JP2010000572A - Vacuum blasting apparatus and vacuum blasting method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vacuum blasting apparatus performing a vacuum blasting effectively without putting a large burden on a worker when a weld line of a steel member is blasted from underneath. <P>SOLUTION: The blasting apparatus, which blasts a weld line of a steel member after on site welded, from underneath, is provided with: a stream guiding gutter 20 closely attached and fixed to the steel member along and just below the weld line, the guiding gutter having internal space S opened upward; supply means 40, 42, 44 for supplying a blasting material 1 and air into the internal space of the stream guiding gutter 20, the supply means connected to one end of the stream guiding gutter 20; suction means 50, 52, 54 for collecting the blasting material 1 by sucking the blasting material in the internal space S of the stream guiding gutter 20, the suction means connected to the other end of the stream guiding gutter 20; and a flow contractor 30 which contracts an airflow 2, for carrying the blasting material 1 in the internal space S, toward the proximity of the welding line, and is disposed within the internal space S of the stream guiding gutter 20. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a vacuum blasting apparatus and a vacuum blasting method, and more particularly to a vacuum blasting apparatus and a vacuum blasting method that can be suitably used even in the vicinity of a scallop when blasting a weld line between steel slabs.

  It is required to improve the coating performance to extend the life of the steel structure, and even if the substrate is adjusted on site, a substrate adjustment equivalent to one kind of keren has been required. Yes. For example, in the steel bridge painting and anticorrosion manual (December 2005 edition), which is the standard for painting steel bridges, among the joint parts for on-site construction of a new bridge, two types of keren using a power tool are allowed for bolt joints. However, welding joints are required up to one kind of keren, and it is necessary to blast them. Also, in the repainting of existing bridges, when durability is particularly required, up to one kind of keren is required, and blasting is required.

  FIG. 1 is a perspective view of a U-rib steel slab as viewed obliquely from above, and FIG. 2 is a perspective view as viewed from obliquely below.

  The U-rib steel slab 100 includes a steel slab (deck plate) 102 formed of a steel plate, a main girder (vertical girder) 104 disposed in the bridge axis direction on the lower surface of the steel slab (deck plate) 102, The main girder 106 is arranged in a direction perpendicular to the bridge axis, and U ribs (vertical ribs) 108 are arranged on the lower surface of the steel deck (deck plate) 102 in the bridge axis direction. This structure is reinforced by arranging in the direction perpendicular to the axis. The size of the U-rib steel slab 100 is about 10 m in the direction of the bridge axis and about 3 m in the direction perpendicular to the bridge axis, and a plurality of U-rib steel slabs 100 are connected to each other by welding or bolting on the road. The superstructure is formed. The code | symbol 112 shows the weld line by the welding joining in a field, and the code | symbol 114 shows a site | part bolt junction part.

  FIG. 3 is a perspective view of a steel deck 100 to be welded in the field as seen obliquely from above. The steel decks (deck plates) 102 are connected to each other by on-site welding, and as shown in FIG. 3, weld lines 112 are formed and connected in the bridge axis direction and the bridge axis perpendicular direction. The weld line 112 is the weld bead 120 (refer FIG. 5) connected in a line. The width of the weld line 112 is about 10 mm. The upper surface of the steel deck (deck plate) 102 is paved, and a road surface is formed.

  4 and 5 are enlarged perspective views showing a situation where the U-rib steel deck 100 is being welded in the field about the portion A in FIG. For in-situ welding of the U-rib steel plate slab 100, as shown in FIG. 4, after installing a special backing material 116 and backing material cover 118 that cause a back wave on the bottom surface of the steel floor slab (deck plate) 102, As shown in FIG. 5, it is common to perform submerged arc welding from the upper surface of the steel deck (deck plate) 102, and between the groove portions of the two steel decks (deck plates) 102 that perform on-site welding. The weld bead 120 (weld line 112) is formed by the weld metal by submerged arc welding, and the two steel decks (deck plates) 102 are connected. On the bottom surface of the steel slab 102, in order to pass the welding backing material 116 and the backing material cover 118 (see FIG. 4), the U rib 108, the main girder 104, the cross beam 106, and the rib material 142 of the horizontal rib 110 are provided. Is provided with a scallop 140 which is a notch.

  However, weld burrs 112 </ b> A (see FIG. 9) are generated on the upper and lower surfaces of the weld line 112. The weld burr 112A needs to be cleaned before performing on-site coating. As described above, since it is a welded joint, up to one kind of keren is required and blasting is required. In this blasting process, it is necessary to avoid scratching the factory-painted part that has been applied in advance. Further, since the weld line 112 exists in a linear form as shown in FIG. 3 and the like, it is necessary to sharpen the weld line 112 in a linear form.

  Also, in blasting, it is becoming necessary to strictly take measures against dust during blasting. For example, silica sand, which has been frequently used as a blasting material (grinding material), is fragile and easily becomes dust. Its use has been prohibited since FY2007. Thus, in blast processing, it is required to avoid dust scattering as much as possible.

  For this reason, it is advantageous to use a vacuum blasting method in the polishing of the weld line 112.

  FIG. 6 is a cross-sectional view schematically showing a state in which vacuum blasting is performed on the welding line 112 on the lower surface of the steel deck 102 using the conventional vacuum blast head 130, and the cross section shows the welding line 112. It is the cross section cut | disconnected in the perpendicular direction by the surface to include. As shown in FIG. 6, a conventional vacuum blast head 130 used for vacuum blasting includes a blast supply unit 132 to which a blast hose for feeding blast material with compressed air is connected, and a blast material or blast material scraped off. And a vacuum part 134 to which a suction vacuum hose is connected. A brush 136 that can follow the unevenness of the blast surface and surrounds the part to be blasted is provided at the tip. In addition, a blast surface is a surface including the site | part used as the object of a blast process, and is a lower surface of the steel deck slab 102 here. The shape of the conventional vacuum blast head 130 is a cylindrical shape having a diameter of about 100 mm and a height of about 200 mm. In order to maintain good blast performance, the vacuum blast head 130 needs to be placed perpendicular to the blast surface. In FIG. 6, two vacuum blast heads 130 are drawn, but in order to show a situation where the vacuum blast head 130 is moved from the right to the left along the weld line 112 in the drawing to show the situation where blasting is performed. It is one drawn.

  However, the vacuum blast head 130 is heavy, and the vacuum blast head 130 must be pressed against the upper blast surface to move along the blast surface while holding the vacuum blast head 130 perpendicular to the blast surface. Therefore, working upward is a heavy labor.

  On the other hand, as a self-propelled blasting device using the vacuum blasting method, for example, blasting devices described in Patent Literature 1 and Patent Literature 2 have been proposed. For example, a blasting device described in Patent Document 3 has been proposed as a blasting device that transports a blasting material into an air stream and blasts a wall surface of a space in which the blasting material travels.

JP 59-124571 A JP 2000-141226 A JP-A-9-141555

  On the other hand, as described above, the U-rib 108, the main girder 104, the cross girder 106, the horizontal girder are provided on the lower surface of the steel floor slab 102 in order to pass the welding backing material 116 and the backing material cover 118 (see FIG. 4). The rib material 142 of the rib 110 is provided with a scallop 140 that is a notch. As shown in FIGS. 1 and 2, since the U ribs 108 having the two rib members 142 are arranged at a narrow interval of about 700 mm, the scallops 140 are arranged at an interval of 400 to 500 mm. The scallop 140 is semicircular, the width is about 80 to 120 mm, and the height is about 35 to 50 mm.

  Although there are many scallops 140, it is necessary to sharpen the weld line 112 immediately above the scallop 140 and the vicinity thereof to remove the weld burrs, and it is necessary to perform one type of selenium by blasting.

  However, the blasting devices described in Patent Document 1 and Patent Document 2 require the arrangement of rails, are difficult to apply beyond scallops, and are difficult to perform continuous blasting. For this reason, the blasting operation cannot be performed efficiently on the weld line.

  Further, even when the worker supports the vacuum blast head from below and performs vacuum blasting, the size of the conventional vacuum blast head 130 is larger than the size of the scallop 140, and the conventional vacuum blast head 130 has the scallop 140. 6, as shown in FIG. 6, in the range of about 25 mm from the side surface of the rib plate 142 immediately above and in the vicinity of the scallop 140 of the rib plate 142, the brush 136 cannot be applied perpendicularly to the blast surface, I can't vacuum blast.

  In addition, the force applied to the vacuum blast head includes its own weight, reaction force of blast injection, vacuum suction force, force applied by the worker, force from unevenness due to movement of the head, etc. While supporting the head and moving the head, it is necessary to keep pressing the vacuum blast head against the blast surface with a constant force, which places a heavy burden on the worker.

  The blasting device described in Patent Document 3 does not require the worker to support the vacuum blasting head from below and can be applied beyond the scallop, but the direction in which the blasting material is conveyed by the airflow is considered. Since it is parallel to the surface to be ground (surface to be blasted), the efficiency of blasting is poor. Here, when the steel surface after welding is blasted, it is necessary to grind the steel having high hardness or the welded portion with high performance. Therefore, in the blasting device described in Patent Document 3, the efficiency of the blasting described above is improved. Evil is a particular problem.

  The present invention has been made in view of such problems, and when blasting a weld line of a steel member from below, vacuum blasting is performed efficiently and without placing a heavy burden on an operator. It is an object of the present invention to provide a blasting apparatus and a blasting method capable of performing the above.

  The present invention solves the above problems by the following blasting apparatus and blasting method.

  That is, the first aspect of the blasting apparatus according to the present invention is a blasting apparatus for blasting a weld line after on-site welding of a steel member from below, having an internal space opened upward, and directly below the weld line. Are connected to the steel member along the weld line, and are connected to one end of the flow guide rod to supply blast material and air into the internal space of the flow guide rod. Supply means for connecting, suction means connected to the other end of the flow guide guide rod, for sucking the interior space of the flow guide guide rod and collecting the blast material, and in the internal space of the flow guide guide rod And a current-reducing device that contracts an air flow that conveys the blasting material in the inner space in the vicinity of the weld line.

  A second aspect of the blasting apparatus according to the present invention is a blasting apparatus for blasting a weld line after on-site welding of a steel member across one or more scallops from below, and has an internal space opened upward, A feed guide rod disposed in one or more of the scallops, and directly fixed to the steel member along the weld line directly below the weld line; and connected to one end of the feed guide rod. A supply means for supplying a blasting material and air into the inner space of the flow guide guide and connected to the other end of the flow guide guide and sucking the inner space of the flow guide guide into the blast A suction means for collecting the material, a current reducer disposed in the internal space of the flow guide guide rod, and the air flow for conveying the blast material in the internal space to be reduced in the vicinity of the welding line; A blasting apparatus comprising:

  The outer shape of the cross-sectional shape of the flow guide rod is a shape that matches the shape of the scallop, and the workability in installing the flow guide rod and the flow guide rod are supported from below. It is preferable because it is easy to.

  Moreover, it is preferable from the viewpoint of economical efficiency and workability that the flow guide rod is closely fixed to the steel member by magnetic force.

  In addition, the feed guide rod may be tightly fixed to the steel member by sucking and depressurizing the interior space of the flow guide rod by the suction means.

  The shape of the cross section obtained by cutting the current reducer disposed in the internal space of the flow guide rod along a vertical plane parallel to the longitudinal direction of the flow guide rod is a mountain shape whose width becomes narrower toward the top. This is preferable in that the air flow for conveying the blast material is contracted to increase the speed and the traveling direction of the blast material is changed to the direction toward the blast surface to improve the efficiency of the blast treatment.

  In addition, at the top of the current reducer disposed in the internal space of the flow guide guide rod, the end portion in the direction orthogonal to the longitudinal direction of the flow guide guide rod is higher than the other regions. It is preferable that the air flow for conveying the blast material can be reliably reduced in the vicinity of the weld line to increase the speed. Moreover, an edge part becomes a surface which contacts a steel member and slides.

  Further, the current reducing device has a current reducing surface, and the current reducing surface is in contact with an air flow that conveys the blast material in an internal space of the flow guide guide rod, and the air flow is connected to the welding line. When the current reducer is disposed in the internal space of the flow guide guide rod, an inclination of the flow reduced surface with respect to the longitudinal direction of the flow guide guide rod is The continuous change at the top of the vessel is preferable in terms of further increasing the flow velocity of the air flow conveying the blast material.

  Further, when the current reducer is disposed in the internal space of the flow guide guide rod, the current reducer with respect to the longitudinal direction of the flow guide guide rod increases as the height increases within a predetermined height or more. It is preferable that the inclination of the contracted flow surface is steep because the collision angle of the blasting material with respect to the blasting surface becomes close to the vertical, so that the efficiency of the blasting process is further improved.

  Further, when the current reducer is disposed in the inner space of the flow guide guide rod, the position of the maximum height of the current reducer depends on the position in the direction perpendicular to the longitudinal direction of the flow guide guide rod. The difference in the longitudinal direction of the flow guide guide rod is preferable in that it suppresses the vortex vibration of the current reducer itself caused by the air flow conveying the blast material. When vibration is generated in the current reducer due to the air flow, not only the smooth movement of the current reducer is hindered, but also the blasting object and the blasting device (feed guide rod, current reducing device) may be damaged. . For example, in the state that “the position of the maximum height of the current reducer differs in the longitudinal direction of the flow guide guide rod depending on the position in the direction orthogonal to the longitudinal direction of the flow guide guide rod”, the maximum When there are multiple height positions at different positions in the longitudinal direction of the flow guide rod, the line connecting the maximum height positions is oblique to the longitudinal direction of the flow guide rod, The case where it becomes is included.

  Further, it is preferable that the current reducer is movable in the longitudinal direction in the inner space of the flow guide guide rod. In this case, the upper end portion of the flow guide guide rod is folded inward and folded. The upper end of the current reducer is in contact with the inner surface of the upper end of the flow guide guide, and the current reducer is movable in the longitudinal direction in the inner space of the flow guide guide. It is more preferable in terms of stability when the current reducer slides.

  A first aspect of the blasting method according to the present invention is a blasting method for blasting a weld line after on-site welding of a steel member from below, wherein a feed guide rod having an internal space opened upward is used as the weld line. And a step of closely fixing to the steel member along the air flow, and an air flow for conveying the blasting material in the inner space of the flow guide guide rod in the vicinity of the welding line. And a blast material and air are supplied from one end of the flow guide rod into the internal space of the flow guide rod, and the other end of the flow guide rod And a step of moving the current reducer in the longitudinal direction of the flow guide guide rod while sucking the interior space of the flow guide guide rod.

  A second aspect of the blasting method according to the present invention is a blasting method for blasting a weld line after on-site welding of a steel member across one or more scallops from below, and having an internal space opened upward A guide rod is disposed in one or more of the scallops, and a step immediately below the steel member along the weld line is fixed to the steel member; and in the internal space of the flow guide rod, A step of arranging a current reducer for reducing the air flow for conveying the blast material in the vicinity of the welding line, and from one end of the flow guide rod into the internal space of the flow guide rod. And the air are supplied, and the current reducer is moved in the longitudinal direction of the flow guide guide rod in a state where the interior space of the flow guide guide rod is sucked from the other end of the flow guide guide rod. And a bra characterized by comprising: It is a door way.

  The direction of movement of the current reducer is a direction from the one end that supplies blast material and air into the inner space of the flow guide guide rod toward the other end that sucks the inner space of the flow guide rod. It is preferable in that it is easy to move the current reducer.

  In addition, blast material and air are supplied from one end of the flow guide guide into the internal space of the flow guide guide, and from the other end of the flow guide guide to the internal space of the flow guide guide. In this state, after moving the current reducer from the one end to the other end in the longitudinal direction of the flow guide rod, the flow guide rod is then moved from the other end of the flow guide rod. The blast material and air are supplied into the inner space of the flow guide rod, and the current reducer is sucked into the inner space of the flow guide rod from one end of the flow guide rod. Moving from the other end to the one end in the longitudinal direction of the flow guide guide rod is preferable in terms of reducing unevenness in the unevenness of the blast surface subjected to the blasting process and making the blast surface uniform.

  A blasting apparatus according to the present invention has an internal space that opens upward, and a flow guide rod that is tightly fixed to the steel member along the weld line directly below the weld line, and the flow guide rod Connected to one end and supplying means for supplying a blast material and air into the inner space of the flow guide guide, and connected to the other end of the flow guide guide and in the inner space of the flow guide guide And a suction means for collecting the blast material by suction and an air flow that is disposed in the internal space of the flow guide guide rod and transports the blast material in the internal space near the weld line Therefore, when the welding line of the steel member is blasted from below, the vacuum blasting can be performed efficiently and without placing a heavy burden on the worker.

  Further, the blasting method according to the present invention includes a step of arranging a flow guide guide rod having an internal space opened upward and directly under the weld line along the weld line, and fixing the flow guide guide rod to the steel member; In the internal space of the guide rod, a step of disposing a current reducer that contracts the air flow that conveys the blast material in the internal space in the vicinity of the welding line, and from one end of the flow guide guide rod, In the state where blast material and air are supplied into the inner space of the flow guide guide and the inside of the flow guide guide is sucked from the other end of the flow guide guide, And moving the welding guide rod in the longitudinal direction, the vacuum blasting can be performed efficiently and without placing a heavy burden on the operator when blasting the welding line of the steel member from below. can do.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 7 is a schematic view of a situation where the blasting process is performed using the blasting apparatus 10 according to the embodiment of the present invention as viewed from the side.

  The blasting device 10 according to the embodiment of the present invention includes a flow guide rod 20, a current reducer 30, a supply device 40, a supply duct 42, a supply side lid member 44, a suction device 50, and a suction duct 52. And a suction side lid member 54.

  The flow guide rod 20 has an internal space S opened upward, and the opening is pressed against the lower surface of the steel slab 102, and one end of the flow guide rod 20 (an end on the blast material supply side). ) Is provided with a supply-side lid member 44, and a suction-side lid member 54 is provided at the other end (suction side end) of the flow guide guide 20, so that the internal space S of the flow guide guide 20 is It is partitioned from the outside and is a closed space.

  The current reducer 30 is disposed in the internal space S of the flow guide guide 20 and is an air flow (hereinafter referred to as a blast material transfer flow 2) that transports the blast material 1 in the internal space S of the flow guide guide 20. ) In the vicinity of the lower surface of the steel deck 102.

  The current reducing device 30 has a current reducing surface 30D. The current reducing surface 30D is a surface that is in contact with the blast material conveying flow 2 and causes the blast material conveying flow 2 to be reduced, and the inside of the flow guide guide 20 The shape of the cross section obtained by cutting the current reducer 30 disposed in the space along a vertical plane parallel to the longitudinal direction of the flow guide rod 20 is a mountain shape whose width becomes narrower toward the top. For this reason, the blast material transport flow 2 is contracted as it travels along the contracted surface 30D, and its speed increases. Further, when the blast material transport flow 2 travels along the contracted surface 30D, the traveling direction of the blast material 1 is changed to a direction toward the blast surface. By these things, the efficiency of a blast process improves. Further, the current reducing device 30 is movable in the longitudinal direction in the internal space S of the flow guide guide 20.

  The supply device 40 supplies the blast material 1 and air into the internal space S of the flow guide rod 20 through the supply duct 42. Therefore, the supply device 40 and the supply duct 42 serve as supply means for supplying the blast material 1 and air into the internal space S of the flow guide rod 20. One end of the supply duct 42 is connected to the duct connection port 40 </ b> A of the supply device 40, and the other end is attached to the supply-side lid member 44.

  The suction device 50 sucks the interior space S of the flow guide rod 20 through the suction duct 52 and collects the blast material 1 and the rust 3 removed by the blast material 1. Therefore, the suction device 50 and the suction duct 52 serve as suction means for sucking the interior space S of the flow guide guide 20 and collecting the blast material 1. One end of the suction duct 52 is connected to the duct connection port 50 </ b> A of the suction device 50, and the other end is attached to the suction side lid member 54.

  Next, the configuration of the blasting device 10 will be further described with reference to the drawings showing in detail each main part of the blasting device 10 according to the embodiment of the present invention.

  8-12 is a figure which shows the state which the flow guide rod 20 of the blasting apparatus 10 which concerns on embodiment of this invention is arrange | positioned in the scallop 140, and was installed in the lower surface of the steel deck 102. FIG. FIG. 8 is a cross-sectional view showing a cross section of the flow guide guide 20 and the current reducer 30 taken along a plane including the weld line 112 parallel to the longitudinal direction of the flow guide guide 20, and FIGS. 9 is a cross-sectional view showing a cross section of the flow guide guide 20 cut along a plane perpendicular to the longitudinal direction of the flow guide guide 20, FIG. 9 is a cross-sectional view taken along the line IX-IX of FIG. 8, and FIG. FIG. 11 is a sectional view taken along line XI-XI in FIG. 8 (a sectional view including a supply side lid member 44), and FIG. 12 is a sectional view taken along line XII-XII in FIG. It is sectional drawing containing the member 54). For convenience of illustration, the background other than the cut surface is not shown in FIG. In FIGS. 11 and 12, the flow guide rod 20 and the elastic body 26 are drawn by a two-dot chain line for reference.

  The flow guide rod 20 has an internal space S that opens upward, has a semicircular cross-sectional shape, and can be provided along the weld line 112 directly below the weld line 112 for blasting. It can arrange | position in the above scallop 140. FIG. The flow guide rod 20 has a role of forming a passage for an air flow (blast material conveyance flow 2) conveying the blast material 1 supplied by the supply device 40 via the supply duct 42 to travel. The blast material conveying flow 2 obtains a driving force by the applied pressure supplied from the supply device 40 and the suction force supplied from the suction device 50, and proceeds in the internal space S of the flow guide guide 20.

  Moreover, the flow guide rod 20 supports the current-reducing device 30 that moves in the inner space S in the longitudinal direction from below, and smoothly moves the current-reducing device 30 along the welding line 112 to be blasted. It also has a guiding role. Although it is conceivable that an unexpected force is applied to the current reducer 30 due to the unevenness of the lower surface of the steel slab 102, it is possible to stably support the current reducer 30 even in such a case. Alternatively, even if the suction force varies, the flow guide rod 20 is appropriately supported by the fixing band 22 (see FIG. 10) so that the flow guide rod 20 is closely fixed to the lower surface of the steel deck 102. As shown in FIG. 10, the fixed band 22 is attached to the lower surface of the steel deck 102 by a magnet 24.

  Moreover, since the flow guide rod 20 forms a closed space by the inner space S and the lower surface of the steel deck 102, the blast material 1 and the rust 3 scraped off by the blast material 1 are scattered outside. Since the closed space is sucked by the suction device 50, the flow guide rod 20 can collect the blast material 1 supplied by the supply device 40 and the rust 3 scraped off by the blast material 1 or the like. Also has a role to make. Since the flow guide rod 20 that is a component of the blasting device 10 has such a role, the blasting process by the blasting apparatus 10 of the present embodiment is a vacuum blasting process.

  The outer shape of the cross-sectional shape of the flow guide rod 20 is a semicircular shape that matches the shape of the scallop 140 (a semicircle having a width of about 80 to 120 mm and a height of about 35 to 50 mm). It is possible to fix the position easily.

  Elastic bodies 26 are attached to both ends of the semicircular cross section of the flow guide guide rod 20 (upper end portions of the flow guide guide rod 20 in FIGS. 9 and 10). Here, in order for the blast material 1 to travel at high speed in the closed space formed by the inner space S of the flow guide rod 20 and the lower surface of the steel deck 102, the pressure applied by the supply device 40 and the suction by the suction device 50 It is important not to miss the force, and it is preferable to prevent a gap from being formed between the upper end portion of the flow guide rod 20 and the lower surface of the steel deck 102. Further, it is important to prevent the blast material 1 from being scattered to the outside so as not to generate a gap between the upper end portion of the flow guide rod 20 and the lower surface of the steel deck 102. For this reason, it is preferable that the elastic body 26 has a flexibility that can follow the unevenness of the lower surface of the steel deck 102.

  Further, when the elastic body 26 has such flexibility, the flow guide rod 20 is appropriately pushed up from below by the fixing band 22 and the elastic body 26 is pressed against the lower surface of the steel deck 102. As a result, the elastic body 26 absorbs the irregularities on the lower surface of the steel slab 102, thereby stabilizing the position of the flow guide rod 20. In FIG. 9, reference numeral 122 denotes a welded portion between the steel deck 102 and the rib plate 142.

  Fixing the position of the flow guide rod 20 is important in that it determines the part to be blasted. If the fixed position is shifted during the work, the target part cannot be blasted. Further, if the fixing position of the flow guide rod 20 is shifted, the blast material 1 may be scattered to the outside, or the flow guide rod 20 may be distorted and the passage space of the current reducer 30 may not be secured. . Therefore, it is necessary that the flow guide rod 20 can be positioned and fixed reliably.

  Here, in the blasting apparatus 10 according to the embodiment of the present invention, the blast material 1 is blown into the closed space formed by the inner space S of the flow guide rod 20 and the lower surface of the steel floor slab 102, Therefore, there is a possibility that a large force is applied to the flow guide guide 20 to shift the fixing position. Therefore, special attention is required for fixing the position of the flow guide rod 20.

  When the position of the flow guide rod 20 is fixed, first, the flow guide rod 20 is temporarily fixed in a state in which pressure reduction (suction) and pressure (pressure feed) are not performed on the flow guide rod 20, and is temporarily fixed. Confirm the position with. At the time of temporary fixing, the temporary fixing band (not shown) is attached to the lower surface of the steel deck 102 with a magnetic force by a magnet (not shown). It may be strong enough to support at most about 1 kg / m per unit length in the direction, and may be weak magnetic force.

  After temporary fixing, even if the inside space S of the flow guide rod 20 is depressurized (suctioned) or pressurized (pressure fed), the flow guide rod 20 is secured by the fixing band 22 and the magnet 24 so that the position does not move. Secure the book. When the main fixing is performed, a strong magnetic force is particularly required so that the flow guide rod 20 is not separated from the lower surface of the steel deck 102 with respect to pressurization (pressure feeding). Specifically, for example, it is preferable to have a magnetic force of about 500 to 1000 kg / m per unit length in the axial direction, and the magnetic force of the magnet 24 of the fixed band 22 is a strong magnetic force of about 100 to 200 kg per 20 cm. It is preferable to have power.

  Although the position of the flow guide rod 20 may be fixed without using magnetic force, for example, by mechanical fixing with bolts or the like, the fixing band 22 and the magnet 24 can be repeatedly attached to and detached from the steel member. Since it can be used repeatedly, the position fixing by the fixing band 22 and the magnet 24 is more economical. Further, the position fixing by the fixing band 22 and the magnet 24 is easy to work and excellent in workability.

  Further, when the flow guide rod 20 passes through the scallop 140, a reaction force from the scallop 140 can be used, and a wedge or the like is provided between the lower surface of the flow guide rod 20 and the upper end portion of the scallop 140. These spacers may be inserted to secure the supporting force. Here, since the outer shape of the cross-sectional shape of the flow guide rod 20 is a semicircular shape that matches the shape of the scallop 140 as described above, a wedge is formed between the lower surface of the flow guide rod 20 and the upper end portion of the scallop 140. It is easy to secure a supporting force by inserting a spacer such as.

  In addition, after temporary fixing, the flow guide guide 20 is fixed to the lower surface of the steel deck 102 with sufficient force by the suction force generated when the suction device 50 sucks the inside space S of the flow guide guide 20. In this case, the main fixation may be performed using this adsorption force. In this case, fixing by the fixing band 22 and the magnet 24 is not used at all or is used as an auxiliary.

  The structure of the flow guide rod 20 is a double structure, the inner layer is made of hard rubber with less surface irregularities and excellent wear resistance, and the outer layer is a pressure resistant structure as shown in FIG. 13 (side view). (A structure in which a flexible rubber member 20A is reinforced with a semicircular reinforcing ring 20B). Since the inner layer is made of hard rubber with less surface irregularities and excellent wear resistance, the surface of the inner layer is prevented from being cut by the blast material conveying flow 2. Further, since the outer layer has a pressure-resistant structure as described above, the pressure in the closed space formed by the inner space S of the flow guide rod 20 and the lower surface of the steel deck slab 102 varies in the range of about 0 to 2 atmospheres. Even so, the flow guide rod 20 is not deformed. The thickness of the inner layer made of hard rubber having excellent wear resistance is, for example, about 10 mm. FIG. 13 shows a state where the right side of the divided flow guide rod 20 is bent downward.

  Although the flow guide rod 20 has a double structure as described above, it is preferable that the flow guide rod 20 has a structure that can be bent and deformed in the longitudinal direction from the viewpoint of facilitating the installation in the scallop 140. Here, the inner layer of the double-flow flow guide rod 20 is made of a hard rubber having a thickness of about 10 mm. However, even if it is a hard rubber, it has a certain degree of flexibility as long as it has a thickness of about 10 mm. The inner layer of the heel 20 has a certain degree of flexibility. Moreover, although the outer layer of the flow guide rod 20 has a pressure-resistant structure, as shown in FIG. 13, it has a structure in which a flexible rubber material 20A is reinforced by a semicircular reinforcing ring 20B and has flexibility. For this reason, the flow guide rod 20 has a structure that can be bent to some extent in the longitudinal direction, and it is easy to arrange the long length of the flow guide rod 20 along the weld line. Moreover, the operation | work at the time of inserting the feed guide rod 20 in the scallop 140 is also easy.

  In addition, if it can be set as the feed guide rod 20 which has sufficient pressure resistance only by the hard rubber excellent in abrasion resistance, it is more economical than a double structure and is preferable.

  Moreover, it is preferable from the point of workability | operativity of installation work to divide the flow guide rod 20 into the length according to the space | interval between the scallops 140, and to make it into a division | segmentation element body. Moreover, the length does not need to be constant, and may be a plurality of lengths so as to facilitate the work. By dividing the flow guide rod 20 into a length corresponding to the interval between the scallops 140, for example, even when the interval between the scallops 140 is as short as about 400 to 500 mm, the flow guide rod 20 is Can be installed inside. Then, by connecting the flow guide rods 20 installed in the scallop 140, the long flow guide rods 20 can be continuously inserted into the plurality of scallops 140 as a result. It becomes.

  As shown in FIG. 14A (side view) and FIG. 14B (front view), for example, as shown in FIG. 14 (A) (side view) and FIG. 14 (B) (front view), the divided flow guide rods 20 (dividing element bodies) are connected to each other. The connecting jig 28 that can cover the connecting end portions between each other from the outside can be performed by fixing the connecting jig 28 to the connecting end portion of the flow guide rod 20 with a bolt 28A. The connecting jig 28 is a semicircular shape formed in accordance with the outer shape of the flow guide guide rod 20, and can cover the connection end portion of the flow guide guide rod 20 from the outside. Further, for example, as shown in FIG. 15 (side view), it may be carried into the site with the connecting jig 28 attached to one end of each divided feed guide rod 20, and the installation work may be performed. Note that the divided flow guide rods 20 (dividing element bodies) may be connected by the fixing band 22 and the magnet 24 instead of the connecting jig 28 and the bolt 28A.

  By allowing the long flow guide rod 20 to be continuously inserted into the plurality of scallops 140, the current reducer 30 can pass through the plurality of scallops 140 continuously. For this reason, even if the work space is divided into a large number by the rib plate 142, the blasting work can be performed from only two work spaces each including one of both ends of the inserted flow guide rod 20. The target welding line blasting process can be efficiently performed.

  Here, the scallop 140 is a semicircular through hole that is opened in the rib plate 142 that obstructs the welding operation when the two ribbed steel decks (deck plates) 102 are joined by welding. Therefore, since the scallop 140 is inevitably disposed directly below the weld line, the flow guide rod 20 that is disposed through the plurality of scallops 140 extends along the weld line directly below the weld line. Will be placed.

  Note that the scallop 140 is usually arranged on the same straight line in a structure such as a steel deck. For this reason, the connected flow guide rod 20 is also usually linear. If the connected flow guide rods 20 are straight, it is easy to satisfactorily perform suction in the closed space formed by the internal space S of the flow guide rods 20 and the lower surface of the steel deck 102, and the current reducer The resistance when 30 moves in the flow guide rod 20 is also reduced.

  Further, the flow guide guide 20 may be formed of a transparent material. By forming with a transparent material, the degree of blasting for the weld line can be visually recognized from the outside.

  Next, supply means (supply device 40, supply duct 42, supply side lid member 44) for supplying blast material 1 and air and suction means (suction device 50, suction duct 52, suction side lid member) for recovering blast material 1 54) will be described. The supply means for supplying the blast material 1 and air and the suction means for collecting the blast material 1 have a role of forming the blast material transport flow 2 in the internal space S of the flow guide rod 20 and collect the blast material 1. Further, the suction means for collecting also has a role of recovering the used blast material 1 and rust 3 scraped off by the blast material 1.

  The supply device 40 supplies the blast material 1 and air into the internal space S of the flow guide rod 20 through the supply duct 42. In the supply device 40, the blast material 1 supplied from the blast material supply unit 40B is conveyed into the supply duct 42 by the compressed air supplied from the compressed air generation device 40A. In order to convey the blast material 1 by the air flow (blast material conveyance flow 2) in the internal space S of the flow guide rod 20, the flow velocity of the air flow (blast material conveyance flow 2) needs to be about 40 to 80 m / s. However, in the blasting apparatus 10 according to the embodiment of the present invention, the current reducing device 30 is disposed in the flow guide guide 20 and becomes a resistance to the flow of the air flow (blasting material conveying flow 2). It may be necessary to pressurize the interior space S of the flow guide rod 20 upstream of the vessel 30. Therefore, it is preferable that the supply device 40 has an ability to output a sufficient pressure more than the pressure necessary to supply the blast material 1 into the internal space S of the flow guide rod 20. .

  The suction device 50 sucks the interior space S of the flow guide guide 20 through the suction duct 52 to give a driving force to the blast material transport flow 2 and is scraped off by the blast material 1 or the blast material 1. It has a role to collect rust etc. 3. The blast material 1 sucked by the blast material separating portion 50B by the suction force supplied from the negative pressure generating device 50A of the suction device 50 and the rust 3 scraped off by the blast material 1 are blasted in the blast material separating portion 50B. The material 1 and the blast material 1 are separated into rust 3 (rust, dust, etc.) scraped off. For this reason, the recovered blast material 1 can be reused. This recovery / separation function is a function provided in a conventional vacuum blasting apparatus.

  The supply duct 42 and the suction duct 52 may have the same performance as the duct used in the conventional vacuum blasting apparatus, and the required performance is that the inner surface has wear resistance, and the diameter is about 1 m during transportation and operation. And having a structural strength that can withstand internal pressure and suction force.

  One end of the supply duct 42 is connected to the duct connection port 40 </ b> C of the supply device 40, and the other end is attached to the supply-side lid member 44, and the blast material 1 supplied from the supply device 40 is supplied to the feed guide rod 20. This is a route for delivery into the internal space S.

  One end of the suction duct 52 is connected to the duct connection port 50 </ b> C of the suction device 50, and the other end is attached to the suction-side lid member 54. The suction force supplied from the suction device 50 is applied to the inside of the flow guide rod 20. In addition to being a path for transmission into the space S, it is a path for sending the sucked blast material 1 and the rust 3 scraped off by the blast material 1 to the suction device 50.

  The supply-side lid member 44 and the suction-side lid member 54 are supplied from the pressure and suction device 50 supplied from the supply device 40 to the closed space formed by the inner space S of the flow guide rod 20 and the lower surface of the steel floor slab 102. In order to prevent the suction force generated from escaping from the inner space S to the outside, and to attach the supply duct 42 and the suction duct 52 to both ends of the flow guide guide 20, they are provided at both ends of the flow guide guide 20. It is a member to be.

  As shown in FIGS. 7 and 8, the supply-side lid member 44 is provided at the end portion on the side where the supply duct 42 for supplying the blast material 1 is inserted. The shape of the supply-side lid member 44 viewed from the longitudinal direction of the flow guide guide 20 is a semicircular shape similar to the cross-sectional shape of the flow guide guide 20, as shown in FIG. The cross section of the flow guide rod 20 is slightly larger than the semicircular shape, and the supply-side lid member 44 is installed so as to abut against the end surface of the flow guide rod 20 and the end of the flow guide rod 20 Cover the part and cover it. Further, a portion located outside the cross-sectional shape of the flow guide rod 20 protrudes in the longitudinal direction of the flow guide rod 20 to form a protruding portion 44A, which is the end portion of the flow guide rod 20. Cover from the outside. Thereby, the adhesiveness of the supply side cover member 44 and the edge part of the flow guide rod 20 is improved. Further, a sealing material is provided between the inner surface of the protruding portion 44A of the supply side lid member 44 and the outer surface of the end portion of the flow guide rod 20, and between the upper end portion of the supply side lid member 44 and the lower surface of the steel deck 102. It is also preferable to improve the sealing property of the internal space S of the flow guide rod 20 by providing a flexible elastic body.

  A duct insertion port 44 </ b> B through which the supply duct 42 is inserted is provided at the center of the supply-side lid member 44. The size of the duct insertion port 44B is approximately the same as the outer shape of the supply duct 42. When the supply duct 42 is inserted into the duct insertion port 44B and attached, there is no gap between the supply duct 42 and the duct insertion port 44B. The pressure applied from the supply duct 42 does not escape to the outside. In addition, a cable insertion hole 44C through which the cable 32 for pulling and moving the current reducer 30 is provided below the duct insertion port 44B. The diameter of the cable insertion hole 44C is about the same as the outer shape of the cable 32, and when the cable 32 is inserted into the cable insertion port 44C, there is no gap between the cable 32 and the cable insertion port 44C. The applied pressure supplied from the supply duct 42 does not escape to the outside. The thickness of the supply side lid member 44 is, for example, about 2 to 3 cm.

  As shown in FIGS. 7 and 8, the suction side cover member 54 is a side to which a suction duct 52 for sucking in the closed space formed by the inner space S of the flow guide rod 20 and the lower surface of the steel deck 102 is attached. (The end opposite to the side on which the supply duct 42 is attached). The shape of the suction side lid member 54 is the same as that of the supply side lid member 44, and the shape of the suction side lid member 54 viewed from the longitudinal direction of the flow guide guide 20 is as shown in FIG. The semicircular shape is the same as the cross-sectional shape of the ridge 20, but the size of the semicircle is slightly larger than the semicircular shape of the cross section of the flow guide rod 20, and the suction side lid member 54 is a flow guide. It is installed so as to be abutted against the end surface of the gutter 20, and covers the end of the flow guide gutter 20 and covers it. Further, a portion located outside the cross-sectional shape of the flow guide rod 20 protrudes in the longitudinal direction of the flow guide rod 20 to form a protruding portion 54A, which is the end portion of the flow guide rod 20. Cover from the outside. Thereby, the adhesiveness of the suction side lid member 54 and the end of the flow guide rod 20 is improved. Further, between the inner surface of the protruding portion 54A of the suction side lid member 54 and the outer surface of the end portion of the flow guide guide 20, and between the upper end portion of the suction side lid member 54 and the lower surface of the steel deck 102, It is also preferable to improve the sealing property of the internal space S of the flow guide rod 20 by providing a flexible elastic body.

  A duct insertion port 54 </ b> B through which the suction duct 52 is inserted is provided at the center of the suction side lid member 54. The size of the duct insertion port 54B is approximately the same as the outer shape of the suction duct 52. When the suction duct 52 is inserted and attached to the duct insertion port 54B, there is no gap between the suction duct 52 and the duct insertion port 54B. The suction force supplied from the suction duct 52 does not escape to the outside. Further, a cable insertion hole 54C through which the cable 32 for pulling and moving the current reducer 30 is provided below the duct insertion port 54B. The diameter of the cable insertion hole 54C is about the same as the outer shape of the cable 32, and when the cable 32 is inserted into the cable insertion port 54C, no gap is formed between the cable 32 and the cable insertion port 54C. The suction force supplied from the suction duct 52 does not escape to the outside. The thickness of the suction side lid member 54 is, for example, about 2 to 3 cm.

  The method of attaching the supply side lid member 44 and the suction side lid member 54 to the flow guide rod 20 and the steel deck slab 102 is not particularly limited. Alternatively, a method of attaching to the lower surface of the steel deck 102 with a magnet may be used.

  Further, neither the supply-side lid member 44 nor the suction-side lid member 54 may be integrally formed. For example, the supply-side lid member 44 and the suction-side lid member 54 may be divided into two at the left and right central portions. When the supply-side lid member 44 is divided into two, the supply-side lid member 44 is installed by sandwiching the supply duct 42 from the left and right at the portion of the insertion port 44A. When the suction side cover member 54 is divided into two, the suction side cover member 54 is installed by sandwiching the suction duct 52 from the left and right at the portion of the insertion port 54A.

  Next, the current reducer 30 will be described. FIG. 16 is a perspective view of the current reducer 30 as viewed obliquely from above, but for convenience of illustration, only a part of the flow guide guide 20 is indicated by a two-dot chain line.

  As shown in FIG. 8, the cross-sectional shape of the current reducer 30 viewed from the side is a mountain shape. Further, as shown in FIGS. 8 and 16, the lower surface of the current reducer 30 is along the inner surface of the flow guide guide 20 and is covered with the brush 30 </ b> A, and the air flow guide guide 20 is secured while ensuring airtightness. Can be slid in the longitudinal direction. Of the surface of the current reducing device 30, the surface other than the lower surface covered with the brush 30 </ b> A along the inner surface of the flow guide guide 20 contacts the blast material conveying flow 2 and contracts the blast material conveying flow 2. It is a surface 30D. The top portion of the current reducer 30 is at a position where the upper end of the end portion 30C is substantially in contact with the lower surface of the steel deck 102, and the central portion 30B is slightly lower than the end portion 30C. For this reason, when the current reducing device 30 is disposed in the flow guide guide 20, a slight gap G is formed between the central portion 30B of the top of the current reducing device 30 and the lower surface of the steel deck 102. The gap G becomes a contracted portion. The width of the central portion 30B, that is, the width of the gap (constricted portion) G is, for example, 30 to 40 mm.

  For this reason, the blast material transporting flow 2 traveling in the internal space S of the flow guide guide 20 from the supply side to the suction side is contracted by the current reducing device 30 and passes through the top of the current reducing device 30. In this case, a slight gap G between the central portion 30 </ b> B at the top of the current reducer 30 and the lower surface of the steel deck 102 is passed. Further, by contracting, the flow rate of the blast material transporting flow 2 is increased, and the blast material 1 collides with the lower surface of the steel deck 102 at a certain angle. Therefore, by using the current reducing device 30, the lower surface of the steel deck 102 in the range of the gap (current reducing portion) G is efficiently blasted.

  As described above, the blast material 1 violently collides with the lower surface of the steel floor slab 102 in the region near the gap G between the central portion 30B at the top of the current reducer 30 and the lower surface of the steel floor slab 102. The blasting process is performed more efficiently than the area where the container 30 is not disposed. For this reason, in order to efficiently blast the target range, it is necessary to move the current reducer 30 in the longitudinal direction of the flow guide rod 20. And if the width | variety (constriction part) G is 30-40 mm, for example, the width | variety of the area | region where the steel floor slab 102 lower surface will be 30-40 mm.

  In order to further increase the flow velocity of the blast material conveying flow 2 at the top of the current reducer 30, as shown in FIG. 8, the inclination of the current reducing surface 30 </ b> D at the top of the current reducer 30 (feed guide rod 20 (Tilt with respect to the longitudinal direction) is preferably continuously changed so that a point at which the slope changes discontinuously does not occur. By doing so, it is possible to reduce the air pressure difference between the supply side and the suction side necessary for generating the blast material conveyance flow, and to reduce energy loss when generating the blast material conveyance flow. be able to.

  The movement of the current reducer 30 can be made by pulling a cable 32 attached to the current reducer 30. The cable 32 is disposed in the flow guide rod 20 from the outside through the cable insertion hole 44 </ b> B of the supply side lid member 44 and the cable insertion hole 54 </ b> B of the suction side lid member 54. The direction in which the cable 32 is pulled (moving direction of the current reducer 30) is basically the same direction as the traveling direction of the blast material transport flow 2, and the downstream cable 32 is pulled in principle. The blast material 1 bites into the gap between the current reducer 30 and the inner surface of the flow guide guide 20 or between the current reducer 30 and the lower surface of the steel floor slab 102, thereby preventing smooth movement of the current reducer 30. This is so that there is no such thing. In order to prevent the current reducer 30 from flowing downstream by the blast material conveying flow 2, it is preferable to apply tension to the upstream cable 32 to the extent that it can serve as a spot. The cable 32 may be a steel wire, for example.

  Here, although depending on the mass of the entire current reducing device 30, when the current reducing device 30 moves in the longitudinal direction in the flow guide guide 20, the end portion of the top portion of the current reducing device 30 is the steel plate slab 102. It is thought that it is in contact with the lower surface. This is because when the blast material conveying flow 2 passes through the current reducing device 30, the pressure above the current reducing device 30 becomes negative pressure, and the current reducing device 30 receives an uplift force.

  On the other hand, the lower surface of the steel slab 102 is often a rough surface to which rust or the like is attached, and is not in a constant state. Therefore, when the current reducer 30 moves while the top end of the current reducer 30 is in contact with the lower surface of the steel slab 102, the sliding may not be stable. As a countermeasure against this, as shown in FIG. 17, the upper end of the flow guide rod 20 is folded back to provide a folded portion 30D substantially parallel to the lower surface of the steel deck 102, and the lower surface of the folded portion 30D is connected to the current reducer. It can be mentioned that the sliding surface is in contact with the top end of 30. If it does in this way, since the end part of the top part of current reducing device 30 will not be in direct contact with the undersurface of steel floor slab 102, stable sliding can be obtained.

  Even if the current reducing device 30 is lifted upward by the uplift force when the blast material conveying flow 2 passes through the current reducing device 30, the central portion 30B at the top of the current reducing device 30 is slightly smaller than the end 30C. Therefore, regardless of whether or not the folded portion 30D is provided, a gap (constricted portion) G is secured, and the blast material conveying flow 2 is welded to the bottom surface of the steel deck 102. 112 can be reliably contracted in the vicinity of 112.

  The material of the current reducer 30 is preferably a metal such as steel. Since the blast material conveying stream 2 collides with the current reducer 30, the current reducer 30 is required to have higher wear resistance than the inner surface of the flow guide rod 20, while the current reducer 30 has flexibility. Because it is not required. In addition, the entire current reducing device 30 is not made of a metal such as steel, but a metal having high wear resistance may be used only at the top of the current reducing device 30 that is particularly easily worn. Moreover, when using steel for the current reducer 30, it is also preferable to perform a treatment for improving the wear resistance only at the top.

  Further, as will be described later, in the actual blasting process, it is preferable to replace the supply side and the suction side and supply the blast material 1 from both directions to perform the blasting process. The shape of the cross section of the current reducer 30 cut along a vertical plane parallel to the direction is preferably symmetrical.

  Next, a current reducing device 70 that is a modification of the current reducing device 30 of the blasting apparatus 10 according to the present embodiment will be described.

  FIG. 18 (A) is a top view schematically showing the current reducer 70, and FIG. 18 (B) is a cross-sectional view taken along the line BB of FIG. 18 (A). In FIG. 18 (B), for convenience of illustration, the top end portion 70C of the current reducing device 70 visible behind is not drawn.

  As shown in FIG. 18 (B), the shape of the cross section obtained by cutting the current reducer 70 along a vertical plane parallel to the longitudinal direction of the flow guide rod 20 is a mountain shape whose width becomes narrower at the top, and In the range above the predetermined height, the inclination of the contracted surface 70D (inclination relative to the longitudinal direction of the flow guide rod 20) becomes steeper as the height increases. For this reason, while the flow velocity of the blast material conveyance flow 2 streamed by the top part of the current reducer 70 is raised, the collision angle with respect to the blast processing surface of a blast material is closely approximated. For this reason, the lower surface of the steel deck 102 is blasted more efficiently.

  However, since the inclination of the flow-reducing surface 70D becomes steeper as the height increases at the top of the current-reducing device 70, the inclination of the current-reducing surface 70D changes discontinuously at the top. For this reason, the blast material conveyance flow 2 after passing through the uppermost discontinuous point is turbulent and becomes a turbulent air current, generating a vortex. When a vortex is generated, there is a concern that the current reducer 70 itself vibrates due to the vortex.

  Here, the generation mechanism of the vortex vibration will be briefly described with reference to FIG. First, the blast material transport flow 2 is contracted while rising along the contracted surface 70D at the top of the current contractor 70 as indicated by an arrow a in the figure, and is applied to the lower surface of the steel deck 102 at an angle close to vertical. Collide and perform blasting. After passing through the top, the blast material transport stream 2 generates a vortex b. This vortex b tends to vibrate the current reducer 70 in the vertical direction.

  However, as shown in FIGS. 18 (A) and 18 (B), the central portion 70B at the top of the current reducing device 70 has a maximum height depending on the position in the direction perpendicular to the longitudinal direction of the flow guide rod 20. The position is different in the longitudinal direction of the flow guide rod 20. For this reason, since the generation timing of the vortex differs depending on the position in the direction orthogonal to the longitudinal direction of the flow guide rod 20, the occurrence of the vortex is less likely to occur at the same timing. Vortex vibration is less likely to occur, and the current reducer 70 can smoothly move in the longitudinal direction in the flow guide guide 20. Moreover, if the current reducer itself causes vortex vibration, there is a risk of damaging the flow guide rod 20 and the current reducer itself. However, as described above, the current reducer 70 is less likely to cause vortex vibration. Damage is unlikely to occur.

  In addition, as for the shape of the cross section which cut | disconnected the current reducer 70 shown to FIG. 18 (A) and FIG. 18 (B) with the perpendicular surface parallel to the longitudinal direction of the flow guide rod 20, the uppermost part becomes a linear area | region. However, the uppermost part may not be a straight region, and the position of the maximum height differs even in the longitudinal direction of the flow guide guide 20 depending on the position in the direction orthogonal to the longitudinal direction of the flow guide guide 20. If it is, even if it becomes a curve and a vertex, generation | occurrence | production of a vortex vibration is suppressed.

  Further, in order to make it difficult for vortex vibration to occur in the current reducer 70, as shown in FIG. 18, there are a plurality of positions at the maximum height at different positions in the longitudinal direction of the flow guide rod. For example, the line connecting the positions of the maximum heights may be inclined or curved with respect to the longitudinal direction of the flow guide guide rod.

  Next, the procedure of blasting performed using the blasting apparatus 10 according to the embodiment of the present invention will be described by taking as an example the case where the welding line 112 in the direction perpendicular to the bridge axis of the steel deck 102 is blasted from the lower surface. . In this case, the flow guide rod 20 is inserted into the scallop 140 provided on the U rib 108 and the lateral rib 110.

(1) Arrangement and fixing of the flow guide rod 20 First, the flow guide rod 20 adjusted to a predetermined length is inserted into the scallop 140 from one direction side of the plurality of U ribs 108 provided with the scallops 140. Insert through all the scallops 140.

  Next, with the temporary fixing band, the feed guide rod 20 is temporarily fixed so that it is located immediately below the welding line 112. If the position of the flow guide rod 20 is appropriate, the fixed guide band 20 and the magnet 24 are used for permanent fixing ( Final fixing). At this time, it is not necessary to remove the temporary fixing band, and it may be left as it is. Further, a wedge is inserted into the gap between the lower surface of the flow guide rod 20 and the scallop 140 at the position of the scallop 140 provided on the U rib 108 and the lateral rib 110, thereby fixing the flow guide rod 20 more firmly. To do.

(2) Arrangement of the Current Shrinker 30 in the Flow Guide Guide 20 First, a steel wire for drawing (not shown) is stretched over the entire length of the flow guide guide 20 in the internal space S of the flow guide guide 20. hand over.

  Next, one end of the steel wire for calling is temporarily attached to one steel wire (cable 32) of the current reducer 30 with the steel wire (cable 32) attached to both sides (traveling direction side and retreating direction side). Then, after the current-contracting device 30 is arranged in the current-feeding guide rod 20, a steel wire for drawing in is drawn in, and one of the steel wires (cables 32) attached to the current-limiting device 30 is the current-feeding guide rod 20 It is to be stretched over the entire length. Remove the steel wire that is no longer needed.

  By doing in this way, the current reducer 30 and the steel wire (cable 32) attached to both sides of the current reducer 30 are disposed in the flow guide guide 20.

(3) Attachment of lid members to both ends of the flow guide guide 20 The supply side lid member 44 to which the supply duct 42 is attached and the suction side lid member 54 to which the suction duct 52 is attached are connected to the flow guide guide 樋. Attach to both ends of 20. It is arbitrary whether the supply side lid member 44 and the suction side lid member 54 are disposed at the end of the flow guide rod 20.

(4) The position of the current reducer 30 in the flow guide rod 20 is moved to the supply side end.

(5) Confirmation of circulation of air flow The blast material 1 is not supplied, but only air blowing from the supply device 40 is started, and suction by the suction device 50 is started. Then, the circulation of the air flow in the order of the supply device 40, the supply duct 42, the internal space S of the flow guide guide 20, the suction duct 52, and the suction device 50 is confirmed. Since the current reducer 30 receives pressure due to the air flow, tension is applied to the steel wire (cable 32) on the front side of the current reducer 30 to fix the current reducer 30 in advance.

(6) Blast treatment Supply of the blast material 1 from the supply device 40 is started. In the internal space S of the flow guide rod 20, the blast material 1 is conveyed by the blast material conveyance flow 2, and the weld line 112 of the steel plate slab 102 is formed in the gap G (constriction portion) at the top of the current reducer 30. Blasted.

  At the stage of confirming the circulation of the air flow, tension was applied to the steel wire (cable 32) on the front side of the current reducer 30, but at the stage of actual blasting, the steel wire on the front side was gradually removed. While feeding out, the steel wire (cable 32) of the rear surface side of the current reducing device 30 is pulled, and the current reducing device 30 is moved in the traveling direction of the blast material conveying flow 2. Then, the current reducer 30 is moved over the entire length from the supply side to the suction side of the flow guide guide rod 20.

(7) The supply of the blast material 1 is stopped by stopping the blowing by the supply device 40.

(8) Replacement of supply side and suction side The supply duct 42 is removed from the duct connection port 40C of the supply device 40 and attached to the duct connection port 50C of the suction device 50, and the suction duct 52 is connected to the duct connection port 50C of the suction device 50. It removes and attaches to the duct connection port 40C of the supply apparatus 40, and the supply side and the suction side are switched. The attachment state of the supply duct 42 and the suction duct 52 to both ends of the flow guide rod 20 is left as it is, and the supply duct 42 and the suction duct 52 are not attached to and detached from the supply-side lid member 44 and the suction-side lid member 54. . Thereby, the advancing direction of the blast material conveyance flow 2 is reversed, the supply duct 42 becomes the suction duct 52, and the suction duct 52 becomes the supply duct 42.

After (9), returning to (5), the operations (5) to (7) are performed, and the blasting process for the case where the blast material 1 is supplied from both directions of the flow guide rod 20 is completed. In (8), the supply side and the suction side are switched on the device (supply device 40 and suction device 50) side, the workability is good, and the blast material 1 is removed from both directions of the flow guide guide rod 20. Since the blasting process for the supplied case is completed, a sufficient blasting process is performed, the unevenness of the blasted surface subjected to the blasting process is reduced, and a uniform blasting surface is obtained.

  The procedure of the blasting process using the blasting apparatus 10 described above is the procedure of the blasting process when the blasting material 1 is supplied from both directions of the flow guide rod 20, but the weld line of the steel deck 102 Depending on the situation of 112, it is conceivable that the blasting process performed by supplying the blast material 1 from one direction of the flow guide rod 20 without replacing the supply side and the suction side is sufficient. In this case, the operation may be completed by a blasting process in which the blast material 1 is supplied from one direction of the flow guide rod 20 without replacing the supply side and the suction side.

  Moreover, when pulling the steel wire (cable 32) on the front surface side and the rear surface side of the current reducer 30, it may be pulled by a winch or the like, or may be pulled manually.

Perspective view of U-rib steel slab viewed from diagonally above Perspective view of U-rib steel slab viewed from diagonally below Perspective view of steel floor slab welded on site viewed from diagonally above 2, an enlarged perspective view showing the situation where the U-rib steel slab 100 is welded in the field (stage in which a backing material and a backing material cover are installed on the lower surface of the steel floor slab (deck plate)). 2 is an enlarged perspective view showing a situation where the U-rib steel slab 100 is being welded in the field (stage where submerged arc welding is performed from the upper surface of the steel slab (deck plate)). Sectional view schematically showing the situation where vacuum blasting is performed on the weld line on the bottom of the steel deck using a conventional vacuum blast head (cross section cut in the vertical direction on the plane including the weld line) The schematic diagram which looked at the condition which is performing the blasting process using the blasting apparatus which concerns on embodiment of this invention from the side. Sectional drawing which shows the cross section which cut | disconnected the flow guide guide rod and the current reducer by the surface which is parallel to the longitudinal direction of the flow guide rod and includes a weld line in the said blast apparatus. IX-IX sectional view of FIG. XX sectional view of FIG. XI-XI line sectional view of FIG. XII-XII sectional view of FIG. Side view showing the outer layer of the flow guide rod of the blasting device The (A) side view and (B) front view which show the condition of the connection of the divided flow guide gutters of the said blasting apparatus The side view which shows the state which attached the connection jig to the end of the divided flow guide rod of the said blasting apparatus The perspective view which looked at the current reducer of the said blasting apparatus from diagonally upward Sectional drawing (cutting position is the IX-IX line of FIG. 8) which shows the modification (feed guide rod which turned up the upper end) of the flow guide rod in the said blasting apparatus (A) Top view schematically showing a modification of the current reducer of the blast device, (B) BB cross-sectional view of FIG. 18 (A)

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Blast material 2 ... Blast material conveyance flow 3 ... Rust etc. 10 ... Blasting device 20 ... Flow guide guide rod 20A ... Rubber material 20B ... Reinforcement ring 22 ... Fixed band 24 ... Magnet 26 ... Elastic body 28 ... Connecting jig 28A ... Bolts 30, 70 ... Current-contracting devices 30A ... Brushes 30B, 70B ... Central portions 30C, 70C ... End portions 30D, 70D ... Constriction surfaces 32 ... Cables 40 ... Suction devices 40A ... Pressure air generating devices 40B ... Blast material supply portions 40C ... Duct connection port 42 ... Supply duct 44 ... Supply-side cover member 44A ... Protrusion 44B ... Duct insertion hole 44C ... Cable insertion hole 50 ... Suction device 50A ... Negative pressure generator 50B ... Blast material separator 50C ... Duct connection port 52 ... Suction duct 54 ... Suction side cover member 54A ... Projection 54B ... Duct insertion hole 54C ... Cable insertion hole G ... Gap (constriction part)
S ... Internal space 100 ... U-rib steel plate slab 102 ... Steel plate (deck plate)
104 ... Main digit (vertical digit)
106 ... Cross beam 108 ... U rib 110 ... Horizontal rib 112 ... Weld line 112A ... Weld burr 114 ... In-situ bolt joint 140 ... Scallop 142 ... Rib plate

Claims (16)

A blasting apparatus for blasting a weld line after on-site welding of a steel member from below,
An internal space opened upward, and a flow guide rod that is tightly fixed to the steel member along the weld line directly below the weld line;
A supply means connected to one end of the flow guide rod and supplying blast material and air into the internal space of the flow guide rod;
A suction means connected to the other end of the flow guide guide rod and sucking the interior space of the flow guide guide rod to collect the blast material;
A current reducer that is disposed in the internal space of the flow guide guide rod and that contracts an air flow that conveys the blast material in the internal space in the vicinity of the welding line;
A blasting device comprising: A blasting apparatus for blasting a weld line after in situ welding of a steel member across one or more scallops from below,
An internal space that opens upward, disposed in one or more of the scallops, and a flow guide rod that is tightly fixed to the steel member along the weld line directly below the weld line;
A supply means connected to one end of the flow guide rod and supplying blast material and air into the internal space of the flow guide rod;
A suction means connected to the other end of the flow guide guide rod and sucking the interior space of the flow guide guide rod to collect the blast material;
A current reducer that is disposed in the internal space of the flow guide guide rod and that contracts an air flow that conveys the blast material in the internal space in the vicinity of the welding line;
A blasting device comprising:   The blasting apparatus according to claim 2, wherein the outer shape of the cross-sectional shape of the flow guide guide rod is a shape that matches the shape of the scallop.   The blasting device according to any one of claims 1 to 3, wherein the flow guide rod is closely fixed to the steel member by a magnetic force.   5. The close contact and fixation of the flow guide rod to the steel member is performed by sucking and depressurizing the interior space of the flow guide rod by the suction means. The blasting device according to 1.   The shape of the cross section obtained by cutting the current reducer arranged in the inner space of the flow guide guide rod with a vertical plane parallel to the longitudinal direction of the flow guide guide rod is a mountain shape whose width becomes narrower toward the top. The blasting device according to any one of claims 1 to 5, wherein:   At the top of the current reducer disposed in the inner space of the flow guide guide rod, the end in the direction perpendicular to the longitudinal direction of the flow guide guide rod is higher than the other regions. The blasting apparatus according to claim 1, wherein the blasting apparatus is a blasting apparatus.   The current reducer has a current reducing surface, and the current reducing surface is in contact with an air flow that conveys the blast material in the inner space of the flow guide guide rod, and the air flow is adjacent to the weld line. When the current reducer is disposed in the inner space of the flow guide guide rod, the inclination of the flow reduced surface with respect to the longitudinal direction of the flow guide guide rod is The blasting device according to any one of claims 1 to 7, wherein the blasting device continuously changes at the top.   When the current reducer is disposed in the internal space of the flow guide guide rod, the height of the current guide guide is reduced in the longitudinal direction of the flow guide guide rod as the height increases within a predetermined height or more. The blasting device according to any one of claims 1 to 7, wherein the slope of the flow surface is steep.   When the current reducer is disposed in the internal space of the flow guide guide rod, the position of the maximum height of the current reducer depends on the position in the direction perpendicular to the longitudinal direction of the flow guide guide rod. The blasting device according to claim 1, wherein the blasting device is different in the longitudinal direction of the flow guide rod.   The blasting device according to any one of claims 1 to 10, wherein the current reducer is movable in the longitudinal direction in the internal space of the flow guide guide rod.   The upper end portion of the flow guide guide is folded inward, and the upper end of the current reducer is in contact with the inner surface of the folded upper end portion of the flow guide guide, and the current reducer is connected to the flow guide. 12. The blasting device according to claim 11, wherein the blasting device is movable in the longitudinal direction in the inner space of the bag. A blasting method for blasting a weld line after in-situ welding of a steel member from below,
A step of arranging a flow guide guide rod having an internal space opened upward, and directly fixing it to the steel member along the weld line; and
Disposing a current reducer in the internal space of the flow guide guide rod for contracting an air flow for conveying the blast material in the internal space in the vicinity of the welding line;
Blast material and air are supplied from one end of the flow guide rod into the internal space of the flow guide rod, and the interior space of the flow guide rod is sucked from the other end of the flow guide rod. A step of moving the current reducer in the longitudinal direction of the flow guide guide rod,
A blasting method characterized by comprising: A blasting method for blasting a weld line after on-site welding of a steel member across one or more scallops from below,
A step of disposing a flow guide rod having an internal space opened upward in one or more of the scallops, and fixing the portion directly below the steel member along the weld line;
Disposing a current reducer in the internal space of the flow guide guide rod for contracting an air flow for conveying the blast material in the internal space in the vicinity of the welding line;
Blast material and air are supplied from one end of the flow guide rod into the internal space of the flow guide rod, and the interior space of the flow guide rod is sucked from the other end of the flow guide rod. A step of moving the current reducer in the longitudinal direction of the flow guide guide rod,
A blasting method characterized by comprising:   The direction of movement of the current reducer is a direction from the one end that supplies blast material and air into the inner space of the flow guide guide rod toward the other end that sucks the inner space of the flow guide rod. The blasting method according to claim 13 or 14, wherein the blasting method is provided.   A blast material and air are supplied from the one end of the flow guide rod into the internal space of the flow guide rod, and from the other end of the flow guide rod into the internal space of the flow guide rod. In the state where the current guide is sucked, the current reducer is moved from the one end to the other end in the longitudinal direction of the flow guide guide rod, and then, from the other end of the flow guide guide rod, In the state where the blast material and air are supplied into the inner space of the flow guide guide 、 and the inside of the flow guide guide 吸引 is sucked from the one end of the flow guide guide 前 記, The blasting method according to claim 13 or 14, wherein the blasting guide rod is moved from the other end to the one end in the longitudinal direction of the flow guide rod.