a plurality of wing plates and space portions having the same shape as the wing plate are alternately arranged in a circular band shape along the end face of the PHC pile so that the wing plate of the other acupressure connecting plate fits into the space portion of the one acupressure connecting plate. It is configured to be coupled, the both sides of the wing plate is formed with a coupling groove portion in the longitudinal direction of the side end, the shear fixing pin is fitted into the fixing hole formed by the coupling groove portion of the adjacent two wing plate is a pair of acupressure connecting plate is mutually coupled It provides a PHC file connector characterized in that.

According to another embodiment of the present invention, a through hole for fastening and fastening a bolt to a joint surface of a PHC pile is formed in a wing plate of the acupressure connecting plate, and a bolt head is formed at a joint surface of the other PHC pile at an inlet side of the through hole. It provides a PHC pile connector characterized in that the expansion hole is inserted is formed to be in close contact with the supported depth.

The present invention according to another preferred embodiment provides a PHC pile connector characterized in that the wing plate of the acupressure connecting plate is interconnected by a connection ring formed on the inside or outside of the wing plate.

According to another preferred embodiment of the present invention, the connecting ring is formed to have a thickness of 1/2 of the wing plate, and provides a PHC pile connector characterized in that it is configured to overlap the connecting ring of the acupressure connecting plate to be coupled.

According to the present invention as described above has the following effects.

First, there is no need for a separate vertical reinforcement to separate the upper and lower acupressure connecting plate constituting the PHC pile connector. Therefore, the thickness of the PHC pile connector can be made very thin, thereby minimizing the amount of steel required.

Second, PHC pile connector is a simple process of inserting shear fixing pins into the fixing holes formed between the wing plate and the space part after arranging the upper and lower shiatsu connecting plates bolted to the joint surfaces of one side PHC pile and the other side PHC pile. Can be constructed. Therefore, it is easy to connect neighboring PHC files without welding process, so the safety is excellent. In addition, since the acupressure connecting plate is bolted in advance before the PHC file connection, PHC file connection work can be easily performed without interference with the bolt, so the construction is excellent.

Third, since there is no member buckling at the PHC pile connector and direct stress transfer is made by the upper and lower bearing plate having the same shape and area as the concrete, the stress distribution is very uniform and there is no stress concentration. The use of high-strength concrete in the body does not cause any problem in stress transmission.

Fourth, because the shear fixing pin is supported by the front end of the longitudinal section (rectangular) rather than the front end of the bolt cross-section (circular), the bearing strength is very high at the boundary where the wing plate of the upper and lower shiatsu connection plate is coupled.

Fifth, since the PHC file connector connected to the one side PHC file and the other side PHC file can be manufactured in the same shape, the production and management efficiency is excellent, and the work management during the field assembly is easy.

Sixth, when the expansion hole is formed at the inlet end of the through hole formed to bolt the wing plate of the upper and lower pressure connecting plate, the bolt head is inserted into the expansion hole is not exposed to the outside. Accordingly, the fastening force of the bolt can be firmly coupled without external force due to external force such as driving.

Seventh, even if there is a predetermined distance between the wing plate of the one pile and the wing plate of the other pile to facilitate the assembly of the two piles, the connecting ring may serve as a guide to the center of the two piles.

1 shows a PHC file joined by a conventional connector.

Figure 2 is a perspective view showing a coupling relationship of the PHC file using the present invention PHC file connector.

Figure 3 is a perspective view showing the coupling state of the PHC file coupled by the present invention PHC file connector.

4 is a perspective view showing the acupressure connecting plate.

Fig. 5 is a sectional perspective view showing a coupling relationship between the upper and lower pressure bearing plates.

Figure 6 is a cross-sectional perspective view showing a state in which the upper and lower acupressure connecting plate is coupled.

Figure 7 is a perspective view showing a coupling relationship of the upper and lower shiatsu connecting plate by a shear fixing pin.

8 is a view showing a load and stress transfer concept of the acupressure connector and the shear fixing pin.

9 is a view showing a shear force supporting cross section of a shear fixing pin.

Figure 10 is a side cross-sectional view showing a bonding state of the PHC file using the present invention PHC file connector.

Figure 11 is a plan view showing the upper and lower shiatsu connecting plate coupled by an outer connection ring.

In order to achieve the above object, the PHC file connector of the present invention is a PHC file connector consisting of a pair of acupressure connector plate is fixed to each end of the PHC file and the other side of the PHC file to be connected to each other to interconnect the PHC file Regarding, the acupressure connecting plate is a plurality of wing plates and the space portion having the same shape as the wing plate is alternately arranged in a circular band shape along the end face of the PHC pile is the other side of the space portion of the acupressure connecting plate The wing plate of the acupressure connecting plate is configured to be fitted, the pair of coupling grooves are formed at both side ends of the wing plate in the longitudinal direction of the side end, and a pair of shear fixing pins are fitted into the fixing holes formed by the coupling grooves of the adjacent two wing plates. Acupressure connecting plate is characterized in that the mutual coupling.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings and preferred embodiments.

Figure 2 is a perspective view showing a coupling relationship of the PHC file using the present invention PHC file connector, Figure 3 is a perspective view showing a coupling state of the PHC file joined by the present invention PHC file connector. 4 is a perspective view illustrating the acupressure connecting plate, FIG. 5 is a cross-sectional perspective view illustrating a coupling relationship between the upper and lower acupressure connecting plates, and FIG. 6 is a cross-sectional perspective view showing a state in which the upper and lower acupressure connecting plates are coupled to each other. In addition, Figure 7 is a perspective view showing a coupling relationship between the upper and lower acupressure connecting plate by the shear fixing pin, Figure 8 is a view showing the load and stress transmission concept of the acupressure connecting plate and the shear fixing pin, Figure 9 is a shear fixing pin It is a figure which shows the shear force supporting cross section of. 10 is a side cross-sectional view showing a coupling state of a PHC file using the PHC file connector of the present invention.

As shown in Figures 2 to 7, etc., the PHC file connector of the present invention is fixed to the ends of one side PHC file (1a) and the other side PHC file (1b) to interconnect the PHC file (1a, 1b), respectively Consists of a pair of acupressure connecting plate (2, 3), the acupressure connecting plate (2, 3) has the same shape as the plurality of wing plates (21, 31) and the wing plate (21, 31) The spaces 22 and 32 are alternately arranged in a circular band shape along the end faces of the PHC piles 1a and 1b, and the other side pressure is applied to the spaces 22 and 32 of the one pressure connection plate 2 and 3. The wing plates 21 and 31 of the connecting plates 2 and 3 are fitted to each other, and coupling grooves 211 and 311 are formed at both side ends of the wing plates 21 and 31 in the longitudinal direction of the side ends, and are adjacent to each other. The shear fixing pins 4 are inserted into the fixing holes H formed by the coupling grooves 211 and 311 of both wing plates 21 and 31 to couple the pair of acupressure connecting plates 2 and 3 to each other. As a feature do.

The present invention is to provide a PHC file connector that is excellent in economy and excellent pile joint construction and stability by minimizing the size of the PHC file connector when connecting the neighboring PHC file (1a, 1b) up and down.

Hereinafter, for convenience, the lower PHC file will be described as one PHC file 1a and the upper PHC file as another PHC file 1b.

Acupressure connecting plates 2 and 3 are respectively fixed to end portions of the one side PHC pile 1a and the other side PHC pile 1b that are coupled to each other, and the one side PHC is connected by a pair of acupressure connecting plates 2 and 3. The pile 1a and the other PHC pile 1b are combined.

The acupressure connecting plates 2 and 3 have a plurality of wing plates 21 and 31 and spaces 22 and 32 having the same shape as the wing plates 21 and 31 are formed of the PHC piles 1a and 1b. Wing plates 21 and 31 of the other acupressure connecting plates 2 and 3 are fitted into the spaces 22 and 32 of the one acupressure connecting plates 2 and 3 so as to be alternately arranged in a circular band shape along the end face. Configured to be combined.

That is, the wing plates 21 and 31 and the space portions 22 and 32 of the acupressure connecting plates 2 and 3 are formed in a shape corresponding to each other, so that the wing plate 21 of the acupressure connecting plate 2 is It is inserted into the space portion 32 of the other acupressure connection plate 3, and the wing plate 31 of the other acupressure connection plate 3 is inserted into the space portion 22 of the one acupressure connection plate (2).

Accordingly, the acupressure connecting plates 2 and 3 respectively coupled to the one side PHC file 1a and the other side PHC file 1b may be manufactured in the same shape.

In the state where the pair of acupressure connecting plates 2 and 3 are coupled to each other, the shape and area of the PHC pile connector are the same as the shape and area of the tips of the PHC piles 1a and 1b.

The widths of the spaces 22 and 32 may be slightly larger than the widths of the wing plates 21 and 31 so that the wing plates 21 and 31 can be inserted into the spaces 22 and 32.

The wing plates 21 and 31 of the upper and lower acupressure connecting plates 2 and 3 may be configured to be in close contact with each other without generating gaps at neighboring boundaries.

The upper and lower parts of the connecting plate (2, 3) can be produced by cutting the plate which is a steel plate or by casting.

Coupling grooves 211 and 311 are formed at both side ends of the wing plates 21 and 31 in the longitudinal direction, and fixing holes formed by the coupling grooves 211 and 311 of the adjacent wing plates 21 and 31 are adjacent to each other. Shear fixing pin 4 is fitted to (H) is a pair of acupressure connecting plate (2, 3) are mutually coupled.

That is, coupling grooves 211 and 311 are formed at both side ends of the wing plates 21 and 31 so that the wing plates 21 and 31 of one of the acupressure connecting plates 2 and 3 and the other acupressure connecting plate adjacent thereto. A pair of acupressure connecting plates (2, 3) are inserted by inserting the shear fixing pin (4) into the fixing hole (H) formed by the coupling grooves (211, 311) between the wing plates (21, 31) of the 2,3. Fix to each other (FIG. 7).

Unlike conventional connectors that transfer loads by in-plane axial forces of conventional vertical reinforcement plates, the present invention transfers loads by direct bearing stress of the acupressure connecting plates 2 and 3, which are face members.

Accordingly, there is no concern about buckling, and the joint strength is large, and even if ultra-high strength concrete is applied to the main bodies of the PHC piles 1a and 1b, the strength of the PHC piles 1a and 1b can be sufficiently utilized.

As shown in FIG. 8, when one wing plate 21, 31 of the upper and lower pressure connecting plates 2 and 3 is considered, a tensile force acts on the upper and lower PHC piles 1a and 1b, thereby causing a tensile stress in the PHC pile connector. In this case, the shear fixing pin 4 has one side (the wing plate 21 side connected to the lower PHC pile 1a) on the other side (the wing plate 31 side connected to the upper PHC pile 1b). ) Acupressure at the bottom. Accordingly, the wing plates 21 and 31 on the left and right sides of the shear fixing pins 4 generate a force that spreads outward from each other. However, since the wing plates 21 and 31 form a circular closed loop in which a plurality of the wing plates 21 and 31 are in close contact with each other, the wing plates 21 and 31 are restrained from each other so that the wing plates 21 and 31 on the left and right sides of the shear fixing pins 4 are separated. It is firmly supported without opening.

The shear fixing pin 4 may be manufactured in various cross-sectional shapes, but it is preferable that the shear fixing pin 4 has a circular cross section in consideration of manufacturability and performance. At this time, it is preferable that the shear fixing pin 4 uses the same diameter as the fixing hole (H) so that it can be inserted into the fixing hole (H) by hitting with no extra play.

As shown in Figure 9, the front end of the shear fixing pin (4) it is preferable to form a chamfer (chamfer) to facilitate insertion into the fixing hole (H) inlet.

The shear fixing pin 4 may use a bolt, it is preferable to use a pin without a thread on the outer peripheral surface of the bolt body so that it can be quickly installed by the hit.

The upper and lower acupressure connecting plates 2 and 3 may be fixed to the joint surface of one side PHC pile 1a and the joint surface of the other side PHC pile 1b before being connected to each other in a manufacturing factory or a site of PHC piles 1a and 1b. Do.

As shown in FIG. 10, the upper and lower acupressure connecting plates 2 and 3 fasten the bolt B to the PC nut 11 embedded at the ends of the PHC piles 1a and 1b for fixing the steel wire 12. It can be fixed to the joint surface of one side PHC file (1a) and the other side PHC file (1b), respectively. In this case, the wing plates 21 and 31 of the upper and lower acupressure connecting plates 2 and 3 respectively have bolt fastening holes formed on the joint surfaces of one side PHC pile 1a and the other side PHC pile 1b, that is, the number of PC nuts 11. It can be provided as much.

Alternatively, the upper and lower acupressure connecting plates 2 and 3 may be fixed to directly contact the ends of the concrete body without a separate upper and lower caps (not shown).

As illustrated in FIG. 10, chamfers may be formed at upper and lower edges of the wing plates 21 and 31 to smoothly couple these members.

According to the present invention, there is no need for a separate vertical reinforcement for separating the upper and lower pressure connecting plates 2 and 3 constituting the PHC pile connector. Therefore, the thickness of the PHC pile connector can be made very thin, thereby minimizing the amount of steel required.

In addition, the upper and lower acupressure connecting plates (2, 3) bolted to the joint surfaces of the one side PHC pile (1a) and the other side PHC pile (1b) respectively arranged so that the wing plates (21, 31) to cross each other formed between PHC pile connector can be constructed by a simple process of inserting the shear fixing pin (4) into the fixing hole (H). Therefore, it is possible to simply connect the upper and lower neighboring PHC piles 1a and 1b without the welding process. In addition, since the bolt is fastened before the connection of the PHC files 1a and 1b, the connection work of the PHC files 1a and 1b can be easily performed without interference with the bolts.

In addition, there is no buckling member at the PHC pile end. In addition, since the stress is directly transferred by the upper and lower pressure connecting plates (2, 3) having the same shape and area as the concrete, the stress distribution is very uniform, so there is no stress concentration. Even if there is no problem in stress transmission.

Furthermore, as shown in FIG. 9, the edges of the wing plates 21 and 31 of the upper and lower acupressure connecting plates 2 and 3 are supported by the front end of the longitudinal section (rectangular) rather than the cross section (circular) front end of the shear fixing pin 4. The bearing strength is very high at.

In addition, since the PHC pile connector connected to the upper and lower PHC piles 1a and 1b can be manufactured in the same shape, the manufacturing and management efficiency is excellent, and the work management during the field assembly is easy.

As shown in FIG. 10, through-holes 212 for fastening and fixing bolts B to joint surfaces of PHC piles 1a and 1b are formed on wing plates 21 and 31 of the acupressure connecting plates 2 and 3. , 312 is formed to penetrate through the inlet side of the through hole (212, 312) so that the expansion head (213, 313) is inserted into the depth to be supported in close contact with the joint surface of the other PHC pile (1b) Can be configured.

The through holes 212 and 312 are for bolting the wing plates 21 and 31 of the upper and lower pressure connecting plates 2 and 3 to the one side PHC pile 1a and the other side PHC pile 1b, respectively.

When the expansion holes 213 and 313 are formed at the inlet end portions of the through holes 212 and 312, the heads of the bolts B are accommodated in the expansion holes 213 and 313. Therefore, the bolt (B) does not protrude to the outside of the wing plate (21, 31) can minimize the overall thickness of the PHC pile connector. That is, the sum of the thicknesses of the upper and lower acupressure connecting plates 2 and 3 becomes equal to the thickness of the entire PHC pile connector.

The expansion holes 213 and 313 formed in the wing plates 21 and 31 are formed to have depths at which the bolt heads to be inserted are in close contact with the joint surface of the other side PHC pile 1b and the joint surface of one side PHC pile 1a, respectively. Can be.

As a result, the bolt head is in close contact with the tip ends of the PHC piles 1a and 1b and the movement of the bolt B is constrained, thereby preventing the bolt B from being loosened due to external vibration or impact such as driving.

If there is a washer, the depth of the expansion holes (213, 313) is preferably made of the sum of the thickness of the washer and the thickness of the bolt head.

Figure 11 is a plan view showing the upper and lower shiatsu connecting plate coupled by an outer connection ring.

As shown in FIG. 11, the wing plates 21 and 31 of the acupressure connecting plates 2 and 3 may be interconnected by connecting rings 23 and 33 formed inside or outside the wing plates 21 and 31. Can be.

Each vane plate 21, 31 of the acupressure connecting plate (2, 3) may be coupled to the end surface of the PHC pile (1a, 1b) by a bolt (B). However, when the plurality of wing plates 21 and 31 are separated from each other, it is difficult to combine the wing plates 21 and 31 at an accurate angle. When the bolt B is fastened, the wing plates 21 and 31 are rotated by the bolt rotation force so that the shape of the space portions 22 and 32 between the wing plates 21 and 31 is different from that of the wing plates 21 and 31. The wing plates 21 and 31 of the other acupressure connecting plates 2 and 3 may be difficult to be inserted into the spaces 22 and 32.

Therefore, by assembling and connecting the plurality of wing plates 21 and 31 with the connection rings 23 and 33, assembling work and material management can be facilitated.

In addition, even if there is a predetermined distance between the wing plate 21 of the one side PHC pile (1a) and the wing plate 31 of the other side PHC pile (1b) to facilitate the assembly of the two pile connection ring (23, 33) It can serve as a guide to match the center of these two PHC files (1a, 1b).

When the connection rings 23 and 33 are coupled to the inside of the wing plates 21 and 31, the inner circumferential surfaces of the connection rings 23 and 33 may be formed to coincide with the inner circumferential surfaces of the hollow PHC piles 1a and 1b. Can be.

11 shows an embodiment in which the connection rings 23 and 33 are coupled to the outside of the wing plates 21 and 31.

In general, since the PC nut 11 is formed to be eccentrically outward from the center of the thickness of the concrete flesh, the connection rings 23 and 33 are preferably provided inside the wing plates 21 and 31 having a relatively spatial margin. However, when the pile diameter is sufficiently large, as shown in FIG. 11, the coupling rings 23 and 33 may be formed outside the wing plates 21 and 31 as necessary. At this time, the fixing hole (H) is formed through the connecting rings (23, 33).

In addition, although not shown in the drawings, when the connection rings 23 and 33 are formed to protrude to the outside of the outer circumferential surface of the PHC piles 1a and 1b, the pile supporting force may be improved at the pile joint.

The connecting rings 23 and 33 may be formed to have a thickness of 1/2 of the wing plates 21 and 31 so as to overlap the connecting rings 23 and 33 of the acupressure connecting plates 2 and 3 to be joined. have.

Accordingly, by forming the connecting rings 23 and 33 in a stepped shape, the connecting rings 23 and 33 of the upper and lower pressure connecting plates 2 and 3 may be configured to engage each other.

Then, the connection rings 23 and 33 of the one side acupressure connection plates 2 and 3 and the connection rings 23 and 33 of the other acupressure connection plates 2 and 3 are closely attached to each other to form the same thickness as the PHC pile connector. .

Thus, the pile load can be transmitted not only in the blade plates 21 and 31 but also in the connection rings 23 and 33.

Even in this case, since the pair of acupressure connecting plates 2 and 3 constituting the PHC pile connector have the same shape, it is only necessary to produce one type of acupressure connecting plates 2 and 3.

In addition, since the acupressure connecting plates 2 and 3 having the same shape are respectively coupled to the upper and lower PHC piles 1a and 1b, it is easy to perform field work and management.

PHC pile connector of the present invention can be configured to a very thin thickness can minimize the amount of steel required, there is an industrial use in that the safety is excellent because it can simply connect the neighboring PHC file without a welding process.

Claims (4)

1. PHC file consisting of a pair of acupressure connecting plates (2, 3) fixed to one end of the PHC file (1a) and the other side of the PHC file (1b) to be connected to each other to interconnect the PHC file (1a, 1b) Regarding the connector,

   The acupressure connecting plate (2, 3) is a plurality of wing plates (21, 31) and the space portion (22, 32) having the same shape as the wing plates (21, 31) of the PHC pile (1a, 1b) Alternatingly arranged in a circular band shape along the end face so that the wing plates 21 and 31 of the other acupressure connecting plates 2 and 3 fit into the space portions 22 and 32 of the one acupressure connecting plates 2 and 3. Configured to be combined,

   Coupling grooves 211 and 311 are formed at both side ends of the wing plates 21 and 31 in the longitudinal direction, and fixing holes formed by the coupling grooves 211 and 311 of the adjacent wing plates 21 and 31 are adjacent to each other. (H) PHC pile connector characterized in that the shear fixing pin (4) is fitted to a pair of acupressure connecting plate (2, 3) are mutually coupled.
2. In claim 1,

   Wing plates 21 and 31 of the acupressure connecting plates 2 and 3 have through holes 212 and 312 formed therein for fastening and fixing bolts B to joint surfaces of PHC piles 1a and 1b. PHC file connector, characterized in that the inlet side of the through hole (212, 312) is formed with an expansion hole (213, 313) is inserted into the depth to be supported in close contact with the joint surface of the other side PHC pile (1b).
3. In claim 1,

   Wing plate (21, 31) of the shiatsu connecting plate (2, 3) is connected to each other by the connection ring (23, 33) formed on the inside or outside of the wing plate (21, 31) PHC pile connector .
4. In claim 3,

   The connecting rings 23 and 33 are formed to have a thickness of 1/2 of the wing plates 21 and 31 so as to overlap the connecting rings 23 and 33 of the acupressure connecting plates 2 and 3 to be joined. Featuring PHC file connector.

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