U.S. patent application number 15/302151 was filed with the patent office on 2017-06-29 for joint mechanism and connection method for steel pipe.
This patent application is currently assigned to Kubota Corporation. The applicant listed for this patent is KUBOTA CORPORATION. Invention is credited to Shunsuke KIKUCHI, Takeshi NAGASHIMA, Tomoyuki SUZUKI, Masashi TOYAMA, Hiroyuki YAMAMOTO.
Application Number | 20170183837 15/302151 |
Document ID | / |
Family ID | 56692620 |
Filed Date | 2017-06-29 |
United States Patent
Application |
20170183837 |
Kind Code |
A1 |
SUZUKI; Tomoyuki ; et
al. |
June 29, 2017 |
JOINT MECHANISM AND CONNECTION METHOD FOR STEEL PIPE
Abstract
Contemplated are simplification and cost reduction in
arrangement of connecting a pair of steel pipes to each other. A
joint mechanism for a pair of steel pipe piles 1A, 1B includes an
inner joint 10A provided in the steel pipe pile 1A, an inner joint
10B, an outer joint 20 disposed circumferentially between and
across the inner joint 10A of the steel pipe pile 1A and the inner
joint 10B of the steel pipe pile 1B, and a key member 30 configured
to prevent relative movement between the pair of steel pipe piles
1A, 1B in a longitudinal direction of these steel pipes 1. The
outer joint 20 includes an opening portion 22 (22A, 22B) for
inserting, from its outer circumferential face, split key members
31 constituting the key member 30 into a key groove constituted of
an outward circumferential groove 13 (13A, 13B) provided in the
outer circumference of the inner joint 10A and the inner joint 10B
respectively and an inward circumferential groove 23 (23A, 23B)
provided in the inner circumference of the outer joint 20 in
opposition to the outward circumferential groove 13 (13A, 13B).
Inventors: |
SUZUKI; Tomoyuki; (Chuo-ku,
Tokyo, JP) ; KIKUCHI; Shunsuke; (Chuo-ku, Tokyo,
JP) ; TOYAMA; Masashi; (Chiba, JP) ;
NAGASHIMA; Takeshi; (Chiba, JP) ; YAMAMOTO;
Hiroyuki; (Chiba, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
KUBOTA CORPORATION |
Osaka-shi, Osaka |
|
JP |
|
|
Assignee: |
Kubota Corporation
Osaka-shi, Osaka
JP
|
Family ID: |
56692620 |
Appl. No.: |
15/302151 |
Filed: |
December 22, 2015 |
PCT Filed: |
December 22, 2015 |
PCT NO: |
PCT/JP2015/085892 |
371 Date: |
October 5, 2016 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
E02D 5/24 20130101; E02D
5/28 20130101; E02D 5/523 20130101; E02D 5/526 20130101; E02D 5/30
20130101 |
International
Class: |
E02D 5/28 20060101
E02D005/28; E02D 5/52 20060101 E02D005/52 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 20, 2015 |
JP |
2015-032279 |
Claims
1. A joint mechanism for a steel pipe comprising: a first inner
joint provided at one end of one steel pipe; a second inner joint
provided at the other end of the other steel pipe; an outer joint
disposed circumferentially between and across the first inner joint
and the second inner joint for connecting a pair of the steel pipes
to each other when the first inner joint of one steel pipe is
placed adjacent the second inner joint of the other steel pipe; a
key member for engaging the first inner joint with the outer joint
and also engaging the second inner joint with the outer joint,
thereby to prevent relative movement between the pair of steel
pipes in a longitudinal direction of these steel pipes; an outward
circumferential groove provided respectively in an outer
circumference of the first inner joint and an outer circumference
of the second inner joint; an inward circumferential groove
provided in an inner circumference of the outer joint in opposition
to the outward circumferential grooves provided in the outer
circumferences of the first inner joint and the second inner joint
respectively; and the outer joint includes an opening portion for
inserting the key member from an outer circumference of the outer
joint into a key groove constituted of the outward circumferential
groove and the inward circumferential groove.
2. The joint mechanism according to claim 1, wherein the key member
comprises a plurality of split key members each constituting a
portion of a circle, and a closing member having a function of the
split key member and a function of closing the opening portion.
3. The joint mechanism according to claim 2, wherein the outer
joint comprises a plurality of unit members disposed side by side
around the first inner joint and the second inner joint.
4. The joint mechanism according to claim 3, wherein the plurality
of unit members include an opening unit member having the opening
portion and a standard unit member not having the opening
portion.
5. The joint mechanism according to claim 3 or 11, wherein: the
plurality of unit members include: a reference unit member to be
disposed circumferentially across and between the first inner joint
and the second inner joint when the first inner joint and the
second inner joint are placed in contact with each other; and an
extended unit member to be disposed circumferentially across and
between the first inner joint and the second inner joint when the
first inner joint and the second inner joint are placed apart from
each other.
6. The joint mechanism according to claim 5, wherein: each of the
first inner joint and the second inner joint includes a base
portion and an inner fitting portion extending continuously from
the base portion; an annular engaging sunk portion is provided
annularly in an end face of the base portion facing the inner
fitting portion; the outward circumferential groove is provided
annularly in an outer circumference of the inner fitting portion;
at upper and lower end portions of the reference unit member and
the extended unit member respectively, there are provided a pair of
engaging projecting portions engageable with the engaging portion
when the reference unit member and the extended unit member are
disposed circumferentially across and around the first inner joint
and the second inner joint; in an inner circumference of the
reference unit member and the extended unit member respectively, a
pair of the inward circumferential grooves are provided in
opposition to a pair of the outward circumferential grooves; a
distance between the pair of inward circumferential grooves of the
reference unit member is set equal to a distance between the pair
of outward circumferential grooves when the first inner joint and
the second inner joint are placed in contact with each other; and a
distance between the pair of inward circumferential grooves of the
extended unit member is set equal to a distance between the pair of
outward circumferential grooves when the first inner joint and the
second inner joint are placed apart from each other.
7. The joint mechanism according to claim 1, wherein: at least the
outer joint comprises a straight seam steel pipe; and the bonding
portion is disposed at a position not overlapped with the opening
portion in the outer joint.
8. The joint mechanism according to claim 1, wherein: at least the
outer joint comprises a straight seam steel pipe; and a bonding
portion included in the straight seam steel pipe is disposed at a
position not overlapped with a position of fixing the closing
member in the inner joint.
9. The joint mechanism according to claim 1, wherein: at least the
outer joint comprises a straight seam steel pipe; and a bonding
portion included in the straight seam steel pipe is disposed at a
position not overlapped with a counter bore portion formed in the
inner joint or with a counter bore portion formed in the outer
joint constituting a rotation preventing key groove.
10. A connection method connecting a pair of steel pipes to each
other with using the joint mechanism according to claim 1, the
method comprising the steps of: disposing an outer joint
circumferentially of a first inner joint provided at one one end of
one steel pipe; disposing the first inner joint and a second inner
joint provided at the other end of the other steel pipe adjacent
each other to insert the second inner joint to an inner face of the
outer joint, thereby to dispose the outer joint across and between
the first inner joint and the second inner joint; inserting a key
member for engaging the first inner joint with the outer joint and
engaging the second inner joint with the outer joint to prevent
relative movement between the pair of steel pipes in the
longitudinal direction of these steel pipes through an opening
portion provided in the outer joint from an outer circumferential
face of the outer joint into a key groove including an outward
circumferential groove provided in an outer circumference of the
first inner joint and the second inner joint respectively and an
inward circumferential groove provided in an inner circumference of
the outer joint in opposition to the outward circumferential groove
and then sliding the key member inserted into the key groove along
a circumferential direction within the key groove, so that the key
member is disposed at a predetermined position within the key
groove, except for a portion of the key groove corresponding to the
opening portion; and closing the opening portion with using a
closing member having a function of the key member and having also
a function of closing the opening portion.
11. A connection method connecting a pair of steel pipes to each
other with using the joint mechanism according to claim 1, the
method comprising the steps of: disposing an outer joint
circumferentially of a first inner joint provided at one one end of
one steel pipe; disposing the first inner joint and a second inner
joint provided at the other end of the other steel pipe adjacent
each other to insert the second inner joint to an inner face of the
outer joint, thereby to dispose the outer joint across and between
the first inner joint and the second inner joint; inserting a key
member for engaging the first inner joint with the outer joint and
engaging the second inner joint with the outer joint to prevent
relative movement between the pair of steel pipes in the
longitudinal direction of these steel pipes through an opening
portion provided in the outer joint from an outer circumferential
face of the outer joint into a key groove including an outward
circumferential groove provided in an outer circumference of the
first inner joint and the second inner joint respectively and an
inward circumferential groove provided in an inner circumference of
the outer joint in opposition to the outward circumferential groove
and then sliding the key member inserted into the key groove along
a circumferential direction within the key groove, so that the key
member is disposed at a predetermined position within the key
groove, except for a portion of the key groove corresponding to the
opening portion; and closing the opening portion with using a
closing member having a function of the key member and having also
a function of closing the opening portion; wherein the step of
disposing the outer joint circumferentially includes a step of
tilting an axis of the one steel pipe and an axis of the other
steel pipe by constituting the outer joint disposed across and
between the first inner joint and the second inner joint of a
plurality of unit members one or some of which constitute the
reference unit members and the other of which constitute the
extended unit members.
Description
TECHNICAL FIELD
[0001] The present invention relates to a joint mechanism and a
connection method for a steel pipe.
BACKGROUND ART
[0002] For forming a foundation pipe, a soil retaining sheet pile
for a structure, an anti-landslide pile, a pier post, etc., a steel
pipe pile is employed as an example of a steel pipe. In order to
reach an inside of a support layer which is a solid ground present
under a soft ground, a long steel pipe is required. However, for
the sake of convenience of manufacture, transport etc., it has been
practiced to carry a steel pipe pile manufactured in a factory and
having a length ranging from a few meters to a few tens of meters
to a site of its installment and to connect a plurality of such
steel pipe piles vertically to each other one after another on the
site to form an assembly having a required length.
[0003] As a mechanism for connecting steel pipe piles as above,
Patent Document 1 proposes a machine-based joint mechanism.
[0004] With this joint mechanism, an inward circumferential groove
of an outer fitting member and an outward circumferential groove of
an inner fitting member are formed in advance to have a same groove
width. Then, the inward circumferential groove and the outward
circumferential groove are brought into opposition to each other
when the outer fitting member and the inner fitting member are
fitted to each other, and then a key member incorporated within the
inward circumferential groove is pushed out toward the outward
circumferential groove to realize fitting across and between the
inward circumferential grove and the outward circumferential
groove. As a result, a pair of steel pipe piles are connected not
to be movable relative to each other along a longitudinal direction
of these steel pipe piles.
BACKGROUND ART DOCUMENT
[Patent Document]
[0005] [Patent Document 1] Japanese Patent No. 3158081
SUMMARY OF THE INVENTION
Problem to be Solved by Invention
[0006] However, the above-described arrangement wherein a key
member is incorporated in advance within the inward circumferential
groove to be pushed out toward the outward circumferential groove
at the time of connection tends to be complicated. Further, as the
inward circumferential groove needs to be formed with a groove
width capable of accommodating the key member entirely, the
thickness of the outward fitting member is increased
correspondingly.
[0007] The present invention has been made in view of the
above-described state of the art and its object is to simplify an
arrangement for connecting a pair of steel pipes and to achieve
cost reduction also.
Solution
[0008] According to a first characterizing feature of a joint
mechanism relating to the present invention, a joint mechanism for
a steel pipe comprises:
[0009] a first inner joint provided at one end of one steel
pipe;
[0010] a second inner joint provided at the other end of the other
steel pipe;
[0011] an outer joint disposed circumferentially between and across
the first inner joint and the second inner joint for connecting a
pair of the steel pipes to each other when the first inner joint of
one steel pipe is placed adjacent the second inner joint of the
other steel pipe;
[0012] a key member for engaging the first inner joint with the
outer joint and also engaging the second inner joint with the outer
joint, thereby to prevent relative movement between the pair of
steel pipes in a longitudinal direction of these steel pipes;
[0013] an outward circumferential groove provided respectively in
an outer circumference of the first inner joint and an outer
circumference of the second inner joint;
[0014] an inward circumferential groove provided in an inner
circumference of the outer joint in opposition to the outward
circumferential grooves provided in the outer circumferences of the
first inner joint and the second inner joint respectively; and
[0015] the outer joint includes an opening portion for inserting
the key member from an outer circumference of the outer joint into
a key groove constituted of the outward circumferential groove and
the inward circumferential groove.
[0016] When the first inner joint provided at one end of one steel
pipe and the second inner joint provided at the other end of the
other steel pipe are placed adjacent each other and the outer joint
is placed circumferentially across and between these first inner
joint and second inner joint, through the opening portion formed in
the outer joint, the key member can be disposed from the outer
circumferential face of the outer joint into the key grove
constituted of the outward circumferential groove and the inward
circumferential groove.
[0017] Accordingly, there is no need for providing such arrangement
provided by the conventional joint mechanism in which a key member
is incorporated in advance within the inward circumferential
groove. Consequently, the thickness of the outer joint can be
reduced and material cost can be reduced correspondingly. Moreover,
as the first inner joint and the second inner joint can be provided
with an identical shape, reduction of processing cost can be
realized also.
[0018] According to a second characterizing feature of the present
invention, the key member comprises a plurality of split key
members each constituting a portion of a circle, and a closing
member having a function of the split key member and a function of
closing the opening portion.
[0019] At the opening portion, there is disposed the closing member
having a function similar to the split key member of preventing
relative movement between the pair of steel pipes in the
longitudinal direction of these steel pipes. With this, it is
possible to removal of the split key members disposed in the key
groove through the opening portion to the outside.
[0020] According to a third characterizing feature of the present
invention, the outer joint comprises a plurality of unit members
disposed side by side around the first inner joint and the second
inner joint.
[0021] If the outer joint is comprised of a plurality of unit
members of a size allowing hand pickup thereof by a worker, a
lifting operation by a machine such as a crane can be omitted, so
that work efficiency for steel pipe connection can be improved.
[0022] According to a fourth characterizing feature of the present
invention, the plurality of unit members include an opening unit
member having the opening portion and a standard unit member not
having the opening portion.
[0023] With the above, the opening unit member having the opening
portion allowing insertion of the key member can be disposed at a
desired position. That is, working efficiency can be improved in
the respect of the possibility of desired setting of the opening
portion used for insertion of the key member into the key groove,
in accordance with a situation of the work site, such as a working
space.
[0024] According to a fifth characterizing feature of the present
invention, the plurality of unit members include a reference unit
member to be disposed circumferentially across and between the
first inner joint and the second inner joint when the first inner
joint and the second inner joint are placed in contact with each
other and an extended unit member to be disposed circumferentially
across and between the first inner joint and the second inner joint
when the first inner joint and the second inner joint are placed
apart from each other.
[0025] By constituting one part of the outer joint disposed
circumferentially across and between the first inner joint and the
second inner joint of the reference unit member and constituting
the other part thereof of the extended unit member, it is possible
to tilt the axis of one steel pipe and the axis of the other steel
pipe.
[0026] Namely, when steel pipe piles are to be connected to each
other and driven into the ground, if the posture of a steel pipe
firstly driven into the ground is deviated from a predetermined
posture, e.g. a perpendicular posture, the steel pipes can be
connected to each other, with tilting the axes thereof in such a
manner as to correct the posture of the subsequent steel pipe to be
connected to the firstly driven steel pipe to a predetermined
posture, e.g. to a posture near a perpendicular posture.
[0027] According to a sixth characterizing feature of the present
invention:
[0028] each of the first inner joint and the second inner joint
includes a base portion and an inner fitting portion extending
continuously from the base portion;
[0029] an annular engaging sunk portion is provided annularly in an
end face of the base portion facing the inner fitting portion;
[0030] the outward circumferential groove is provided annularly in
an outer circumference of the inner fitting portion;
[0031] at upper and lower end portions of the reference unit member
and the extended unit member respectively, there are provided a
pair of engaging projecting portions engageable with the engaging
portion when the reference unit member and the extended unit member
are disposed circumferentially across and around the first inner
joint and the second inner joint;
[0032] in an inner circumference of the reference unit member and
the extended unit member respectively, a pair of the inward
circumferential grooves are provided in opposition to a pair of the
outward circumferential grooves;
[0033] a distance between the pair of inward circumferential
grooves of the reference unit member is set equal to a distance
between the pair of outward circumferential grooves when the first
inner joint and the second inner joint are placed in contact with
each other; and
[0034] a distance between the pair of inward circumferential
grooves of the extended unit member is set equal to a distance
between the pair of outward circumferential grooves when the first
inner joint and the second inner joint are placed apart from each
other.
[0035] When the reference unit member and the extended unit member
are disposed circumferentially across and between the first inner
joint and the second inner joint, engagement is established between
the engaging projecting portion and the engaging sunk portion,
thereby to prevent detachment of the reference unit member and the
extended unit member to the outside. Even when the axis of one
steel pipe and the axis of the other steel pipe are tilted, the key
member can still be inserted into the key groove.
[0036] According to a seventh characterizing feature of the present
invention, at least the outer joint comprises a straight seam steel
pipe; and
[0037] the bonding portion is disposed at a position not overlapped
with the opening portion in the outer joint.
[0038] A straight seam steel pipe is manufactured by a sheet
rolling technique. The sheet rolling technique is inexpensive in
comparison with other techniques such as ring forging technique
employed for manufacturing a seamless steel pipe, with the cost
thereof being much less than that of the latter techniques. By
constituting the outer joint of a straight seam steel pipe
respectively, the outer joint can be obtained inexpensively.
[0039] On the other hand, the straight seam steel pipe has the
bonding portion along its longitudinal direction, so that
uniformity in the circumferential direction cannot be obtained,
thus suffering the disadvantage of lower rigidness at its
circumferential portion, hence being less resistant against an
inner pressure or a torsion.
[0040] Further, the circumferential portion of the outer joint
where the opening portion is formed, due to the smaller amount of
forming material at this portion, has lower rigidness than the
other circumferential portion.
[0041] For this reason, the opening portion is provided in the
outer joint in such a manner that the opening portion is disposed
at a position different from the positon across and between the
bonding portion included in the straight seam steel pipe.
[0042] Therefore, by the arrangement of avoiding overlap between
the circumferential portion formed with the opening portion and the
bonding portion in the longitudinal direction of the straight seam
steel pipe, it is possible to reduce the disadvantageous effect of
reduced rigidness in one portion of the first inner joint and the
second inner joint as compared with the other portion thereof
[0043] According to an eighth characterizing feature of the present
invention:
[0044] at least the outer joint comprises a straight seam steel
pipe; and
[0045] a bonding portion included in the straight seam steel pipe
is disposed at a position not overlapped with a position of fixing
the closing member in the inner joint.
[0046] A straight seam steel pipe is manufactured by a sheet
rolling technique. The sheet rolling technique is inexpensive in
comparison with other techniques such as ring forging technique
employed for manufacturing a seamless steel pipe, with the cost
thereof being much less than that of the latter techniques. By
constituting the outer joint of a straight seam steel pipe
respectively, the outer joint can be obtained inexpensively.
[0047] On the other hand, the straight seam steel pipe has the
bonding portion along its longitudinal direction, so that
uniformity in the circumferential direction cannot be obtained,
thus suffering the disadvantage of lower rigidness at its
circumferential portion, hence being less resistant against an
inner pressure or a torsion.
[0048] Further, at the position of the inner joint for fixing the
closing member, there is formed e.g. a bolt hole for fixing a bolt
as a fixing arrangement, and the circumferential portion of this
position, due to the less amount of material used, has lower
rigidness as compared with the other circumferential portion.
[0049] Then, at the positon in the inner joint for fixing the
closing member is provided in this inner joint at a positon not
across the bonding portion included in the straight seamless steel
pipe.
[0050] With the above arrangement of avoiding overlap between the
position in the inner joint for fixing the closing member with the
bonding portion in the longitudinal direction of the straight seam
steel pipe, it becomes possible to avoid excessive reduction in the
rigidness in a portion of the inner joint as compared with the
remaining portion.
[0051] According to a ninth characterizing feature of the present
invention:
[0052] at least the outer joint comprises a straight seam steel
pipe; and
[0053] a bonding portion included in the straight seam steel pipe
is disposed at a positon not overlapped with a counter bore portion
formed in the inner joint or with a counter bore portion formed in
the outer joint constituting a rotation preventing key groove.
[0054] A straight seam steel pipe is manufactured by a sheet
rolling technique. The sheet rolling technique is inexpensive in
comparison with other techniques such as ring forging technique
employed for manufacturing a seamless steel pipe, with the cost
thereof being much less than that of the latter techniques. By
constituting the outer joint of a straight seam steel pipe
respectively, the outer joint can be obtained inexpensively.
[0055] On the other hand, the straight seam steel pipe has the
bonding portion along its longitudinal direction, so that
uniformity in the circumferential direction cannot be obtained,
thus suffering the disadvantage of lower rigidness at its
circumferential portion, hence being less resistant against an
inner pressure or a torsion.
[0056] Further, the circumferential portion where a counter bore
portion is formed in the inner joint or a counter bore portion is
formed in the outer joint constituting a rotation preventing key
groove, due to the less amount of material used therein, has lower
rigidness as compared with the other circumferential portion.
[0057] Then, the counter bore portion formed in the inner joint and
the counter bore portion formed in the outer joint constituting the
rotation preventing key groove are provided in the inner joint and
the outer joint respectively at such positions not across the
bonding portion included in the straight steam steel pipe.
[0058] With the above arrangement of avoiding overlap in the
longitudinal direction of the straight seam steel pipe between the
circumferential portion where a counter bore portion is formed in
the inner joint or a counter bore portion is formed in the outer
joint constituting the rotation preventing key groove and the
bonding portion, it becomes possible to avoid excessive reduction
in the rigidness in a portion of the inner joint as compared with
the remaining portion.
[0059] According to a first characterizing feature of a connection
method of the present invention, the connection method connecting a
pair of steel pipes to each other with using the joint mechanism
having any one of the first through seventh characterizing features
described above, the method comprises the steps of:
[0060] disposing an outer joint circumferentially of a first inner
joint provided at one one end of one steel pipe;
[0061] disposing the first inner joint and a second inner joint
provided at the other end of the other steel pipe adjacent each
other to insert the second inner joint to an inner face of the
outer joint, thereby to dispose the outer joint across and between
the first inner joint and the second inner joint;
[0062] inserting a key member for engaging the first inner joint
with the outer joint and engaging the second inner joint with the
outer joint to prevent relative movement between the pair of steel
pipes in the longitudinal direction of these steel pipes through an
opening portion provided in the outer joint from an outer
circumferential face of the outer joint into a key groove including
an outward circumferential groove provided in an outer
circumference of the first inner joint and the second inner joint
respectively and an inward circumferential groove provided in an
inner circumference of the outer joint in opposition to the outward
circumferential groove and then sliding the key member inserted
into the key groove along a circumferential direction within the
key groove, so that the key member is disposed at a predetermined
position within the key groove, except for a portion of the key
groove corresponding to the opening portion; and
[0063] closing the opening portion with using a closing member
having a function of the key member and having also a function of
closing the opening portion.
[0064] According to a second characterizing feature of a connection
method of the present invention, the connection method connecting a
pair of steel pipes to each other with using the joint mechanism
having any one of the fifth through seventh characterizing features
described above, the method comprises the steps of:
[0065] disposing an outer joint circumferentially of a first inner
joint provided at one one end of one steel pipe;
[0066] disposing the first inner joint and a second inner joint
provided at the other end of the other steel pipe adjacent each
other to insert the second inner joint to an inner face of the
outer joint, thereby to dispose the outer joint across and between
the first inner joint and the second inner joint;
[0067] inserting a key member for engaging the first inner joint
with the outer joint and engaging the second inner joint with the
outer joint to prevent relative movement between the pair of steel
pipes in the longitudinal direction of these steel pipes through an
opening portion provided in the outer joint from an outer
circumferential face of the outer joint into a key groove including
an outward circumferential groove provided in an outer
circumference of the first inner joint and the second inner joint
respectively and an inward circumferential groove provided in an
inner circumference of the outer joint in opposition to the outward
circumferential groove and then sliding the key member inserted
into the key groove along a circumferential direction within the
key groove, so that the key member is disposed at a predetermined
position within the key groove, except for a portion of the key
groove corresponding to the opening portion; and
[0068] closing the opening portion with using a closing member
having a function of the key member and having also a function of
closing the opening portion;
[0069] wherein the step of disposing the outer joint
circumferentially includes a step of tilting an axis of the one
steel pipe and an axis of the other steel pipe by constituting the
outer joint disposed across and between the first inner joint and
the second inner joint of a plurality of unit members one or some
of which constitute the reference unit members and the other of
which constitute the extended unit members.
BRIEF DESCRIPTION OF THE DRAWINGS
[0070] FIG. 1 is an explanatory view of a steel pipe and a joint
mechanism,
[0071] FIG. 2 is a perspective view of an outer joint,
[0072] FIG. 3 is an explanatory view regarding inner joints and the
outer joint,
[0073] FIG. 4 is an explanatory view regarding the inner joints and
the outer joint,
[0074] FIG. 5 is an explanatory view regarding the inner joints and
the outer joint,
[0075] FIG. 6 is a side view in section regarding the inner joints
and the outer joint,
[0076] FIG. 7 is an explanatory view regarding engagement by a key
member,
[0077] FIG. 8 is a side view in section regarding engagement by the
key member,
[0078] FIG. 9 is a plane view in section regarding engagement by
the key member,
[0079] FIG. 10 is an explanatory view regarding a closing
member
[0080] FIG. 11 is a side view in section regarding the closing
member,
[0081] FIG. 12 is a plane view in section regarding the closing
member,
[0082] FIG. 13 is an explanatory view of a using method of a joint
mechanism,
[0083] FIG. 14 is a perspective view of an outer joint according to
a further embodiment,
[0084] FIG. 15 is a perspective view of an outer joint according to
a further embodiment,
[0085] FIG. 16 is a plane view in section of principal portions of
an outer joint according to a further embodiment,
[0086] FIG. 17 is a plane view in section of principal portions of
an outer joint according to a further embodiment,
[0087] FIG. 18 is a perspective view of an outer joint according to
a further embodiment,
[0088] FIG. 19 is a side view in section of principal portions of
an outer joint according to a further embodiment,
[0089] FIG. 20 is a side view in section of principal portions of
an outer joint according to a further embodiment,
[0090] FIG. 21 is a side view in section of principal portions of
an outer joint according to a further embodiment, and
[0091] FIG. 22 is an explanatory view of a steel pipe joint
mechanism according to a further embodiment.
EMBODIMENTS
[0092] Next, a steel pipe joint mechanism and connection method
according to the present invention will be described in details
with reference to the accompanying drawings.
[0093] FIG. 1 shows a steel pipe pile 1, as an example of a steel
pipe, which has a cylindrically shaped outer circumferential face
and which is to be driven into a ground by means of a hydraulic
hammer, a jacking machine, a rotary jacking machine, etc. FIG. 1
also shows a joint mechanism for connecting a pair of steel pipe
piles 1 to each other along the longitudinal direction of these
steel pipe piles 1. Incidentally, although all of the steel pipe
piles 1 are of an identical construction, where there arises a need
for explaining one steel pipe pile 1 in distinction from the other
steel pipe pile 1, reference numerals provided to respective
components of one steel pipe pile 1 will be provided with an
subscript A, whereas reference numerals provided to respective
components of the other steel pipe pile 1 will be provided with an
subscript B, respectively.
[0094] Each steel pipe pile 1 (1A, 1B) comprises a tubular body 2
(2A, 2B) and inner joints 10 having a generally cylindrical shape,
formed of cast iron and welded coaxially to opposed ends of the
tubular body 2 (2A, 2B).
[0095] As shown in FIG. 1, the inner joint 10 includes a base
portion 11 having a slightly larger outside diameter than an
outside diameter of the tubular body 2 and an inner fitting portion
12 having a smaller outside diameter than the base portion 11, the
inner fitting portion 12 extending continuously from the base
portion 11. In the instant embodiment, the outside diameter of the
base portion 11 is about 18 mm larger than the outside diameter of
the tubular body 2.
[0096] In the outer circumference of the inner fitting portion 12,
there is defined a single line of outward circumferential groove 13
for engagement of an annular key member 30 which will be described
later herein. In an end face of the base portion 11 facing the
inner fitting portion 12 side, there is provided, in the form of a
circular ring, an engaging sunk portion 14 for engagement of an
engaging projecting portion 24 provided at an end portion of an
outer joint 20 to be described later.
[0097] Incidentally, the inner joints 10 welded to the opposed ends
of the tubular body 2 are of an identical construction, yet,
reference numerals provided to the respective components of the
inner joint 10 which is to be disposed on the lower side when the
steel pipe pile 1 is driven into the ground are provided with the
subscript A, whereas reference numerals provided to the respective
components of the inner joint 10 which is to be disposed on the
upper side then are provided with the subscript B, respectively.
That is, one of the pair of inner joints 10A, 10B constitutes "a
first inner joint", and the other thereof constitutes "a second
inner joint". As the first inner joint and the second inner joint
have the identical construction, manufacturing cost reduction is
made possible as compared with a case of providing them with
different constructions.
[0098] As shown in FIG. 1 and FIG. 2, the outer joint 20 is
comprised of eight unit members 21 which are formed by splitting a
cylindrical body formed of cast iron and having an outside diameter
slightly larger than the outside diameter of the tubular body 2 and
an inside diameter allowing fitting/insertion of the inner joint
10, into eight equal parts. In the instant embodiment, the outside
diameter of the outer joint 20 is about 18 mm larger than the
outside diameter of the tubular body 2.
[0099] Incidentally, the splitting into eight equal parts described
above is only exemplary. The number of the unit members 21 obtained
by splitting can be smaller than or greater than eight. But, it is
preferred that the size of the unit member 21 obtained by such
splitting be such a size as allows hand lifting of this member by a
worker. Alternatively, the unit members 21 could be manufactured
also by bending separate iron plates one by one. However, with use
of the above-described simple manufacturing method of splitting a
straight seam steel pipe, manufacturing cost can be reduced as
compared with the case of manufacturing them one by one.
[0100] In the inner circumference of the outer joint 20 constituted
of the eight unit members 21, two parallel lines of annular inward
circumferential grooves 23 (23A, 23B) having a depth substantially
same as a depth of outward circumferential grooves 13 (13A, 13B)
provided in the inner joint 10A and the inner joint 10B
respectively are provided at positions where these grooves 23 may
be in opposition to the outward circumferential grooves 13 (13A,
13B) when the outer joint 20 is disposed circumferentially around
inner fitting portions 12 (12A, 12B) of the inner joints 10 (10A,
10B).
[0101] An annular space constituted of the outward circumferential
groove 13 and the inward circumferential groove 23 when the outer
joint 20 is disposed circumferentially of the inner joint 10
constitutes a key groove for engaging the key member 30.
[0102] When, the key member 30 is engaged with this key groove,
i.e. across and between the inward circumferential groove 13 and
the inward circumferential groove 23, the inner joint 10A and the
outer joint 20 and also the inner joint 10B and the outer joint 20
are engaged respectively with each other, whereby the pair of steel
pipe piles 1A, 1B are connected to each other along the
longitudinal direction of these steel pipe piles 1.
[0103] Each unit member 21 has engaging projecting portions 24
(24A, 24B) formed at its upper and lower end portions thereof as
shown. When the unit member 21 is disposed circumferentially of the
inner joint 10, the engaging projecting portions 24 (24A, 24B) come
into engagement with engaging sunk portions 14 (14A, 14B) of the
inner joint 10, thus preventing detachment of the unit member 21 to
the outside.
[0104] Of the eight unit members 21, four unit members 21
respectively include two opening portions 22 (22A, 22B) for
allowing a longitudinal groove portion of the outward
circumferential groove 13 (13A, 13B) to face outwards along the
entire width of the outward circumferential groove 13 (13A, 13B) in
order to allow the key member 30 to be disposed in the key groove
constituted of the outward circumferential groove 13 and the inward
circumferential groove 23, when the outer joint 20 is disposed
circumferentially of the inner joint 10. These unit members 21
constitute "an opening unit member 21A".
[0105] Each opening portion 22 (22A, 22B) is provided in the form
of a cut along the portion forming each inward circumferential
groove 23 (23A, 23B) along the entire width of this inward
circumferential groove 23 (23A, 23B).
[0106] The key member 30 consisting essentially of the outward
circumferential groove 13 and the inward circumferential groove 23
is inserted via the opening portion 22 (22A, 22B) from the outer
circumferential face of the outer joint 20.
[0107] The other four unit members 21, except for the absence of
the opening portions 22 (22A, 22B) therein, are identical to the
opening unit members 21A. These unit members 21 constitute
"standard unit members 21B".
[0108] In the instant embodiment, the opening unit members 21A and
the standard unit members 21B four of which respectively are
provided are disposed side by side in alternation around the inner
joints 10, thus together constituting the cylindrical outer joint
20. The opening unit member 21A, due to the present of the opening
portions 22 formed therein, has lower rigidness than the standard
unit member 21B. For this reason, by disposing the opening unit
members 21A and the standard unit members 21B side by side in
alternation, there is realized uniformity of rigidness of the outer
joint 20 as a whole.
[0109] As shown in FIG. 1 and FIG. 12, the key member 30 is formed
of a plurality of arcuate pieces fitting within the key groove and
obtained by e.g. splitting an annular body into 16 (sixteen) equal
parts.
[0110] However, of these sixteen arcuate pieces, 12 (twelve) of
them are split key members 31 to be fitted in the key groove and
functioning as the key members 30, whereas the other four of them
constitute closing members 32 having the function of the key member
20 and having also the function of closing the opening portion
22.
[0111] In each single key groove, the twelve split key members 21
and the four closing members 32 are fitted, thus together
constituting the annular key member 30.
[0112] Each split key member 31 has its size along the longitudinal
direction of the steel pipe pile 1 which size is slightly smaller
than the size of the opening portion 22 in this direction and has
also its size along the circumferential direction of the steel pipe
pile 1 which size is slightly smaller than the size of the opening
portion 22 in this circumferential direction and has also its size
along the radial direction of the steel pipe pile 1 which size is
slightly smaller than the size of the key groove, that is, the
outward circumferential groove 13 and the inward circumferential
groove 23 along this radial direction.
[0113] Each closing member 32 has its size along the longitudinal
direction of the steel pipe pile 1 which size is slightly smaller
than the size of the opening portion 22 in this direction and has
also its size along the circumferential direction of the steel pipe
pile 1 which size is slightly smaller than the size of the opening
portion 22 in this circumferential direction and has also its size
along the radial direction of the steel pipe pile 1 which size is
approximately equal to the size of the outward circumferential
groove 13 from the bottom face to the surface of the opening
portion 22.
[0114] Further, the closing member 32 is configured to be fixable
to the inner joint 10 with using the bolt 33, after its insertion
into the opening portion 22. Alternatively, the closing member 32
can be configured to be fixable to the outer joint 20.
[0115] Further, at boundary portions of the outer circumferences of
the inner joint 10 and the outer joint 20 respectively, there are
provided rotation preventing keys for preventing relative movement
in the circumferential direction between the inner joint 10A and
the inner joint 10B connected to each other via the outer joint
20.
[0116] Though not shown, the rotation preventing key is disposed
across a rotation preventing key groove consisting of a counter
boring portion formed in an outer circumferential face of the base
portion 11 of the inner joint 10 and a counter boring portion
formed in an outer circumferential face of the outer joint 20 in
opposition to the above-mentioned counter boring portion.
Incidentally, the sizes and the numbers of the rotation prevention
key and the counter boring portions described above will be
appropriately set according to an installment method for the steel
pipe piles 1. The rotation preventing key may be formed integral
with one of the inner joint 10 and the outer joint 20. In such
case, the counter boring portion will be formed only in the other
of the joints 10, 20.
[0117] The arrangement for preventing circumferential relative
movement between the inner joint 10A and the inner joint 20B is not
limited to the above arrangement using the rotation preventing key.
Alternatively, for instance, the arrangement may be an arrangement
of making a length of the engaging projecting portion 24 of at
least one of the eight unit members 21 in the longitudinal
direction of the steel pipe piles 1 different from a length in the
same direction of the engaging portions 24 of the other unit
members 21. In such case, the unit members 21 will provide the
similar function to the rotation preventing key.
[0118] Next, with reference to FIGS. 3 through 12, there will be
explained a connection method of the present invention for
connecting a subsequent steel pipe pile 1B to a foregoing steel
pipe pile 1 which has been driven firstly, in construction method
of driving into the ground with using e.g. a hydraulic hammer.
[0119] In this connection method of connecting the pair of steel
pipe piles 1A, 1B, the above-described joint mechanism is
employed.
[0120] Firstly, as shown in FIG. 1 and FIG. 3, the four opening
unit members 21A and the four standard unit members 21B will be
disposed side by side in alteration with engaging the respective
engaging projecting portions 24A (24) with the engaging sunk
portion 14A (14) of the inner joint 10A provided at the upper end
of the firstly driven one steel pipe pile 1A, whereby the
cylindrical outer joint 20 will be formed around the inner joint
10A, as illustrated in FIG. 4.
[0121] Next, as shown in FIG. 5 and FIG. 6, relative to the steel
pipe pile 1A, the other steel pipe pile 1B will be suspended, and
the engaging projecting portions 24B (24) of the opening unit
members 21A and the standard unit members 21B constituting the
outer joint 20 will be engaged with the engaging sunk portion 14B
(14) of the inner joint 10B, whereby the inner joints 10A, 10B of
the pair of steel pipe piles 1A, 1B will be disposed at
predetermined positions inside the outer joint 20.
[0122] Next, as shown in FIGS. 7 through 9, the split key member 31
will be inserted into the opening portion 22 of the opening unit
member 21A. Then, the split key member 31 inserted into the opening
portion 22 will be slid along the longitudinal direction of the key
groove. And, the next split key member 31 will be inserted into the
opening portion 22.
[0123] Upon completion of insertion of a predetermined number of
split key members 31, as shown in FIGS. 10 through 12, the closing
member 32 inserted into the opening portion 22 will be fixed with
using the bolt 33, thus closing this opening portion 22.
[0124] As described above, the pair of steel pipe piles 1A, 1B can
be connected to each other so as not to be movable relative to each
other in the longitudinal direction of the steel pipe piles 1.
[0125] Lastly, the rotation preventing key will be disposed across
the rotation preventing groove consisting of the counter bore
portion formed in the outer circumferential face of the base
portion 1 of the inner joint 10 in opposition to the counter bore
portion formed in the outer circumferential face of the outer joint
20, whereby the pair of steel pipe piles 1A, 1B are connected to
each other not to be movable relative to each other in the
circumferential direction of the steel pipe piles 1A also.
[0126] Incidentally, the arrangement of constituting the outer
joint 20 in the inventive joint mechanism of the plurality of unit
members 21 achieves the following advantage in addition to the
advantage of manufacture cost reduction described above.
[0127] The unit members 21 together constituting the outer joint 20
are formed by splitting a cylindrical body formed of cast steel
into eight equal pieces.
[0128] This unit member 21 can also be formed of a cylindrical body
whose height along the longitudinal direction of the steel pipe
piles 1 has a reference distance to be disposed across and between
the inner joint 10A and the inner joint 10B when the inner joint
10A and the inner joint 10B are placed in contact with each other,
or of a cylindrical body having a distance slightly longer than the
above reference distance, e.g. longer by 0.5 mm approximately or of
a cylindrical body having a distance longer by 1.0 mm approximately
than the same. Incidentally, the unit member 21 formed of the
cylindrical body having the above-described reference distance
constitutes the "reference unit member 21C", whereas the unit
member 21 formed of a cylindrical body having such longer distance
than the reference distance constitutes the "extended unit member
21D". Meanwhile, the reference unit member 21C and the extended
unit member 21D, if provided with the opening portion 22, will
constitute also "the opening unit member 21A and will constitute
the "standard unit member 21B" if not provided with the opening
portion 22.
[0129] At the upper and lower end portions of the extended unit
member 21D, like the reference unit member 21C, there are provided
engaging projecting portions 24A, 24B to come into engagement with
the engaging sunk portions 14A, 14B of the inner joints 10, when
the unit member 21 is disposed circumferentially of the inner
joints 10. In the inner circumference of the extended unit member
21D, like the reference unit member 21C, there are formed two lines
of annular inward circumferential grooves 23 (23A, 23B).
[0130] The distance between the pair of inward circumferential
grooves 23 (23A, 23B) of the reference unit member 21C is set to be
equal to the distance between the pair of outward circumferential
grooves 13 (13A, 13B, when the inner joint 10A and the inner joint
10B are placed in contact with each other.
[0131] The distance between the pair of inward circumferential
grooves 23 (23A, 23B) of the extended unit member 21D is set to be
equal to the distance between the pair of outward circumferential
grooves 13 (13A, 13B, when the inner joint 10A and the inner joint
10B are placed apart from each other.
[0132] The distance between the pair of inward circumferential
grooves 23 (23A, 23B) of the extended unit member 21D is 0.5 mm or
1.0 mm longer than the reference distance.
[0133] Namely, the distance between the inward circumferential
grooves 23 (23A, 23B) in the extended unit member 21D is set longer
than the distance between the inward circumferential grooves 23
(23A, 23B) in the reference unit member 21C. Incidentally, above
described 0.5 mm and 1.0 mm are only exemplary, and actually any
appropriate value will be set based on e.g. the diameter of the
steel pipe pile 1 or dimensional tolerance thereof.
[0134] If the outer joint 20 is formed of the reference unit
members 21C, mutually opposing faces of the inner joint 10A of the
steel pipe pile 1A and the inner joint 10B of the steel pipe pile
1B to be connected to each other will come into contact with each
other.
[0135] On the other hand, if the outer joint 20 is formed of the
extended unit members 21D having the length which is 0.5 mm longer
than the reference distance, a gap of 0.5 mm will be formed between
mutually opposing faces of the inner joint 10A of the steel pipe
pile 1A and the inner joint 10B of the steel pipe pile 1B.
Similarly, if the outer joint 20 is formed of the extended unit
members 21D having the length which is 1.0 mm longer than the
reference distance, a gap of 1.0 mm will be formed between mutually
opposing faces of the inner joint 10A of the steel pipe pile 1A and
the inner joint 10B of the steel pipe pile 1B.
[0136] Then, if a group of outer joints 20 having different lengths
in the longitudinal direction of the steel pipe pile 1 are prepared
in stock, then, when there arises a situation of the posture of the
firstly driven steel pipe pile 1A being deviated from the posture
along the perpendicular direction, by using the reference unit
member 21C and the extended unit member 21D in combination to
dispose e.g. the reference unit member 21C on the left side in the
drawing and dispose the extended unit member 21D on the right side,
the subsequent steel pipe pile 1B can be driven with a posture
along the perpendicular direction, so that the steel pipe piles 1A,
1B can be connected to each other with correcting the postures
thereof along the perpendicular direction. Since the inward
circumferential groove 23 (23A, 23B) has such a width with some
"play" relative to the split key member 31, even when the steel
pipe piles 1A, 1B are tilted relative to each other, the sliding
movement of the split key member 31 along the longitudinal
direction of the key groove will not be interfered.
[0137] In the foregoing embodiment, the opening portions 22 of the
outer joint 20 are provided centrally of the opening unit member
21A. Instead, the opening portions 22, as shown in FIG. 14 for
instance, can be formed across and between two adjacent unit
members 21. Further alternatively as shown in FIG. 15, the opening
portions 22 can be formed with their upper and lower positions
being different within the opening unit member 21A. With such
arrangement of offsetting the forming positons of the opening
portions 22 to the left/right side, it becomes possible to restrict
reduction in the rigidness of the opening unit member 21A, as
compared with a case of forming these opening portions 22 side by
side vertically.
[0138] In the foregoing embodiment, the splitting face of the unit
member 21 constituting the outer joint 20 is formed flat. Instead,
as shown in FIG. 16 or 17, mutually opposing faces of adjacent unit
members 21 may be provided with mutually engaging portions. In
addition to the engagement between the engaging projecting portion
24 and the engaging sunk portion 14, mutual engagement between the
unit members 21 adjacent each other will prevent detachment of the
unit members 21 to the outside.
[0139] In the foregoing embodiment, the outer joint 20 is formed of
the unit members 21 provided as eight equal parts. Instead, the
outer joint 20 can be formed directly of a cylindrical body formed
of cast steel as shown in FIG. 18. In this case, as shown in FIG.
19, the inner joint 10 may omit the engaging sunk portion 14.
However, during an operation of connecting the steel pipe pile 1A
and the steel pipe pile 1B to each other, there will be needed a
mechanism and a work for retaining the outer joint 20 relative to
the circumference of the inner joints 10 until the split key
members 31 are inserted into the key groove.
[0140] As a solution to the above problem, as shown in FIG. 20, an
engaging step portion 15 for retaining the outer joint 20 to the
circumference of the inner joint 10 may be provided in at least the
inner joint 10A of the steel pipe pile 1A.
[0141] Further, as shown in FIG. 21, the outer circumferential face
of the outer joint 20 may not be formed flush with the outer
circumferential face of the base portion 11 of the inner joint
10.
[0142] In the foregoing embodiment, respecting the inner joints 10
and the outer joint 20, the configurations thereof obtained by
working a cylindrical body formed of cast iron into the respective
predetermined shape were explained. However, the invention is not
limited to such embodiment. For instance, as shown in FIG. 22, the
inner joints and the outer joint 20 can be formed of straight steam
steel pipes. Incidentally, the tubular body 2 can be formed of a
spiral steel pipe.
[0143] Such straight steam steel pipe is manufactured generally by
using a sheet rolling technique comprising forming a flat-plate
like steel sheet into a cylindrical shape with using a huge roll or
press and welding the bonding portion 3 from the inner and outer
faces thereof. The sheet rolling technique is more inexpensive than
other techniques such as the ring forging technique used for
manufacturing a seamless steel pipe, with much lower costs than the
costs required for the latter technique. By forming the inner
joints 10 and the outer joint 20 of straight seam steel pipes, the
inner joints 10 and the outer joint 20 can be obtained
inexpensively.
[0144] However, the straight seam steel pipe, due to the presence
of the bonding portion 3 along its longitudinal direction, suffers
non-uniformity in the circumferential direction unlike the seamless
steel pipe, thus being unable to obtain uniform rigidness in the
circumferential direction, hence being less resistant to inside
pressure or torsion.
[0145] Further, in the opening unit member 21A and the standard
unit member 21B constituting the outer joint 20, the
circumferential portion of the opening unit member 21A where the
opening portions 22 are formed has lower rigidness due to the
smaller amount of material at the opening portions 22 as compared
with the portion of the opening unit member 21A where such opening
portions 22 are not formed or with the standard unit member
21B.
[0146] Therefore, the bonding portion 3 is provided in the standard
unit member 21B.
[0147] By the arrangement of avoiding overlap between the
circumferential portion formed with the opening portion 22 and the
bonding portion 3 along the longitudinal direction of the straight
seam steel pipe, it is possible to avoid excessive reduction in the
rigidness of one portion in the outer joint 20 as compared with the
other portion thereof
[0148] Also, preferably, in the outer joint 20, the circumferential
portion of the opening unit member 21A where the opening portion 22
is formed and the standard unit member 21B are disposed
circumferentially relative to the inner joint 10A and the inner
joint 10B, at positions different from the positions where the
bonding portions 3 are formed in the inner joint 10A and the inner
joint 10B.
[0149] By the arrangement of avoiding overlap between the
circumferential portion of the outer joint 20 having lower
rigidness and the circumferential portions of the inner joint 10A
and the inner joint 10B having lower rigidness along the
longitudinal direction of the straight seam steel pipe, it is
possible to avoid excessive reduction in the rigidness of a certain
portion of the joint mechanism as compared with the other portion
thereof.
[0150] Incidentally, preferably, the inner joint 10A and the inner
joint 10B are configured to be connected such that the respective
bonding portions 3 thereof are not overlapped along the
longitudinal direction of the steel pipe piles 1.
[0151] The joint mechanism according to the present invention may
be used not only for the foundation piles for structure
installment, but also for steel pipes such as soil retaining steel
pipe sheet piles, anti-landslide piles, pier posts, etc.
[0152] The foregoing embodiments are only specific non-limiting
examples of the present invention. The description thereof does not
limit the scope of the present invention in any way. The specific
arrangements of the respective parts or portions thereof can be
modified in any way appropriately as log as the intended
advantageous functions/effects of the present invention can be
achieved.
DESCRIPTION OF REFERENCE MARKS/NUMERALS
[0153] 1: steel pipe pile (steel pipe) [0154] 2: tubular body
[0155] 10: inner joint [0156] 11: base portion [0157] 12: inner
fitting portion [0158] 13: outward circumferential groove (engaged
portion) [0159] 14: engaging sunk portion [0160] 20: outer joint
[0161] 21: unit member [0162] 21A: opening unit member [0163] 21B:
standard unit member [0164] 21C: reference unit member [0165] 21D:
extended unit member [0166] 22: opening portion [0167] 23: inward
circumferential groove [0168] 24: engaging projecting portion
[0169] 30: key member [0170] 31: split key member [0171] 32:
closing member [0172] 33: bolt
* * * * *