JP4369029B2 - Flexible joint - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention is a flexible joint that is attached to a tube body such as a box culvert or shield tunnel buried in the ground or underwater, and exhibits a water stop function while allowing relative displacement in each direction between adjacent tube bodies. It is about.
[0002]
[Prior art]
Conventionally, at the joints between tubular bodies such as box culverts, which are cylindrical rigid members, follow the relative displacement between the tubular bodies caused by ground subsidence, earthquakes, etc., and groundwater or the like has entered the structure. Or, a flexible joint is used to prevent outflow.
[0003]
For example, as a flexible joint for a box culvert, as shown in FIG. 3, both ends of the elastic member 11 constituting the flexible joint main body are attached to the tubular body, and a space between the two attached parts is formed in a bellows shape. Things are known. The tubular body to which the flexible joint is attached is a cylindrical rigid member 31 made of concrete. Generally, a steel frame 32 having an L-shaped cross section is embedded in the end of the cylindrical rigid member 31. It is.
[0004]
And the attachment part in the both ends of the elastic member 11 is connected to the L-shaped steel frame body 32 of the cylindrical rigid member 31 which adjoins each other by the fastener (nut) 13 through the presser fitting 12, and the figure is shown. A flexible joint as shown in FIG. That is, the flexible joint here allows the relative displacement in each direction of the cylindrical rigid member 31 by the elastic member 11, and when a water pressure such as ground water is applied, the bellows-like elastic member is initially formed. 11 is deformed in a semicircular shape as indicated by a dotted line in FIG. 3 and exhibits a water stop function.
[0005]
Here, the fixing force between the elastic member 11 and the L-shaped steel frame 32 is determined by the frictional force generated by the fastener (nut) 13, and the water stop function is a cross-sectional view in the vicinity of the mounting portion. As shown in FIG. 4 (A), this is exhibited by the convex band 11A provided at the contact portion of the elastic member 11 with the L-shaped steel frame 32.
[0006]
On the other hand, as shown in FIG. 4B, the rubber flexible expansion joint used for a shield tunnel or the like has a thick wall at the end portion in the attachment portion with the tubular rigid member 31 connected to the tunnel segment. There is also a flexible joint using the formed elastic member 21 and the presser fitting 22 that matches the shape of the mounting portion.
[0007]
In this case, the fixing force and the water stopping force between the elastic member 21 and the cylindrical rigid member 31 are the pulling force generated by the frictional force generated by the fastener (nut) 23 and the presence of the inclined surface 21A formed on the elastic member 21. It is determined by the sum of the force components in the horizontal and vertical directions.
[0008]
[Problems to be solved by the invention]
However, in the flexible joint shown in FIG. 4 (A), the fixing force and the water stopping force are such that the finished state of the contact portion between the elastic member 11 and the L-shaped steel frame 32 and the fastening of the fastener (nut) 13 are not affected. Since it is easy to be affected by the applied force, the creep of the elastic member 11 and the like, and the performance may not always be constant, it has been necessary to make an over-design that allows for greater safety than necessary.
[0009]
On the other hand, in the flexible joint shown in FIG. 4B, such an influence can be avoided, but the presser fitting 22 must be manufactured according to the shape of the mounting portion of the elastic member 21, and the productivity and There was a problem that economy was bad. In addition, when the pulling force is applied to the elastic member 21, the presser fitting 22 is lifted by the inclined surface 21A, and there is a concern that the frictional force is reduced on the flat surface 21B near the inclined surface 21A. .
[0010]
[Problems to be solved by the invention]
Accordingly, the present invention improves such a conventional flexible joint, and provides a highly reliable flexible joint that can always obtain sufficient fixing force and water stopping power without deteriorating productivity and economy. It is intended to do.
[0011]
[Means for Solving the Problems]
The present invention has been made in order to solve the above problems, and the gist of the present invention is that the attachment portions with the cylindrical rigid member on both ends of the elastic member constituting the flexible joint body are on the end side. The present invention relates to a flexible joint that has an inclined surface that gradually increases in thickness, and the presser fitting is disposed in the inclined surface. Preferably, the presser fitting is a flat plate having no change in thickness.
[0012]
Here, the elastic member is attached to the cylindrical rigid member by the fastener via the presser fitting, but the presser fitting and the fastener are preferably in surface contact. To do this, for example, a taper washer is interposed between the presser fitting and the fastener to correct the inclination of the contact surface between the presser fitting and the fastener. Moreover, the inclination of a contact surface can also be correct | amended by providing a notch in the contact surface with the fastener in a presser fitting.
[0013]
It is even more preferable to provide a protrusion on the elastic member outside the presser fitting. This is because it serves as a stopper for the presser fitting and a guide for attaching the presser fitting.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
The flexible joint of the present invention comprises at least an elastic member constituting the joint body, a presser fitting, and a fastener. As this elastic member, for example, a rubber plate or a plate-like body in which reinforcing fibers are embedded in rubber can be suitably used. In addition, a plated steel plate, a stainless steel plate, or the like can be suitably used as the presser fitting, and bolts and nuts are usually used as fasteners, but are not limited thereto.
[0015]
That is, as in the conventional case, at the connection part between tubular bodies such as box culverts which are cylindrical rigid members, the flat elastic member is bent into a substantially Ω shape or a bellows shape, or the elastic member is formed into a substantially Ω shape from the beginning. It is molded into a bellows shape and attached to the cylindrical rigid member with a fastener through a presser fitting. Therefore, the occurrence of relative displacement between the tubular bodies due to crustal movement or the like can be allowed, and water tightness is provided on the contact surface between the elastic member and the cylindrical rigid member.
[0016]
A characteristic point of the flexible joint of the present invention is that the attachment portions with the cylindrical rigid member on both ends of the elastic member have inclined surfaces that gradually increase in thickness toward the end. is there. The presser fitting is arranged in the inclined surface. The reason why the inclined surface is provided is to make it difficult to pull out by giving a wedge effect to the presser fitting. That is, by utilizing not only the fixing force due to friction as in the conventional flexible joint shown in FIG. 4 (A), but also the pullout resistance generated by inclining the contact surface with the presser fitting, Even when loosening of the fastener or creep of the elastic member occurs, it is difficult to pull out and the reliability is further improved.
[0017]
Further, in the present invention, since the presser fitting is arranged in the inclined surface, the shape of the presser fitting becomes extremely simple, and the productivity and economy are excellent. That is, since the conventional presser fitting shown in FIG. 4B has a cross-sectional shape composed of an inclined surface and a flat surface, the shape is not only complicated but also the horizontal movement is restricted by the inclined surface. Therefore, it is necessary to accurately provide the position of the through hole of the fastening bolt. Therefore, the manufacturing cost of the presser fitting becomes very high.
[0018]
On the other hand, if the presser fitting is disposed only on the inclined surface of the elastic member as in the present invention, the discontinuous portions such as the inclined surface and the flat surface are eliminated, and the presser fitting is not simply a plate-like body, By sliding the surface, it is possible to easily align the bolt through holes. In particular, if a flat plate having no change in thickness is used, a press fitting can be obtained using an inexpensive material that is not specially processed.
[0019]
However, it is preferable that the presser fitting and the fastener are brought into surface contact so that bending stress is not generated in the fastener. For that purpose, for example, the shape of the presser fitting is opposite to the elastic member, and it has an inclined surface where the thickness gradually decreases toward the end, or when the thickness is not changed, it is fastened with the presser fitting. A taper washer may be interposed between the presser and the contact surface between the presser fitting and the fastener may be cut to correct the inclination of the contact surface between the presser fixture and the fastener.
[0020]
The angle of the inclined surface of the elastic member is not particularly limited, but is preferably 5 ° to 20 °. If the angle is less than 5 °, the wedge effect may not be sufficiently exhibited. If the angle exceeds 20 °, it is difficult to correct the inclination of the contact surface between the presser fitting and the fastener.
[0021]
Further, if a protrusion is provided on the elastic member outside the presser fitting, the protrusion becomes an obstacle and the elastic member becomes more difficult to pull out. The protrusion is particularly effective when the angle of the inclined surface of the elastic member is relatively small. Although the height of the protrusion is not particularly limited, it is preferable to set the height to 5 mm or more in consideration of sufficient catching with the presser fitting.
[0022]
Such a flexible joint of the present invention is a joint part of a tunnel excavated below the groundwater level such as a box culvert or a shield tunnel, a joint part that becomes a groundwater level in the underground part of a building, a water channel, It can be used widely in joints of civil engineering structures where liquids such as reservoirs and tanks are present, and is economical and reliable in all applications, whether square or circular. Very flexible joint.
[0023]
In applications such as box culverts, the cylindrical rigid member can be applied to a single member such as reinforced concrete or a steel frame member embedded in the end of the cylindrical rigid member. Here, in the latter case, each of the adjacent steel frames can be made flexible at the same time as the manufacture of the steel frame by fixing the attachment portions of the flexible joints to the two steel frames in advance. The joints can be connected as expected, and it is not necessary to separately attach a flexible joint after manufacturing the cylindrical rigid member. Therefore, it is not necessary to perform excavation of the ground in the vicinity of the connecting portion of the cylindrical rigid member for the attachment work, and the flexible joint can be made into an endless structure with a predetermined circumferential length. The reliability of the water stop performance is further improved.
[0024]
On the other hand, in applications such as shield tunnels, an elastic member is attached between a pair of cylindrical rigid members connected to a general segment, and is incorporated into a seam such as a shield tunnel as a tubular flexible joint of both end flanges.
[0025]
【Example】
Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a perspective view showing a flexible joint of the present invention. Here, the cylindrical rigid member 31 is a box culvert in which a steel frame 32 is embedded with anchor bolts 33 at the end of reinforced concrete. The elastic member 1 serving as a flexible joint body is a rubber plate having a thickness of 10 mm, and a fiber reinforcing material 1C having a thickness of 0.7 mm to 1.0 mm made of nylon fiber or polyester fiber is contained therein. It is inserted into a strength member.
[0026]
And both ends of the elastic member 1 are watertight attachment portions with the steel frame 32 in the cylindrical rigid member 31, and through holes of the anchor bolts 33 are provided here. Further, the presser fitting 2 has a flat contact surface with the elastic member 1 so that the elastic member 1 and the presser fitting 2 are in close contact with each other, and a fastener (nut) 3 is attached to the anchor bolt 33 penetrating to the taper washer 4. The elastic member 1 is pressure-bonded to the steel frame 32 by tightening.
[0027]
The outer shape of the elastic member 1 is substantially Ω-shaped as shown in FIG. 1, and even if a relative displacement occurs between adjacent cylindrical rigid members 31 due to crustal deformation or the like, the displacement should be sufficiently allowed. Can do. However, the initial state of the outer shape of the elastic member 1 may be an accordion-like shape, and the outer shape is determined in consideration of manufacturing convenience, mounting workability, and the like, and thus affects flexibility and water stoppage. It does not affect.
[0028]
FIG. 2 is a cross-sectional view showing the flexible joint of the present invention. As shown in FIG. 2, the attachment portions with the cylindrical rigid member 31 on both ends of the elastic member 1 gradually increase in thickness toward the end, and become an inclined surface 1A having an angle θ = 5 °. . And the protrusion 1B is provided in the tip of 1 A of inclined surfaces, and the level | step difference of height H = 5mm is formed.
[0029]
The presser fitting 2 is arranged in the inclined surface 1A of the elastic member 1 so that a wedge effect is obtained. Moreover, the fixing force of the elastic member 1 is further improved by the presence of the protrusion 1B. The presser fitting 2 has a width of 65 mm, a thickness of 16 mm, and is simply a flat plate of SS400 (or SUS304 or SM490A). Therefore, the presser fitting 2 is excellent in productivity and economical efficiency. The adjustment can be performed very easily because it is only necessary to move laterally along the inclined surface 1A.
[0030]
Here, the pressing force by the presser fitting 2 is obtained by the tightening force of the anchor bolt 33 that penetrates the elastic member 1 and the presser fitting 2 and is embedded in the cylindrical rigid member 31. That is, the pulling resistance is exhibited by the friction of the contact surface between the elastic member 1 and the steel frame 32 and the axial force of the anchor bolt 33.
[0031]
However, if the fastener (nut) 3 is tightened in this state, bending stress is generated in the anchor bolt 33 because the upper surface of the presser fitting 2 is inclined. Accordingly, the inclination of the contact surface between the presser fitting 2 and the fastener (nut) 3 is corrected to bring them into surface contact so that bending stress is not generated in the anchor bolt 33 and the tightening force of the anchor bolt 33 is reduced. In the example shown in FIG. 2 (A), a taper washer 4 is interposed so as to act evenly on the mounting portion of the elastic member 1.
[0032]
As shown in FIG. 2 (B), the same effect can be obtained even if the presser fitting 2 is provided with a notch 2A for inclination correction.
[0033]
【The invention's effect】
The flexible joint of the present invention has an inclined surface in which the attachment portions with the cylindrical rigid member on both ends of the elastic member constituting the joint main body gradually increase in thickness toward the end side, Since it is arranged in the inclined surface, the shape of the presser fitting can be made into a very simple plate shape while having a wedge effect, which is excellent in productivity and economy. In addition, the presser fitting can be easily aligned by sliding the inclined surface.
[0034]
In other words, even if loosening of the fastener or creeping of the elastic member occurs by causing the fastening force of the fastener to act as a fixing force in addition to the frictional force without deteriorating productivity and economy. A sufficient fixing force and water stopping force can be obtained, and this is a highly reliable flexible joint.
[Brief description of the drawings]
FIG. 1 is a perspective view showing a flexible joint of the present invention.
FIG. 2 is a cross-sectional view showing the flexible joint of the present invention.
FIG. 3 is a cross-sectional view showing a conventional flexible joint.
FIG. 4 is a cross-sectional view showing the vicinity of a mounting portion of a conventional flexible joint.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Elastic member 1A ... Inclined surface 1B ... Protrusion 1C ... Fiber reinforcement 2 ... Holding metal 2A ... Notch 3 ... Fastener 4 ... Taper washer 11 ... Elastic member 11A ... Convex band 12 ... Holding metal 13 ... Fastening 21 ... Elasticity 21A ··· Inclined surface 21B ··· Flat surface 22 · Presser fitting 23 · Fastener 31 · Cylindrical rigid member 32 · Steel frame 33 · Anchor bolt

Claims (6)

A flexible joint used between adjacent cylindrical rigid members, comprising an elastic member constituting a flexible joint main body, a presser fitting, and a fastener, and the cylinders at both ends of the elastic member The flexible joint is characterized in that the attachment portion with the shaped rigid member has an inclined surface whose thickness gradually increases toward the end side, and the presser fitting is disposed in the inclined surface. 2. The flexible joint according to claim 1, wherein the presser fitting is a flat plate having no change in thickness. The flexible joint according to claim 1 or 2, wherein the presser fitting and the fastener are in surface contact. 4. The flexible joint according to claim 3, wherein the inclination of the contact surface between the presser fitting and the fastener is corrected by interposing a taper washer between the presser fitting and the fastener. 4. The flexible joint according to claim 3, wherein the inclination of the contact surface is corrected by providing a cut in the contact surface of the presser fitting with the fastener. The flexible joint according to claim 1, wherein a protrusion is provided on the elastic member outside the presser fitting.

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