JP2011047279A - Casing molding device of centrifugal blower - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a device moldable without causing thermal deformation on partial manufacture in a side plate and a back board even if a casing of a centrifugal blower is enlarged, and also moldable by substantially continuing a process of forming a seaming groove in the back board and a process of meshing and joining the side plate on one device. <P>SOLUTION: This casing molding device includes a molding roll 7 for molding the seaming groove 6 forming a cross-sectional U shape required as the back board 3 on both side edges of a belt-like plate 20 and sending out a work, and a seam roller 8 for fixing the side edge of the back board 3 to the peripheral edge of the side plate 2 by deforming the seaming groove 6 fitted with an edge part of the side plate 2 by pressing from the side. The casing 4 of the centrifugal blower for forming a spiral chamber 5 for an impeller is molded by fixing the back board 3 to the opposed two side plates 2 having the peripheral edge of continuing a spiral edge part 2A and a straight line-shaped edge part 2B so as to surround the peripheral edge (see, Fig.5 and also Fig.20). <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a casing forming device for a centrifugal blower, and more specifically, seam grooves are formed on both side edges of a back plate, and the peripheral edge of the side plate is fitted into the seam grooves, and the groove is pressed from the left and right so that the casing is not welded. The present invention relates to a molding apparatus that can be assembled.

  The centrifugal blower shown in FIG. 18 is used for supplying a large amount of air to, for example, a combustion apparatus in a plant facility. The air taken in from the suction port 41 is pressurized by a centrifugal blade (not shown) rotated by a motor 42 mounted on the installation table 42a, and sent out from the discharge port 4a via a duct. When a large amount of air is required with this centrifugal blower, it is not uncommon for the impeller diameter to be 1.5 meters. In this case, the back plate is disposed between the side plate 2a on the front side that supports the bell mouth-shaped suction port and the side plate 2b on the opposite side that partitions the impeller and the motor, and is fixed to the periphery of the side plate so as to cover the spiral space. The unfolding length of 3 is nearly 5 meters.

  As shown in FIG. 19 (a), the casing 4 forming the spiral chamber 5 has a side edge of the side plate that is cut into a spiral face plate by abutting the side edge of the back plate 3b against the periphery of the side plates 2a and 2b. It is manufactured by welding along An example of a casing formed by such butt welding is described in FIG. 7 of JP-A-2000-9087. The welding that forms the continuous bead 43 maintains the hermeticity of the spiral chamber 5, so that a pressure resistance of about 500 mmAq can be easily exhibited.

  The thickness of the side plate or the back plate that can withstand such a pressure is sufficient if it is, for example, 1.6 to 2.3 millimeters. However, when the amount of air flow increases, not only the diameter of the side plate but also the width of the back plate must be increased. When a thin and wide iron plate is applied to the casing, local heating by welding deforms the back plate and the side plate. Rework by sheet metal work is indispensable to make the casing with less distortion. Since the degree of deformation differs depending on the size of the side plate and the working environment, reworking must be entrusted to a skilled worker, and the number of production steps increases.

  In order to avoid welding distortion, the back plate must be attached to the side plate at room temperature. It can be said that the mesh joint is preferable because it only relies on plastic deformation of the base material. In FIG. 3 of Japanese Patent Application Laid-Open No. 2004-218622, as shown in FIG. 19B, a flange formed by forming a seaming groove 6A in the periphery of the side plate 2c in advance and bending the side edge of the back plate 3c. It is disclosed that 44 is seamed.

  Since the seaming groove is formed in advance by folding the peripheral edge of the side plate having a spiral outline, wrinkles are likely to enter the groove. Although it is easy to set up a flange on the side edge of the back plate in the flat plate stage, the seaming groove forming process of the side plate 2c and the flange forming process of the back plate 3c are independent from each other, so it cannot be denied that the number of man-hours increases. . That is, since a spiral casing cannot be processed substantially continuously from a flat plate state by one molding device, a device for molding each and a device for transporting them are also required, and the equipment cost is It is necessary to secure a large installation area with high costs.

  In addition, if wrinkles are formed in the seaming grooves in the side plate, it is difficult to expect high-density engagement even when seaming is performed with the flange of the back plate interposed. Eventually, a sealing process that relies on chemical materials is required. FIG. 9 of the aforementioned Japanese Patent Application Laid-Open No. 2004-218622 discloses a seaming mechanism that is convenient for avoiding such a situation. As shown in FIG. 19C, the peripheral edge of the side plate 2 is not bent, and the seaming grooves 6 and 6 are formed only on the side edge of the back plate 3.

  The casing 4 can be assembled as shown in the upper part by preparing and fitting the three parts at the lower part of FIG. As shown in FIG. 21, the back plate 3 is formed by forming a seaming groove 6 (exaggerated display is drawn corresponding to each cross section) on the side edge and being bent in a spiral shape as a whole. That's fine. However, even if a back plate having such a shape can be formed, if a side plate is fitted into each seaming groove to be assembled as a casing, a dedicated jig for constantly retaining the shape is required. Since this jig must be suitable for the diameter of the side plate and the width of the back plate, it is necessary to prepare several jigs suitable for the size each time a different-size casing is manufactured.

JP 2000-9087 A JP 2004-218622 A

  The present invention has been made in view of the above problems, and the object of the present invention is that even if the casing is enlarged, it can be molded without causing partial deformation of the side plate and the back plate, and a seaming groove is formed in the back plate. The process and the process of mating and joining the side plates can be made substantially continuous on a single device, making the molding equipment compact, and eliminating the need for shape-retaining jigs for casings of different sizes. It is providing the casing shaping | molding apparatus of the centrifugal blower which implement | achieved what can be done.

  In the present invention, the back plate 3 is fixed to the two side plates 2 which are opposed to each other with the peripheral edge where the spiral edge 2A and the linear edge 2B shown in FIG. 20 are connected to each other. Thus, the present invention is applied to a casing forming device for a centrifugal blower in which a spiral chamber 5 for an impeller is formed. The feature is that referring to FIG. 1, a seaming groove 6 having a U-shaped cross section required as a back plate 3 on both side edges of a belt-like plate 20 supplied in a horizontal posture (see FIG. 3). The spiral edge 2A of the side plate 2 is fitted in several forming rolls 7 arranged in the longitudinal direction for feeding the workpiece and the seaming groove 6 immediately after coming out of the final forming roll 7 ( 5), the first support means 10 for mounting the seaming groove 6 and the edge of the side plate 2 fitted in the seaming groove 6 on the first support means are urged to the groove bottom. The pressing roller 9 to be placed and the seaming groove 6 positioned immediately below the pressing roller 9 and fitted with the edge portion of the side plate 2 are pressed and deformed from the side, and the side edge of the back plate 3 is changed to the peripheral edge of the side plate 2. Seam roller 8 to be fixed (see also FIG. 3) and spiral edge A second support means 11 for carrying the work that has been advanced to seam the back plate 3 on the linear edge 2B after seaming A, and a seam roller 8 to seam the linear edge 2B. And an actuator 16 for moving the pressing roller 9 forward in accordance with the speed of the work moving forward on the support means 11.

  As shown in FIG. 1, the pressing roller 9 is supported by a swingable arm 18 so as to be disposed in a space immediately above the seam roller 8. A roller 17 for preventing the side plate 2 from falling may be attached to the swingable arm.

  One group of forming rolls 7, the first support means 10, the pressing roller 9, the seam roller 8, the second support means 11, and the actuator, of the two groups arranged corresponding to the side edges of the belt-like plate 20 shown in FIG. 3. 16 is mounted on one movable support frame 13. This is movable to and away from the other group (the movable support frame 13 can traverse) (see FIG. 2).

  The seam roller 8M has a trapezoidal cross section (see FIG. 14E) so that the side plate 2 deformed by the pressing roller 9 (warping is generated by a pressing force at a position slightly deviated from the plate surface) can be corrected. ing.

  According to the present invention, the first support means for mounting the seaming groove, the pressing roller disposed above the seam roller, and the seam roller at a position sandwiching the seaming groove from the left and right are provided. The seam groove is supported, and the edge of the side plate fitted to the seam groove is securely urged to the bottom of the groove and can be engaged and joined by the seam roller. Then, it is possible to sequentially feed the succeeding seaming grooves on the first support means while forming them on the back plate.

  On the second support means, there are provided the second support means for mounting the work that has advanced after finishing the spiral edge and the actuator for moving the pressing roller in accordance with the speed of the work to be advanced. Also, the edge of the side plate fitted in the seaming groove is still securely urged to the groove bottom. The straight edge of the side plate is seamed by the seam roller continuously to the seamed spiral edge.

  Since no weld bead is formed, a pressed casing free from thermal distortion due to welding is possible. The side plate and the back plate do not undergo thermal deformation, and the step of forming seaming grooves on the back plate and the step of engaging and joining the side plates can be substantially continued on one apparatus. Since the forming equipment is merely provided with mechanical means for forming seaming grooves and subsequent seaming processing means, the equipment can be downsized and the occupied area can be reduced. Even if the sizes of the casings are different, it is not particularly necessary to prepare a shape-retaining jig for each workpiece.

  If the presser roller is supported by a swingable arm, it is placed in the space directly above the seam roller, and high-density seaming can be performed with the peripheral edge of the side plate firmly pressed against the bottom of the seam groove on the back plate. .

  If the side plate fall prevention roller is attached to the swingable arm, the fall prevention roller can be applied to the side plate simply by placing the pressing roller at a desired position. If the roller is made long, it can function regardless of the size of the side plate.

  The forming roll, the first support means, the pressing roller, the seam roller, the second support means, and the actuator of one of the two groups arranged corresponding to both side edges of the belt-like plate are mounted on one movable base. If the movable base can be traversed, seaming grooves can be simultaneously formed on both side edges of the back plate having different width dimensions. In addition, a side plate can be engaged with and joined to the groove, and a casing having a desired width can be formed by a series of processes using a single forming apparatus.

  If the seam roller has a trapezoidal cross section so that the side plate deformed by the pressing roller can be corrected, the side plate generated due to the side plate being thin and the pressing roller acting at a position displaced from the plate surface Warpage can be corrected with a seam roller.

The whole front view of the casing shaping | molding apparatus of the centrifugal air blower which concerns on this invention. FIG. 2 is a front view of the molding apparatus as viewed in the direction of arrows II-II in FIG. 1. The molding concept explanatory drawing by a shaping | molding apparatus. The process figure which meshes and joins the seaming groove | channel of a backplate to the periphery of a side plate sequentially. FIG. 5 is a work diagram in which a pressing roller is arranged on the opening edge of the side plate and a fall prevention roller is applied to the side plate. Operation | movement explanatory drawing of the mechanism which displaces a pressing roller to an up-down direction. Operation | movement explanatory drawing of the mechanism which displaces a press roller in the left-right direction. The formation principle figure of the seaming groove | channel in a shaping | molding apparatus. Explanatory drawing immediately before seaming in the case of using a back plate with rectifying vanes. Work explanatory drawing which fitted the spiral edge part start point part of the side plate to the seaming groove. Working drawing of seaming about 90 degrees of the spiral edge. The back plate support conceptual diagram in the seam roller vicinity. Each arrow line view in FIG. Explanatory drawing of generation | occurrence | production and correction | amendment of the press aspect of a side plate by a pressing roller, and the curvature of a side plate. It is explanation when attaching the ring-shaped rail to the large-diameter opening of the side plate, (a) is a left side view of (d), (b) is a right side view of (d), (c) is a preparation diagram for jig mounting. (D) is the state figure which attached the jig to the side board. It is description when attaching a ring-shaped rail to the small-diameter opening of a side plate, (a) is a pair of perspective views of a side plate for a single suction fan having different opening sizes, (b) is a left side view of (e), and (c). (E) is a right side view of (e), (d) is a preparation diagram for mounting a jig, and (e) is a state diagram in which the jig is mounted on a side plate. Explanatory drawing immediately before seaming in the case of a backplate without a rectifying vane. The perspective view of an example of the air blower with which this invention is applied. The aspect figure which attaches a back board to a side board in order to form a casing. The exploded view of a casing. The perspective view of a back board.

  Below, the casing shaping | molding apparatus of the centrifugal air blower which concerns on this invention is demonstrated in detail based on drawing showing the embodiment. FIG. 1 is an overall view of a device 1 for forming a casing of a centrifugal blower. As shown in FIG. 19C, which is a view taken along line XX in FIG. 18, the peripheral edges of two opposing side plates 2 are shown. Is applied to a casing 4 to which the back plate 3 is fixed by seaming so as to surround. The casing forms the spiral chamber 5 for the impeller, and the periphery of the side plate 2 used for the casing is a portion where the spiral edge 2A shown in FIG. 20 occupies most and faces the discharge port 4a. A continuous peripheral edge is formed as a straight edge 2B. This is intended to realize the integration of the side plate 2 and the back plate 3 with a non-welded casing that does not cause welding heat distortion regardless of the weld bead.

  The main forming means in this forming apparatus is a forming roll 7 for forming the seaming groove 6 shown in FIG. 3 and a seam roller 8 for engaging and joining the side plate to the back plate via the seaming groove. In order to ensure seaming, as shown in FIG. 4 (a), a pressing roller 9 that presses the side plate 2 against the bottom of the seaming groove is also provided, and these act to form the casing 4 (see FIG. 20). It has come to be. In addition to these, the first support roller 10 that supports the seaming groove 6 that is about to seam the spiral edge 2A of the side plate 2, and the straight edge after seaming of the spiral edge 2A shown in FIG. A second support roller 11 is provided as a first support means and a second support means, which are supported while the workpiece is linearly moved to seam the portion 2B.

  The seaming grooves 6 are formed at both edges of the back plate 3 as shown in FIG. 21, but the molding process and the subsequent seaming process are performed at the same time for each edge. Therefore, the forming roll 7, the seam roller 8, the pressing roller 9, the first support roller 10 and the second support roller 11 shown in FIG. 1 acting on one edge form one group as shown in FIG. 3 (FIG. 3). Then, the pressing roller 9 is not shown), and these are mounted on the support base 12 shown in FIG. The forming roll 7, the seam roller 8, the pressing roller 9, the first support roller 10, and the second support roller 11 acting on the other edge portion are also mounted on the support frame 13 in another group. Although one of the gantry 12 is fixed, the support gantry 13 can be traversed on the molding apparatus, and even if the back plate 3 has a different width, the seaming groove can be formed and seamed. As described above, the fixed support frame 12 can be separated from and connected to the fixed support frame 12 (see the arrow 14 in FIGS. 3 and 2).

  When seaming the spiral edge 2A of the side plate 2, as shown in FIGS. 4A to 4C, the pressing roller 9 is allowed to move up and down. In addition, the side plate 2 indicated by a two-dot chain line in each drawing is a posture in a state when the side plate 2 indicated by a solid line is 90 degrees before. When seaming the straight edge 2B, it is necessary to advance the pressing roller 9 as indicated by an arrow 15 in FIG. 4D, and a linear motion cylinder (hydraulic cylinder) 16 shown in FIG. Is done. Further, in order to prevent the unseamed portion 2m (see FIG. 4C) from flapping or falling during seaming of the spiral edge 2A of the side plate 2, as shown in FIG. A fall prevention roller 17 that comes into contact with the side plate 2 is provided.

  The pressing roller 9 and the fall prevention roller 17 are attached to each arm 18 that can swing vertically and horizontally. As shown in FIG. 1, the swingable arm 18 and the hydraulic cylinder 16 that moves the arm forward and backward are also installed in the arm carrier 1A for each group (see also FIG. 2). As shown in FIG. 1, a lifting cylinder 19 is supported on the support column 1B mounted on the arm carrier, and as shown in FIG. 6, the tip of the operating rod 19a is connected to a swingable arm 18. If the fall prevention roller 17 applied to the side plate 2 is made long, it can function regardless of the size of the side plate. In addition, the code | symbol 18a in FIG. 6 is a grip for moving the rockable arm 18 so that an operator may carry the press roller 9 etc. to the desired position in the state which made the cylinder etc. unloaded.

  The above is a general outline and will be described in detail below. The forming roll 7 is composed of, for example, eight sets of upper and lower rolls arranged in the longitudinal direction for feeding the workpiece as shown in FIG. 1, and forms the seaming groove 6 as shown in FIG. 3 and feeds the back plate 3 in the direction of the arrow 3M. To work. FIG. 8 shows the change of the caliber meshing the lower half of the upper roll 7U and the upper half of the lower roll 7L. The edge of the back plate 3 is shallowly deformed on the upstream side and gradually deeply deformed on the downstream side, so that the U-shaped cross section required as the back plate 3 is formed on both side edges of the belt-like plate 20 supplied in a horizontal posture. The seaming groove 6 is formed.

  As can be seen from FIG. 1, the two sets on the most upstream side are rotated by the power transmitted from the electric motor 21 to the drive gear 22, but the third and subsequent forming rolls 7 are the upstream lower rolls. It is driven via a tuning gear 23 that transmits rotation. As shown in FIG. 2, the upper and lower rolls are rotated at the same speed by meshing gears 24 and 25 attached to the roll shafts. Therefore, the forming roll 7 forms seaming grooves while advancing the belt-like plate 20 all at once. As shown in FIG. 8, even if the seaming groove 6 is completed at the leading portion of the belt-like plate 20, the seaming groove is in a state of being formed at the subsequent portion.

  This is because the belt-like plate can be advanced by the frictional force during molding until the molding roll 7 completes the seaming groove 6 over the entire length of the belt-like plate 20. As a result, the back plate 3 being molded pushes the portion where the seaming groove 6 is completed toward the seam roller 8 (see FIG. 3). Since the seam roller 8 also acts to send out the seamed portion, as shown in FIG. 4A, the peripheral edge of the side plate 2 having the spiral edge 2A and only allowed to rotate lifts the back plate 3 that has been seamed. Eventually, the back plate 3 seamed to the spiral edge 2 </ b> A comes to surround the side plate 2 by extrusion by the forming roll 7.

  The first support roller 10 mounts the seaming groove 6 immediately after coming out of the final forming roll 7. Of course, even if the side plate 2 in which the spiral edge 2A is fitted in the seaming groove 6 is pressed against the groove bottom by the pressing roller 9, the seaming groove 6 is supported so as not to sink. In this state, the seam roller 8 fixes the side edge of the back plate 3 to the periphery of the side plate 2 while feeding the periphery of the side plate 2 in the tangential direction, so that the seaming groove 6 is the periphery of the side plate 2 in which only rotation is allowed. Follow. Even if the finished seaming groove 6 is seamed with the side plate 2, as long as there is an unfinished portion of the seaming groove 6 on the belt-like plate 20, the forming roll continues to form the following seaming groove 6 and extrude the back plate 3, as shown in FIG. As shown in (b) of FIG.

  As shown in FIG. 4, the pressing roller 9 constantly urges the edge of the side plate 2 fitted in the seaming groove 6 on the first support roller 10 to the groove bottom. In this manner, the swingable arm 18 is disposed immediately above the seam roller 8. When the urging force by the pressing roller 9 is strong, the spiral edge 2 A being seamed by the seam roller 8 is always at the lowest point of the side plate 2. As shown in FIGS. 11 and 4, the seaming groove 6 that has been seamed rises while rotating together with the spiral edge 2 </ b> A, and eventually the seaming groove 6 reliably surrounds the spiral edge.

  If this urging force is weak and the spiral edge 2A floats from the bottom of the seaming groove, the seaming portion at the position of the seam roller 8 will not be able to sandwich the side plate 2, and the seaming groove 6 will eventually come off the side plate 2. Become. Therefore, the pressing roller 9 plays an extremely important role. As described above, when the pressing roller 9 can be disposed in the space immediately above the seam roller 8 or in the vicinity thereof, high-density seaming can be performed in a state where the peripheral edge of the side plate 2 is firmly pressed against the bottom of the seaming groove of the back plate 3. . Incidentally, after the swingable arm 18 is disposed immediately above the seam roller, the lateral vibration suppression cylinder 26 shown in FIG. 7 stops the lateral vibration.

  As shown in FIG. 5, the above-described seam roller 8 is positioned directly below the pressing roller 9 and presses and deforms the seaming groove 6 in which the edge of the side plate 2 is fitted from both sides, and the side edge of the back plate 3 is changed to the side plate. It fixes to the periphery of 2. FIG. 12 shows the vicinity of the seam roller 8, and each arrow view is taken out in FIG. (A) shows a state immediately before seaming, and a seaming groove 6 supported by a first support roller 10 and a side plate 2 fitted thereto are arranged between a pair of left and right seam rollers 8. Out of the seam rollers 8 in each pair, the inner roller 8B takes a non-moving position on a support frame (not shown). The outer roller 8A can be connected to and disconnected from the seaming groove 6 by a hydraulic cylinder (not shown) as indicated by a black arrow 27 in FIG. This displacement presses the seaming groove 6 from the side to produce a joining force.

  The outer roller 8A is not only displaced but also driven around the vertical axis as shown in FIG. 13C, and is fed out while seaming the side plate 2 into the seaming groove 6 in cooperation with the idle inner roller 8B. The contact surface of the seam roller 8 with the seaming groove 6 may be a smooth cylindrical surface, but a knurling 8a may be provided as shown in FIG. Since many small irregularities are generated on the seaming surface, pressurization by a large number of points substantially increases the contact surface pressure and raises the jointing force.

  As shown in FIG. 4 (d), the second support roller 11 mounts a work that has been advanced to seam the back plate 3 on the linear edge 2B after the seaming of the spiral edge 2A is finished. Then, the back plate 3 is supported in the process of shifting from (c) to (d). In the seaming of the straight edge portion 2B, since the lowest point of the side plate 2 continues horizontally, the side plate 2 does not rotate and eventually the workpiece advances straight. This seaming of the linear edge 2B is continued to a position just before the discharge port 4a. The second support roller 11 does not support the seaming groove 6 as shown in FIG. 13D, but supports the abdominal surface of the back plate 3 inside. This is to stabilize the direction during the movement of the workpiece after passing the seam roller. Therefore, the second support roller 11 does not support anything at the stage of FIG. 10 or FIG.

  By the way, in the state of FIG. 4C, the back plate 3 in which the seaming grooves 6 are formed has come out of the final forming roll 7. Although the feeding action of the back plate 3 by the forming roll 7 disappears, seaming by the seam roller 8 advances the work. When the workpiece comes out of the seam roller 8 and is on the second support roller 11, the forward force is lost and the work stops (see FIG. 4D). Until this stop, pressing of the side plate 2 against the seaming groove 6 by the pressing roller 9 is indispensable, but the pressing roller 9 that only moves up and down as shown in FIGS. At the stage of transition from (d) to (d), it must be moved horizontally. For this purpose, the swingable arm 18 fitted with the pressing roller 9 is advanced by a hydraulic cylinder 16 (see FIG. 1). Needless to say, the speed is matched to the speed of the work moving forward on the second support means 10 by the seam roller 8, but a slight discrepancy is allowed.

  Based on the configuration described above, the operation procedure of the molding apparatus will be described. First, the movable support frame 13 indicated by the phantom line in FIG. 2 is brought closer to the fixed support frame 12 by the rotation of the screw rod 28 so as to match the width of the casing 4 to be manufactured, and the facing interval of the forming rolls 7 is adjusted. The belt-like plate 20 shown in FIG. 8 is placed on the roller bed 29 shown in FIG. 1 and aligned with the pass line 31 by the width determining roller 30. The electric motor 21 is driven to rotate the forming roll 7, and the seaming groove 6 is formed while the belt-like plate 20 is advanced (see FIG. 3). When the leading end of the belt-like plate 20 placed on the first support roller 10 reaches the seam roller 8 (state shown in FIG. 3), the rotation of the forming roll 7 is stopped. The example to be described is directed to the casing 4 having the rectifying vane 32 as shown in FIG. This rectifying vane is for reducing disturbance of the flow of air pressurized by the impeller from the spiral chamber 5 to the discharge port 4a.

  As shown in FIG. 9, the rectifying vane 32 is temporarily attached to the tip of the strip plate 20 by spot welding 34. Next, as shown in FIG. 10, the side plate 2 is disposed in the seaming groove 6. And it fits so that the part used as the starting point of 2 A of spiral edge parts may reach the bottom of the seaming groove | channel 6. FIG. The side plate 2 has a large hole for the suction port, but is merely a thin iron plate. Therefore, in order to maintain the posture until seaming is started, spot welding is performed at a location in contact with the seaming groove 6. 34 is temporarily fixed. Several spot welds 34 are also applied to the contact portion with the rectifying vane 32. Similar processing is performed on the side plates 2 in the other seaming grooves 6.

  Next, the grip 18a shown in FIG. 5 is grasped and guided, the pressing roller 9 is placed on the edge 35 of the round opening provided in the side plate 2, and the side plate 2 is pushed down (see (a) of FIG. 14). reference). If the pressing roller 9 cannot be placed on the thin edge 35 of the round opening of the side plate 2, a jig 37A having, for example, a ring-shaped rail 36a shown in FIGS. 14 and 15 may be used. This consists of a side plate surface pressing 36A and a locking claw 36b for fixing to the side plate, thereby reinforcing the side plate 2. Then, the pressing roller 9 may be placed on the rail 36a at a position displaced by L (see FIG. 14) which is a portion substantially corresponding to the edge 35 of the opening.

  By the way, in FIG. 14E, the seam roller 8M has a trapezoidal cross section, that is, a truncated cone shape, and the side plate 2 deformed by the pressing roller 9 (in the case of a thin side plate such as 1.6 mm), the pressing at a position displaced from the plate surface. It can be corrected. That is, when the point of action of the pressing roller 9 is deviated from the side plate 2, a warp 38 is generated as shown in FIG. This leaves the warp on the workpiece after seaming. In order to avoid this, the deformation as shown in FIG. 14F is applied to correct the in-plane deformation of the side plate 2 due to the reverse warp 39.

  The above description has been made by taking the single suction type blower shown in FIG. 18 as an example, but the present invention can also be applied to a double suction type blower. It can be seen that FIG. 14 described above explains the deformation of the side plate 2 for both suction types. FIG. 15 shows a mode in which the pressing roller 9 is applied to the large-diameter opening 40L regardless of one of the single suction type and the both suction type. Since FIG. 16 is intended for a single suction type, one side plate 2 has a small-diameter opening 40S. In this case, since it is impossible to arrange the pressing roller 9 directly in the opening, a jig 37B including a side plate back surface pressing unit 36B with a rotation handle 36c that enables the pressing roller 9 is provided in (b), (c), Adopted in the configuration described in (d). (E) shows a state in which it is mounted.

  Incidentally, FIG. 9 has been described on the assumption that the rectifying vane 32 is attached to the tip of the belt-like plate 20. However, in a blower that does not employ a rectifying vane, the welding operation of the rectifying vane is skipped as shown in FIG. 17 and the process proceeds to the next step. In addition, the first support means and the second support means are exemplified as the first support roller 10 and the second support roller 11, but these means are based on the above description, and the skid that supports the back plate and enables movement is used. It can be replaced with something like this.

  As described above in detail, the seam groove is supported by the seam roller immediately after coming out of the final forming roll, and the edge of the side plate fitted to this is firmly urged to the bottom of the groove and can be joined by the seam roller. In addition, the following seaming grooves can be sequentially fed onto the first support means while being formed on the back plate. Even on the second support means, the edge of the side plate fitted in the seaming groove is still securely urged to the groove bottom, and the straight edge of the side plate continues to the seamed spiral edge. And seamed by a seam roller.

  Since no weld bead is formed, a press-worked casing free from thermal distortion due to welding is realized. The step of forming seaming grooves in the back plate and the step of engaging and joining the side plates can be substantially continued on one apparatus. Since the molding equipment only includes mechanical means for forming seaming grooves and continuous seaming treatment means, the equipment can be downsized and the occupied area can be reduced. Even when the casings have different sizes, it is not particularly necessary to prepare a shape-retaining jig for each workpiece.

  The forming roll, the first support means, the pressing roller, the seam roller, the second support means, and the actuator of one of the two groups arranged corresponding to both side edges of the belt-like plate are mounted on one movable support base, Since this movable support frame can be traversed, seam grooves can be formed on both side edges of the back plate of different width dimensions, and the side plate is meshed and joined to the groove with a single molding device. A casing having a desired width can be formed.

  DESCRIPTION OF SYMBOLS 1 ... Molding apparatus, 2 ... Side plate, 2A ... Spiral edge part, 2B ... Linear edge part, 3 ... Back board, 4 ... Casing, 5 ... Spiral chamber, 6 ... Seaming groove, 7 ... Forming roll, 8, 8M ... Seam roller, 9 ... Pressing roller, 10 ... First support roller (first support means), 11 ... Second support roller (second support means), 12 ... Support base (fixed support base), 13 ... Support base (movable) Support frame), 16 ... Actuator (cylinder for linear motion, hydraulic cylinder), 17 ... rolling prevention roller, 18 ... oscillating arm, 19 ... cylinder for lifting, 20 ... band plate, 38 ... warping, 39 ... reverse warping .

Claims (5)

A spiral chamber for an impeller is formed by fixing a back plate to two opposing side plates having a peripheral edge where a spiral edge and a linear edge are connected to each other so as to surround the peripheral edge. In a casing forming device for a centrifugal blower,
Forming seaming grooves having a U-shaped cross section required as a back plate on both side edges of a belt-like plate supplied in a horizontal posture, and several forming rolls arranged in the longitudinal direction for feeding out the workpiece;
First support means for mounting the seaming groove in a state in which the spiral edge of the side plate is fitted in the seaming groove immediately after coming out of the final forming roll;
A pressing roller for urging the edge of the side plate fitted in the seaming groove on the first support means to the groove bottom;
A seam roller that is positioned directly below the pressing roller and presses and deforms a seaming groove into which the edge of the side plate is fitted from the side, and fixes the side edge of the back plate to the periphery of the side plate;
A second support means for carrying the workpiece advanced to seam the back plate to the linear edge after finishing the spiral edge;
An apparatus for forming a casing of a centrifugal blower, comprising: an actuator for advancing the pressing roller in accordance with the speed of a workpiece advancing on the second support means by a seam roller for seaming a linear edge.   The casing forming device for a centrifugal blower according to claim 1, wherein the pressing roller is supported by a swingable arm so as to be disposed in a space immediately above the seam roller.   3. The casing forming apparatus for a centrifugal blower according to claim 2, wherein a roller for preventing the side plate from falling is attached to the swingable arm.   A forming roll of one group out of two groups arranged corresponding to both side edges of the belt-like plate, a first support means, a pressing roller, a seam roller, a second support means, and an actuator are mounted on one movable frame, 2. The casing forming apparatus for a centrifugal blower according to claim 1, wherein the casing can be moved toward and away from the other group.   The casing forming apparatus for a centrifugal blower according to claim 1, wherein the seam roller has a trapezoidal cross section so that a side plate deformed by the pressing roller can be corrected.