JP2564674B2 - Steel joint welding equipment - Google Patents

Description

TECHNICAL FIELD The present invention relates to an apparatus for welding an H-shaped beam, a box beam or the like to a box column, a cross column, an H-shaped column or the like for a steel structure.

[Conventional technology]

There are two modes of column penetration and column penetration for welding the steel beam to the steel column. In any case, the corner where the column and the beam intersect is welded. Conventionally, this type of welding is performed by hand welding using a semi-automatic welding machine, or by a small orthogonal robot mounted on the work piece, and the horizontal direction within the groove. Alternatively, downward automatic welding, welding by an articulated robot mounted on a traveling carriage, or the like is performed.

[Problems to be Solved by the Invention] Since all of them are multi-layer internal welding, in the above, the burden on the operator is large and the labor efficiency of the operator is low. Since the above-mentioned and are robot welding, the burden on the worker is reduced and the work efficiency is improved, but the adaptability to irregular groove changes and gap changes is low, and problems are likely to occur in welding quality.

An object of the present invention is to reduce the burden on a worker, improve the work efficiency, and avoid the deterioration of welding quality due to a change in groove and a change in gap.

[Means for solving the problem]

The steel-frame joint welding device of the present invention is a gate-shaped stand (3-5) straddling a steel frame (BX); moving in the longitudinal axis direction y, the vertical direction z of the steel frame (BX), and the direction x orthogonal to these directions. Freely
At least two carriages (39 ₂₁ , 39 ₂₂ ), which are supported by a gate-shaped stand (3-5) in the x and y directions; an electroslag welding electrode (13 ₂₁ , 13 ₂₂ ), and a tip positioning mechanism for the electrode. Including each of the carriages (39 ₂₁ , 39 ₂₂ )
At least two pairs of electro-slag welding device mounted on each of the (12 _21, 12 _22); reserve for enclosing the corner between the steel (BX) and steel material to be welded thereto (BR3) ( 35 ₂₁ , 35 ₂₂ ) for supporting at least two money support means (33); and each corresponding gold support means (3)
At least two sets of advancing and retracting mechanisms (20 ₂₁ , 20 ₂₂ ), which support 3) so as to be able to advance and retreat in a direction intersecting the x direction and the y direction;
Is provided.

The symbols in parentheses indicate the corresponding elements in the embodiments shown in the drawings and described later.

[Action]

The steel-frame joint welding device of the present invention has at least two supporting members (35 ₂₁ , 35 ₂₂ ) for surrounding the corner between the steel frame (BX) and the steel frame material (BR3) to be welded thereto. A plurality of such supporting means (33), and these supporting means (3
Since 3) is provided with at least two sets of advancing and retracting mechanisms (20 ₂₁ , 20 ₂₂ ) for supporting the advancing / retreating itself in the direction intersecting with the x direction and the y direction, the worker is (BR3)
At each of two corners extending in the vertical direction z, the metal support supported by the metal support means (33) extends in the vertical direction z along the corner without supporting the metal load. It can be easily positioned in a curved shape, the labor of the operator is small, and the metal member is accurately positioned.

Therefore, in the steel joint welding apparatus of the present invention, at least two sets of electroslag welding apparatuses (12 ₂₁ , 12 ₂₂ ) each including an electroslag welding electrode (13 ₂₁ , 13 ₂₂ ) and a tip positioning mechanism for the electrode are provided. The carriages (39 ₂₁ , 39 ₂₂ ) are mounted, and each of these carriages (39 ₂₁ , 39 ₂₂ ) moves in the longitudinal axis direction y of the steel frame (BX), the vertical direction z, and the direction x orthogonal to these directions. Freely, the gate-type mount (3
˜5) and arranged along at least one of the x and y directions, each of the electroslag welding electrodes (13 ₂₁ , 13 ₂₂ ) can be routed via these carriages as described above. Each of the two locations of the steel frame (BR3) with respect to the steel frame (BX), which have been applied in the above manner, are in the vertical direction z.
The position can be easily and accurately positioned directly above the corner extending to, without requiring special arm force.

With such positioning, the electrodes of the electroslag welding device can be hung by the tip positioning mechanism into the corner space surrounded by the metal to perform electroslag welding. In this welding, the metal leak is prevented from leaking, so that a sufficient quality of welding can be obtained even in the case of irregular groove changes and gap changes.
At the same time, since welding of at least two corners can proceed, welding work efficiency is high. In the embodiment of the present invention described later, since four sets of electroslag welding devices and the like are provided, two corners of one steel aggregate (BR3) with respect to the steel frame (BX) and the steel frame (BX) are provided.
Another one that is substantially symmetrical to the steel aggregate (BR3) with respect to
Two steel corners (BR1), two corners, a total of four corners can be welded simultaneously, and the welding work efficiency is very high.

Various objects and features of the present invention will become apparent from the following description of embodiments with reference to the drawings.

〔Example〕

FIG. 1a shows a side view of an embodiment of the present invention, and FIG. 1b shows a front view. Please refer to these drawings at the same time. Two rail abutments 1 ₁ and 1 ₂ are fixed to the floor FL in parallel with a certain horizontal direction y. Rails 2 ₁ and 2 ₂ are fixed on the abutments 1 ₁ and 1 ₂ , and two wheels are mounted on the rails 2 ₁ and 2 ₂ , respectively. The two wheels on rail 2 ₁ are lower beams 3 ₁ extending in the y direction.
Is supported by bearings on one side, and one wheel is rotationally driven by an electric motor via a speed reducer. Two wheels of the rail 2 ₂ is supported through a bearing on the lower beam 3 ₂ extending in the y-direction, one wheel is rotated by an electric motor via a reduction gear.

The lower beam 3 _1, two of the pillar 4 _11, 4 ₁₂ are erected,
The lower beam 3 _2, two of the pillar 4 _21, 44 ₂₂ are erected. The mouth-shaped girder 5 is supported by these four pillars 4 ₁₁ , 4 ₁₂ , 4, ₂₁ and 4 ₂₂ in total. These lower beams 3 ₁ , 3 ₂ and pedestals 4 ₁₁ , 4 ₁₂ ,
The gate-type mount 100 is composed of 4 ₂₁ , 4 ₂₂ and the mouth-shaped girder 5.

The gate-shaped mount 100 moves in the forward and reverse directions in the y direction by the synchronized forward and reverse rotational urging of the two electric motors of the lower beams 3 ₁ and 3 ₂ . That is, it is possible to reciprocate in the y direction by self-propelling.

The mouth-shaped girder 5 has two rails 6 ₁ , 6 ₂ extending in the y direction.
Are fixed in parallel to each other, and y-direction traveling beams 7 ₁ and 7 _{2 which} are horizontal and extend parallel to the x-direction orthogonal to the y-direction are located below the rails 6 ₁ and 6 ₂ . y at both ends of a direction running beam ₇₁ has wheels attached to the rail 6 _and 62 are coupled to an electric mechanism, the y-direction traveling beams 7 rail 6 ₁ coupled to an electric mechanism at both ends of the _2, 6 ₂ There are wheels that are combined. The y-direction traveling beams 7 ₁ , 7 ₂ are
These electric mechanisms can be independently driven in the y direction.

The y-direction traveling beam 7 ₁ has vertical guide pipes 9 ₁₁ and 9 in the z-direction.
₁₂ and is secured the upper end of, the y-direction traveling beams 7 _2, the upper end of the z-direction guide pipe 9 _21, 9 ₂₂ are fixed. Welder support beams 10 ₁ and 10 ₂ , respectively parallel to the y-direction traveling beams 7 ₁ and 7 ₂ , respectively, are guided by guide pipes 9 ₁₁ , 9 respectively.
It is attached to ₁₂ and 9 ₂₁ and 9 ₂₂ so as to be movable in the vertical z direction. The welder support beam 10 ₁ is suspended on the electric hoist 11 ₁ suspended on the y-direction traveling beam 7 ₁ , and the welder support beam 10 ₂ is suspended on the y-direction traveling beam 7 ₂ on the electric hoist 11 1. Suspended in ₂ . The welder support beam 10 ₁ can be moved in the vertical z direction by the electric hoist 11 ₁ , and the welder support beam 10 ₂ can be moved in the vertical z direction by the electric hoist 11 ₂ .

Two carriages 39 ₁₁ and 39 ₁₂ are movably connected to the welding machine supporting beam 10 ₁ in the x direction in which the beam 10 ₁ extends, and the electroslag welding machines 12 ₁₁ and 12 12 are connected to the carriages, respectively.
Each of the ₁₂ is fitted. Carriage 39 ₁₁ , 39 ₁₂
Each of them has a lock mechanism (not shown) for restraining movement in the x direction. Similarly, welder supporting the beam 10 _2, two carriages 39 _21, 39 ₂₂ are movably coupled to the x-direction of extension of beam 10 _2, electroslag welding machine 12 ₂₁ in each of the carriages, 12 Each of the ₂₂ is fitted. Each of the carriages 39 _21, 39 _22, are equipped with a lock mechanism (not shown) for Kakawatome movement in the x direction. Operator can these to unlock the locking mechanism moves the welding machine in the x-direction, and fixing the welder to lock the locking mechanism to the support beams 10 _1, 10 _2.

The electro slag welding machine 12 ₁₁ equipped on the carriage 39 ₁₁ has a nozzle 13 ₁₁ and a nozzle 1 through which the electrode wire is passed.
3 Nozzle automatic drive mechanism that supports ₁₁ and drives in the z direction, z direction manual fine adjustment mechanism that supports this mechanism with adjustable position in the z direction, and x direction fine adjustment mechanism that supports this mechanism with adjustable position in the x direction. Equipped with an adjustment mechanism.

The nozzle 13 _11, electrode wires and welding power is supplied. The welders 12 ₁₂ , 12 ₂₁ and 12 ₂₂ mounted on the other carriages 39 ₁₂ , 39 ₂₁ and 39 ₂₂ have the same mechanism as 12 ₁₁ .

Welders 12 ₁₁ , 12 ₁₂ ,
Wire drawing device 14 for supplying welding wire to 12 ₂₁ and 12 _22
11 , 14 ₁₂ , 14 ₂₁ , 14 ₂₂ , Welding power supply device 1 that gives welding power
5 ₁₁ , 15 ₁₂ , 15 ₂₁ , 15 ₂₂ etc. are installed.

For each of the pedestals 4 ₁₁ , 4 ₁₂ , 4 ₂₁ , 4 ₂₂ , the crimping device 20 ₁₁ ,
20 ₁₂ , 20 ₂₁ , 20 ₂₂ are installed.

In Figure 2a shows an enlarged side of the crimping device 20 ₂₂ that is mounted to the pedestal 4 ₂₂ is an enlarged plan to FIG. 2b. z-direction guide case z-position adjusting mechanism 21 is one that is fixed firmly to the pillar 4 _22. A screw rod (not shown) stands at the center of the inside of the guide case, and a z position adjusting knob 21a is fixed to the upper end of the screw rod protruding outward. The operator can rotate the screw rod with this knob 21a. The right end of the arm 22 protruding horizontally from the guide case is inside the guide case and is guided up and down in the z direction by the guide case, and is screwed to the above-mentioned screw rod. Arm 2 when turned in the direction
2 rises and descends when turned counterclockwise.

A rotating mechanism 26 supports a rotating arm 26 on the arm 22 so as to horizontally rotate about the z-axis. That is, the arm
At the left end of 22 is a shaft 24 extending in the z direction,
The right end of the rotating arm 26 supported in the z direction is rotatably connected to the shaft body 24. The rotation mechanism 23 is provided with a lock mechanism, and the rotation arm 26 is locked by tightening and rotating the lock screw 25, and when it is loosened, rotation is possible.

The dowel support beam 27 is inserted into the rotating arm 26 so as to be able to move forward and backward, and this forward and backward movement is locked by tightening the lock screw 28 and rotating the drive.

The tip of the reserve support beam 27 is secured jack 36, the start tab (lower losses) on the jack 36 37 ₂₂ is placed.

An advancing / retreating mechanism 29 is further installed in the middle of the monetary support beam 27. With this advancing / retreating mechanism 29, a vertical metal (copper metal) supporting mechanism 32
The lower bottom of the guide case 31 is supported so as to be movable back and forth in the extending direction of the metal support beam 27 (the direction of the synthetic vector of the x component and the y component: the direction intersecting with x and y). Rotate the adjustment knob 30 of the mechanism 29 clockwise to guide the mechanism 32.
When 31 advances toward the jack 36 and rotates counterclockwise, it retracts toward the mechanism 21.

The vertical metal support mechanism 31 is a mechanism similar to the z position adjustment mechanism 21 described above, and when the knob 34 is rotated clockwise, the arm 33 is rotated.
Goes up and turns counterclockwise to go down. Extending in the z-direction at the right end of the arm 33, there is removably z-axis member in the z-direction, longitudinal losses (copper losses) losses support ring secured to 35 _22, the z-direction by the arm 33 It is supported and rotatable about the z-axis. By pulling out the z-axis body from the left end hole of the arm 33, the vertical metal plate 35 ₂₂ to be mounted can be exchanged.

Crimping device mounted on pedestal 4 ₁₁ , 4 ₁₂ , 4 ₂₁ 20 ₁₁ , 2
The structure of 0 ₁₂ and 20 ₂₁ is the same as that of the crimping device 20 ₂₂ .

Rail 1 ₁ portal frame 100 is superimposed, 1 between the _2, as shown in Figure 3a, at a considerable distance in the y direction and the two turn roller devices 110, 120 are disposed. FIG. 3b shows the front of the turn roller device 120. Turn roller device 120
Is a large-diameter cylindrical ring supported by rollers underneath. Four threaded rods for supporting the steel column BX to be welded are arranged in a cross shape on the tubular ring, and each threaded rod is screwed into a nut (not shown) attached to the tubular ring. The screw rod moves (projects) toward the center of the tubular ring by turning a handle (not shown) clockwise.
Then, by rotating it counterclockwise, it moves (retracts) in a direction away from the center. At the tip (free end) of each screw rod,
A shoe (not shown) is installed and is shown in Figures 3a and
FIG. 3b shows a state in which the steel column BX to be welded is supported by the tubular ring via these shoes and screw rods. The roller that supports the tubular ring below is coupled to the rotating shaft of the electric motor via the speed reducer, and the tubular ring rotates by urging the electric motor to rotate, and the steel column BX supported by the tubular ring BX, It rotates around its longitudinal axis (y direction). The base that supports the roller that supports the cylindrical ring below is mounted on two rails that extend in the y direction via electrically driven wheels, and is capable of self-propelling in the y direction. The structure of the turn roller device 110 is also the same as the structure of the turn roller device 120.

Next, a usage mode of the above equipment will be described. First, the turn roller devices 110 and 120 are respectively connected to the platform (3a
It is placed on the outside (y direction) of FIG. 2), and the portal frame 100 is also placed on the outside of the platform. The steel column BX, which was temporarily welded and fixed to four locations of three steel beam components BR1 to BR4 at three locations (positions near the right end, middle position, and left end of BX in FIG. 3) in the cross direction, (Not shown)
Then, it is carried around the position shown in FIG. 3a. With the steel column BX stationary, the turn roller devices 110 and 120 are driven to the platform to support the steel column BX as shown in Figures 3a and 3b. The turn roller devices 110 and 120 are adjusted so that the center axis (y direction) of the steel column BX is aligned with the centers of their cylindrical rings.

Next, the portal frame 100 is driven to the platform to weld the steel column BX at three points in the y direction.

Hereinafter, as shown in FIG. 3a, a mode in which the portal frame 100 is placed at an intermediate position in the y direction of the steel column BX and the four steel beam members BR1 to BR4 are welded will be described.

When the portal frame 100 is set at the positions of the steel beam parts BR1 to BR4, the crimping device 20 that has been retracted for the movement of the frame 100
_The rotation arm 26 of ₂₂ is rotated to extend the support beam 27, and the start tab 37 ₂₂ on the jack 36 is connected to the steel column BX and the steel beam part BR.
Position it just below the corner between 3 (Fig. 4c). Next, raise the rotating arm 26 with the knob 21a, and set the start tab 37 ₂₂ to the steel column BX.
Close to, and to the start tab 37 ₂₂ in the jack 36 is pressed against the lower surface of the steel beam component BR3 (FIG. 4a). Next knob 3
Adjust the position of the arm 33 in the z direction with 4, rotate the knob 30, and push out the guide case 31. Then, as shown in FIGS. 4a and 4c, the copper metal plate 35 ₂₂ is attached to the steel column BX and the steel beam part BR3.
Press on the side of. Similar to the above, the other crimping device 2
By operating 0 ₁₁ , 20, ₁₂ and 20 _{21 as} well, the start tab and the copper plate are positioned with respect to the four corners of the steel column BX and the steel column parts BR3 and BR1 extending in the Z direction.

Next, the welding machine support beams 10 ₁ and 10 ₂ which are retracted upward by the hoists 11 ₁ and 11 ₂ are set so that the lower ends of the nozzles 13 ₁₁ , 13 ₁₂ , 13, ₂₁ and 13 ₂₂ are slightly above the upper surface of the steel column BX. Lower to the position (Z
Positioning). Then, the y-direction traveling beams 7 ₁ and 7 ₂ are connected to the nozzle 13
Drive (y position adjustment) until the lower ends of ₁₁ , 13, _{12 21} , 13 ₂₁ , and 13 ₂₂ are located above the side surface of the steel column BX and adjust the carriage 3
9 _11, 39 _12, 39 _21, 39 _22, the nozzle 13 _11, 13 _12, 13 _21, 13 ₂₂ driving until positioned above the near side of the steel beam component BR3 and BR1 (x position adjustment) is. As mentioned above, if necessary,
Adjust the z, y, and x position to make the nozzle 13 ₁₁ , 13 ₁₂ , 13 ₂₁ , 13 ₂₂
At the lower end of the steel column BX and the steel beam parts BR3 and BR1, Z
Positioned just above the four corners extending in the direction.

When positioning of the lower ends of the nozzles 13 ₁₁ , 13 ₁₂ , 13, _{21 21} , 13 ₂₂ is completed as described above, the nozzles of the electroslag welding machine are
13 ₁₁ , 13 ₁₂ , 13 ₂₁ , 13 ₂₂ Pull down the electrode wire to connect the steel column BX and the steel beam parts BR3 and BR1 with copper
35 ₁₁ , 35 ₁₂ , 35 ₂₁ , 35 ₂₂ Inserted in the space of the four corners extending in the Z direction, and the lower end is the start tab 37 ₁₁ , 37 ₁₂ , 37 ₂₁ , 37
Apply to ₂₂ . The nozzle 13 _11, 13 _12, 13 _21, 13 ₂₂ and lowered to a predetermined position to start welding.

When the electroslag welding of the four corners extending in the Z direction between the steel column BX and the steel column parts BR3 and BR1 is completed, the crimping device 2
0 ₁₁ , 20 ₁₂ , 20 ₂₁ , 20 ₂₂ and electro slag welder 1
2 _11, 12 _12, 12 _21, 12 ₂₂ moves to the retracted position. Then, the turn columns 110 and 120 rotate the steel column BX by 90 degrees about the longitudinal axis (y). Then, in the same manner as described above, the crimping device 20 ₁₁ , 20 ₁₂ ,
Operate 20 ₂₁ , 20 ₂₂ to reset the start tab and copper metal, and reset the electroslag welder,
Electroslag welding of the four corners extending in the Z direction between the steel column BX and the steel beam parts BR4 and BR2 is performed. Upon completion of this, the crimping device 20 _11, 20 _12, 20 _21, 20 ₂₂ and electro-slag welding machine 12 _11, 12 _12, 12 _21, 12 move ₂₂ in the retracted position.

From the above, four steel beam parts at one location of the steel column BX
We have finished welding BR1 to BR4. Next is the gate mount 10
Drive 0 to the next weld point and perform the weld in the same way.

In this way, welding of all parts is completed and the crimping device 20 ₁₁ , 2
0 ₁₂ , 20 ₂₁ , 20 ₂₂ and electro slag welder 12 ₁₁ , 1
Moving 2 _12, 12 _21, 12 ₂₂ to the retracted position, to drive the gate-shaped frame 100 to the outside of the platform (Figure 3a). And steel pillar BX
Is hung by a crane, and the turn rollers 110 and 120 are detached from the steel column BX and driven outside the platform, and the steel column BX is carried out of the platform. Then place the next steel column to be welded on the platform with a crane,
Start the work described above.

In this embodiment, since four electroslag welders simultaneously weld four corners, the welding process efficiency is extremely high. Since the welding is electroslag welding, welding of sufficient quality can be obtained even with irregular groove changes and gap changes. Even if the start tab and the copper dowel are large and heavy, the labor to support them is practically unnecessary, so that the burden on the worker is extremely light and the work efficiency of the worker is extremely high. Further, since the labor of the operator is not required for positioning and rotating the steel frame column BX, the welding process efficiency of the steel frame column BX is remarkably improved.

Although four electroslag welders are provided in the above-mentioned embodiment, even two electroslag welders can perform welding processing with considerably high efficiency. In this case, the steel column BX is rotated by 90 degrees each time welding of one steel beam component BRi is completed, and the steel frame is welded at one location (four bone beam components) three times (270 degrees). Rotate the pillar BX. Since the steel columns BX are supported by the turn rollers 110 and 120, such rotating work is extremely easy.

〔The invention's effect〕

As described above, according to the present invention, high-quality and highly efficient steel joint welding is realized. The burden on workers, especially heavy labor, is greatly reduced, and the working efficiency of workers is greatly improved.

[Brief description of drawings]

FIG. 1a is a side view of an embodiment of the present invention, and FIG. 1b is a side view of the embodiment. FIG. 2a is an enlarged side view of the crimping device 20 ₂₂ equipped with this embodiment, and FIG. 2b is an enlarged plan view. FIG. 3a is a side view showing the gate mount 100 shown in FIGS. 1a and 1b and the turn roller devices 110 and 120 supporting the steel column BX, and FIG. 3b is a front view. FIG. 4a is a side view showing the relative positional relationship between the crimping device 20 ₂₁ shown in FIG. 1b and the steel column BX and the steel beam component BR3 welded thereto. FIG. 4b is a front view showing the relative positional relationship between the steel frame column BX to be welded and the steel beam components BR1 to BR4 to be welded thereto. FIG. 4c shows a steel frame column BX to be welded and steel beam parts BR1 to BR3 to be welded thereto, and a crimping device 20 ₂₁ shown in FIG. 1b.
It is a top view which shows the relative relationship with. 1 ₁ , 1 ₂ : Rail abutment, 2 ₁ , 2 ₂ : Rail 3 ₁ , 3 ₂ : Lower beam, 4 ₁₁ to 4 ₂₂ : Pedestal 5: B-shaped girder, 6 ₁ , 6 ₂ : Rail 7 ₁ , 7 ₂ : Y direction traveling beam, 8 ₁₁ 〜 8 ₂₂ : Pipe support 9 ₁₁ 〜 9: Guide pipe, 10 ₁ , 10 ₂ : Welder support beam 11 ₁ , 11 ₂ : Electric hoist 12 ₁₁ 〜 12 ₂₂ : Electroslag welding machine (electroslag welding device) 13 _{11 to} 13 ₂₂ : Nozzle, 14 _{11 to} 14 ₂₂ : Wire drawing device 15 ₁₁ to 15 ₂₂ : Welding power supply device 16 _{11 to} 16 ₂₂ : Drop stopper leg 20 _{11 to} 20 ₂₂ : Crimping device (expansion and contraction mechanism) 21: z position adjustment mechanism, 21a: Knob 22: Arm, 23: Rotating mechanism 24: Shaft body, 25: Lock screw 26: Rotating arm, 27: Support beam 28: Lock Screw, 29: Advance / retreat mechanism 30: Adjustment knob, 31: Guide case 32: Vertical metal support mechanism, 33: Arm (metal support means) 34: Knob, 35 _{11 to} 35 ₂₂ : Vertical metal (metal) 36 : Jack, 37 _{11 to} 37 ₂₂ : Start tab 38 _{11 to} 38 ₂₂ : Back plate 39 _{11 to} 39 ₂₂ : Carriage (Carriage) 100: Gate type frame (gate type frame), 110,120: Turn roller device FL: Floor, BX: Steel frame column (steel frame) BR1 to BR4: Steel beam parts (steel frame material)

Claims (1)

(57) [Claims] 1. A gate-type mount straddling a steel frame; movably supported by the gate-type mount in the longitudinal axis direction y, the vertical direction z of the steel frame, and a direction x orthogonal to these directions, and in the x and y directions. At least two carriages arranged along at least one direction; electroslag welding electrodes and at least two sets of electroslag weldings each mounted on each of said carriages, including a tip positioning mechanism for said electrodes. An apparatus; at least two dowel support means for supporting a dowel for surrounding a corner between the steel frame and the steel aggregate to be welded thereto; and a respective gold support means in the x direction and A steel-frame joint welding device comprising at least two sets of advancing and retracting mechanisms for supporting the advancing and retracting in a direction intersecting with the y direction.