Patent Description:
For example, as illustrated in <FIG> and <FIG>, such a pipe transport device is conventionally used when a first pipe <NUM> and a second pipe <NUM> are joined to a rearmost pipe <NUM> of a pipeline in a pipeline construction shaft <NUM>. A pipe transport device <NUM> can travel on rails <NUM> in the pipeline construction shaft <NUM> and includes a first transport trolley <NUM> for transporting the first pipe <NUM>, a second transport trolley <NUM> for transporting the second pipe <NUM>, and a coupling bar <NUM> coupling the first transport trolley <NUM> and the second transport trolley <NUM>. One end of the coupling bar <NUM> and the first transport trolley <NUM> are detachably coupled to each other via a first coupling pin <NUM> while the other end of the coupling bar <NUM> and the second transport trolley <NUM> are detachably coupled to each other via a second coupling pin <NUM>.

By using the pipe transport device <NUM> thus configured, the pipes are joined as follows:.

First, as illustrated in <FIG>, the first pipe <NUM> is loaded on the first transport trolley <NUM>, and the second pipe <NUM> is loaded on the second transport trolley <NUM>. In this state, the pipe transport device <NUM> is moved forward to be stopped near the rearmost pipe <NUM>.

Subsequently, the first coupling pin <NUM> is removed to decouple the coupling bar <NUM> and the first transport trolley <NUM>, the second coupling pin <NUM> is removed to decouple the coupling bar <NUM> and the second transport trolley <NUM>, and the coupling bar <NUM> is removed, so that the first transport trolley <NUM> and the second transport trolley <NUM> are separated from each other.

Thereafter, the first transport trolley <NUM> is moved forward, and one end of the first pipe <NUM> is joined to another end of the rearmost pipe <NUM>.

After that, as illustrated in <FIG>, a sleeper <NUM> is set under the first pipe <NUM>, the first pipe <NUM> is laid on the sleeper <NUM>, and the first transport trolley <NUM> is moved backward to be drawn from beneath the first pipe <NUM> to the near side of the first pipe <NUM>.

The first transport trolley <NUM> thus drawn is lifted and collected into the second pipe <NUM> loaded on the second transport trolley <NUM>.

The second transport trolley <NUM> is then moved forward, so that one end of the second pipe <NUM> on the second transport trolley <NUM> is joined to the other end of the first pipe <NUM> joined to the rearmost pipe <NUM>.

See <CIT> for a description on the pipe transport device and the pipe joining method.

In the conventional form, however, the first pipe <NUM> is joined to the rearmost pipe <NUM> as illustrated in <FIG>, and then the first transport trolley <NUM> drawn from beneath the first pipe <NUM> to the near side of the first pipe <NUM> is lifted and transferred into the second pipe <NUM> on the second transport trolley <NUM>. Thus, if the first transport trolley <NUM> is large and heavy, it takes much time and effort to lift and transfer the first transport trolley <NUM> into the second pipe <NUM> on the second transport trolley <NUM>.

Moreover, in the conventional form, the first pipe <NUM> is loaded on the first transport trolley <NUM>, and the second pipe <NUM> is loaded on the second transport trolley <NUM>. In this state, the coupling bar <NUM> is hidden under the first and second pipes <NUM> and <NUM>. A space under the first pipe <NUM> and a space under the second pipe <NUM> are quite small. Thus, when the first coupling pin <NUM> is removed to decouple the coupling bar <NUM> and the first transport trolley <NUM>, the first pipe <NUM> may interfere with the removal of the first coupling pin <NUM>, making the removal difficult to perform. Moreover, when the second coupling pin <NUM> is removed to decouple the coupling bar <NUM> and the second transport trolley <NUM>, the second pipe <NUM> may interfere with the removal of the second coupling pin <NUM>, making the removal difficult to perform.

Hence, it takes time and effort to remove the coupling bar <NUM> to separate the first transport trolley <NUM> and the second transport trolley <NUM>.

An object of the present invention is to provide a pipe transport device configured for use inside a pipeline construction shaft so as to reduce time and effort to remove a coupler to separate the first transport trolley and the second transport trolley. Solution to Problem.

The present invention is directed to a pipe transport device according to claim <NUM>. Advantageous embodiments of the invention are characterized by the features of the dependent claims.

According to the present invention, after joining the first pipe to the rearmost pipe, the first transport trolley is drawn to the near side of the first pipe, the first transport trolley is drawn below the second pipe loaded on the second transport trolley, the second transport trolley is moved forward with the first transport trolley, and the second pipe on the second transport trolley is joined to the rearmost pipe, thereby saving time and effort to lift and transfer the first transport trolley into the second pipe on the second transport trolley.

The operation part is operated to operate the switching device, so that the engaging member is switched from the engaged state to the disengaged state by the switching device, and one of the first transport trolley and the second transport trolley is disengaged from the coupler. At this point, the operation part can be operated without interfering with the first pipe and the second pipe. Thus, even if a small space is formed under the first pipe loaded on the first transport trolley or the second pipe loaded on the second transport trolley, one of the transport trolleys can be easily disengaged from the coupler by operating the operation part. This can reduce time and effort to remove the coupler to separate the first transport trolley and the second transport trolley.

Embodiments of the present invention will be described below in accordance with the accompanying drawings.

In a first embodiment, as illustrated in <FIG>, <FIG>, and <FIG>, reference numeral <NUM> denotes a pipeline construction shaft that is constructed underground by a shield machine and is subjected to primary lining. Constructed in the pipeline construction shaft <NUM> are a pipeline <NUM> including a plurality of pipes joined together and a pair of left and right rails <NUM> (an example of rails). The rails <NUM> each include a plurality of separate rails <NUM> that are joined to one another.

The pipeline construction shaft <NUM> includes a pipe transport device <NUM> and an automotive vehicle <NUM>, for example, a battery powered car for traveling the pipe transport device <NUM>. As illustrated in <FIG>, the pipe transport device <NUM> includes a first transport trolley <NUM> for transporting a first pipe <NUM>, a second transport trolley <NUM> for transporting a second pipe <NUM>, and a coupling device <NUM> for coupling the first transport trolley <NUM> and the second transport trolley <NUM>.

A pipe constituting the pipeline <NUM>, a rearmost pipe <NUM> of the pipeline <NUM>, the first pipe <NUM>, and the second pipe <NUM> each have a spigot <NUM> on one end and a socket <NUM> on the other end. The automotive vehicle <NUM> is detachably coupled to the second transport trolley <NUM>.

As illustrated in <FIG> and <FIG>, the first transport trolley <NUM> can travel on rails <NUM> in the pipeline construction shaft <NUM> and includes a trolley body <NUM>, a plurality of traveling wheels <NUM> provided on the trolley body <NUM>, a plurality of trolley jacks <NUM> (an example of a lifting device) for raising and lowering the first pipe <NUM> supported on the trolley body <NUM>, and temporary placing plates <NUM> for temporarily placing the removed separate rails <NUM>.

The trolley body <NUM> includes a pair of support frames <NUM> longitudinally supporting the first pipe <NUM> and a coupling frame <NUM> coupled between the support frames <NUM>. The traveling wheels <NUM> can roll on the rails <NUM>, the trolley jacks <NUM> are provided on the trolley body <NUM>, and the temporary placing plates <NUM> are provided on both side ends of the trolley body <NUM>.

As illustrated in <FIG>, <FIG>, <FIG>, and <FIG>, the second transport trolley <NUM> is identical in configuration to the first transport trolley <NUM>, and the second pipe <NUM> is supported on the trolley body <NUM>. As illustrated in <FIG> and <FIG>, the trolley body <NUM> of the second transport trolley <NUM> has a coupling plate <NUM> on one end. The coupling plate <NUM> has a vertically penetrating engagement hole <NUM>.

The coupling device <NUM> has a coupler <NUM> one end of which is attachable and detachable to and from the trolley body <NUM> of the first transport trolley <NUM> and the other end of which is attachable and detachable to and from the trolley body <NUM> of the second transport trolley <NUM>. Furthermore, the coupler <NUM> can be divided into a first coupler <NUM> and a second coupler <NUM>.

As illustrated in <FIG>, <FIG>, and <FIG>, one end of the first coupler <NUM> is detachably coupled to the trolley body <NUM> of the first transport trolley <NUM> via a first coupling pin <NUM>. As illustrated in <FIG> and <FIG>, the other end of the first coupler <NUM> and one end of the second coupler <NUM> are detachably coupled to each other via a plurality of junction coupling pins <NUM>.

As illustrated in <FIG>, the second coupler <NUM> is a channel-shaped member that is opened on the underside and has a support plate <NUM> on the top surface of the other end. The support plate <NUM> has a holding hole <NUM> vertically penetrating the second coupler <NUM>.

The second coupler <NUM> includes an engagement pin <NUM> (an example of an engaging member) that can be engaged and disengaged into and from the second transport trolley <NUM> and a switching device <NUM> for switching the engagement pin <NUM> from an engaged state to a disengaged state.

The engagement pin <NUM> is fit into the holding hole <NUM> of the second coupler <NUM> and can be engaged and disengaged into and from the coupling plate <NUM> of the second transport trolley <NUM>. The engagement pin <NUM> can be switched between an engagement position P1 where the engagement pin <NUM> is placed into the engagement hole <NUM> from below and is engaged with the coupling plate <NUM> of the second transport trolley <NUM> as illustrated in <FIG> and <FIG> and a disengagement position P2 where the engagement pin <NUM> is dropped below the engagement hole <NUM> from the engagement position P1 and is disengaged from the coupling plate <NUM> of the second transport trolley <NUM> as illustrated in <FIG> and <FIG>. The engaged state corresponds to a state in which the engagement pin <NUM> is switched to the engagement position P1, whereas the disengaged state corresponds to a state in which the engagement pin <NUM> is switched to the disengagement position P2.

The switching device <NUM> switches the engagement pin <NUM> from the engagement position P1 to the disengagement position P2 and includes a support plate <NUM> that supports the engagement pin <NUM> from below at the engagement position P1, a link rod <NUM> slidable in a pipe length direction A, and an operation lever <NUM> (an example of an operation part) for operating the switching device <NUM> from the outside.

The support plate <NUM> is supported by a support piece <NUM> inside the other end of the second coupler <NUM> and is slidable in the pipe length direction A. The link rod <NUM> is provided in the second coupler <NUM>, the operation lever <NUM> is provided on one end of the link rod <NUM>, and the support plate <NUM> is provided on the other end of the link rod <NUM>.

Provided inside the other end of the second coupler <NUM> is a receiving plate <NUM> that receives the engagement pin <NUM> from below after the engagement pin <NUM> is dropped from the engagement position P1 to the disengagement position P2.

As illustrated in <FIG>, <FIG>, <FIG>, and <FIG>, one end of the second coupler <NUM> has a long hole <NUM> that penetrates vertically and extends in the pipe length direction A. The operation lever <NUM> is inserted into the long hole <NUM> from the inside of the second coupler <NUM>, is protruded above the second coupler <NUM>, and is exposed into a space <NUM> formed between the first pipe <NUM> loaded on the first transport trolley <NUM> and the second pipe <NUM> loaded on the second transport trolley <NUM>.

As illustrated in <FIG>, <FIG>, and <FIG>, the other end of the second coupler <NUM> has a drop preventing member <NUM>. The drop preventing member <NUM> is a member for preventing the second coupler <NUM> from dropping by its own weight (and the weight of the engagement pin <NUM> and the urging force of a coil spring <NUM>, which will be discussed later) when the engagement pin <NUM> is engaged with the coupling plate <NUM> of the second transport trolley <NUM>. The drop preventing member <NUM> is inverted-L-shaped with a vertical plate <NUM> raised on the top surface of the second coupler <NUM> and a horizontal plate <NUM> provided on the upper end of the vertical plate <NUM>.

As illustrated in <FIG>, when the other end of the second coupler <NUM> and the second transport trolley <NUM> are coupled to each other, the coupling plate <NUM> of the second transport trolley <NUM> is held between the support plate <NUM> of the second coupler <NUM> and the horizontal plate <NUM> of the drop preventing member <NUM>, and the horizontal plate <NUM> is engaged with the coupling plate <NUM> from above.

When the other end of the second coupler <NUM> and the second transport trolley <NUM> are coupled to each other, the horizontal plate <NUM> is engaged with the coupling plate <NUM> from above, so that the other end of the second coupler <NUM> can be provisionally (temporarily) laid on the coupling plate <NUM>. Thus, also when the other end of the second coupler <NUM> and the second transport trolley <NUM> are coupled to each other, the second coupler <NUM> can be prevented from dropping by its own weight, facilitating the coupling operation.

The coupling plate <NUM> of the second transport trolley <NUM> is provided with the coil spring <NUM> (an example of an urging member) that urges the engagement pin <NUM> from the engagement position P1 to the disengagement position P2. The coil spring <NUM> is stored in a box-shaped storage member <NUM> provided on the top surface of the coupling plate <NUM>. At the top of the engagement pin <NUM>, a lifting internal thread portion <NUM> is formed for lifting the engagement pin <NUM> switched to the disengagement position P2 and setting the engagement pin <NUM> to the engagement position P1.

With the switching device <NUM> thus configured, as illustrated in <FIG> and <FIG>, the engagement pin <NUM> switched to the engagement position P1 is protruded into the engagement hole <NUM> and is engaged with the coupling plate <NUM> while being supported on the support plate <NUM>. This couples the second coupler <NUM> and the second transport trolley <NUM> via the engagement pin <NUM> and the coupling plate <NUM>. At this point, the coil spring <NUM> is compressed with the operation lever <NUM> switched to a coupling position P3.

Thereafter, as illustrated in <FIG> and <FIG>, the operation lever <NUM> is separated from the coupling position P3 and is switched to a separating position P4, causing the link rod <NUM> to slide in the pipe length direction A in synchronization with the operation lever <NUM> and the support plate <NUM> to retract forward from below the engagement pin <NUM>. With this configuration, the engagement pin <NUM> is dropped, is switched from the engagement position P1 to the disengagement position P2, and is received by the receiving plate <NUM>. Thus, the engagement pin <NUM> is dropped below the engagement hole <NUM> and is separated from the coupling plate <NUM>, thereby decoupling the second coupler <NUM> from the second transport trolley <NUM> as illustrated in <FIG>.

At this point, the engagement pin <NUM> is urged from the engagement position P1 to the disengagement position P2 by the coil spring <NUM> and thus can be securely switched to the disengagement position P2.

As illustrated in <FIG>, reference numeral <NUM> denotes a lifting jig for lifting the pipe in the pipeline construction shaft <NUM>. The lifting jig <NUM> includes a jig frame <NUM>, a holding mechanism <NUM> that holds the opening end of the socket <NUM> of the first pipe <NUM> in a pipe diameter direction B, and a hydraulic jack <NUM>.

The jig frame <NUM> has a backplate part <NUM> and an inner plate part <NUM> and an outer plate part <NUM> that are provided on both ends of the backplate part <NUM>. The backplate part <NUM> has handles <NUM>.

The holding mechanism <NUM> has a pair of a fixed plate <NUM> and a movable plate <NUM> that are opposed to each other in the pipe diameter direction B, and a moving member <NUM> that moves the movable plate <NUM> relative to the fixed plate <NUM>. The fixed plate <NUM> is fixed to the backplate part <NUM>. The jack <NUM> has an extendable ram <NUM> that is attached to the fixed plate <NUM> and penetrates the outer plate part <NUM>.

The moving member <NUM> has a bolt body <NUM> with an external thread on the outer surface, and an engagement piece <NUM> provided on the head of the bolt body <NUM>. The inner plate part <NUM> has a screw hole <NUM> that is internally threaded. The bolt body <NUM> of the moving member <NUM> is rotatably inserted into the screw hole <NUM> with the external thread and the internal thread screwed to each other. The movable plate <NUM> includes an engagement member <NUM> on the top surface. The engagement piece <NUM> has a larger diameter than the bolt body <NUM>. The engagement piece <NUM> and the engagement member <NUM> are engaged with each other.

As indicated by a virtual line in <FIG>, the lifting jig <NUM> thus configured holds the opening end of the socket <NUM> between the fixed plate <NUM> and the movable plate <NUM> and rotates the moving member <NUM> in one direction to bring the movable plate <NUM> close to the fixed plate <NUM>. With this configuration, a clearance C between the fixed plate <NUM> and the movable plate <NUM> in the pipe diameter direction B is reduced, the opening end of the socket <NUM> is sandwiched between the fixed plate <NUM> and the movable plate <NUM>, and the lifting jig <NUM> is attached to the opening end of the socket <NUM>.

In this way, as illustrated in <FIG>, the two lifting jigs <NUM> are attached to the lower part of the opening end of the socket <NUM>, and the rams <NUM> of the jacks <NUM> of the lifting jigs <NUM> are extended so as to press the heads of the rams <NUM> to an inner wall <NUM> of the pipeline construction shaft <NUM>. Thus, the socket <NUM> of the first pipe <NUM> is lifted.

The moving member <NUM> is reversely turned to move the movable plate <NUM> away from the fixed plate <NUM>, thereby increasing the clearance C between the fixed plate <NUM> and the movable plate <NUM> in the pipe diameter direction B. Thus, the lifting jig <NUM> can be removed from the opening end of the socket <NUM>.

Likewise, the socket <NUM> of the second pipe <NUM> can be lifted or the spigot <NUM> can be lifted by using the lifting jigs <NUM>.

A joining method for joining pipes by using the pipe transport device <NUM> and the lifting jigs <NUM> in the pipeline construction shaft <NUM> will be described below.

As illustrated in <FIG>, the first pipe <NUM> is loaded on the trolley body <NUM> of the first transport trolley <NUM> of the pipe transport device <NUM>, the second pipe <NUM> is loaded on the trolley body <NUM> of the second transport trolley <NUM>, and the automotive vehicle <NUM> is caused to travel forward to press the pipe transport device <NUM> forward. Thus, the first transport trolley <NUM> and the second transport trolley <NUM> are moved forward to transport the first pipe <NUM> and the second pipe <NUM>, so that the spigot <NUM> (one end) of the first pipe <NUM> is inserted into the socket <NUM> (the other end) of the rearmost pipe <NUM> of the pipeline <NUM> and is joined thereto.

At this point, the coupler <NUM> is hidden under the first and second pipes <NUM> and <NUM>. Moreover, the trolley jacks <NUM> of the first transport trolley <NUM> vertically adjust the position of the first pipe <NUM>, thereby centering the pipes being joined to each other.

Subsequently, as illustrated in <FIG>, <FIG>, and <FIG>, the two lifting jigs <NUM> are attached to the lower part of the opening end of the socket <NUM> of the first pipe <NUM>, and the rams <NUM> of the jacks <NUM> of the lifting jigs <NUM> are extended to lift the socket <NUM> (the other end) of the first pipe <NUM>. Thus, the first pipe <NUM> is lifted above the first transport trolley <NUM>.

After that, as illustrated in <FIG>, the automotive vehicle <NUM> is caused to travel backward to move the pipe transport device <NUM> rearward, and the first transport trolley <NUM> is drawn from beneath the first pipe <NUM> to the near side of the first pipe <NUM>.

Subsequently, as indicated by virtual lines in <FIG> and <FIG>, the separate rails <NUM> of the rails <NUM> under the first pipe <NUM> are removed and are loaded on the temporary placing plates <NUM> of the first transport trolley <NUM>.

Thereafter, as illustrated in <FIG>, an H-shaped steel support member <NUM> is installed under the socket-side end of the first pipe <NUM>. The rams <NUM> of the jacks <NUM> of the lifting jigs <NUM> are retracted to lower the socket-side end (the other end) of the first pipe <NUM> onto the support member <NUM>, so that the socket-side end of the first pipe <NUM> is supported by the support member <NUM>. Thereafter, the two lifting jigs <NUM> are removed from the opening end of the socket <NUM> of the first pipe <NUM> and are transferred into the second pipe <NUM> so as to be temporarily stored therein. As has been discussed, the socket-side end of the first pipe <NUM> is supported by the support member <NUM>, thereby preventing the socket-side end of the first pipe <NUM> from being displaced downward.

After that, as illustrated in <FIG>, the coupler <NUM> is removed to separate the first transport trolley <NUM> and the second transport trolley <NUM>. Specifically, the first coupling pin <NUM> is removed to decouple the first coupler <NUM> and the first transport trolley <NUM> as indicated by virtual lines in <FIG>, and the junction coupling pins <NUM> are removed to decouple the first coupler <NUM> and the second coupler <NUM> as indicated by virtual lines in <FIG>, so that the first coupler <NUM> between the first transport trolley <NUM> and the second coupler <NUM> is removed. With this configuration, the first coupling pin <NUM> can be removed to separate the first coupler <NUM> and the first transport trolley <NUM> without interfering with the first pipe <NUM>.

Thereafter, as illustrated in <FIG> and <FIG>, the operation lever <NUM> is operated for switching from the coupling position P3 to the separating position P4. This can switch the engagement pin <NUM> from the engagement position P1 to the disengagement position P2 and disengage the second coupler <NUM> from the second transport trolley <NUM> by a remote operation. As illustrated in <FIG>, the second coupler <NUM> is removed from the second transport trolley <NUM>, and the coupler <NUM> between the first transport trolley <NUM> and the second transport trolley <NUM> is removed, thereby separating the first transport trolley <NUM> and the second transport trolley <NUM>.

As illustrated in <FIG>, such an operation by the operation lever <NUM> can be performed at a point remote from the engagement pin <NUM>, that is, a vacant space in front of the spigot <NUM> of the second pipe <NUM>, thereby switching the engagement pin <NUM> from the engagement position P1 to the disengagement position P2 by a remote operation. Hence, when the engagement pin <NUM> is switched from the engagement position P1 to the disengagement position P2, the second pipe <NUM> on the second transport trolley <NUM> does not interfere with the switching.

Thus, even if a small space is formed under the second pipe <NUM> loaded on the second transport trolley <NUM>, the other end of the coupler <NUM> and the second transport trolley <NUM> can be easily disengaged from each other by operating the operation lever <NUM>. This can reduce time and effort to remove the coupler <NUM> to separate the first transport trolley <NUM> and the second transport trolley <NUM>.

The first coupler <NUM> and the second coupler <NUM> that have been thus removed are transferred into the second pipe <NUM> and are temporarily stored therein as illustrated in <FIG>. Furthermore, the second pipe <NUM> loaded on the second transport trolley <NUM> is lifted by the trolley jacks <NUM>.

After that, as illustrated in <FIG>, the first transport trolley <NUM> is pressed to move backward and is drawn below the second pipe <NUM> on the second transport trolley <NUM>. This draws the first transport trolley <NUM> below the second pipe <NUM> along with the separate rails <NUM> removed to be loaded on the temporary placing plates <NUM>.

A space under the second pipe <NUM> is extended upward by lifting the second pipe <NUM> on the second transport trolley <NUM> by using the trolley jacks <NUM>, thereby obtaining a space <NUM> under the second pipe <NUM> so as to draw the first transport trolley <NUM> below the second pipe <NUM>.

Thereafter, as illustrated in <FIG>, the automotive vehicle <NUM> is caused to travel forward to move the second transport trolley <NUM> forward with the first transport trolley <NUM>. As illustrated in <FIG>, the spigot <NUM> of the second pipe <NUM> on the second transport trolley <NUM> is joined to the socket <NUM> of the first pipe <NUM> joined to the rearmost pipe <NUM>.

At this point, the trolley jacks <NUM> of the second transport trolley <NUM> vertically adjust the position of the second pipe <NUM>, thereby centering the pipes being joined to each other.

Subsequently, as illustrated in <FIG>, the two lifting jigs <NUM> are attached to the lower part of the opening end of the socket <NUM> of the second pipe <NUM>, and then the lifting jigs <NUM> lift the socket <NUM> (the other end) of the second pipe <NUM>. Thus, the second pipe <NUM> is lifted above the second transport trolley <NUM>.

After that, as illustrated in <FIG>, the automotive vehicle <NUM> and the first and second transport trolleys <NUM> and <NUM> are moved backward to draw the first and second transport trolleys <NUM> and <NUM> from beneath the second pipe <NUM> to the near side of the second pipe <NUM>. This joins the first pipe <NUM> and the second pipe <NUM> to the rearmost pipe <NUM> of the pipeline <NUM>. The pipeline <NUM> in the pipeline construction shaft <NUM> is extended by repeatedly performing the joining step.

The pipe joining method eliminates the need for lifting the vacant first transport trolley <NUM> and transferring the first transport trolley <NUM> into the second pipe <NUM> on the second transport trolley <NUM>, thereby saving time and effort for the operations.

Furthermore, the vacant first and second transport trolleys <NUM> and <NUM> are collected, and other pipes are transported on the first and second transport trolleys <NUM> and <NUM> and are sequentially joined to the rearmost pipe. The operations can be repeatedly performed.

Moreover, when the operation lever <NUM> is switched from the coupling position P3 (<FIG>) to the separating position P4 (<FIG>), the engagement pin <NUM> drops from the engagement position P1 (<FIG>, <FIG>) so as to be switched to the disengagement position P2 (<FIG>, <FIG>). Thus, the engagement pin <NUM> can be switched from the engagement position P1 to the disengagement position P2 without using a special drive unit, e.g., a motor or a hydraulic cylinder, thereby reducing the consumption of power or the like.

The engagement pin <NUM> is urged from the engagement position P1 to the disengagement position P2 by the coil spring <NUM> and thus can be securely switched to the disengagement position P2.

As indicated by the virtual lines in <FIG>, and <FIG>, the removed separate rails <NUM> are loaded on the temporary placing plates <NUM> of the first transport trolley <NUM>, so that the removed separate rails <NUM> can be easily collected with the first transport trolley <NUM>.

After the second pipe <NUM> is joined to the first pipe <NUM>, the first coupler <NUM> and the second coupler <NUM> can be easily collected from the inside of the second pipe <NUM>.

A second embodiment will be described below. The same members as the members of the first embodiment are indicated by the same reference numerals and the detailed explanation thereof is omitted.

In the second embodiment, a first pipe <NUM> and a second pipe <NUM> are sequentially joined to a rearmost pipe <NUM> of a pipeline <NUM> in a pipeline construction shaft <NUM> by using a pipe transport device <NUM>, lifting jigs <NUM>, and an auxiliary rail device <NUM> (an example of an auxiliary rail device).

As illustrated in <FIG>, the auxiliary rail device <NUM> includes a plurality of auxiliary crossties <NUM> and a pair of left and right auxiliary rails <NUM> supported on the auxiliary crossties <NUM>. The auxiliary rail <NUM> includes a tilted rail part <NUM> (an example of a tilted part) that is diagonally tilted upward from the front end to the rear, and a horizontal rail part <NUM> extending rearward from the rear end of the tilted rail part <NUM>. The ends of the tilted rail part <NUM> and the horizontal rail part <NUM> are detachably coupled to each other via a bolt, a nut or the like.

Moreover, an automotive vehicle <NUM> is provided with a wire rope <NUM> having a hook at one end of the rope and a winch <NUM> for winding up the wire rope <NUM>. Rails <NUM> in the pipeline construction shaft <NUM> are supported on crossties <NUM>.

A joining method for joining pipes by using the pipe transport device <NUM>, the lifting jigs <NUM>, and the auxiliary rail device <NUM> in the pipeline construction shaft <NUM> will be described below.

As illustrated in <FIG>, the first pipe <NUM> is loaded on a trolley body <NUM> of a first transport trolley <NUM> of the pipe transport device <NUM>, the second pipe <NUM> is loaded on a trolley body <NUM> of a second transport trolley <NUM>, and the automotive vehicle <NUM> is caused to travel forward to press the pipe transport device <NUM> forward. Thus, the first transport trolley <NUM> and the second transport trolley <NUM> are moved forward to transport the first pipe <NUM> and the second pipe <NUM>, so that a spigot <NUM> (one end) of the first pipe <NUM> is inserted into a socket <NUM> (the other end) of the rearmost pipe <NUM> of the pipeline <NUM> and is joined thereto.

At this point, a coupler <NUM> is hidden under the first and second pipes <NUM> and <NUM>. Moreover, trolley jacks <NUM> of the first transport trolley <NUM> vertically adjust the position of the first pipe <NUM>, thereby centering the pipes being joined to each other.

Subsequently, as illustrated in <FIG>, <FIG>, and <FIG>, the two lifting jigs <NUM> are attached to the lower part of the opening end of the socket <NUM> of the first pipe <NUM>, and rams <NUM> of jacks <NUM> of the lifting jigs <NUM> are extended to lift the socket <NUM> (the other end) of the first pipe <NUM>. Thus, the first pipe <NUM> is lifted above the first transport trolley <NUM>.

After that, as illustrated in <FIG>, the coupler <NUM> is removed to separate a first coupler <NUM> and a second coupler <NUM>. Specifically, a first coupling pin <NUM> is removed to decouple the first coupler <NUM> and the first transport trolley <NUM> as indicated by the virtual lines in <FIG>, and a junction coupling pins <NUM> are removed to decouple the first coupler <NUM> and the second coupler <NUM> as indicated by the virtual lines in <FIG>, so that the first coupler <NUM> between the first transport trolley <NUM> and the second coupler <NUM> is removed. With this configuration, the first coupling pin <NUM> can be removed to separate the first coupler <NUM> and the first transport trolley <NUM> without interfering with the first pipe <NUM>.

Thereafter, as illustrated in <FIG> and <FIG>, an operation lever <NUM> is operated for switching from a coupling position P3 to a separating position P4. This can switch an engagement pin <NUM> from an engagement position P1 to a disengagement position P2 and disengage the second coupler <NUM> from the second transport trolley <NUM> by a remote operation. The second coupler <NUM> is removed from the second transport trolley <NUM>, and the coupler <NUM> between the first transport trolley <NUM> and the second transport trolley <NUM> is removed, thereby separating the first transport trolley <NUM> and the second transport trolley <NUM>.

The first coupler <NUM> and the second coupler <NUM> that have been thus removed are transferred into the first pipe <NUM> and are temporarily stored therein as illustrated in <FIG>.

Thereafter, as illustrated in <FIG> and <NUM>, the auxiliary rail device <NUM> is installed in the second pipe <NUM> on the second transport trolley <NUM>. At this point, the horizontal rail part <NUM> is installed in the second pipe <NUM>, and the tilted rail part <NUM> is attached to the front end of the horizontal rail part <NUM> and is protruded forward from the spigot <NUM> of the second pipe <NUM>. With this configuration, the auxiliary rail device <NUM> is installed so as to branch upward from the rails <NUM> on the near side of the first pipe <NUM> and extend into the second pipe <NUM>.

Thereafter, as illustrated in <FIG>, the hook of the wire rope <NUM> provided for the automotive vehicle <NUM> is hung on the first transport trolley <NUM> in an unloaded state, and then the winch <NUM> is operated to wind up the wire rope <NUM>. Thus, the first transport trolley <NUM> is pulled by the wire rope <NUM>, moves backward from the near side of the first pipe <NUM>, and is transferred from the rails <NUM> onto the auxiliary rail device <NUM>. As illustrated in <FIG>, <FIG>, and <FIG>, the first transport trolley <NUM> passes along the tilted rail part <NUM>, travels on the horizontal rail part <NUM>, and is transferred into the second pipe <NUM>. As illustrated in <FIG>, the first transport trolley <NUM> is stored in the second pipe <NUM> while being supported on the horizontal rail part <NUM>.

Subsequently, as illustrated in <FIG>, separate rails <NUM> of the rails <NUM> under the first pipe <NUM> are removed and are loaded on the temporary placing plates <NUM> of the first transport trolley <NUM> in the second pipe <NUM>. Moreover, the first coupler <NUM> and the second coupler <NUM> are transferred from the inside of the first pipe <NUM> onto the first transport trolley <NUM> in the second pipe <NUM>.

The tilted rail part <NUM> of the auxiliary rail device <NUM> is removed from the horizontal rail part <NUM> and is temporarily stored in the second pipe <NUM>. The tilted rail part <NUM> corresponds to a tilted part of the auxiliary rail device <NUM> that branches from the rails <NUM> and protrudes forward from the spigot <NUM> of the second pipe <NUM>.

Thereafter, as illustrated in <FIG>, the automotive vehicle <NUM> is caused to travel forward to move the second transport trolley <NUM> forward. The spigot <NUM> of the second pipe <NUM> on the second transport trolley <NUM> is joined to the socket <NUM> of the first pipe <NUM> joined to the rearmost pipe <NUM>.

Subsequently, as illustrated in <FIG>, the two lifting jigs <NUM> are attached to the lower part of the opening end of the socket <NUM> of the second pipe <NUM>, and then the lifting jigs <NUM> lift the socket <NUM> (the other end) of the second pipe <NUM>. Thus, the second pipe <NUM> is lifted above the second transport trolley <NUM>. The automotive vehicle <NUM> and the second transport trolley <NUM> are caused to travel backward, and the second transport trolley <NUM> is drawn from beneath the second pipe <NUM> to the near side of the second pipe <NUM> and is retracted behind the second pipe <NUM>.

Subsequently, as illustrated in <FIG>, the separate rails <NUM> of the rails <NUM> under the second pipe <NUM> are removed and are loaded on the temporary placing plates <NUM> of the second transport trolley <NUM>. Furthermore, the H-shaped steel support member <NUM> is installed under the socket-side end of the second pipe <NUM>. The rams <NUM> of the jacks <NUM> of the lifting jigs <NUM> are retracted to lower the socket-side end (the other end) of the second pipe <NUM> onto the support member <NUM>, so that the socket-side end of the second pipe <NUM> is supported by the support member <NUM>. The two lifting jigs <NUM> are then removed from the opening end of the socket <NUM> of the second pipe <NUM>.

After that, as illustrated in <FIG>, the tilted rail part <NUM> is attached to the rear end of the horizontal rail part <NUM> and is protruded rearward from the socket <NUM> of the second pipe <NUM>, and the rear end of the tilted rail part <NUM> is connected onto the rails <NUM>.

As illustrated in <FIG>, the hook of the wire rope <NUM> provided for the automotive vehicle <NUM> is hung on the first transport trolley <NUM> in the second pipe <NUM>, and then the winch <NUM> is operated to wind up the wire rope <NUM>. Thus, the first transport trolley <NUM> is moved backward on the horizontal rail part <NUM> in the second pipe <NUM> and is unloaded from the tilted rail part <NUM> onto the rails <NUM>.

This joins the first pipe <NUM> and the second pipe <NUM> to the rearmost pipe <NUM> of the pipeline <NUM>. The pipeline <NUM> in the pipeline construction shaft <NUM> is extended by repeatedly performing the joining step.

In the first and second embodiments, as illustrated in <FIG>, the engagement pin <NUM> (an example of an engaging member) that can be engaged and disengaged into and from the second transport trolley <NUM> is provided on the other end of the coupler <NUM> (that is, the second coupler <NUM>) and the switching device <NUM> is provided in the second coupler <NUM>. The engagement pin <NUM> (an example of an engaging member) that can be engaged and disengaged into and from the first transport trolley <NUM> may be provided on one end (that is, the first coupler <NUM>) of the coupler <NUM>, and the switching device <NUM> may be provided in the first coupler <NUM>.

With this configuration, the operation lever <NUM> is operated to operate the switching device <NUM>, so that the engagement pin <NUM> is switched from the engagement position P1 to the disengagement position P2 and the first transport trolley <NUM> and the coupler <NUM> are disengaged from each other. At this point, the operation lever <NUM> can be operated without interfering with the first pipe <NUM> and the second pipe <NUM>. Thus, even if a small space is formed under the first pipe <NUM> loaded on the first transport trolley <NUM>, the first transport trolley <NUM> and the coupler <NUM> can be easily disengaged from each other by operating the operation lever <NUM>. This can reduce time and effort to remove the coupler <NUM> to separate the first transport trolley <NUM> and the second transport trolley <NUM>.

Moreover, a first engagement pin that can be engaged and disengaged into and from the first transport trolley <NUM> may be provided on one end of the coupler <NUM>, a second engagement pin that can be engaged and disengaged into and from the second transport trolley <NUM> may be provided on the other end of the coupler <NUM>, and a first switching device for switching the first engagement pin from an engaged state to a disengaged state and a second switching device for switching the second engagement pin from an engaged state to a disengaged state may be provided for the coupler <NUM>.

In the foregoing embodiments, the pipes are joined by inserting the spigot <NUM> of another pipe into the socket <NUM> of the pipe joined to the pipeline <NUM>. The pipes may be joined by fitting the socket <NUM> of another pipe onto the spigot <NUM> of the pipe joined to the pipeline <NUM>.

In the foregoing embodiments, the coupling plate <NUM> of the second transport trolley <NUM> is provided with the coil spring <NUM>. The coil spring <NUM> may be omitted.

Claim 1:
A pipe transport device (<NUM>) for transporting a pipe, comprising:
a first transport trolley (<NUM>) configured for transporting a first pipe (<NUM>), a second transport trolley (<NUM>) configured for transporting a second pipe (<NUM>), and a coupling device (<NUM>) for coupling the first transport trolley (<NUM>) and the second transport trolley (<NUM>),
wherein the coupling device (<NUM>) has a coupler (<NUM>) one end of which is attachable and detachable to and from the first transport trolley (<NUM>) and the other end of which is attachable and detachable to and from the second transport trolley (<NUM>),
characterised in that one end of the coupler (<NUM>) includes an engaging member (<NUM>) that is engageable and disengageable into and from one of the first transport trolley (<NUM>) and the second transport trolley (<NUM>),
the engaging member (<NUM>) is switchable between an engaged state for engagement with one of the transport trolleys (<NUM>, <NUM>) and a disengaged state for disengagement from one of the transport trolleys (<NUM>, <NUM>),
the coupler (<NUM>) includes a switching device (<NUM>) for switching the engaging member (<NUM>) from the engaged state to the disengaged state,
the switching device (<NUM>) includes an operation part (<NUM>) for operating the switching device (<NUM>) from outside, and
the operation part (<NUM>) is exposed to a space (<NUM>) formed between the first pipe (<NUM>) when being loaded on the first transport trolley (<NUM>) and the second pipe (<NUM>) when being loaded on the second transport trolley (<NUM>).