JPH108460A - Screw pile coupling - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pile coupling, by which the perpendicularity of piles to be joined can be kept, joining can be executed very easily, and further even if piles and its coupling part are reversed in a non-earth discharge rotary burying engineering method, loosening of the coupling part is not caused. SOLUTION: A coupling structure of pile main bodies 1, 2 is such that a male coupling 3 having a screw part 7 on the outer peripheral surface and a female coupling 4 having a screw part 9 on the inner peripheral surface are connected to each other by screw engagement. A ring-like reverse loosening stop member 12 having several downhill grades of 3 deg.-6 deg. in the fastening directions of a screw in several places on one surface 12a is fitted to the forward end part of the male coupling 3, the inner bottom part 10 of the female coupling 4 is provided with a projecting and recessed surface 10a engaged with the above one surface 12a, and the whole area of one surface 12a is one-third or more as large as the total area of contact surfaces of the screw parts 7, 9 of the male and female couplings 3, 4, and also have an area 130-160% of the area where the outer diameter base part 6 of the male coupling 3 and the forward end part of the female coupling 4 mutually press to come into contact with each other.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a threaded pile joint in which a locking mechanism is interposed between a male joint and a female joint to be screw-connected, particularly when a reverse rotation force is applied after the connection is completed. The present invention also relates to a threaded pile joint configured so that a joint part is not loosened.

[0002]

2. Description of the Related Art Conventionally, for example, Japanese Utility Model Application Laid-Open No. 60-19532.
No. 8, Japanese Patent Publication No. 50-25255, Japanese Utility Model Publication No. 40
No. 6043, Japanese Utility Model Application Laid-Open No. 61-84734, Japanese Utility Model Application Laid-Open No. 56-130034, Japanese Unexamined Patent Application Publication No. 8-60652.
As shown in JP-B-56-36248, etc.,
A threaded joint for connecting a male joint and a female joint using screws has been developed.

[0003] These known threaded joints generally relate to threaded joints used to connect prefabricated piles installed in pile holes drilled in the ground where the piles will be constructed in advance. In the method of installing piles in pile holes preliminarily excavated in this way and injecting concrete milk around them, fixing the pile joints used in this method to the bending strength and vertical load Only the compressive strength of the pile was required functionally, and no axial torque was applied to the pile itself and the pile joints connecting these piles.

[0004]

However, the threaded joint shown in the above-mentioned prior art can be used for connection when a ready-made pile is installed in a pile hole excavated in the ground. Without a pile hole in the ground, a spiral blade is protruded around the periphery of the pile, and the soil is cut with the spiral blade while applying torsional torque to the pile, and the pile is buried. When these are used, there are many problems as follows.

That is, in the non-discharged rotary burial method, depending on the properties of the ground where the pile is to be buried, it is necessary to combine the work of pulling out the pile while reversing it at the time of pile construction. Similarly, forward and reverse forces also act on the joints of the piles, and a large axial torque is applied to the joints. When such a large shaft torque is applied to the threaded joint, the conventional joints of the prior art described above do not provide adequate reverse rotation prevention measures. There was a problem that it was reversed and loosened.

[0006] Since the above-mentioned conventional threaded pile joint does not have an appropriate countermeasure for preventing reversal, when connecting piles used for rotary burial without earth removal, it is necessary to rely on welding joints that have been performed for a long time. In fact, there was no other means.

[0007] However, in the structure in which the ready-made piles are connected by welding, there is a problem that it is difficult to protect the vertical accuracy of the piles, while the whole structure is simple. Furthermore, when performing the welding work of the pile, there are many problems such as the skill being required and the work being impossible in rainy weather when there is a fear that an electric shock accident may occur.

Further, even if the locking prevention mechanism is incorporated in the threaded pile joint, the rotation angle is also a problem, and the joint surface is required until the reverse rotation locking mechanism incorporated in the joint operates. If the pile is rotated so that it opens, even if it can be loosened, when the pile rotates forward, mud will enter the gap and become bitten, which will cause problems at the joint, There was also a problem of losing trust in the company.

In general, when piles are constructed by the non-discharged rotary burial method, the piles are buried by being rotated forward at about 60% of the maximum torque that can be generated by the rotary burial apparatus. If an unexpected situation occurs, 100% reverse torque must be applied.
Therefore, the pile joint at the time of reverse rotation needs a locking mechanism that can sufficiently withstand the maximum torque generated by the rotary burying device.

[0010] The threaded pile joint according to the present invention is a completely new technique developed in view of the above-mentioned many problems of the prior art, and in particular, can maintain the verticality of the pile to be joined, and can achieve the joining. To provide a threaded pile joint technology that can be constructed extremely easily and prevents the joint portion from being loosened even when the pile and its joint portion are reversed in the non-discharged rotary burial method. Things.

[0011]

The thread type pile joint according to the present invention is a technique which fundamentally improves the above-mentioned conventional problems, and the gist of the first invention is that the threads are mutually connected. In a pile joint in which a ring-shaped reverse rotation preventing member is interposed between a male joint and a female joint, a plurality of surfaces having a downward slope of 3 ° to 6 ° are provided on one surface of the ring-shaped reverse rotation preventing member. The entire surface of one surface of the ring-shaped reverse rotation preventing member provided with the projections and having the plurality of projections is at least one third of the total area of the screw contact surfaces of the male joint and the female joint. A threaded pile joint characterized by having an area of 130 to 160% of the area of the surface which is pressed against and brought into contact with the male joint and the female joint.

The gist of the second invention of the present invention is that the ring-shaped reverse rotation stopping member interposed between the male joint and the female joint is constituted by one or two pairs. It is a thread type pile joint of the first invention.

The thread type pile joint according to the present invention is characterized in that a plurality of protrusions having a downward slope in the screw tightening direction are provided on one surface and a ring-shaped reverse rotation preventing member provided with a non-slip on one surface is screwed. It is configured to be interposed between a male joint and a female joint of the formula.

Further, there are a case where two ring-shaped reverse rotation preventing members are used as a pair and a case where a single member is used. In the former case, each ring-shaped reverse rotation prevention member is attached to a male joint and a female joint, respectively, and a pair of these ring-shaped reverse rotation prevention members are engaged with each other. In the latter case, one ring-shaped reverse rotation preventing member is attached to a male joint or a female joint, and the ring-shaped reverse rotation preventing member is not attached to a predetermined portion of the other joint.
This is a case in which an uneven surface that can be engaged with the uneven surface provided on one surface of the ring-shaped reverse rotation preventing member is provided.

Further, the place where the ring-shaped reverse rotation preventing member is mounted or the place where the concave-convex surface which can be engaged with the concave-convex surface on one surface of the ring-shaped reverse rotation-preventing member are provided for each of the male joint and the female joint. Are possible. That is, a male joint can have a distal end and an outer diameter base, and a female joint can have an inner bottom and a distal end.

In the pile joint according to the present invention, a ring-shaped reverse rotation preventing member having a downward slope in the screw tightening direction and having a lead angle larger than the lead angle of the screw is provided between the male joint and the female joint. The ring-shaped reverse rotation preventing member generates a repulsive force when a reverse torque is applied to the pile and the joint of the pile, so that the pile is loosened against the frictional force of the screw. Can be prevented from occurring.

Since the pile joint according to the present invention is a pile that supports a structure, it is not possible to guarantee all loads acting on the pile unless concentricity and verticality are maintained at the joint surface as described above. Generally, under the guidance of the Ministry of Construction, the guaranteed strength of that part is reduced by 5%, called weld joint efficiency. This is based on the fact that it is a welding work on site and that the joining conditions are difficult to control, and that the verticality of the two piles, which are pillars, can be checked only by blindness against the size of the joint surface. Have been.

In the pile joint according to the present invention, since the joining property is controlled and guaranteed in the factory production, it is not necessary to consider the reduction. If the joint is tightened with a specified torque, a very slight elastic deformation occurs on the joint surface, so that the joint can be made more reliable.

That is, when the pile rotates in the forward direction and the male joint and the female joint are joined to each other with a specified torque at the threaded portion, the ring-shaped reverse rotation loosely interposed between the male joint and the female joint. A plurality of protrusions on one surface of the stop member are meshed with each other,
Thus, the axial force generated by the torsional torque can be all supported on one surface.

However, when the pile is reversed as described above, the plurality of protrusions provided on the male joint and the female joint move relatively in different directions. It becomes difficult to support all the axial force generated by the torsional torque on one surface of the ring-shaped reverse rotation preventing member. Therefore, the contact area on one surface of the ring-shaped reverse rotation preventing member needs to be large.

As described above, in the threaded pile joint of the present invention, a ring-shaped reverse rotation preventing member provided on one surface with an uneven cam surface comprising a plurality of projecting portions having a downward slope is used. Since the male joint and the female joint are screw-joined by being interposed between the joint and the female joint, the cam surfaces of both begin to climb the protruding protrusions due to the relative motion, and the axial clearance of the screw part is lost, The male joint and the female joint can be stably fixed to each other while being balanced with the force generated in the axial direction by the engagement action of the cam of the ring-shaped reverse rotation preventing member.

[0022]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 (A) and (B) show an embodiment of the threaded joint according to the present invention in detail.
1 is a longitudinal sectional view showing the structure of a pile joint according to a first embodiment of the present invention, FIG. 2 is a perspective view showing a ring-shaped reverse rotation preventing member, and FIGS. FIG. 4 is an explanatory view showing the relationship between the surface of the male joint pressed against and in contact with the contact portion of the screw portion, and FIG. It is explanatory drawing which shows the relationship of two places touched.

FIG. 6 is an explanatory view for comparing the strength when the male and female joints are pressed and contacted with each other at one location and at two locations, and FIGS. 7A and 7B show the present invention. FIGS. 8A and 8B are longitudinal sectional views showing the pile joints of the third and fourth embodiments, respectively, and FIG. 9A is a longitudinal sectional view showing the pile joint of the second embodiment. 10 (A) and 10 (B) are longitudinal sectional views showing the pile joint of the sixth embodiment, and FIGS. 10 (A) and 10 (B) are longitudinal sectional views showing the pile joint of the sixth embodiment. FIG. 11 (B) is a diagram showing a force relationship on a slope surface of the reverse rotation preventing mechanism, and FIG. 12 is a diagram showing a torsion test of a pile joint provided with the reverse rotation preventing mechanism of the present invention. It is a graph showing a result.

In FIGS. 1A and 1B, reference numerals 1 and 2 denote steel pipe pile bodies, respectively, and a cylindrical male joint 3 is attached to an end of the pile body 1; A cylindrical female joint 4 is attached to an end of the pile main body 2. The outer peripheral wall of the male joint 3 is provided with a step 5 to which the end of the pile body 1 can be fitted and an outer diameter base 6 to which the tip of the female joint 4 can abut. A screw portion 7 is provided on the outer peripheral surface of the small diameter portion.

The outer peripheral wall of the female joint 4 is provided with a step 8 to which the pile main body 2 can be fitted. On the inner peripheral surface of the female joint 4, a screw portion 9 that can be screwed with the screw portion 7 of the female joint 3 is provided. When the male joint 3 and the female joint 4 having the above-described structure are connected to each other, the distal end of the female joint 4 comes into contact with the outer diameter base 6 of the male joint 3 and at the same time, the male joint 3 Of the female joint 4 is abutted against the inner bottom 10 of the female joint 4, and the male joint 3 and the female joint 4 are pressed against each other at these two places.

In the above embodiment, the outer diameter base 6 of the male joint 3 is formed so as to have a plane (standing plane) perpendicular to the longitudinal direction of the male joint 3. The upright plane of the outer diameter base 6 has a wall thickness equal to or larger than the wall thickness of the pipe section of the pile bodies 1 and 2. Further, a V-groove groove 11 used for welding is provided in a connection outer peripheral portion between the pile main bodies 1 and 2 and the male and female joints 3 and 4.

Next, in FIGS. 1 to 3, reference numeral 12 denotes a ring-shaped reverse rotation stopping member, which is formed of a ring body which can be fitted into the inner bottom portion 10 of the female joint 4 as shown in the figure. The one surface 12a is provided with a plurality of concave and convex surfaces having a plurality of radially downwardly protruding slopes in the screw tightening direction, and the one back surface 12b is provided with anti-slip projections. I have. Care is taken to ensure that the friction on one side 12b is greater than that on the one side 12a by the non-slip. The non-slip can be formed by press-fitting a spherical object made of a high-strength material into the back surface of the ring-shaped reverse rotation preventing member 12, or by raising a bead by welding. In FIG. 1 (B), a concave portion into which the convex portion of the one back surface 12b can fit is formed in the distal end portion of the male joint 3 and the inner bottom portion 10 of the female joint 4. It is formed by crimping and does not need to be provided in advance.

The ring-shaped reverse rotation preventing member 12 is a male joint 3
It is attached to the tip. And the inner bottom 1 of the female joint 4
0, one surface 12 of the ring-shaped reverse rotation preventing member 12
a male and female joints 4 are screwed to each other, and one surface of the ring-shaped reverse rotation preventing member 12 is formed when the male and female joints 3 and 4 are screwed to each other. 12
a and the uneven surface 10a of the inner bottom portion 10 are configured to be engaged with each other. Thus, even when a reverse force is applied to the male and female joints 3 and 4, the reverse rotation of the two can be prevented.

In FIG. 3A, one surface 12a of the ring-shaped reverse rotation preventing member 12 and the inner bottom 1 of the female joint 4 are shown.
0, the angle 1 of the downward slope of the plurality of projections provided respectively.
2α is formed at 3 ° to 6 °, respectively. The angle 12α of the downward slope of these projections is formed to be larger than the lead angle of the threaded portions 7 and 9 of the male and female joints 3 and 4.

The reason for this is that when a reverse force is applied to the pile bodies 1 and 2 and the male and female joints 3 and 4 connecting these pile bodies 1 and 2, the lead of the screw portions 7 and 9 is applied. Also, the lead amount of the contact surface between the one surface 12a of the ring-shaped reverse rotation preventing member 12 and the inner bottom portion 10 of the female joint 4 is increased, and when the force at the time of reverse rotation increases, the male-female joints 3 and 4 are removed. This is because the binding can be performed in a stable state in the axial direction.

As described above, the ring-shaped reverse rotation preventing member 12 and the inner bottom portion 10 of the female joint 4 are engaged with each other with their uneven surfaces, but the outer diameter base 6 of the male joint 3 and the distal end of the female joint 4. At the outer peripheral portions of the male and female joints 3 and 4 where the parts are in contact with each other, elastic deformation occurs, and the two are in close contact with each other and joined. In this state, the pile bodies 1 and 2 and the male and female joints 3
When 4 is reversed, the surface of 12c as shown in FIG. 3 (A) is separated from the conventional contact surface, and the surface of 12d is in contact.

In the present invention, the downward slope angle 12α of the projection provided on the ring-shaped reverse rotation preventing member 12 and the inner bottom portion 10 of the female joint 4 is set to 3 ° to 6 ° as described above. ,
Where various experiments were performed, the outer diameter was 100 mm to 270 mm,
In the pile bodies 1 and 6 with the screw pitches of the screw portions 7 and 9 (the lead and the pitch are the same amount for the single thread),
Those around 3.5-4 ° have been found to be the most effective. Experimentally, an angle of 5.71 ° is also effective, and the frictional force of the uneven cam surface and the ring-shaped reverse rotation stopper 12
Since the friction angle greatly changes depending on the installation condition, etc., it is preferable that the angle in the range of 3 ° to 6 ° is considered in view of these facts.

Next, from various viewpoints and experiments on the shape of the ring-shaped reverse rotation preventing member 12, it is necessary to specify the entire area of the one surface 12a of the ring-shaped reverse rotation preventing member 12. found. That is, the area where the ring-shaped reverse rotation preventing member 12 and the inner bottom portion 10 of the female joint 4 are in contact is greatly related to the design of the pile main bodies 1 and 2 themselves.

For example, when the effective diameters of the screw portions 7 and 8 are 243 mm and the screw leads are 6 mm in the steel pipe piles 1 and 2 having a fastening torque of 3 ton-m, the force generated in the axial direction is about 72 tons. Become. Thus, the number of threads of the screw portions 7, 9 is experimentally determined from the required strength of the piles 1, 2.

As a result, the entire area of one surface 12a of the ring-shaped reverse rotation preventing member 12 needs to be equal to or more than one third of the total area of the contact surfaces of the screw portions 7, 9 of the male joint 3 and the female joint 4. Further, the area of the surface in which the male joint 3 and the female joint 4 are pressed against each other by the outer diameter base portion 6 of the male joint 3 and the distal end portion of the female joint 4 on the outer peripheral portion to be in contact with each other is 130 to 160%. It was found that it was necessary to have an area of

One surface 12a of the ring-shaped reverse rotation preventing member 12
Is required to be equal to or more than one-third of the contact area of the threaded parts 7 and 9 based on the contact area of the outer peripheral part of the male joint 3 and the female joint 4 and one surface of the ring-shaped reverse rotation preventing member 12. If the total area of the contact area between 12a and the inner bottom part 10 of the female joint 4 is larger than the contact area of the thread parts 7, 9, the thread part 7, 9
Male and female joints joined by the threaded portions 7 and 9 when the contact stress generated on the threaded surface of the female joint 9 exceeds the stress generated on the contact surface between the ring-shaped reverse rotation preventing member 12 and the inner bottom portion 10 of the female joint 4. This is because the joints of the screw portions 7 and 9 are deformed, deviating from the original joining purpose of the joints 3 and 4.

Further, as described above, the area of one surface 12a of the ring-shaped reverse rotation preventing member 12 is 3
It is shown in FIG. 4 that it is necessary to use one-third or more. That is, in FIG. 4, A1 indicates a joint pressing portion between the distal end portion of the male joint 3 and the inner bottom portion 10 of the female joint 4, and A2 indicates the connection between the outer diameter base portion 6 of the male joint 3 and the distal end portion of the female joint 4. A3 indicates a joint pressing portion, and A3 indicates a meshing portion of the screw portions 7, 9 of the male joints 3, 4.

Further, the area of one surface 12a of the ring-shaped reverse rotation preventing member 12, that is, the contact area between the ring-shaped reverse rotation preventing member 12 and the inner bottom portion 10 of the female joint 4 is equal to the outer diameter base 6 of the male joint 3 and the female. The area of 130% to 160% of the contact area with the tip end of the joint 4 is required because when the male and female joints 3 and 4 are slightly reversed and their relative positions change, the ring-shaped reverse rotation stopper 12 Is the same as the contact area of the outer diameter base 6 of the male joint 3, the stress generated on the contact surface of the outer diameter base 6, and the stress generated on the contact surface of the ring-shaped reverse rotation preventing member 12. This is because the stress distribution becomes almost equilibrium, and when viewed as a joint as a whole, the stress distribution can be made nearly uniform.

As described above, the contact area between the ring-shaped reverse rotation preventing member 12 and the inner bottom portion 10 of the female joint 4 (the area of one surface 12a of the ring-shaped reverse rotation preventing member 12) is equal to the outer diameter base 6 of the male joint 3. FIG. 5 shows the reason why an area of 130 to 160% of the contact area between the metal joint 4 and the tip end of the female joint 4 is required.
In other words, the reverse force is generated in the male and female joints 3 and 4, and the contact surface 12a of the ring-shaped reverse rotation preventing member 12 is displaced from the tip of the male joint 3 to reduce the area of the contact surface 12a. I do. Here, if the ring-shaped reverse rotation stopping member 12 is manufactured at the area ratio according to the present invention, the ring-shaped reverse rotation stopping member 12 is provided at the position where the slip preventing mechanism works most effectively by the ring-shaped reverse rotation stopping member 12. Since the contact area between the stop member 12 and the inner bottom portion 10 of the female joint 4 and the contact area between the outer diameter base 6 of the male joint 3 and the distal end of the female joint 4 become substantially equal, the stress state on the contact surface between the two. As shown in FIG. 5, the stress F1 ′ is smaller than the stress F1 on the contact surface 12a of the ring-shaped reverse rotation preventing member 12 because the contact surface is relatively large at the distal end portion of the male joint 3.
The stresses F2 and F2 'at the outer diameter base portion 6 of the male joint 3 or the distal end portion of the female joint 4 are similarly in a stress state of about F1, and no extreme partial stress is generated on both contact surfaces. Can be sufficiently expressed.

As shown in the graph of FIG. 6, by pressing the male joint 3 and the female joint 4 at two places, respectively,
It is also clear that the connection of the pile joints can have a great strength. That is, the graph shows that the male and female joints 3 and 4 are 1
The graph shows the case where the male and female joints 3 and 4 are pressed together at two places, and the graph shows the case where the male and female joints 3 and 4 are pressed together. Shows a value about 30% higher.

In the first embodiment, the ring-shaped reverse rotation preventing member 12 is attached to the distal end of the male joint 3 and the inner bottom 10 of the female joint 4 is provided with an uneven surface. A),
As in the second embodiment shown in (B), the ring-shaped reverse rotation preventing member 13 is attached to the inner bottom portion 10 of the female joint 4, and meshes with the uneven surface provided on one surface 13a of the ring-shaped reverse rotation preventing member 13. A similar effect can be obtained by providing the obtained uneven surface 3a at the distal end of the male joint 3 and combining them.

In the third embodiment and the fourth embodiment shown in FIGS. 8A and 8B, the ring-shaped reverse rotation stopping members 14 and 15 are respectively connected to the outer diameter base 6 of the male joint 3 and the distal end of the female joint 4. This is an embodiment in the case of interposing between the first and second parts. In FIG. 2A, a ring-shaped reverse rotation preventing member 14 is attached to the distal end of the female joint 4 and one surface 14a of the ring-shaped reverse rotation preventing member 14 is attached.
The outer diameter base 6 is provided with an uneven surface 6a that can mesh with the uneven surface provided on the outer diameter base 6. In FIG. 2B, the ring-shaped reverse rotation preventing member 15 is connected to the outer diameter base 6 of the male joint 3.
And the female joint 4 is provided with an uneven surface 4a at the tip thereof. In the case of the third and fourth embodiments shown in FIGS. 8A and 8B, the area of the uneven surface of one surface 14a, 15a of the ring-shaped reverse rotation preventing members 14, 15 is equal to that of the male joint. 3 and 130% to 160% of the pressing joint surface between the inner bottom portion 10 of the female joint 4.

In the above embodiment, one ring-shaped reverse rotation preventing member 12, 13, 14, 15 is used independently and inserted between the male and female joints 3, 4. , FIG. 9
As shown in (A), (B) and the fifth and sixth embodiments of FIGS. 10 (A), (B), a pair of ring-shaped anti-rotation members 1 are provided.
6, 17 or ring-shaped reverse rotation stopping members 18, 19, respectively, and these ring-shaped reverse rotation stopping members 16, 17, 1 are used.
It is also possible to assemble and assemble 8, 19 by attaching them in a state corresponding to the predetermined position of the male joint 3 or the female joint 4.

FIG. 11 (A) is a view for explaining the operation of the reverse rotation locking mechanism.
The case where the lead of the ring-shaped reverse rotation preventing member is set to 48 mm will be described numerically as follows. The lead is the amount that the screw advances when rotated by 360 degrees. For example, assuming that a pair of ring-shaped reverse rotation preventing members act when relatively displaced by 15 degrees, the screw is loosened by 0.25 mm, but the ring-shaped reverse rotation preventing member is loosened by 2 mm, and the difference is 1.75 mm. Clearly acts as a binding force on the threaded portion of the male-female joint.

The above relationship is described in more detail with mathematical expressions as follows. That is, the number of protrusions on one surface 12a of the ring-shaped reverse rotation preventing member 12 in the first embodiment is
The contact stress between the contact area of the inner joint 10 and the inner bottom portion 10 of the female joint 4 and the contact surface pressure is determined from a contact stress of 20 kg / mm ² which does not damage the contact surface. In this case, it was configured as 16 peaks.

At the point A in FIG.
After the contact of No. 4, the pin is further tightened by 0.5 mm for positioning. Point B is a position where the reverse rotation is performed and the position returns by 0.25 mm. As described above, if the lead of the screw is 6 mm and the lead of the ring-shaped reverse rotation preventing member 12 is 48 mm, 6 mm
0.25 = 24, 360 ° ÷ 24 = 15 °, 48 × 15
° ÷ 360 ° = 2 mm, that is, when the screw surface is reversed by 0.25 mm from the position where the screw surface is tightened by 0.5 mm, it is returned by 15 ° in the circumferential direction, and the ring-shaped reverse rotation preventing member 1
2A, the surface 12d of the ring-shaped reverse rotation preventing member 12 shown in FIG. However, since the leads of the threaded portions 7 and 9 of the male and female joints 3 and 4 are also moving in the same direction, actually, 2 mm-0.
This means that a binding force of 25 mm = 1.7 mm is generated inside.

FIG. 11 (B) is a diagram showing the relationship of the force on the inclined surface of the reverse rotation stopping mechanism, and shows the frictional resistance required on one side of the ring-shaped reverse rotation stopping member. It is a figure showing a relation. The slip prevention on one surface of the ring-shaped reverse rotation preventing member is, as apparent from the expression of the force relationship of the inclined surface in FIG. 11B, the axial force W generated by the screw tightening force and the gradient force. It is given as the relationship between the angle α ° and the coefficient of friction μ of the surface. That is, F = W between the above symbols
× tan α. From this, it is necessary to set the frictional resistance required for the slip prevention on one side to give a numerical value larger than this value, and the result of the experiment is F = Cn
+ Tan 5.71 was found. Here C
Is the frictional force per non-slip, and n is the number of non-slip installed.

When the torsion test was performed on the pile joint of the first example according to the present invention, the results shown in the graph of FIG. 12 were obtained. That is, this graph shows the process in which a torque of about 3 ton-m is applied to the pile joint to perform fastening, and then reverse torque is applied to loosen the joint. As is clear from this graph, the tightening torque is about 3 tons-
It was found that joints tightened at m did not loosen when subjected to a reverse torque of about 5 ton-m.

[0049]

Since the threaded pile joint according to the present invention has the above-described structure and operation, the following great effects can be obtained by implementing the threaded pile joint according to the present invention. Can be done.

(1) In the present invention, since the ring-shaped reverse rotation preventing member is interposed between the male and female joints, the ring-shaped reverse rotation preventing member reversely rotates to the connecting portion of the male and female joints. Can be prevented from becoming loose. (2) Particularly, by connecting the male and female joints so as to satisfy the conditions described in claim 1, the two can be completely joined to each other, and a reversing force is required at the joint part depending on the situation of pile driving. Also in this case, no loosening occurs in the connection portion.
(3) The pile can be easily and accurately joined without being affected by the weather at the site of the pile driving, the intuition or skill of the construction engineer.

[Brief description of the drawings]

FIGS. 1A and 1B are longitudinal sectional explanatory views showing the structure of a pile joint according to a first embodiment of the present invention.

FIG. 2 is an explanatory perspective view of a ring-shaped reverse rotation preventing member.

3 (A) and 3 (B) are a side view and a front view of the ring-shaped reverse rotation preventing member of FIG. 2;

FIG. 4 is an explanatory diagram showing a relationship between a surface of the male and female joints which is pressed against and contacted and a contact surface of a screw portion.

FIG. 5 is an explanatory view showing a relationship between two places where the male and female joints are pressed and contacted with each other.

FIG. 6 is an explanatory diagram for comparing the strength when the male and female joints are pressed and contacted with each other at one location and at two locations.

FIGS. 7A and 7B are longitudinal sectional explanatory views showing a pile joint according to a second embodiment of the present invention.

FIGS. 8A and 8B are a third embodiment and a fourth embodiment, respectively.
It is a longitudinal section explanatory view showing a pile joint of an example.

FIGS. 9A and 9B are longitudinal sectional explanatory views showing a pile joint according to a fifth embodiment.

FIGS. 10A and 10B are longitudinal sectional explanatory views showing a pile joint according to a sixth embodiment.

FIG. 11A is an explanatory diagram of an operation of a reverse rotation stopping mechanism,
FIG. 11B is a diagram showing a force relationship on a slope surface of the reverse rotation stopping mechanism.

FIG. 12 is a graph showing the results of a torsion test of a pile joint provided with the reverse rotation locking mechanism of the present invention.

[Explanation of symbols]

 1,2 pile body 3 male joint 4 female joint 5 steps 6 outer diameter base 7 screw section 8 steps 9 screw section 10 inner bottom section 11 V groove groove 12,13,14,15,15 12a, 13a, 14a, 15a One side 12b, 13b, 14b, 15b One side 16,17,18,19 Ring-shaped anti-rotation member 16a, 17a, 18a, 19a One side 16b, 17b, 18b, 19b One side

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Masaho Tanaka 1-5 Nakanoyo Terao, Tsurumi-ku, Yokohama-shi, Kanagawa Prefecture (72) Inventor Takeshi Iguchi 1064-16 Tamado, Shimodate-shi, Ibaraki Pref. In-company (72) Inventor Tsuyoshi Ikeda 1064-16 Tamado, Shimodate-shi, Ibaraki Pref.

Claims (2)

[Claims] In a pile joint in which a ring-shaped reverse locking member is interposed between a male joint and a female joint which are screw-connected to each other, one surface of the ring-shaped reverse locking member is 3 °. ~ 6 °
A plurality of protrusions having a downward slope are provided, and the entire area of one surface of the ring-shaped reverse rotation preventing member provided with the plurality of protrusions is the total of the screw contact surfaces of the male joint and the female joint. An area of at least one third of the area, and an area of 130 to 1 of an area of a surface which is pressed and contacted with each other by the male joint and the female joint.
A threaded pile joint having an area of 60%. 2. The threaded pile joint according to claim 1, wherein the ring-shaped reverse rotation preventing member interposed between the male joint and the female joint is constituted by one or two pairs.