JP5920378B2 - Fan and hot water supply apparatus including the same - Google Patents

Description

  The present invention relates to a fan and a hot water supply apparatus including the same, and more particularly to a latent heat recovery type fan and an exhaust suction combustion type hot water supply apparatus including the same.

  When replacing an installed hot water storage type hot water supply device with an instantaneous type hot water supply device, there is a site where the installed exhaust pipe cannot be removed from the viewpoint of maintaining the appearance of the building.

  In the field as described above, it is possible to cope with replacement of the hot water supply apparatus by leaving the existing exhaust pipe and inserting the exhaust pipe into the exhaust pipe. However, if the outer diameter of the exhaust pipe is large, the exhaust pipe cannot be installed in the exhaust cylinder, so it is necessary to reduce the diameter of the exhaust pipe. In order to maintain a stable combustion state even when the diameter of the exhaust pipe is reduced, it is necessary to employ an exhaust suction combustion system in the hot water supply apparatus.

  An exhaust suction combustion type hot water supply apparatus is disclosed in, for example, Japanese Patent Application Laid-Open No. 60-186627. In the hot water supply apparatus described in this publication, a heat exchanger for recovering sensible heat, a heat exchanger for recovering latent heat, and a fan are disposed downstream of the flow of combustion gas generated in the burner. Arranged in order. In other words, in this type of hot water supply apparatus, the fan is arranged downstream of the heat exchanger from the flow of the combustion gas, and the fan sucks the combustion gas after passing through the heat exchanger to the outside of the hot water supply apparatus. Discharge.

  On the other hand, as a component of a fan, an impeller having a plurality of blades around a rotating shaft is known (for example, JP 2000-356197 A, JP 2010-242543 A, and JP 2010-281256 A). No., US Patent Application Publication No. 2008/0279682). This impeller is driven and rotated by a motor or the like, so that the fan blowing function is exhibited.

  Such an impeller is composed of a plurality of parts. As a method for producing such an impeller, a method of assembling parts by ultrasonic welding of resin parts such as blades to each other is known.

JP-A-60-186627 JP 2000-356197 A JP 2010-242543 A JP 2010-281256 A US Patent Application Publication No. 2008/0279682

  Ultrasonic welding is a processing technique in which thermoplastic resin is instantly melted and bonded by fine ultrasonic vibration and pressure, but the welded part by ultrasonic waves is generally brittle when the material is once melted. Therefore, the durability and strength are often lower than those of the base material. Further, in the case where the welding is insufficient, there is a possibility that durability and strength are further reduced.

  Therefore, when producing an impeller by welding, such as ultrasonic welding, in order to maintain the durability and intensity | strength of an impeller, it is calculated | required that welding of a welding part is fully performed.

  And since the fan impeller used for the hot water supply apparatus of an exhaust suction combustion system is installed in the passage of combustion gas, it is exposed to a higher temperature environment than before. Furthermore, the fan impeller used in the latent heat recovery type exhaust suction combustion type hot water supply apparatus is exposed to a strongly acidic drain generated along with the recovery of the latent heat in addition to the high temperature environment. In such a case, it is required to sufficiently weld the welded portion, and particularly to maintain the durability of the impeller.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a fan having high durability capable of maintaining sufficient durability even in a high temperature environment or an acidic environment, and the fan. It is to provide a hot water supply device.

  The fan of the present invention includes a main plate having a first surface, and a plurality of first blade members extending from the inner peripheral side of the first surface of the main plate to the outer peripheral side and protruding from the first surface. An impeller that includes one blade, a shroud that covers the first blade and is formed integrally with the first blade, a fan case that houses the impeller, and a fan case that drives the impeller And a rotating shaft that connects the impeller and the driving source. The first blade member has a linear projecting region in which the height linearly increases from the outer peripheral side toward the inner peripheral side with respect to the height of the first blade member protruding from the first surface, and the height is the outer periphery. A curved projecting region that is curvedly increased from the side toward the inner peripheral side, the curved projecting region is located on the inner peripheral side of the first surface relative to the linear projecting region, and the linear projecting region is welded to the main plate. Yes.

  In the fan of the present invention, the outer peripheral portion of the shroud is linearly inclined in the radial direction of the main plate in accordance with the shape of the linear protrusion region of the first blade member. By pressing the jig of the ultrasonic welding machine, the adhesion between the jig and the shroud is enhanced, and ultrasonic vibration can be stably transmitted to the welded portion. Thereby, the welding part of a main board and a 1st blade | wing can fully be welded. Therefore, the fan of the present invention has a high durability.

  In the above fan, the curved protruding area is a non-welded area that is not welded to the main plate. When trying to weld the curved protruding area to the main plate, it is necessary to transmit the ultrasonic vibration by pressing the jig of the ultrasonic welder against the curved inclined area of the shroud (the part corresponding to the curved protruding area of the first blade member). However, ultrasonic vibration is not transmitted well to a curved surface, and welding is insufficient or variation in welding strength occurs. Therefore, by preventing the curved projecting region from being welded to the main plate, it is possible to produce an impeller having a stable quality without variation in the welding strength between the main plate and the first blade, and to stabilize the quality of the fan. .

  In the above fan, the impeller further extends from the inner peripheral side to the outer peripheral side of the second surface of the main plate on the side opposite to the first surface and protrudes from the second surface. A second blade made of a blade member is included. When the main plate is viewed from the axial direction of the rotation shaft, the second blade member is located between two first blade members adjacent to each other. Thereby, at the time of ultrasonic welding, the welded portion of the main plate is supported by the surface from the second surface (second blade side surface) side by the welding jig, and the main plate is stably held, so ultrasonic vibration is welded. It becomes easy to be sufficiently transmitted to the part. Therefore, the welded portion between the main plate and the first blade can be sufficiently welded.

  In the fan described above, when the main plate is viewed from the axial direction of the rotation shaft, the portions including the outer peripheral ends of the plurality of first blade members are arranged along the radial direction of the main plate. Thereby, since the air current can be smoothly sent in the direction along the centrifugal force at the outer peripheral side portion where the centrifugal force due to the rotation of the impeller greatly acts, the welded portion is hardly peeled off.

  In the above fan, when the main plate is viewed from the axial direction of the rotation shaft, the portions including the outer peripheral ends of the plurality of second blade members are arranged along the radial direction of the main plate. Accordingly, when the main plate is viewed from the axial direction of the rotation shaft, the second blade member can be easily disposed so as to be positioned between the two first blade members adjacent to each other.

  In the above fan, a plurality of positioning recesses are formed on the first surface of the main plate, and each of the plurality of first blade members is inserted into and welded to the plurality of positioning recesses. Thereby, the position shift at the time of welding with a main board and a 1st blade | wing can be prevented, and welding intensity | strength can be raised.

  In the above fan, a positioning projection is formed at the end of the first blade member on the side opposite to the shroud of the curved projection region, and the projection fits into a hole provided on the first surface of the main plate. Are combined. Thereby, the position shift of the curve protrusion area | region (non-welding area | region) of a 1st blade | wing member can be prevented.

  The hot water supply apparatus of the present invention is a latent heat recovery type hot water supply apparatus capable of heating hot water by recovering the latent heat of the combustion gas, and hot water flowing in the interior by heat exchange between the burner that generates the combustion gas and the combustion gas And a fan that sucks the combustion gas after passing through the heat exchanger and discharges it to the outside of the hot water supply apparatus. The above fan is mounted as a fan so that the shroud side is the burner side. As a result, the shroud and the first blade are integrally formed, and the main plate and the first blade (which is formed integrally with the shroud) are welded, so that the welded portion having low durability is formed on the lower side of the main plate ( Therefore, the welded portion becomes difficult to be exposed to the drain, and the welded portion can be protected from corrosion due to the drain. Therefore, it is possible to provide a hot water supply apparatus including a fan having high durability that can withstand a high temperature environment.

  In the above hot water supply apparatus, the impeller is made of a thermoplastic resin having acid resistance. This further enhances the durability of the fan against the drain that is generated as the latent heat is recovered.

  As described above, according to the present invention, it is possible to provide a fan having high durability capable of maintaining sufficient durability even in a high-temperature environment or an acidic environment, and a hot water supply apparatus including the fan.

It is a front view which shows roughly the structure of the hot water supply apparatus in Embodiment 1. FIG. It is a partial cross section side view which shows the structure of the hot water supply apparatus shown in FIG. FIG. 3 is a partial cross-sectional view schematically showing a fan and an exhaust box in the first embodiment. FIG. 3 is a side view schematically showing a configuration of an impeller in the first embodiment. FIG. 2 is a perspective view schematically showing a configuration of an impeller in the first embodiment. FIG. 3 is a cross-sectional view schematically showing a configuration of an impeller in the first embodiment. FIG. 3 is a perspective view schematically showing the constituent material of the impeller in the first embodiment. It is another figure which shows roughly the constituent material of the impeller shown in FIG. FIG. 6 is a perspective view schematically showing another constituent material of the impeller in the first embodiment. FIG. 10 is a perspective view from another direction schematically showing the constituent material of the impeller shown in FIG. 9. It is an exploded top view for demonstrating the structure of the 1st blade | wing which the impeller of the hot water supply apparatus shown in FIG. 1 has. It is a top view for demonstrating the structure of the 2nd blade | wing which the impeller of the hot water supply apparatus shown in FIG. 1 has. It is sectional drawing which shows roughly the state at the time of welding of the main plate and 1st blade | wing in Embodiment 1. FIG. It is sectional drawing which shows roughly the state at the time of welding of the main plate and 1st blade | wing in Embodiment 2. FIG. It is sectional drawing which shows roughly the state at the time of welding of the main plate and 1st blade | wing in Embodiment 3. FIG. It is a schematic sectional drawing for demonstrating the difference between a welding part and a non-welding part.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[First embodiment]
<Configuration>
A configuration of a fan and a hot water supply apparatus in an embodiment of the present invention will be described with reference to FIGS. In each figure, the same element is denoted by the same reference numeral, and the description thereof is not repeated.

  Referring mainly to FIGS. 1 and 2, hot water supply apparatus 100 of the present embodiment is an exhaust suction combustion type latent heat recovery type hot water supply apparatus. The hot water supply apparatus 100 includes a housing 1, a burner 2, a primary heat exchanger 3, a secondary heat exchanger 4, an exhaust box 5, a fan 6, an exhaust pipe 7, a drain tank 8, and a pipe. 9 to 15 mainly.

(Burner)
The burner 2 is for generating combustion gas by burning fuel gas. A gas supply pipe 10 is connected to the burner 2. The gas supply pipe 10 is for supplying fuel gas to the burner 2. For example, a gas valve (not shown) made of an electromagnetic valve is attached to the gas supply pipe 10.

  Above the burner 2, a spark plug 2a is arranged. The spark plug 2a is for generating a flame in the fuel-air mixture jetted from the burner 2 by generating an ignition spark with a target (not shown) provided in the burner 2. is there. The burner 2 generates heat by burning the fuel gas supplied from the gas supply pipe 10 (this is called combustion operation).

(Heat exchanger)
Referring mainly to FIG. 2, the primary heat exchanger 3 is a sensible heat recovery type heat exchanger. The primary heat exchanger 3 mainly includes a plurality of plate-like fins 3b, a heat transfer tube 3a that penetrates the plurality of plate-like fins 3b, and a case 3c that accommodates the fins 3b and the heat transfer tubes 3a therein. Have. The primary heat exchanger 3 performs heat exchange with the combustion gas generated in the burner 2, and specifically, in the heat transfer tube 3 a of the primary heat exchanger 3 by the amount of heat generated by the combustion operation of the burner 2. It is for heating the hot water flowing through.

  Referring mainly to FIG. 2, the secondary heat exchanger 4 is a latent heat recovery type heat exchanger. The secondary heat exchanger 4 is located downstream of the primary heat exchanger 3 in the flow of the combustion gas, and is connected to the primary heat exchanger 3 in series with each other. Thus, since the hot water supply apparatus 100 of this Embodiment has the latent heat recovery type secondary heat exchanger 4, it is a latent heat recovery type hot water supply apparatus.

  The secondary heat exchanger 4 mainly has a drain outlet 4a, a heat transfer tube 4b, a side wall 4c, a bottom wall 4d, and an upper wall 4g. The heat transfer tubes 4b are stacked by being spirally wound. The side wall 4c, the bottom wall 4d, and the upper wall 4g are arranged so as to surround the periphery of the heat transfer tube 4b.

  In the secondary heat exchanger 4, hot water flowing in the heat transfer pipe 4 b is preheated (heated) by heat exchange with the combustion gas after heat exchange in the primary heat exchanger 3. In this process, the temperature of the combustion gas is lowered to about 60 ° C., so that moisture contained in the combustion gas is condensed and latent heat can be obtained. Further, the latent heat is recovered by the secondary heat exchanger 4 and the moisture contained in the combustion gas is condensed to generate drain.

  The bottom wall 4 d is for partitioning between the primary heat exchanger 3 and the secondary heat exchanger 4, and is also an upper wall of the primary heat exchanger 3. An opening 4e is provided in the bottom wall 4d, and a space in which the heat transfer tube 3a of the primary heat exchanger 3 is arranged by this opening 4e and a space in which the heat transfer tube 4b of the secondary heat exchanger 4 is arranged. And communicate with each other. As shown by the white arrow in FIG. 2, the combustion gas can flow from the primary heat exchanger 3 to the secondary heat exchanger 4 through the opening 4 e. In this embodiment, for simplicity, the bottom wall 4d of the secondary heat exchanger 4 and the upper wall of the primary heat exchanger 3 are shared, but the primary heat exchanger 3 and the secondary heat exchanger 4 are the same. An exhaust collecting member may be connected between the two.

  An opening 4h is provided in the upper wall 4g, and the space in which the heat transfer tube 4b of the secondary heat exchanger 4 is arranged communicates with the internal space of the exhaust box 5 through the opening 4h. As indicated by white arrows in FIG. 2, the combustion gas can flow from the secondary heat exchanger 4 into the internal space of the exhaust box 5 through the opening 4 h.

  The drain outlet 4a is provided in the side wall 4c or the bottom wall 4d. This drain outlet 4a is the lowest position in the space surrounded by the side wall 4c, the bottom wall 4d, and the upper wall 4g (the lowest position in the vertical direction in the installed state of the hot water supply device), and is the lowest position of the heat transfer tube 4b. It opens below the lower end. As a result, the drain generated in the secondary heat exchanger 4 can be guided to the drain outlet 4a through the bottom wall 4d and the side wall 4c as shown by black arrows in FIG.

(Exhaust box)
Referring mainly to FIGS. 2 and 3, the exhaust box 5 constitutes a flow path of the combustion gas between the secondary heat exchanger 4 and the fan 6. With this exhaust box 5, it is possible to guide the combustion gas after heat exchange in the secondary heat exchanger 4 to the fan 6. The exhaust box 5 is attached to the secondary heat exchanger 4 and is located downstream of the secondary heat exchanger 4 in the flow of the combustion gas.

  The exhaust box 5 mainly has a box body 5a and a fan connection portion 5b. The internal space of the box body 5a communicates with the internal space where the heat transfer tube 4b of the secondary heat exchanger 4 is disposed through the opening 4h of the secondary heat exchanger 4. The fan connection portion 5b is provided so as to protrude from the upper portion of the box body 5a. The fan connecting portion 5b has, for example, a cylindrical shape, and the internal space 5ba communicates with the internal space of the box body 5a.

(fan)
Referring mainly to FIG. 1 and FIG. 3, the fan 6 mainly has a fan case 61, an impeller 62, a drive source 63, and a rotating shaft 64. The fan 6 is for sucking the combustion gas after passing through the secondary heat exchanger 4 (heat exchanged in the secondary heat exchanger 4) and discharging it to the outside of the hot water supply apparatus 100. It is connected to the exhaust pipe 7 located outside the 100.

  This fan 6 is located downstream of the exhaust box 5 and the secondary heat exchanger 4 in the flow of the combustion gas. That is, in the hot water supply device 100, the burner 2, the primary heat exchanger 3, the secondary heat exchanger 4, the exhaust box 5, and the fan 6 are arranged in order from the upstream side to the downstream side of the flow of combustion gas generated in the burner 2. Are lined up. In this arrangement, since the combustion gas is sucked and exhausted by the fan 6 as described above, the hot water supply device 100 of the present embodiment is an exhaust suction combustion type hot water supply device.

(Fan case)
Referring mainly to FIG. 3, the fan case 61 mainly has a back wall 61a provided with a through hole 61c and a peripheral wall 61b surrounding the back wall 61a, and the impeller 62 is rotated in the internal space 61d. Accommodate as possible. In FIG. 3, the back wall 61a and the peripheral wall 61b are configured by different members, but the back wall 61a and the peripheral wall 61b may be formed integrally.

(Impeller)
Referring mainly to FIGS. 3 to 6, impeller 62 is accommodated in fan case 61 (one side of rear wall 61 a). The impeller 62 mainly includes a disk-shaped main plate 620, a first blade 621, a second blade 622, and a shroud 623. The main plate 620 has a first surface 620a and a second surface 620b opposite to the first surface 620a. The first blade 621 is provided on the first surface 620a, and the second surface 620b. A second blade 622 is provided on the top. Further, the shroud 623 is provided so as to cover the entire first blade 621, and an opening 623c is opened at the center thereof.

  Referring mainly to FIG. 3 and FIG. 4, the impeller 62 is arranged in the fan case 61 (on the rear wall 61a so that the first surface 620a is located on the fan connecting portion 5b side opposite to the rear wall 61a. One side). Moreover, as shown in FIG. 3, the opening 623c of the shroud 623 is disposed so as to face the internal space 5ba. In addition, the 2nd blade | wing 622 is arrange | positioned so as to face the back wall 61a side.

  With the above configuration, it is possible to suck combustion gas into the fan case 61 from the box main body 5a of the exhaust box 5 through the fan connecting portion 5b as shown by the white arrow in FIG. . That is, in the present embodiment, the combustion gas in the exhaust box 5 is sucked from the inner peripheral side of the first surface 620a of the impeller 62 and discharged to the outer peripheral side by the rotation of the impeller 62.

  In addition, the 1st blade | wing 621 is covered with the shroud 623 which has the opening part 623c, and can improve the ventilation capability of a fan compared with the case where there is no shroud 623.

[First feather]
Referring mainly to FIG. 6, the first blade 621 extends from the inner peripheral side of the first surface 620a toward the outer peripheral side and is formed to protrude from the first surface 620a. 621A. Each first blade member 621A is individually provided on the first surface 620a and does not contact each other.

  Regarding the height of the first blade member 621A protruding from the first surface 620a, a linear projecting region (A region in FIG. 6) in which the height increases linearly from the outer peripheral side toward the inner peripheral side, and the height is It has a curved protruding area (B area in FIG. 6) that increases in a curve from the outer peripheral side toward the inner peripheral side. In the first surface 620a, the curved protruding area is located on the inner peripheral side of the linear protruding area, and the linear protruding area is welded to the main plate 620.

  Thereby, since the surface on the opposite side to the linear protrusion area | region of the shroud 623 becomes a plane (surface which inclines linearly), the jig | tool and the shroud 623 are pressed by pressing the jig | tool of an ultrasonic welding machine to this plane part. Therefore, ultrasonic vibration can be stably transmitted to the welded portion. Therefore, the welded portion between the main plate 620 and the first blade 621 can be sufficiently welded.

  Note that the distance of the first blade member 621A in the direction protruding from the first surface 620a (the first position that is farthest from the first surface 620a in the axial direction of the position from the position that contacts the first surface 620a of the first blade member 621A). The distance from the first blade member 621A) is the “height” of the first blade member 621A. The same applies to the second blade member 622A.

  In the present embodiment, the curved projecting region of the first blade member 621A is a non-welding region that is not welded to the main plate 620. When trying to weld the curved protruding area to the main plate 620, the ultrasonic vibration is transmitted by pressing the jig of the ultrasonic welding machine against the curved inclined area of the shroud 623 (the portion corresponding to the curved protruding area of the first blade member). Although it is necessary, ultrasonic vibration cannot be transmitted well to a curved surface, and welding is insufficient or variation in welding strength occurs. Therefore, by preventing the curved protruding region from being welded to the main plate 620, it is possible to produce an impeller having a stable quality without variation in the welding strength between the main plate 620 and the first blade 621, and to stabilize the quality of the fan. be able to.

  Referring mainly to FIGS. 6 and 11, when the first surface 620a is viewed from the axial direction of the rotation shaft 64 (A axis indicated by a one-dot chain line in FIG. 3), the first blade member 621A is A linearly extending region (C region in FIG. 11) linearly extending from the outer peripheral side of the first surface 620a toward the inner peripheral side, and curvedly from the outer peripheral side of the first surface 620a toward the inner peripheral side. And an extended curve extending region (D region in FIG. 11). The curved extension region is located on the inner peripheral side of the linear extension region.

  Thereby, with respect to the flow path between the adjacent first blade members 621A, the suction side (inner peripheral side) is formed to bend in the rotation direction of the main plate 620, and the discharge side (outer peripheral side) has a linear flow path. It is formed. In addition, the direction in which the curve extending region is bent is the same direction as the rotation direction of the main plate 620 (white arrow in FIG. 11).

  According to the above configuration, since the inlet of the flow path is bent in the rotation direction with respect to the rotating impeller 62, the combustion gas can be more efficiently introduced into the flow path. In addition, since the direction of the flow path and the direction of the centrifugal force can be more approximated on the discharge side where the centrifugal force is easily applied to the combustion gas flowing in the flow path, the combustion gas toward the discharge side is more efficiently absorbed by the centrifugal force. Accelerated. Therefore, as a result, the air blowing capability of the fan is improved.

[Second feather]
Referring mainly to FIG. 6 and FIG. 12, the second blade 622 extends from the inner peripheral side of the second surface 620b toward the outer peripheral side and is protruded from the second surface 620b. It consists of two blade members 622A. Each of the second blade members 622A is individually provided on the first surface 620a and does not contact each other.

  Referring to FIG. 4, in the impeller 62 of the present embodiment, when the main plate 620 is viewed from the axial direction, each of the second blade members 622A is located between the adjacent first blade members 621A. To do.

  Thus, when the main plate 620 and the first blade 621 are ultrasonically welded (see FIG. 13), the welded portion of the main plate 620 has a plurality of second blade members 622A from the second surface (second blade side surface) side. Since the main plate 620 is stably held by the surface, the ultrasonic vibration is sufficiently transmitted to the welded portion. Therefore, the welded portion between the main plate 620 and the first blade 621 can be sufficiently welded. In particular, when the main plate 620 is viewed from the axial direction, the main plate 620 is more stably held when the distance between the second blade member 622A and the two adjacent first blade members 621A is equal. Vibration is sufficiently transmitted by the welded portion. When the main blade 620 is viewed from the axial direction and the first blade member 621A and the second blade member 622A overlap each other, the jig 65 cannot support the second surface of the main plate 620. In some cases, the ultrasonic vibration is not sufficiently transmitted to the welded portion.

  Further, when the main plate 620 is viewed from the axial direction, each of the second blade members 622A is positioned between the adjacent first blade members 621A, so that the sound generated by the rotation of the first blade 621, Resonance with the sound generated by the rotation of the two blades 622 can be suppressed, so that the effect of suppressing the volume of the sound generated by the fan 6 can also be achieved.

  Further, when the main plate 620 is viewed from the axial direction of the rotation shaft, the portions including the outer peripheral ends of the plurality of first blade members 621A are arranged along the radial direction of the main plate 620. Thereby, since the air current can be smoothly sent in the direction along the centrifugal force at the outer peripheral side portion where the centrifugal force due to the rotation of the impeller greatly acts, the welded portion is hardly peeled off.

  Here, the radial direction is a direction of a straight line on the first surface of the main plate 620 passing through the rotation axis. In addition, as long as the above effect is achieved, the linear protrusion region of the first blade 621 may slightly deviate from the radial direction when the main plate 620 is viewed from the axial direction of the rotation shaft.

  Further, when the main plate 620 is viewed from the axial direction of the rotation shaft, the portions including the outer peripheral ends of the plurality of second blade members 622A are arranged along the radial direction of the main plate 620. Accordingly, when the main plate 620 is viewed from the axial direction of the rotation shaft, the second blade member 622A is easily disposed so as to be positioned between the two first blade members 621A adjacent to each other.

  Here, the radial direction is the direction of a straight line on the second surface of the main plate 620 that passes through the rotation axis. Moreover, if it is the range which has said effect, if it is the range which has such an effect, when the main board 620 is seen from the axial direction of a rotating shaft, the 2nd blade | wing 622 may have shifted | deviated somewhat from the radial direction. .

  11 and 12, in the present embodiment, the number of first blade members 621A and the number of second blade members 622A are the same, but this is not limitative. However, when the number of the first blade members 621A and the number of the second blade members 622A are different, the number of the second blade members 622A is preferably a divisor of the first blade member 621A. The first blade member 621 </ b> A and the second blade member 622 </ b> A having such numbers are preferably arranged so as to have symmetry with respect to the rotation axis, and are arranged at equal intervals. Thereby, the ventilation performance of a fan is stabilized.

  Further, the length of the second blade 622 in the radial direction is not particularly limited, but is preferably half or more of the length of the first blade 621 in the radial direction, and more preferably the length of the linear protrusion region of the first blade 621. That's it. Even if the pressure in the fan case 6 becomes particularly high for some reason, it is difficult to cause a situation in which the balance is inclined to one side and a backflow is generated only on the second blade 622 side.

  In the present embodiment, the height of the second blade 622 is equal to or less than the height of the first blade 621, and preferably equal to or less than half. If the height of the second blade member 622A is increased, the air blowing performance of the first blade 621 may be reduced, and excessively flowing air may affect the flow of combustion gas. In the impeller 62 of the present embodiment, the height of the second blade member 622A is constant from the outer peripheral side toward the inner peripheral side, but is not limited to this.

[Manufacture of impellers]
Next, manufacture of an impeller is demonstrated.

  In the present embodiment, first, a first integrated component in which a shroud 623 and a first blade 621 are integrally formed as shown in FIGS. 7 and 8, and as shown in FIGS. A second integrated component in which the main plate 620 and the second blade 622 are integrally formed is produced. The first integrated component and the second integrated component can be produced by various known integral molding methods.

  In such a state that the first integrated part and the second integrated part are overlapped so that the first blade 621 and the main plate 620 are in contact with each other, the shroud 623 is pressed by an ultrasonic welding jig to perform ultrasonic vibration. As a result, the first blade 621 and the main plate 620 are ultrasonically welded to produce an impeller. Details will be described below, but the configuration of each part is the same as in FIG. 5 and will not be repeated here.

  Referring to FIG. 7, the outer peripheral side (linearly inclined region 623 a) of the surface opposite to the first blade 621 of the shroud 623 has a shape that is linearly inclined in the radial direction in accordance with the shape of the first blade 621. ing. Ultrasonic welding is performed in a state where the linearly inclined region 623a is pressed by a jig that is formed in accordance with the shape of the linearly inclined region 623a. The inclination angle of the surface of the linear inclined region 623a opposite to the first blade 621 is preferably 30 ° or less with respect to the main plate 620. This is because the near horizontal one can stably transmit the vertical ultrasonic vibration from the jig of the ultrasonic welder to the welded portion.

  In addition, the inner peripheral side (curved slope region 623b) of the surface of the shroud 623 opposite to the first blade 621 has a shape that is curved in the radial direction in accordance with the shape of the first blade 621. Thus, generally, the shape of the shroud 623 is formed along the height of the covering blade so as not to hinder the flow of gas passing between the blades.

  With reference to Fig.8 (a), end surface 621Ac on the opposite side to the shroud 623 of 1st blade | wing member 621A exists in one plane. Thereby, it can contact | abut to the 1st surface of the disk shaped main board 620 at the time of ultrasonic welding. However, the end surface 621Ac of the curved protrusion region of the first blade member 621A is not welded even if it is in contact with the main plate 620. This is because it is a portion that is not pressed by the jig of the ultrasonic welder, and a concave portion 620c for positioning the main plate 620 described later is not provided.

  With reference to FIG.8 (b), melt | fusion part 621Ae is formed in edge part 621Ac of the linear protrusion area | region welded with the main board 620. FIG. A melted portion is not formed in the curved protruding region that is not welded to the main plate 620. Thereby, the main plate 620 can be more reliably welded to the linear projecting region of the first blade 621, and the main plate 620 can be prevented from welding to the curved projecting region of the first blade 621.

  The shape of the melting part 621Ae has a triangular shape when viewed from the outer peripheral side end face 621Ad of the first blade 621. It is preferable that the melting part 621Ae has an acute angle at the tip of the triangle toward the inner peripheral side. Thereby, a fusion | melting part can be similarly melted by the inner peripheral side and outer peripheral side of a linear protrusion area | region, and the stable welding intensity | strength can be obtained.

  8A and 8C, the end portion (end surface 621Ac) opposite to the shroud 623 of the curved projecting region (B in FIG. 8C) of the first blade member 621A includes: A positioning projection 621Af is formed. As shown in FIG. 8C, the protrusion is fitted into a hole 620d (FIG. 9) provided in the first surface of the main plate 620. Thereby, the position shift of the curve protrusion area | region (non-welding area | region) of 1st blade member 621A can be prevented.

  Referring to FIG. 9, a plurality of positioning recesses (grooves) 620d are formed on the first surface of main plate 620, and each of the plurality of first blade members 621A of the first integrated component has a plurality of positioning. It is inserted into the concave portion for welding and welded. Thereby, the position shift at the time of welding with the main board 620 and the 1st blade | wing 621 can be prevented, and welding intensity | strength can be raised.

  Referring to FIGS. 10 and 13, when the main plate 620 is viewed from the axial direction of the rotation shaft 64, the second blade member 622 </ b> A is disposed so as to be positioned between two positioning recesses 620 d adjacent to each other. Has been. At the time of ultrasonic welding, the main plate 620 is placed on the jig 66 on the receiving side of the welding machine with the second surface 620b side facing down. Here, the receiving-side jig 66 is a disk-like jig having a size larger than the size of the main plate 620, and a slit-shaped notch is formed at a position corresponding to the second blade member 622A. . At the time of welding, the main plate 620 is installed such that each second blade member 622A is inserted into the notch portion of the jig 66, and the second surface 620b is in contact with the main surface other than the notch portion of the jig 66. For this reason, the notch portion of the jig 66 is designed to be deeper than the height of the second blade member 622A in the protruding direction and larger than the second blade member 622A. In this way, the positioning recess 620d that serves as a welded portion between the main plate 620 and the first blade member 621A is supported by the jig 66 on the receiving side of the welder from the second surface 620b side (lower side) of the main plate 620. Is done. As a result, the ultrasonic vibration is sufficiently transmitted to the welded portion, and sufficient welding can be performed.

  Next, with reference to FIG. 13, the state at the time of welding of the main plate 620 and the first blade 621 in the present embodiment will be further described. As described above, when the main plate 620 and the first blade 621 are welded, the main plate 620 is installed such that the second surface 620b side abuts the upper surface of the jig 66 of the welding machine. Then, the first integrated part composed of the first blade 621 and the shroud 623 is overlaid on the main plate 620 so that the first blade 621 is on the lower side, and the above-described concave portion 620c (FIG. 9) and protrusion 621Af (FIG. 8). Positioning is performed by (a)) and a hole 620d (FIG. 9) and the like, the jig 65 of the ultrasonic welding machine is pressed against the shroud 623 from above, and the main plate 620 and the first blade 621 are ultrasonically welded.

  Here, since the outer peripheral portion of the shroud 623 is linearly inclined in the radial direction of the main plate 620 in accordance with the shape of the linear protrusion region of the first blade member 621A, the end surface of the jig 65 on the shroud 623 side. Can be easily processed into a shape along the shape of the linear protrusion region 621Aa of the first blade member 621A. Then, the adhesiveness between the jig 65 and the shroud 623 is enhanced by pressing the jig 65 of the ultrasonic welder against the outer peripheral portion (linearly inclined region), and the ultrasonic vibration is stably transmitted to the welded portion. Can do. Thereby, the main plate 620 and the linear protrusion region 621Aa of the first blade member 621A can be sufficiently welded.

  The curved projecting region 621Ab of the first blade member 621A may be in contact with the main plate 620, but is not welded. This is because the end surface 621Ac of the curved protrusion region of the first blade member 621A is a portion that is not pressed by the jig 65 of the ultrasonic welding machine and is difficult to transmit ultrasonic vibration in the vertical direction (direction perpendicular to the main plate). Thereby, the dispersion | variation in the welding intensity | strength with a main board and the 1st blade | wing 621 is suppressed, the impeller with stable quality can be produced, and the quality of a fan can be stabilized. Even if the ultrasonic welding is performed in the state shown in FIG. 13, there is a possibility that the curved protruding region 621Ab of the first blade member 621A and the main plate 620 are partially welded due to the propagation of the ultrasonic vibration. Although it can be considered, there is no problem as long as the quality of the fan does not vary.

  Note that ultrasonic welding is a processing technique in which a thermoplastic resin is instantaneously melted by fine ultrasonic vibration and pressure and bonded. Therefore, in the present embodiment, the constituent material of the impeller 62 (the shroud, the first blade, the main plate, and the second blade) is a thermoplastic resin that is melted by heating by ultrasonic vibration.

  Next, referring to FIG. 16, the welded portion (welded portion) between the main plate 620 and the linear protrusion region of the first blade 621 and the curved protrusion region of the main plate 620 and the first blade 621 are connected. The difference between the unwelded portions (non-welded portions) will be described.

  FIG. 16A shows a non-welded part. As shown in FIG. 16 (a), in the welded portion between the main plate 620 and the linear protrusion region of the first blade member 621A, for example, a resin melted by ultrasonic vibration or the like in the concave portion 620c for positioning the main plate Thus, a convex portion 624 is formed. Thus, in the welding part of the main plate 620 and the first blade member 621A, a portion different from the shape of the base material (the main plate 620 and the first blade 621) itself is usually formed.

  FIG.16 (b) is a figure which shows a non-welding part. As shown in FIG. 16 (b), the resin does not melt by ultrasonic vibration or the like at the welded portion between the main plate 620 and the curved protruding region of the first blade member 621A. Usually, the base material (main plate 620 and It consists only of the shape of the first blade 621) itself. In the non-welded part, the first blade member 621A may be in contact with the main plate 620 or may not be in contact.

  As described above, the welded portion and the non-welded portion can be identified also in the impeller after manufacture.

(Drive source)
Referring mainly to FIGS. 1 and 3, drive source 63 is provided outside fan case 61 (on the side opposite to impeller 62 of rear wall 61 a).

(Axis of rotation)
The rotary shaft 64 passes through the through hole 61 c of the fan case 61, thereby connecting the impeller 62 accommodated in the fan case 61 and the drive source 63 provided outside the fan case 61. As a result, the impeller 62 can rotate around the rotation shaft 64 by being given a driving force from the driving source 63.

(Exhaust pipe)
Referring mainly to FIG. 1, exhaust pipe 7 is disposed outside hot water supply apparatus 100 and connected to the outer peripheral side of fan case 61. Therefore, the combustion gas discharged to the outer peripheral side by the first blade 621 of the impeller 62 can be discharged to the outside of the hot water supply device 100 through the exhaust pipe 7.

(Drain tank)
Referring mainly to FIG. 1, the drain tank 8 is for storing drain generated in the secondary heat exchanger 4. The drain tank 8 and the drain outlet 4 a of the secondary heat exchanger 4 Are connected by a drain discharge pipe 9. The acidic drain stored in the drain tank 8 is, for example, temporarily stored in the internal space of the drain tank 8 and then usually discharged from the drain discharge pipe 14 to the outside of the hot water supply apparatus 100.

  The lower portion of the drain tank 8 is connected to a drain removal pipe 15 separately from the drain discharge pipe 14. This drain drain pipe 15 (normally closed) can drain the drain tank 8 that cannot be drained from the drain drain pipe 14 by opening the drain drain pipe 15 during maintenance or the like. Designed to be able to. The interior space of the drain tank 8 may be filled with a neutralizing agent (not shown) for neutralizing acidic drain.

(Plumbing)
Referring mainly to FIG. 1, the gas supply pipe 10 is connected to the burner 2. The water supply pipe 11 is connected to the heat transfer pipe 4b (see FIG. 2) of the secondary heat exchanger 4, and the hot water supply pipe 12 is connected to the heat transfer pipe 3a (see FIG. 2) of the primary heat exchanger 3. Further, the heat transfer tube 3 a of the primary heat exchanger 3 and the heat transfer tube 4 b of the secondary heat exchanger 4 are connected to each other by a connection pipe 13. Each of the gas supply pipe 10, the water supply pipe 11, and the hot water supply pipe 12 communicates with the outside at the upper part of the hot water supply apparatus 100, for example.

  The hot water supply apparatus of the present embodiment is a latent heat recovery type hot water supply apparatus capable of heating hot water by recovering the latent heat of combustion gas. In this case, since acidic drain is generated with the recovery of latent heat, it is particularly useful to provide an impeller having high durability that can withstand acidic drain.

  In the hot water supply apparatus according to the present embodiment, the fan is attached so that the shroud side is the burner side. The opening of the fan case is installed on the lower side to absorb the rising combustion gas, and the impeller is installed so that the shroud side of the impeller is located on the opening side (lower side). Drain tends to accumulate at the boundary between the shroud 623 and the first blade 621 on the upper surface side. For this reason, the shroud 623 and the first blade 621 are integrally formed, and the main plate 620 and the first blade 621 (which are formed integrally with the shroud 623) are welded, so that a weld portion with low durability is formed. Since it becomes the lower side (burner side) of the main plate 620, the welded portion becomes difficult to be exposed to the drain, and the welded portion can be protected from corrosion due to the drain. Thereby, the hot water supply apparatus provided with the fan which has the high durability which can endure high temperature environment can be provided.

  The impeller is preferably made of a thermoplastic resin having acid resistance. This further enhances the durability of the fan against the drain that is generated as the latent heat is recovered.

  Examples of the acid-resistant thermoplastic resin include polyphenylene nylene sulfide (PPS), syndiotactic polystyrene (SPS), polyvinyl chloride (PVC), silicone resin, polytetrafluoroethylene and other fluororesins, and unsaturated polyester. Resin, polycarbonate resin, methacryl styrene (MS) resin, methacryl resin, AS resin (styrene acrylonitrile copolymer), ABS resin (acrylonitrile, butadiene, styrene copolymer synthetic resin), polyethylene, polypropylene, polystyrene, polyethylene terephthalate (PET) It is done.

  For the same reason, other members such as the fan case 61, the exhaust box 5, and the exhaust pipe 7 are preferably made of a material having acid resistance.

  In the present embodiment, the exhaust suction combustion type hot water supply apparatus 100 is used as described above, and therefore, even when the diameter of the exhaust pipe 7 is reduced, the burner 2 is compared with the so-called exhaust push type hot water supply apparatus. The combustion operation due to can be stabilized. This will be described below.

  In a so-called exhaust pushing hot water supply apparatus, a fan, a burner, a primary heat exchanger, and a secondary heat exchanger are arranged in this order from the upstream side to the downstream side of the flow of combustion gas. That is, the combustion gas generated in the burner flows into the exhaust pipe outside the hot water supply device through the primary heat exchanger and the secondary heat exchanger by the fan.

  The combustion gas pushed out of the fan is subjected to flow resistance by the primary heat exchanger and the secondary heat exchanger before reaching the exhaust pipe, so the blowing pressure of the combustion gas immediately before the exhaust pipe is equal to this flow resistance. Lower. For this reason, in order to push combustion gas into the exhaust pipe having a small diameter, it is necessary to increase the blowing pressure by the fan. However, if the fan blowing pressure is increased, the internal pressure in the burner case increases. For this reason, when the supply pressure of the fuel gas supplied to the burner is low, the combustion operation becomes unstable.

  On the other hand, according to the exhaust suction combustion system of the present embodiment, the burner 2, the primary heat exchanger 3, the secondary heat exchanger 4 and the fan 6 are arranged from the upstream side to the downstream side of the flow of the combustion gas. They are arranged in this order. In this system, the upstream side of the fan 6 has a negative pressure, so there is no need to increase the blowing pressure of the fan 6. Thereby, even when the diameter of the exhaust pipe 7 becomes small, the internal pressure in the burner case can be kept low, so that the combustion operation can be stabilized even if the supply pressure of the fuel gas supplied to the burner 2 is low.

  In the present embodiment, an example in which ultrasonic welding is used as the welding method has been described. However, vibration welding or thermal welding can be employed in addition to ultrasonic welding.

[Embodiment 2]
Referring to FIG. 14, the present embodiment is different from the first embodiment in that a build-up portion 623d is provided on the surface of shroud 623 opposite to first blade 621, but the other points are The same as in the first embodiment.

  The side opposite to the first blade 621 of the build-up portion 623d is horizontal to the main plate 620. Thereby, in this Embodiment, the ultrasonic vibration of an up-down direction (direction perpendicular to a main plate) can be more stably transmitted to a welding part, and a welding part can be welded more fully.

  In addition, it is preferable that the build-up portion 623d is provided in a portion overlapping the first blade member 621A when viewed from the rotation axis direction. From the viewpoint of improving the adhesion with the jig of the ultrasonic welder and facilitating the transmission of ultrasonic vibration, it is preferably provided over the entire circumference of the shroud 623.

[Embodiment 3]
Referring to FIG. 15, the present embodiment is different from the second embodiment in that the build-up portion 623d is composed of two parts, but the other points are the same as in the second embodiment. . It should be noted that in each of the overlaid portions 623d, the side opposite to the first blade 621 is horizontal to the main plate 620.

  In the present embodiment, the weight of the impeller can be made lighter than that of the second embodiment while obtaining the same effects as those of the second embodiment.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  100 Hot-water supply device, 1 housing, 2 burner, 2a spark plug, 3 primary heat exchanger, 3a, 4b heat transfer tube, 3b fin, 3c case, 4 secondary heat exchanger, 4a drain outlet, 4c side wall, 4d bottom Wall, 4e, 4h Opening, 4g Upper wall, 5 Exhaust box, 5a Box body, 5b Fan connection, 5ba Internal space, 6 Fan, 7 Exhaust pipe, 8 Drain tank, 9 Piping, 10 Gas supply pipe, 11 Water supply Piping, 12 Hot water piping, 13 Connection piping, 14 Drain discharging piping, 15 Draining piping, 61 Fan case, 61a Back wall, 61b Perimeter wall, 61c Through hole, 61d Internal space, 62 Impeller, 620 Main plate, 620a 1st 1st surface, 620b 2nd surface, 620c Recess (groove), 620d hole, 621 1st blade, 621A 1st blade member, 621A Linear protrusion area, 621Ab Linear protrusion area, 621Ac end face, 621Ad outer peripheral side end face, 621Ae melting part, 621Af protrusion, 622 second blade, 622A second blade member, 622Aa end face, 623 shroud, 623a linear inclination area, 623b curve inclination area , 623c Opening part, 623d Overlaying part, 624 Convex part, 63 Motor, 64 Rotating shaft, 65, 66 Jig.

Claims (8)

A disc-shaped main plate having a first surface and a plurality of first blade members extending from the inner peripheral side to the outer peripheral side of the first surface of the main plate and protruding from the first surface. An impeller including one blade and a shroud that covers the first blade and is formed integrally with the first blade;
A fan case that houses the impeller inside;
A drive source attached to the fan case to drive the impeller;
A rotating shaft connecting the impeller and the driving source,
The first blade member has a linear protrusion region in which the height increases linearly from the outer peripheral side toward the inner peripheral side with respect to the height in the protruding direction of the first blade member protruding from the first surface; A curved projecting region in which the height is curvedly increased from the outer peripheral side toward the inner peripheral side, the curved projecting region is located on the inner peripheral side of the first surface with respect to the linear projecting region;
The fan , wherein the entire linear protruding region is welded to the main plate, and the curved protruding region is not welded to the main plate . The impeller further extends from an inner peripheral side to an outer peripheral side of the second surface of the main plate opposite to the first surface, and a plurality of second blades formed so as to protrude from the second surface. Including a second blade made of a member,
When viewed the main plate in the axial direction of said rotary shaft, said second blade member is located between the two said first blade member adjacent to each other, fan according to claim 1. When viewed the main plate in the axial direction of the rotary shaft, the portion including the outer peripheral end of the plurality of the first blade member is disposed along a radial direction of the main plate, to claim 1 or claim 2 The listed fan. 3. The fan according to claim 2 , wherein when the main plate is viewed from the axial direction of the rotation shaft, the portions including the outer peripheral ends of the plurality of second blade members are arranged along the radial direction of the main plate. . It said main plate has a recess for the plurality of positioning on the first surface,
Each of the plurality of the first blade member and is welded in a state of being inserted in the recess of the plurality of the positioning, the fan according to any one of claims 1 to 4. A positioning projection is formed at an end of the first blade member opposite to the shroud of the curved projecting region, and the projection is fitted into a hole provided in the first surface of the main plate. The fan according to any one of claims 1 to 5 , wherein the fans are combined. A latent heat recovery type hot water supply device capable of heating hot water by recovering the latent heat of combustion gas,
A burner that generates combustion gas;
A heat exchanger for heating hot water flowing inside by heat exchange with the combustion gas;
A fan that sucks the combustion gas after passing through the heat exchanger and discharges it to the outside of the hot water supply device,
The hot water supply apparatus with which the fan of any one of Claims 1-6 is attached as the said fan so that the said shroud side may become the said burner side. The hot water supply device according to claim 7 , wherein the impeller is made of a thermoplastic resin having acid resistance.

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