JP7744801B2 - Deck replacement method and construction machinery used for this - Google Patents

Description

The present invention relates to a deck replacement method used in highway deck replacement work and a construction machine used for this.

Expressway concrete decks deteriorate over time due to aging, fatigue from heavy traffic, and salt damage from antifreeze and airborne salt. In order to maintain the expressway, deck replacement work is carried out, in which the existing deck is removed and replaced with a new one.

Conventionally, in this type of deck replacement work, when the existing deck is removed, the reinforced concrete deck erected on steel main girders is cut to the required size using a special machine, loaded onto a transport vehicle using a crane, and then transported away by the transport vehicle. After cleaning the area where the existing deck was removed, a new deck is installed in its place. When installing a new deck, the new deck is brought in using a transport vehicle, lifted from the transport vehicle using a crane, and lowered into the area where the existing deck was removed.

In this type of deck installation work, mobile cranes and gantry cranes are mainly used to remove and move the existing deck and to move and install the new deck. Mobile cranes have a rotating body and a boom for lifting materials at the top, and a self-propelled mechanism at the bottom; so-called crane vehicles, such as all-terrain cranes and rough terrain cranes, are used. This type of mobile cranes is generally known, not just to those skilled in the art, and there is no need to cite any prior art documents. A gantry crane consists of a gantry frame and a winding device for lifting materials installed at the top. Dedicated rails are installed on the construction surface, and the crane is assembled on these rails and moved along them. This type of gantry crane is proposed in Patent Document 1, among others.

Since this type of deck replacement work is carried out on an in-service expressway, traffic restrictions must be imposed on a certain area of the road for a certain period of time to ensure a construction yard. Because the construction work has a significant negative impact on society and the economy, a construction method is needed to minimize the duration and area of road traffic restrictions. However, deck replacement work requires a large crane with high lifting capacity, as the weight of the load to be lifted exceeds 10 tons, and a construction yard is required to accommodate this large crane. Furthermore, bridges, in particular, often have gradients in both the longitudinal and transverse directions. Therefore, if the crane is driven by wheels, there is a risk that it may run away down the slope. This necessitates equipment to prevent the crane from running away, and the crane's power must be increased to move up the slope. Additionally, if there are existing structures or general road users moving around the construction site that are not subject to construction, such as overhead power lines or overpasses, or vehicles or people passing on the opposite side of the road, it will be necessary to ensure sufficient safety for these objects and people, and measures to address this will be required.

When looking at the applicability of mobile cranes and gantry cranes to the various demands at construction sites, there are the following differences:

When using a mobile crane for construction, the crane is installed using equipment such as outriggers to prevent it from tipping over or running away, requiring a certain amount of space for installation. Furthermore, at construction sites, the deck removal and installation areas, cranes, and deck transport vehicles are lined up in a row, dividing the construction yard into sections with cranes. During construction, the crane's boom rotates 180 degrees, unavoidably for the boom and load to pass outside of a single lane. This makes it extremely difficult to limit the crane's installation space and rotation range to within one lane. Furthermore, if there are overhead restrictions at bridge sites, the tip of the crane's boom must be kept below the restrictions, which can make it difficult to ensure the load's lifting height. However, mobile cranes can be self-propelled on public roads and do not have power issues. Furthermore, the crane is equipped with equipment such as outriggers, which allows it to be installed stably, reducing the possibility of it tipping over or running away.

When using a gantry crane for construction, a reduction in lifting capacity due to a reduced crane width is unlikely. Therefore, by adjusting the crane width in advance and manufacturing the crane, traffic restrictions can be kept within a certain range on the road. Furthermore, because there is space inside the gantry crane's body, deck transport vehicles can be guided to the deck replacement location, eliminating the need for a separate waiting space in the construction yard. Furthermore, since the load carried by this gantry crane is moved only inside the gantry crane's body, the load never passes outside of the traffic restrictions, and overhead restrictions are not an issue as the gantry crane's body can be adjusted to be below the overhead restrictions. Therefore, deck replacement work using a gantry crane can reduce the area of road traffic restrictions. However, because gantry cranes are manufactured at the construction site, crane completion inspections are required during the construction period. Furthermore, the rails used for the gantry crane's movement are also subject to completion inspections. Installing the rails in parallel with deck replacement requires a re-inspection, which is inefficient. In other words, deck replacement work using a gantry crane involves three steps: crane assembly, parallel rail installation, completion inspection, and rail removal when the deck is removed. This results in longer road traffic restrictions compared to deck replacement work using a mobile crane. Furthermore, gantry cranes often use steel rails and steel wheels, resulting in low friction between the two. Therefore, when roads have longitudinal and transverse gradients, such as at bridge construction sites, gantry cranes require increased power to move up the gradient. Furthermore, there is a risk of the crane running away down the gradient, which must be prevented. However, by leveling the rails, increased power is not required and the risk of running away is reduced. Horizontal rail installation is also possible by placing filler material underneath the rails. However, if the rails are installed horizontally across the entire bridge, the rail ends must be raised significantly, making installation difficult. Furthermore, while the raised height can be kept relatively small by installing the divided rails horizontally one by one, steps are created at the joints of each rail, and the gantry crane cannot pass over these steps, so the gantry crane must be disassembled and reassembled for each step.

As such, there are advantages and disadvantages to using both mobile cranes and gantry cranes for deck replacement work. However, when comparing the use of gantry cranes with that of mobile cranes, the use of gantry cranes is more disadvantageous in terms of traffic restriction periods. Therefore, when carrying out deck replacement work, it is necessary to use these construction machines according to the site conditions and to use them only after overcoming the disadvantages of each.

Japanese Patent Application Laid-Open No. 2019-173435

As mentioned above, construction using a gantry crane is at a disadvantage compared to construction using a mobile crane in terms of the period during which traffic is restricted. However, compared to construction using a mobile crane, the lifting capacity is not affected by the width of the machine, the load does not pass outside of traffic restrictions, it can be applied to heights under overhead restrictions, and deck transport vehicles can be guided to the vicinity of the deck replacement area, making it very useful in reducing the area of road traffic restrictions.

The present invention aims to provide a new deck replacement method and construction machinery for use therewith that utilizes the advantages of using a gantry crane in highway deck replacement work and overcomes the disadvantages of using a gantry crane, thereby minimizing the scope and duration of road traffic restrictions.

In order to achieve the above object, the present invention provides:
In a deck replacement method in which the existing deck in the section of a highway where the deck is to be replaced is removed from the main girder and a new deck is installed on the main girder,
The machine body is constructed by connecting at least three pairs of columns that can be extended and retracted in the vertical direction with a predetermined interval between each column, and a pair of conveying guide rails is arranged between the upper parts of each of the columns with both ends in the longitudinal direction extending from each of the columns at both ends, and a telescopic column structure is used, which is configured by bridging each of the conveying guide rails and mounting fasteners that can be connected to the floor slab, and a traveling mechanism that travels the telescopic column structure on the existing floor slab,
The telescopic support structure is installed immediately after the first deck removal position in the deck replacement section via the traveling mechanism, and one end of the pair of conveying guide rails is positioned above the first deck removal position as the conveying start end, and the other end side is positioned as the conveying end,
After cutting the existing deck slab in the deck replacement section to a predetermined size, the entire telescopic support structure is contracted to lower the pair of conveying guide rails, and the fasteners are connected to the cut existing deck slab at the conveying start ends of the pair of conveying guide rails. The entire telescopic support structure is extended to raise the pair of conveying guide rails, and the cut existing deck slab is lifted with the fasteners. The fasteners are moved from the conveying start ends to the conveying end ends of the pair of conveying guide rails via the conveying guides, thereby transporting the cut existing deck slab. This process of removing and transporting the existing deck slab is repeated to remove and transport the existing deck slab from the initial deck slab removal position.
After removing and transporting the existing deck slab from the initial deck slab removal position, the other end of the pair of conveying guide rails is set as the conveying starting end and one end is set as the conveying terminal end, and a new deck slab is transported below the conveying starting end, and then the entire telescopic support structure is contracted to lower the pair of conveying guide rails, and the fasteners are connected to the new deck slab at the conveying starting ends of the pair of conveying guide rails, and the entire telescopic support structure is extended to raise the pair of conveying guide rails and lift the new deck slab with the fasteners, and the fasteners are moved from the conveying starting ends to the conveying terminal ends of the pair of conveying guide rails via the conveying guide to transport the new deck slab, and after the new deck slab has been transported, the entire telescopic support structure is contracted to lower the pair of conveying guide rails and install it at the removal position of the existing deck slab, and this process of transporting and installing the new deck slab is repeated to transport and install the new deck slab at the initial deck slab removal position,
Thereafter, the telescopic support structure is moved by the traveling mechanism immediately after each deck removal position, and the process of removing and carrying out the existing deck and the process of carrying in and installing the new deck are repeated.
The gist of this is as follows.

In this case, it is preferable to use a pair of running wheel units and a pair of running rails for the running mechanism, provide the pair of running wheel units at the lower ends of each pair of pillars, lay the pair of running rails on both sides of the width of the deck replacement section, and place the telescopic support structure on each running rail via each running wheel unit and move on each running rail.
In particular, in the case of a bridge or the like, when the deck replacement section has a gradient, a pair of running rails are configured with a plurality of divided rails having a length that is approximately the same as or slightly longer than the distance between the front end of each running wheel unit on the front side of each pair of adjacent support columns at the front and rear of the telescopic support structure and the rear end of each running wheel unit on the rear side of each pair of adjacent support columns at the rear, and each of the divided rails is installed horizontally in the deck replacement section via filler, and a step is formed between the joints of each of the divided rails, and when the telescopic support structure is moved on each of the running rails, the running wheel unit of one of the pair of support columns reaches the step. It is desirable that the other two running wheel units have a distance to travel before reaching the step, and that the entire telescopic support structure be supported by the other two units each time one of the running wheel units reaches the step, and that the one of the running wheel units be raised to a height that exceeds the step by contracting the supports of the one of the running wheel units, and from this state the other two running wheel units move the telescopic support structure on the running rails, so that the one pair of running wheel units straddles and overcomes the step.

Also, (depending on the construction conditions, site conditions, and design conditions (weight and strength) of the pair of conveying guide rails) a pair of cheek support post guides may be arranged side by side on each end side extending from a pair of posts at one end of the pair of conveying guide rails, and a pair of cheek support posts may be arranged that are relatively movably engaged with each of the end sides via the cheek support post guides and are extendable and contractible in the vertical direction, with each of the end sides being supported by the cheek support posts.

In order to achieve the above object, the present invention provides:
A construction machine used in the above deck replacement method,
a body including at least three pairs of support columns each having a built-in telescopic drive unit that can be extended and retracted in the vertical direction, the support columns being connected with a predetermined interval between each pair of support columns; and a telescopic control unit that controls each of the telescopic drive units collectively or individually;
a pair of conveying guide rails disposed between the upper portions of each pair of support columns, with both ends of the conveying guide rails extending from the support columns at both ends; a conveying guide disposed between the conveying guide rails and capable of advancing and retreating along the conveying guide rails; a forward/backward driving unit that drives the conveying guide to advance and retreat on the conveying guide rails; and a forward/backward control unit that controls the forward /backward driving unit;
an operation unit that is operatively connected to the telescopic control unit and the forward/ backward control unit by wire or wirelessly, and that is common to the telescopic control unit and the forward/ backward control unit or that is separate from the telescopic control unit and the forward/backward control unit;
A fastener mounted on the conveying guide and connectable to the deck slab;
The present invention is configured to include:
The pair of conveying guide rails are installed immediately after each deck removal position in the deck replacement section via a traveling mechanism, and one end of the pair of conveying guide rails is arranged above each deck removal/installation position as the conveying start end or conveying end, and the other end is arranged at the deck removal/import destination as the conveying end or conveying start end.
The gist of this is as follows.

In this case, the running mechanism comprises a pair of running wheel units and a plurality of divided rails having a length approximately the same as or slightly longer than the distance between the front end of each running wheel unit on the front side of each pair of adjacent pillars at the front and rear of the vehicle body and the rear end of each running wheel unit on the rear side of the other, and is provided with a pair of running rails that guide the pair of running wheel units, a running drive unit that drives the pair of running wheel units to run on the pair of running rails, a running control unit that controls the running drive unit, and an operating unit that is connected to the running control unit by wire or wirelessly, and is common to or separate from the telescopic control unit and the forward/ backward control unit (mentioned above (in paragraph 0016)), and is preferably provided at the lower ends of each pair of pillars, and the pair of running rails are laid on both sides of the width of the deck replacement section.

Also, (depending on the construction conditions, site conditions, and design conditions (weight and strength) of the pair of conveying guide rails) a pair of cheek support posts may be provided to support each end of the pair of conveying guide rails extending from a pair of supports at one end of the pair of conveying guide rails, the pair of cheek support posts being telescopic posts with built-in telescopic drive units that allow them to extend and retract in the vertical direction, and a pair of cheek support guides may be provided alongside each of the end sides so that they can move along each end side via the cheek support guides.

The deck replacement method and construction machine used therefor according to the present invention provide the following unique operational effects.
(1) The construction machinery can be made smaller in width and height depending on the construction site, but this does not result in a decrease in the performance of lifting and transporting decks or a decrease in the work efficiency of deck replacement, making it ideal for single-lane construction on elevated roads and construction on bridges with headway restrictions.
(2) The traveling mechanism uses a pair of traveling wheel units and a pair of traveling rails, and the pair of traveling rails is made up of multiple divided rails. Even if there is a longitudinal gradient on the construction surface such as a bridge, these divided rails are installed horizontally and the construction machine moves on this horizontal traveling rail. Therefore, the presence or absence of a longitudinal gradient on the construction surface such as a bridge does not affect the risk of the construction machine running away, and running away can be prevented by equipment other than outriggers, such as wheel brakes. On the other hand, there is no need to increase the power according to the gradient, as is the case when moving a construction machine up a gradient with a conventional gantry crane.
(3) The construction machine has a work space inside, and the deck slab lifting and transporting operations are carried out within this space, so the suspended deck slab will not pass outside the traffic control area, and the deck slab transport vehicle can be guided to the vicinity of the deck slab replacement construction site, allowing the deck slab replacement work to be carried out safely and efficiently.
(4) Even if the work of removing and installing the traveling rails is involved, the construction machine does not have a winding device like a conventional gantry crane, and therefore the construction machine is not considered a crane. Therefore, the work of removing and installing the traveling rails can be performed as the same work in the form of repositioning, and there is no loss in the process of moving the construction machine compared to a mobile crane.
Therefore, this method and the construction machinery used for it are significantly superior to conventional construction machinery in two respects: the scope and duration of traffic restrictions required, and site conditions such as the size of the applicable site, and can reduce the negative impact that previous deck replacement work has had on society and the economy.

FIG. 1 is a side view showing an image of a deck replacement method and a construction machine used therefor according to one embodiment of the present invention. Figures showing the configuration of the construction machine used in the method ((a) is a side view, (b) is a cross-sectional view taken along line B-B in (a), (c) is a cross-sectional view taken along lines A-A and C-C in (a), and (d) is a cross-sectional view taken along line D-D in (a)). FIG. 10 is a side view showing a modified example of a construction machine used in the method. A side view showing the movement method of the construction machine used in the method. A diagram showing a specific example of the method

Next, an embodiment of the present invention will be described using the drawings. Figure 1 shows a deck replacement method according to one embodiment of the present invention, along with a construction machine used for this method. Figure 2 shows a construction machine used for this deck replacement method, Figure 3 shows a modified example of this construction machine, and Figure 4 shows the movement method of this construction machine.

As shown in Figure 1, this deck replacement method (hereinafter referred to as "this method") is used in highway deck replacement work, in which the existing deck in the section of the highway where the deck is to be replaced is removed from above the main girders and a new deck is installed above the main girders.

This method uses a construction machine M consisting of a telescopic support structure that can be extended and retracted in the vertical direction, and a traveling mechanism RL that allows the construction machine M to travel on the existing deck slab.

The telescopic support structure that constitutes the construction machine M comprises at least three pairs of vertically extendable support columns 10, each connected with a predetermined distance between them to form the machine body 1. In this example, the machine body 1 is made up of three pairs of support columns 10. In this machine body 1, a pair of conveying guide rails 2 are horizontally disposed between the upper portions of the support columns 10, with both longitudinal ends extending from the respective support columns 10 at both ends. A conveying guide 3 is horizontally disposed between the conveying guide rails 2. A fastener 4 that can be connected to the deck slab is mounted on this conveying guide 3. In this case, each end of the pair of conveying guide rails 2 extending in the extension direction from a pair of support columns 10 at one end is horizontally supported by a pair of support columns 5. These support columns 5 are a pair of telescopic support columns that can be extended in the vertical direction, and the upper end of each support column 5 is also provided with an engagement portion 51 that can engage with a pair of support column guide rails 6, described below. A pair of cheek support guide rails 6 are installed side by side at one end of the pair of conveyor guide rails 2, and each cheek support 5 is arranged upright and engaged with each end via the cheek support guide rail 6 so that it can move relative to one another.

As shown in FIG. 2, this construction machine M is composed of a machine body 1 formed by connecting (at least) three pairs of support columns 10 facing each other with a predetermined gap between them, each pair having a built-in telescopic drive unit that can be extended and retracted in the vertical direction, an extension/retraction control unit (not shown) that controls each of the telescopic drive units collectively or individually, a pair of conveying guide rails 2 arranged between the upper parts of each pair of support columns 10 with both ends in the length direction extending from each of the support columns 10 at both ends, a conveying guide 3 arranged to span between each of the conveying guide rails 2 and be able to move forward and backward along each of the conveying guide rails 2, an advance/retraction drive unit (not shown) that drives the conveying guide 3 to move forward and backward on each of the conveying guide rails 2, an advance/retraction control unit (not shown) that controls the advance/ retraction drive unit, an operating unit (not shown) that is common to the extension/retraction control unit and the advance/retraction control unit or each separate unit that is operatively connected to the extension/retraction control unit and the advance/retraction control unit by wire or wirelessly, and a fastener 4 that is mounted on the conveying guide 3 and can be connected to the deck slab.

The pair of cheek rest supports 5 are telescopic supports with built-in telescopic drives that can extend up and down and can support each end extending from a pair of supports 10 at one end of the pair of transport guide rails 2, and have multiple guide rollers with gripping structures as engagement parts 51 at their upper ends. A pair of cheek rest guide rails 6 are installed alongside the lower part of each end of the pair of transport guide rails 2. In this way, the pair of cheek rest supports 5 are vertically installed so that they can move along each end, with the guide rollers at their upper ends engaging with the cheek rest guide rails 6 at the lower part of each end.

The pair of support posts 5 are added depending on the construction conditions, site conditions, and strength of the steel beam 11. If a support post 5 is not required, it can be omitted as shown in Figure 3. The construction machine M in Figure 3 is as already explained, and the same reference numerals are used for the parts common to the construction machine M in Figure 2.

As shown in Figure 1, the traveling mechanism RL uses a pair of traveling wheel units R and a pair of traveling rails L. A pair of traveling wheel units R is attached to each lower end of each pair of support columns 10 of the construction machine M. While the pair of traveling rails L may be a long continuous piece on a typical flat elevated road, for bridge applications, the pair of traveling rails L is composed of multiple divided rails L1 with lengths approximately equal to or slightly longer than the distance between the front end of each traveling wheel unit R on the front side of each pair of support columns 10 adjacent to the front and rear of the construction machine M. This pair of traveling rails L is laid on both sides of the width of the deck replacement section. If the deck replacement section has a slope, such as in the case of a bridge, each divided rail L1 is installed horizontally in the deck replacement section via filler material. In this case, a step G is formed between the joints of each divided rail L1. In this way, the construction machine M is placed on each traveling rail L via each traveling wheel unit R and is installed to be movable on each traveling rail L.

2, this traveling mechanism RL is composed of a pair of traveling wheel units R and a plurality of divided rails L1 having a length approximately equal to or slightly longer than the distance between the front end of each traveling wheel unit R on the front side of each pair of pillars 10 adjacent to each other in the front and rear of the construction machine M, and is configured with a pair of traveling rails L that guide the pair of traveling wheel units R, a traveling drive unit (not shown) that drives the pair of traveling wheel units R to travel on the pair of traveling rails L, a traveling control unit (not shown) that controls the traveling drive unit, and an operating unit that is operatively connected to the traveling control unit by wire or wirelessly, and which may be common to the above-mentioned telescopic control unit and forward/backward control unit or each separate unit. A pair of traveling wheel units R is provided at each lower end of each pair of pillars 10, and a pair of traveling rails L is laid on both sides in the width direction of the deck slab replacement section.

In this way, the construction machine M, which consists of a telescopic support structure, is installed immediately after each deck slab removal position (in the direction of construction progress) in the deck slab replacement section via the traveling mechanism RL, as shown in Figure 1.One end of the pair of transport guide rails 2 is positioned above each deck slab removal/installation position as the transport start or end, and the other end is positioned at the deck slab delivery/transport destination as the transport end or start.

When replacing deck slabs on an expressway, the construction machine M is installed immediately after the first deck slab removal position in the deck replacement section via the traveling mechanism RL, and one end of the pair of transport guide rails 2 is positioned above the first deck slab removal position as the transport start point, and the other end as the transport end.

After cutting the existing deck slab in the deck replacement section to the specified size, first, each of the columns 10 of the construction machine M is simultaneously contracted by comprehensive control of the entire columns 10. By contracting the entire telescopic column structure, the pair of conveying guide rails 2 is lowered while maintaining the horizontal, and the fasteners 4 are connected to the cut existing deck slab at the conveying start ends of the pair of conveying guide rails 2. Next, each of the columns 10 of the construction machine M is simultaneously extended by comprehensive control of the entire columns 10. By extending the entire telescopic column structure, the pair of conveying guide rails 2 is raised while maintaining the horizontal, and the cut existing deck slab is lifted by the fasteners 4. The fasteners 4 are then moved horizontally via the conveying guide 3 from the conveying start end to the conveying end of the pair of conveying guide rails 2, thereby transporting the cut existing deck slab. By repeating this process of removing and transporting the existing deck slab, the existing deck slab from the initial deck slab removal position is removed and transported.

After the existing deck slab is removed and transported from the initial deck slab removal location, the other end of the pair of transport guide rails 2 is used as the transport start point and one end as the transport end, and the new deck slab is transported below the transport start point. After the new deck slab is transported, the entire telescopic support structure is contracted, lowering the pair of transport guide rails 2 while maintaining their horizontality, and the fasteners 4 are connected to the transport start points of the pair of transport guide rails 2 at the transport start points of the pair of transport guide rails 2. Next, the entire portal structure is extended, raising the pair of transport guide rails 2 while maintaining their horizontality, and the new deck slab is lifted by the fasteners 4. The fasteners 4 are then used to move the pair of transport guide rails 2 horizontally via the transport guides 3 from the transport start point to the transport end point, thereby transporting the new deck slab. After the new deck slab is transported, the entire telescopic support structure is contracted while maintaining its horizontality, lowering the pair of transport guide rails 2, and the new deck slab is installed (erected) at the removal location (main girder) of the existing deck slab. By repeating this process of transporting and installing the new deck, the new deck will be transported and installed in the same location as the original deck was removed.

After this, the construction machine M is moved by its traveling mechanism to a position immediately after each deck removal location, and the process of removing and carrying out the existing deck and carrying in and installing the new deck is repeated.

In the case of a normal, flat elevated road, there is no step at the joint of a pair of running rails L, but in the case of a slope such as a bridge, multiple divided rails L1 are installed horizontally with filler material interposed on the lower side of the construction surface, resulting in a step G between each divided rail L1. In such cases, the construction machine M moves between each deck slab removal position through the coordinated operation of the construction machine M and the traveling mechanism RL, as shown in Figure 4.

As shown in step 1 of Figure 4 (1), while the deck replacement work is being performed at the previous deck replacement location, the construction machine M is installed immediately behind the previous deck replacement location via a pair of traveling rails L. As previously described, the pair of traveling rails L consists of multiple divided rails L1, each of which is approximately the same length as or slightly longer than the distance between the front end of each traveling wheel unit R on the front side of each pair of adjacent columns 10 on the front and rear of the construction machine M, i.e., the telescopic column structure, and the rear end of each traveling wheel unit R on the rear side. Therefore, on each traveling rail L, the construction machine M is such that one traveling wheel unit R of each pair of columns 10 abuts against the step G ahead (in the direction of travel of the construction machine M), while the other two traveling wheel units R still have some distance to travel before reaching the step G ahead of them. Therefore, when the construction machine M is placed on a pair of traveling rails L immediately after the previous deck replacement position, as shown in Figure 4 (1), the running wheel units R of each of the middle columns 10 of the three pairs of columns 10 of the construction machine M will collide with the step G between the next divided rail L1 on the divided rail L1 immediately after the deck replacement position, and the running wheel units R of each rear column 10 will be at the end of the divided rail L1 immediately after the deck replacement position on the deck replacement position side, with some distance remaining to travel to the step G ahead, and each running wheel unit R of each front column 10 will be on the next divided rail L1, just in front of the next divided rail L1, with some distance remaining to travel to the step G ahead (the length of the running wheel units R), but the construction machine M cannot move forward toward the next deck replacement position in this state.

First, as shown in Figure 4 (2), the columns 10 of the construction machine M are individually controlled to support the entire telescopic column structure with two columns 10, in this case the front columns 10 and the rear columns 10. The remaining column 10, i.e., the middle column 10, is then contracted to raise the running wheel unit R to a height that exceeds the step G. From this state, as shown in Figure 4 (3), the other two pairs of running wheel units R, front and rear, are used to move the construction machine M along the running rails L, causing the middle pair of running wheel units R to straddle and jump over the step G. In this case, the construction machine M travels on the pair of running rails L for the length of the pair of running wheel units R. This moves the middle pair of running wheel units R onto the end of the preceding split rail L1 of the next split rail L1. At this time, the running wheel units R of each rear support 10 are in a midpoint between the ends of each divided rail L1 immediately after the deck replacement position, with some travel distance remaining to reach the step G in front, and each running wheel unit R of each front support 10 on the next divided rail L1 will collide with the step G between the next divided rail L1. Here, as shown in Figure 4 (4), each intermediate support 10 is extended to place each intermediate running wheel unit R on the next divided rail L1. Next, each support 10 of this construction machine M is supported by each intermediate support 10 and each rear support 10 by separately controlling each of the support columns 10, and by contracting the front support columns 10, each running wheel unit R of these support columns 10 is raised to a height that exceeds the step G. From this state, the other intermediate and rear running wheel units R move the construction machine M on each running rail L, causing the front pair of running wheel units R to straddle the step G and place each front running wheel unit R on the next divided rail L1. Following this, in a similar manner, each rear running wheel unit R straddles and jumps over the step G, placing each rear running wheel unit R onto the next divided rail L1, and moving the entire construction machine M from the previous divided rail L1 to the next and further divided rails L1.

Even when there is a slope such as on a bridge, causing a step G between the multiple divided rails L1, the construction machine M can be moved immediately after each deck removal position through the coordinated operation of the telescopic support structure and traveling mechanism RL that make up the construction machine M. Then, at each deck removal position, the process of removing and carrying out the existing deck and the process of carrying in and installing the new deck are repeated.

Figure 5 shows an example of bridge construction as a concrete example of this method using construction machine M.

In Figure 5, the construction machine M is a substitute for a conventional gantry crane, and instead of a crane, it uses three pairs of telescopic pillars 10 as a lifting mechanism, combined with a steel beam 11 connecting the pairs of pillars 10, a rail track (transport guide rail 2, movable guide rail) arranged between the pairs of pillars 10, a movable beam (transport guide 3) that moves along the rail track, a cargo hook (fastener 4), and a counterweight 7. Then, a brace pillar 5 is added depending on the construction conditions, site conditions, and the strength of the steel beams 11.

Each pair of support columns 10 is equipped with two hydraulic lifters whose column length can be adjusted by adjusting the hydraulic pressure. Three hydraulic lifters are connected by steel beams 11 at intervals of 6 meters to form the machine body 1. Typically, a hydraulic lifter consists of two support columns and an upper beam connecting the columns, which constitutes a basic structural unit (one unit). Originally, hydraulic lifters are intended for use alone; even when two or more are used simultaneously, they are not connected and integrated into a unified, controlled system. This construction machine uses three hydraulic lifters arranged horizontally and interconnected to form an integrated unit. By operating the three lifters simultaneously in conjunction with each other or independently at different times, it achieves a deck replacement method not possible with conventional gantry cranes. Furthermore, the lower parts of these support columns 10 are equipped with wheel structures (running wheel units R) that allow the machine to travel on dedicated rails (running rails L), as described below.

The steel beams 11 are paired, each fixed in two parallel rows between each pair of columns 10 arranged on the same side of three pairs of columns 10, connecting each pair of columns 10. These steel beams 11 are parallel to the dedicated rails (running rails L) described below, with both ends extending a predetermined distance in the extension direction from their fixed positions with the pair of columns 10 at both ends. In this case, one end is 8 m or longer. Here, one end of the steel beam 11 extends 8 m in the extension direction from each pair of columns 10 at one end, and the other end extends 7 m in the extension direction from each pair of columns 10 at the other end. The pair of steel beams 11 are equipped with rail tracks: a pair of conveyor guide rails 2 for the conveyor guide 3, a pair of movable guide rails 71 for the counterweight 7, and a pair of cheek support guide rails 6 for the pair of cheek support columns 5. In this case, transport guide rails 2 for the moving beams, i.e., the aforementioned transport guides 3, are installed along almost the entire length of the upper surface of each steel beam 11. A pair of moving guide rails 71 for the counterweight 7 is installed on each outer side of each steel beam 11 between a pair of support columns 10 at both ends. Cheek guide rails 6 for each cheek support column 5 are installed only on the underside of one protruding end of each steel beam 11, in this case, the end side that is rearward in the direction of travel of the construction machine M.

The moving beam is a facility for moving the load hooks, i.e., the aforementioned transport guide 3, and is long enough to traverse the rail tracks of a pair of steel beams 11, in this case, a pair of transport guide rails 2, and has wheel structures at both ends that can engage with each transport guide rail 2 of each steel beam 11. In this case, guide rollers are journaled on both ends of the underside of the moving beam, and it is positioned movably on the pair of transport guide rails 2. In addition, in this case, the moving beam serves as a guide rail that engages and guides the guide rollers of the load hooks, described below, over almost the entire length of its extension.

The cargo hook is a device for lifting a suspended load, i.e., the aforementioned fastener 4, and consists of a hook 41 that can be attached to the deck slab, a rope-like member 42 such as a wire for suspending the hook 41 from the moving beam, and a guide roller 43 with a gripping structure that engages the rope-like member 42 with the guide rail of the moving beam and allows it to move along the moving beam, and is suspended from the moving beam by the guide roller with a gripping structure.

The counterweight 7 is a piece of equipment used to adjust the center of gravity of the construction machine M and prevent it from tipping over. It is mounted on a moving beam 70 for the counterweight 7 and is installed so that it can travel on a pair of moving guide rails 71. As will be described later, in this construction machine M, each pair of support columns 10 is raised from a pair of traveling rails L. This action changes the combination of each pair of support columns 10 supporting the machine body 1, so the position of the counterweight 7 can be changed toward both ends of the machine body 1 (forward and backward) in accordance with the movement of the moving beam on the rail track.

The pair of support struts 5 are equipment for reducing the bending moment acting on the protruding (rear) ends of the pair of steel beams 11 during lifting operations by this construction machine M. They consist of two hydraulic lifters whose column length can be extended or retracted by adjusting the hydraulic pressure, and these support struts 5 aim to reduce the weight of the pair of steel beams 11. Each support strut 5 has a guide roller at its upper end with a gripping structure that can engage with each support strut guide rail 6 on one end side (protruding portion) of the pair of steel beams 11, and is suspended movably along one end side of the pair of steel beams 11 via each support strut guide rail 6. The lower end of each support strut 5 is installed directly on the main girder of the elevated road or bridge.

Note that while the telescopic control unit, travel control unit, operating unit, etc. of the machine body 1 are not specifically shown, they are integrated into the same system. The operator operates this system using a common operating unit. By operating this operating unit, all of the struts 10 of the construction machine M can be extended and retracted simultaneously, and the amount of extension and retraction of each strut 10 can be set relatively, allowing each strut 10 to be extended and retracted uniformly or unevenly.

To enable this construction machine M to move over the existing deck, a pair of running rails L, consisting of a dedicated rail and the aforementioned multiple split rails L1, are temporarily installed horizontally on the existing deck. In this case, each split rail L1 is 8m long, and each pair of running rails L that make up a single track is made up of three split rails L1, with the total length of each running rail L installed at one time being 24m. Each split rail L1 is installed so that it is horizontal. When applied to bridges with a slope in the longitudinal direction, the bottom of each split rail L1 on the lower side of the construction surface is raised with filler material, and each split rail L is installed in a horizontal position.

The method is carried out using such a construction machine M as follows:

First, as shown in Figure 5 (1), a pair of traveling rails L are laid on the existing bridge deck in the direction of the bridge axis, immediately after the initial deck removal position in the deck replacement section. A construction machine M is then assembled on this pair of traveling rails L immediately after the initial deck removal position, with one end of the pair of transport guide rails 2 positioned above the initial deck removal position as the transport start point, and the other end positioned above the deck transport destination/import location as the transport end.

Next, after the existing deck slab in the deck replacement section is cut to the specified size, the counterweight 7 is moved forward of the machine body 1 (forward in the direction of travel of the construction machine), in this case, onto the pair of support columns 10 at the other end (forward in the direction of travel of the construction machine M), by moving the movable beam 70 on the pair of movable guide rails 71. Next, each support column 10 of the construction machine M is simultaneously contracted through comprehensive control of the entire column 10, and the entire telescopic support column structure is contracted, thereby lowering the pair of conveying guide rails 2 while maintaining their horizontality, and the fasteners 4 are connected to the cut existing deck slab at the conveying start end of the pair of conveying guide rails 2. Next, each support column 10 of the construction machine M is simultaneously extended through comprehensive control of the entire column 10, and the entire telescopic support column structure is extended, thereby raising the pair of conveying guide rails 2 while maintaining their horizontality, and the cut existing deck slab is lifted by the fasteners 4. The fasteners 4 are then moved horizontally on the pair of conveying guide rails 2 via the conveying guide 3 from the conveying start end to the conveying end, and the cut existing deck slab is transported out at the conveying end. In this case, the deck slab's destination is below the end of the transport line, where a deck slab transport vehicle is waiting. The existing deck slab is loaded onto the transport vehicle, which then transports it away. By repeating this process of removing and transporting the existing deck slab, the existing deck slab is removed and transported from the initial deck slab removal location.

After removing and transporting the existing deck slab from the initial deck removal location, work such as cleaning the bridge girders is performed, and the new deck slab is transported and installed at the initial deck removal location. In this case, the other end of the pair of transport guide rails 2 serves as the transport start point and one end serves as the transport end point, and the new deck slab is transported below the transport start point. After transporting the new deck slab, the entire construction machine M is retracted, lowering the pair of transport guide rails 2 while maintaining them horizontal, and the fasteners 4 are connected to the new deck slab at the transport start points of the pair of transport guide rails 2. Next, the entire construction machine M is extended, raising the pair of transport guide rails 2 while maintaining them horizontal, and the new deck slab is lifted by the fasteners 4. The new deck slab is then delivered by moving the pair of transport guide rails 2 horizontally from the transport start point to the transport end point via the fasteners 4 and the transport guide 3. After the new deck slab is delivered, the pair of transport guide rails 2 are lowered by contracting the entire telescopic support structure while maintaining it horizontal, and the new deck slab is installed (erected) at the removal position (main girder) of the existing deck slab. By repeating this process of delivering and installing the new deck slab, the new deck slab can be delivered and installed at the original deck removal position.

After completing the replacement of the deck at the first deck replacement location in this way, the construction machine M travels on a pair of running rails L using three pairs of running wheel units R to move to just after the next deck removal location, and the process of removing and transporting the existing deck and the process of transporting and installing the new deck are repeated.

In this case, as shown in Figure 5 (2), first, a pair of support posts 5 are contracted by separate control and raised above the bridge girder. Next, each support post 5 is moved 8 m forward in the direction of travel of the aircraft 1 along a pair of support post guide rails 6, whereupon each support post 5 is extended and reinstalled on the bridge girder.

Next, as shown in Figure 5 (3), by separately controlling each pair of support columns 10 of the construction machine M, the entire machine body 1 is supported by the front support columns 10 and the rear support columns 10, and by retracting the middle support columns 10, the middle running wheel units R are raised above the pair of running rails L to a height that exceeds the step G. From this state, the front and rear running wheel units R move the machine body 1 2 m on each running rail L, causing the middle pair of running wheel units R to straddle and jump over the step G. This moves the middle pair of running wheel units R onto the end of the preceding divided rail L1 of the next divided rail L1. At this time, the running wheel units R of the rear support columns 10 are in a position midway between the ends of the divided rail L1 immediately after the deck replacement position, with some distance remaining before the step G ahead, and the running wheel units R of the front support columns 10 collide with the step G between the next divided rail L1 and the next divided rail L1. At this point, extend each of the intermediate supports 10 to place each of the intermediate running wheel units R onto the next divided rail L1.

Next, as shown in Figure 5 (4), the counterweight 7 is moved on a pair of movable guide rails 71 of the movable beam 70 to the rear of the machine body 1 (rear in the direction of travel of the construction machine), in this case, onto a pair of support columns 10 at one end (rear in the direction of travel of the construction machine M). Next, by separately controlling each pair of support columns 10 of the construction machine M, the construction machine M is supported by the middle support columns 10 and the rear support columns 10, and by contracting the front support columns 10, the running wheel units R of these support columns 10 are raised to a height that exceeds the step G. From this state, the other middle and rear running wheel units R move the construction machine M 2 m on each running rail L, causing the front pair of running wheel units R to straddle the step G. At this point, each front running wheel unit R is placed on the next divided rail L1.

Next, as shown in Figure 5 (5), the counterweight 7 is moved on a pair of movable guide rails 71 of the movable beam 70 to the front of the machine body 1 (forward in the direction of travel of the construction machine M), in this case, onto a pair of support columns 10 at the other end (forward in the direction of travel of the construction machine M). Next, by separately controlling each pair of support columns 10 of the construction machine M, the construction machine M is supported by the middle support columns 10 and the front support columns 10, and by contracting the rear support columns 10, the running wheel units R of these support columns 10 are raised to a height that exceeds the step G. From this state, the other middle and front running wheel units R move the construction machine M 4 m on each running rail L, causing the rear pair of running wheel units R to straddle and jump over the step G. Then, as shown in Figure 5 (6), each rear running wheel unit R is placed on the next divided rail L1.

In one cycle, the deck slab for 8m of the bridge's axis is replaced and the construction machine M is moved. By repeating this cycle, construction of the entire bridge is completed.

This method using construction machine M shares three points in common with conventional gantry cranes: the basic structure is two pairs of support columns 10, with multiple sets of these combined to support the machine body 1; these support columns 10 move on a rail track; and the lifting and moving of deck slabs is carried out within the machine body 1. This provides the same technical benefits as conventional gantry cranes, such as (1) lifting capacity not being affected by the width of the machine, (2) the suspended load does not pass outside of traffic restrictions, (3) it can be used at heights where overhead restrictions exist, and (4) the transport vehicle can be guided to the vicinity of the construction site.

In particular, this construction machine M uses hydraulic lifters on each pair of columns 10, and lifts materials by controlling the hydraulic cylinders inside the columns 10 to extend or retract the column length. Unlike conventional gantry cranes, this allows the deck slab to be raised and lowered without using a winding device. Furthermore, in the case of this construction machine M, when assembling the construction machine M, the steel beams 11 connecting the three pairs of columns 10 and the support columns 5 are leveled (STEP 1 in Figure 4 (1)). When lifting the deck slab, all columns 10 are extended or retracted simultaneously by the same amount, thereby maintaining the steel beams 11 level. When the construction machine M is moving, any two of the three pairs of support columns 10 constituting the machine body 1 are fixed in their extension/retraction states, stably maintaining the height of the steel beam 11. A pair of support columns 5 is selectively installed. From this state, when the remaining support column 10 is retracted, the base point for the retraction of this column becomes the steel beam 11, not the pair of running rails L, and each running wheel unit R at the bottom of each support column 10 can be lifted off the running rail L (STEP 2 in Figure 4 (2)). In this state, the construction machine M can be moved horizontally, and each support column 10 at the step G passes through the step G between the divided rails L1 (STEP 3 in Figure 4 (3)). This ensures applicability to bridges with longitudinal gradients, a problem faced by conventional gantry cranes. Furthermore, because this construction machine M does not have a winding device, it is not considered a crane. Therefore, completion inspections are not required, and there are no restrictions on the running rail L installation process. This allows the construction machine M to be moved in accordance with the progress of construction at each deck replacement location, and then each traveling rail L (each divided rail L1) remaining behind the direction of travel of the construction machine M can be immediately moved forward. Therefore, by performing the removal and installation work of each traveling rail L simultaneously, the process can be shortened.

As explained above, this method using the construction machine M provides the following advantageous effects that were difficult to achieve with conventional mobile cranes or gantry cranes.
(1) The construction machine M can be made smaller in width and height depending on the construction site, but this does not result in a decrease in the performance of lifting and transporting decks or a decrease in the work efficiency of deck replacement. Therefore, it is ideal for single-lane construction on elevated roads, including bridges, and is also ideal for construction on bridges where headway restrictions exist.
(2) The traveling mechanism RL uses a pair of traveling wheel units R and a pair of traveling rails L, and the pair of traveling rails L is made up of a plurality of divided rails L1, which are installed horizontally, and the construction machine M moves on the horizontal traveling rails L. Therefore, the presence or absence of a longitudinal gradient on the construction surface such as a bridge does not affect the risk of the construction machine M running away, and running away can be prevented by equipment other than outriggers, such as wheel brakes. On the other hand, there is no need to increase the power according to the gradient, as is the case when moving the construction machine M up a gradient with a conventional gantry crane.
(3) The construction machine M has a work space inside, and the deck slab lifting and transporting operations are carried out within this space, so the suspended deck slab will not pass outside the regulated area, and the deck slab transport vehicle can be guided to the vicinity of the deck slab replacement construction site, allowing the deck slab replacement work to be carried out safely and efficiently.
(4) Even if the work of removing and installing the traveling rails L is involved, the construction machine M does not have a winding device like a conventional gantry crane and is therefore not considered a crane. Therefore, the work of removing and installing the traveling rails L can be performed as the same work in the form of repositioning, and there is no loss in the process of moving the construction machine compared to a mobile crane.

Therefore, this method using construction machine M is significantly superior to conventional construction machines in terms of two site conditions, such as the scope and duration of traffic restrictions required and the size of the applicable site, and could be a solution to reduce the negative social and economic impacts of previous deck replacement work.

While this embodiment illustrates a deck replacement method and construction machinery used in highway deck replacement work, it goes without saying that this method and construction machinery can also be used on bridges on ordinary roads, achieving the same effects as those described above.

M Construction machine 1 Machine body 10 Support 11 Steel beam 2 Transport guide rail (rail track)
3. Transport guide (moving beam)
4 Fasteners (cargo hooks)
41 Hook 42 Cord-like member 43 Guide roller 5 Cheek support post 51 Engagement portion 6 Cheek support post guide rail (rail track)
7 Counterweight 70 Moving beam 71 Moving guide rail RL Traveling mechanism R Traveling wheel unit L Traveling rail L1 Split rail G Step

Claims (7)

In a deck replacement method in which the existing deck in the section of a highway where the deck is to be replaced is removed from the main girder and a new deck is installed on the main girder,
The machine body is constructed by connecting at least three pairs of columns that can be extended and retracted in the vertical direction with a predetermined interval between each column, and a pair of conveying guide rails is arranged between the upper parts of each of the columns with both ends in the longitudinal direction extending from each of the columns at both ends, and a telescopic column structure is used, which is configured by bridging each of the conveying guide rails and mounting fasteners that can be connected to the floor slab, and a traveling mechanism that travels the telescopic column structure on the existing floor slab,
The telescopic support structure is installed immediately after the first deck removal position in the deck replacement section via the traveling mechanism, and one end of the pair of conveying guide rails is positioned above the first deck removal position as the conveying start end, and the other end side is positioned as the conveying end,
After cutting the existing deck slab in the deck replacement section to a predetermined size, the entire telescopic support structure is contracted to lower the pair of conveying guide rails, and the fasteners are connected to the cut existing deck slab at the conveying start ends of the pair of conveying guide rails. The entire telescopic support structure is extended to raise the pair of conveying guide rails, and the cut existing deck slab is lifted with the fasteners. The fasteners are moved from the conveying start ends to the conveying end ends of the pair of conveying guide rails via the conveying guides, thereby transporting the cut existing deck slab. This process of removing and transporting the existing deck slab is repeated to remove and transport the existing deck slab from the initial deck slab removal position.
After removing and transporting the existing deck slab from the initial deck slab removal position, the other end of the pair of conveying guide rails is set as the conveying starting end and one end is set as the conveying terminal end, and a new deck slab is transported below the conveying starting end, and then the entire telescopic support structure is contracted to lower the pair of conveying guide rails, and the fasteners are connected to the new deck slab at the conveying starting ends of the pair of conveying guide rails, and the entire telescopic support structure is extended to raise the pair of conveying guide rails and lift the new deck slab with the fasteners, and the fasteners are moved from the conveying starting ends to the conveying terminal ends of the pair of conveying guide rails via the conveying guide to transport the new deck slab, and after the new deck slab has been transported, the entire telescopic support structure is contracted to lower the pair of conveying guide rails and install it at the removal position of the existing deck slab, and this process of transporting and installing the new deck slab is repeated to transport and install the new deck slab at the initial deck slab removal position,
Thereafter, the telescopic support structure is moved by the traveling mechanism immediately after each deck removal position, and the process of removing and carrying out the existing deck and the process of carrying in and installing the new deck are repeated.
A deck replacement method characterized by: The deck replacement method described in claim 1, in which the traveling mechanism uses a pair of traveling wheel units and a pair of traveling rails, the pair of traveling wheel units are attached to the lower ends of each pair of support columns, the pair of traveling rails are laid on both sides of the width of the deck replacement section, and the telescopic support structure is placed on each traveling rail via each traveling wheel unit and moved on each traveling rail. In the case of bridges and other structures where there is a slope in the deck replacement section, a pair of running rails is constructed from multiple divided rails with a length approximately equal to or slightly longer than the distance between the front end of each running wheel unit on the front side of each pair of adjacent support columns at the front and rear of the telescopic support structure and the rear end of each running wheel unit on the rear side of the other. Each divided rail is installed horizontally in the deck replacement section via filler material, and a step is created between the joints of each divided rail. When the telescopic support structure is moved on each running rail, when one of the running wheel units on each pair of support columns reaches the step, the other two The deck replacement method described in claim 2, in which each of the running wheel units has a travel distance remaining before the step, and each time one of the running wheel units reaches the step, the other two units support the entire telescopic support structure, and the one of the running wheel units is raised to a height that exceeds the step by contracting the one of the supports. From this state, the other two running wheel units move the telescopic support structure on the running rails, allowing the one pair of running wheel units to straddle and overcome the step. A deck replacement method according to any one of claims 1 to 3, in which a pair of support pillar guides are arranged side by side on each end side extending from a pair of support pillars at one end of a pair of conveyor guide rails, and a pair of support pillars that are vertically extendable and engage with each end side via the support pillar guides so as to be relatively movably engaged with each other, are arranged, and each end side is supported by each support pillar. A construction machine used in the deck replacement method according to any one of claims 1 to 4,
a body including at least three pairs of support columns each having a built-in telescopic drive unit that can be extended and retracted in the vertical direction, the support columns being connected with a predetermined interval between each pair of support columns; and a telescopic control unit that controls each of the telescopic drive units collectively or individually;
a pair of conveying guide rails disposed between the upper portions of each pair of support columns, with both ends of the conveying guide rails extending from the support columns at both ends; a conveying guide disposed between the conveying guide rails and capable of advancing and retreating along the conveying guide rails; a forward/backward driving unit that drives the conveying guide to advance and retreat on the conveying guide rails; and a forward/backward control unit that controls the forward /backward driving unit;
an operation unit that is operatively connected to the telescopic control unit and the forward/ backward control unit by wire or wirelessly, and that is common to the telescopic control unit and the forward/ backward control unit or that is separate from the telescopic control unit and the forward/backward control unit;
A fastener mounted on the conveying guide and connectable to the deck slab;
The present invention is configured to include:
The pair of conveying guide rails are installed immediately after each deck removal position in the deck replacement section via a traveling mechanism, and one end of the pair of conveying guide rails is arranged above each deck removal/installation position as the conveying start end or conveying end, and the other end is arranged at the deck removal/import destination as the conveying end or conveying start end.
A construction machine characterized by: The running mechanism comprises a pair of running wheel units and a plurality of divided rails having a length approximately equal to or slightly longer than the distance between the front end of each running wheel unit on the front side of each pair of adjacent pillars at the front and rear of the body and the rear end of each running wheel unit on the rear side of the other, a pair of running rails that guide the pair of running wheel units, a running drive unit that drives the pair of running wheel units to run on the pair of running rails, a running control unit that controls the running drive unit, and an operating unit that is connected to the running control unit by wire or wirelessly, and is common to or separate from the telescopic control unit and the forward/ backward control unit, wherein the pair of running wheel units are provided at the lower ends of each pair of pillars, and the pair of running rails are laid on both sides of the width of the deck replacement section. A construction machine as described in claim 5 or 6, which is provided with a pair of cheek support posts supporting each end side extending from a pair of posts at one end of a pair of conveying guide rails, the pair of cheek support posts being telescopic posts with built-in telescopic drive units that allow them to extend and retract in the vertical direction, and a pair of cheek support guides are arranged side by side on each of the one end sides, and are arranged so that they can move along each of the one end sides via each of the cheek support guides.