WO2017073500A1

WO2017073500A1 - Method of manufacturing impeller

Info

Publication number: WO2017073500A1
Application number: PCT/JP2016/081401
Authority: WO
Inventors: 栄佐雄山田; 健太郎織田; 貴士山川
Original assignee: 株式会社荏原製作所
Priority date: 2015-10-28
Filing date: 2016-10-24
Publication date: 2017-05-04

Abstract

This method of manufacturing an impeller comprises the steps of forming a side plate or main plate provided with a plurality of vanes, placing a core on the side plate or the main plate so that the core fits in between the vanes, placing on the vanes a main plate or side plate having formed therein grooves matching the shapes of the vanes, and welding the main plate or the side plate and the vanes together.

Description

Manufacturing method of impeller

The present invention relates to a method for manufacturing an impeller.

¡Manufacturing structures using welding technology has long been done. Structures manufactured by welding range from large-sized structures such as ships and bridges to machines that require precision, such as automobiles, car bodies, and impellers of rotating machines. With rotary machines such as pumps, compressors, and turbines, the size of the main plate and the side plate (refer to the size b2 between the main plate and the side plate in FIG. 7D) becomes narrower in recent years as the size and performance of the machine become smaller. The accuracy requirements are becoming stricter.

If the gap between the main plate and the side plate becomes narrower than 10 mm or less, the welding rod does not enter the blade (in the depth direction of the paper surface in the case of FIG. 7D), so it is difficult to perform normal welding. On the other hand, conventionally, when welding a narrow-blade blade where the welding rod does not enter the blade, slot welding is used.

Japanese Patent Publication No.55-23705

However, when the main plate is welded to the blade in a state where the outer peripheral side of the main plate and the outer peripheral side of the side plate are fixed by the fixing jig and the inner peripheral side of the main plate and the inner peripheral side of the side plate are not fixed by the fixing jig (for example, 9), a large deformation occurs in the main plate after welding. Specifically, the large deformation means that the inner peripheral side of the main plate 2 hangs down to the side plate 3 as shown in FIG. The following can be considered as the cause of this deformation. In other words, since welding is performed in a state where the outer peripheral side is fixed but the inner peripheral side is not fixed, the shrinkage force during natural cooling after welding becomes larger as it goes to the inner peripheral side with the fixed part as a fulcrum, It is considered that the largest deformation occurs at the boss portion on the circumferential side (see the boss portion 18 in FIG. 11).

In addition, the deformation of the main plate 2 is such that when the main plate is welded to the blade in a state where the main plate and the side plate are not fixed by the fixing jig on both the outer peripheral side and the inner peripheral side, both the outer peripheral side and the inner peripheral side are Also occurs. Similarly, when the side plate is welded to the blade, the side plate after welding is greatly deformed. Conventionally, such a deformation could be a product if it was processed and deleted and allowed. However, in recent years, since the demand for the dimensional accuracy of the blades is high, such deformation is not tolerable in processing.

The present invention has been made in view of the above problems, and an object of the present invention is to provide an impeller manufacturing method capable of reducing deformation of a main plate or a side plate due to welding.

The impeller manufacturing method according to one aspect of the present invention includes a step of forming a side plate provided with a plurality of blades, and the core is attached to the side plate so that the core is sandwiched between the blades and the blades. A step of disposing the core plate on the blade, and a step of welding the main plate and the blade. The core is provided with a through-hole adapted to the shape of the blade so that the blade can be accommodated in the core.

As a result, since the core physically suppresses deformation of the main plate due to the shrinkage force during natural cooling after welding, an impeller with a small amount of deformation of the main plate can be manufactured, which improves yield and increases production efficiency. Can be significantly improved and the manufacturing cost can be reduced.

An impeller manufacturing method according to an aspect of the present invention is the impeller manufacturing method described above, wherein the core is destroyed when the main plate becomes lower than a predetermined temperature after the welding step. It further has the process of removing.

This makes it possible to manufacture an impeller in which a space is provided between the main plate and the side plate without causing deformation of the main plate because the core is destroyed when contraction force acts on the main plate.

An impeller manufacturing method according to an aspect of the present invention is any one of the impeller manufacturing methods described above, wherein the core is provided with a vent hole, and the welding step is performed before the welding step. The method further includes the step of applying a tape to the gap between the main plate and the core, and filling the space between the main plate, the side plate, and the core with the inert gas from the vent hole.

This makes it possible to prevent the inert gas from leaking through the gap between the main plate, the side plate, and the core by sticking the tape, so that oxidation of the weld metal can be reliably prevented.

An impeller manufacturing method according to an aspect of the present invention is any one of the impeller manufacturing methods described above, wherein the core through-hole has a shape similar to the shape of the blade, and is circumferential. Is wider than the blade.

This makes it possible to insert the core between the blades.

An impeller manufacturing method according to an aspect of the present invention is any one of the above impeller manufacturing methods, wherein the number of through holes in the core is the same as the number of the blades, In the step of arranging the cores, the cores are arranged by covering the side plates so that the horizontal positions of the corresponding through holes substantially coincide with the horizontal positions of the plurality of blades.

This makes it possible to insert a core between the blades.

An impeller manufacturing method according to an aspect of the present invention is any one of the impeller manufacturing methods described above, wherein the side plate and the core are disk-shaped, and the core is disposed on the side plate. In the step of performing, the core is disposed such that the central axis of the core and the central axis of the side plate substantially coincide with each other.

This places the side plate and core on the same axis.

An impeller manufacturing method according to an aspect of the present invention is the impeller manufacturing method described above, wherein the main plate and the core are disk-shaped, and the main plate is disposed on the blade. The main plate is disposed so that the central axis of the main plate and the central axis of the side plate substantially coincide with each other.

This places the main plate and the side plate on the same axis.

The impeller manufacturing method according to an aspect of the present invention is any of the above impeller manufacturing methods, wherein the core is formed using a material used for precision casting.

This can reduce the unevenness of the core surface. For this reason, even if unevenness according to the shape of the surface of the core is made on the surface of the main plate that contacts the core plate by welding, the unevenness of the surface of the core is small, so the unevenness of the surface may be reduced. it can.

The impeller manufacturing method according to an aspect of the present invention is any one of the impeller manufacturing methods described above, wherein the side plate is a side plate that is integrally cut out by machining.

This prevents the blades from being removed from the side plates because there is no seam between the blades and the side plates.

An impeller manufacturing method according to an aspect of the present invention is any one of the impeller manufacturing methods described above, wherein a groove for welding is provided in a groove of the main plate, and the main plate, the blade, In the step of welding, the welding material is poured through the welding hole to weld the main plate and the blade.

This enables the main plate and the blades to be welded even in an impeller having a narrow space where the welding rod is difficult to enter.

The impeller manufacturing method according to an aspect of the present invention is any one of the impeller manufacturing methods described above, and the impeller is an impeller of a rotating machine.

This makes it possible to manufacture an impeller with a small deformation amount of the main plate.

The manufacturing method of the impeller which concerns on 1 aspect of this invention forms the main board of the said main board so that a core may be inserted | pinched between the process of forming the main board in which the several blade | wing was provided, and the said blade | wing. A step of disposing the side plate on the blade, and a step of welding the side plate and the blade. The core is provided with a through-hole adapted to the shape of the blade so that the blade can be accommodated in the core.

As a result, since the core physically suppresses deformation of the side plate due to the contraction force during natural cooling after welding, an impeller with a small amount of deformation of the side plate can be manufactured, which improves yield and increases production efficiency. Can be significantly improved and the manufacturing cost can be reduced.

In the impeller manufacturing method according to the thirteenth aspect of the present invention, the main plate includes a step of forming a main plate provided with a plurality of blades, and a split core is disposed between the adjacent blades. A step of disposing a plurality of split cores; a step of disposing side plates on the main plate and the split core; and a step of welding the side plates and the blades.

Thus, by adopting the split core, the weight of each split core can be reduced, and collapse due to its own weight can be avoided. Further, the bending moment generated in the split core is reduced by lifting the split core, and it is possible to secure the strength that can withstand operations such as manufacturing the split core and welding setup (assembly of the split core). Since the split core has a small size, the amount of deformation during the curing process can be reduced, and the mounting (assembly) workability to the impeller can be improved in combination with the split structure. Further, even if the split core becomes unusable due to deformation or damage, since it has a split structure, it is only necessary to replace one of the split cores, thereby reducing the influence on the manufacturing cost.

The impeller manufacturing method according to the fourteenth aspect of the present invention is the impeller manufacturing method according to the thirteenth aspect, wherein a hollow is formed in the center of the main plate, and the split core is In the step of disposing the split core, the inner peripheral spacer is provided between the adjacent split cores on the inner peripheral side when protruding from the main plate.

This makes it possible to determine the position of the split core.

The impeller manufacturing method according to the fifteenth aspect of the present invention is the impeller manufacturing method according to the fourteenth aspect, wherein the height of the inner peripheral spacer when the inner peripheral spacer is provided is: The inert gas is supplied from the inner peripheral side so that the inert gas flows through the flow path formed between the main plate and the side plate during the welding step, which is lower than the height of the split core. The

Thereby, a slight gap can be provided on the surface of the split core and the split core, and the inert gas can be supplied from this gap. For this reason, it is possible to avoid a vent hole forming operation with a high risk of damaging the core.

An impeller manufacturing method according to a sixteenth aspect of the present invention is an impeller manufacturing method according to any of the thirteenth to fifteenth aspects, wherein a hollow is formed in the center of the main plate, After the step of forming the main plate, the step of mounting a centering jig in the cavity formed in the main plate before disposing the split core, and in the step of disposing the split core, The back surface on the inner peripheral side of the core is disposed so as to contact the surface of the centering jig.

Thereby, since the split core supports the inner peripheral side of the side plate, it is possible to prevent the inner peripheral side of the side plate provided on the core from falling down by welding.

An impeller manufacturing method according to a seventeenth aspect of the present invention is the impeller manufacturing method according to any one of the thirteenth to sixteenth aspects, wherein in the step of disposing the split core, The method further includes a step of disposing outer peripheral spacers on the outer peripheral side of the split core and between the adjacent blades, and a flow path formed between the main plate and the side plate in the welding step. The inert gas is supplied from the inner peripheral side so that the inert gas flows.

Thereby, the presence of the outer peripheral spacer makes it difficult for the inert gas to leak out. It is possible to make the inert gas impinge on the lining produced during the welding of the blade, and to prevent the lining from being oxidized.

An impeller manufacturing method according to an eighteenth aspect of the present invention is the impeller manufacturing method according to any of the thirteenth to seventeenth aspects, wherein the plurality of blades are equal to each other from the center of the main plate. The blades are provided at angular intervals, and the blades have substantially the same shape, and the split cores have substantially the same shape.

Thus, the wooden mold for forming the split core can be a small set and can be formed from the same wooden mold. In addition, the wooden mold for molding the split core has become smaller, and it is also possible to use a small and inexpensive 3D printer for resin molding for the production of the wooden mold. Since the (resin mold) can be manufactured, the split core can be created in a short time and at a low cost. Alternatively, the same split core can be mass-produced by a 3D printer based on the same 3D data.

An impeller manufacturing method according to a nineteenth aspect of the present invention is the impeller manufacturing method according to any of the thirteenth to eighteenth aspects, wherein the thickness of the split core is the surface of the main plate. It is thinner by a predetermined length than the height of the reference blade.

Thereby, since the end face of the blade is melted by welding, the blade contracts and becomes approximately the same height as the thickness of the split core, so that it is possible to prevent an extra force from being applied to the split core.

The impeller manufacturing method according to the twentieth aspect of the present invention includes a step of forming a side plate provided with a plurality of blades, and the side plate such that a split core is disposed between the adjacent blades. A step of disposing a plurality of split cores; a step of disposing a main plate on the side plate and the split core; and a step of welding the main plate and the blades.

According to the present invention, since the core physically suppresses deformation of the main plate or the side plate due to the shrinkage force during natural cooling after welding, an impeller with a small amount of deformation of the main plate or the side plate can be manufactured. The yield can be improved, the production efficiency can be remarkably improved, and the manufacturing cost can be reduced.

It is a perspective view which shows the outline of the manufacturing process of the impeller 1 which concerns on this embodiment. It is sectional drawing which shows the detail of the manufacturing process of the impeller 1 which concerns on this embodiment. FIG. 3 is a cross-sectional view showing a continuation of the manufacturing process of FIG. 2. FIG. 4 is a cross-sectional view showing a continuation of the manufacturing process of FIG. 3. FIG. 5A is a top view of the impeller at the time of FIG. FIG. 5B is a cross-sectional view taken along the line BB ′ in FIG. It is a perspective view of the side plate 3 which concerns on a comparative example. It is the schematic which shows the manufacturing process of the impeller 21 which concerns on a comparative example using sectional drawing at the time of cutting at CC 'line of FIG. It is detail drawing which shows the manufacturing process of the impeller 21 which concerns on a comparative example using sectional drawing at the time of cutting at DD 'line of FIG. FIG. 9 is a detail view illustrating a manufacturing process continued from FIG. 8. FIG. 10 is a detail view illustrating a manufacturing process continued from FIG. 9. It is a figure for demonstrating the contraction amount of the impeller 21 concerning a comparative example. It is a perspective view of the main board before and behind mounting | wearing of a centering jig | tool. It is a perspective view of the main board before and behind arrangement | positioning of a split core. It is a perspective view at the time of seeing one division | segmentation core from the back surface. It is a disassembled perspective view at the time of seeing a division | segmentation core from the back in order to demonstrate an inner peripheral spacer and an outer peripheral spacer. It is a perspective view of a main board when an inner circumference spacer, an outer circumference spacer, and a split core are arranged. It is a partial perspective view of the main board at the time of cut | disconnecting by the broken line L1 and the straight line L2 of FIG. It is a perspective view of the main board before and behind arrangement | positioning of a side board. It is a flowchart which shows an example of the manufacturing method of the impeller which concerns on 2nd Embodiment.

<Comparative example>
In order to clarify the problem of the present invention, before describing a method for manufacturing an impeller for a rotary machine according to an embodiment of the present invention, a method for manufacturing an impeller 21 for a rotary machine according to a comparative example will be described with reference to FIGS. This will be described with reference to FIG. A method for welding blades having a narrow opening between the main plate and the side plate by slot welding will be described.

FIG. 6 is a perspective view of the side plate 3 according to the comparative example. FIG. 7 is a schematic diagram illustrating a manufacturing process of the impeller 21 according to the comparative example, using a cross-sectional view taken along the line CC ′ of FIG. 6. FIG. 8 is a detailed view showing a manufacturing process of the impeller 21 according to the comparative example, using a cross-sectional view taken along the line DD ′ of FIG. FIG. 9 is a detailed view showing a manufacturing process subsequent to FIG. FIG. 10 is a detailed view showing a manufacturing process subsequent to FIG.

The side plate 3 shown in FIG. 6 is obtained by cutting out the side plate 3 in which the blades 4 are integrated from the forged material. As shown in FIG. 6, the side plate 3 is provided with a plurality of blades 4. Further, as shown in FIG. 7A which is a CC ′ sectional view of FIG. 6, the blades 4 are provided substantially perpendicular to the side plate 3. Further, at this time, the blade 4 is provided on the side plate 3 as shown in Step 1 of FIG. 8 which is a DD ′ sectional view of FIG. 6.

Subsequently, as shown in step 2 of FIG. 8, a steel centering jig 8 is installed at the center of the side plate 3. Subsequently, as shown in Step 3 in FIG. 8 and Step 4 in FIG. 9, the main plate 2 is installed on the side plate 3. The main plate 2 is provided with a groove 5 for slot welding the blade 4 and the main plate 2 on the surface opposite to the surface in contact with the blade 4. As shown in FIG. 7B, the shape of the groove 5 is similar to the upper surface (joint surface) of the blade 4 and is slightly larger than the blade 4, and the horizontal position of the blade 4 and the groove 5 is substantially the same. The main plate 2 is installed so as to match. Further, as indicated by a broken line in step 3 of FIG. 8, a plurality of holes 9 for welding are provided in the groove 5.

Next, as shown in step 5 of FIG. 9, the outer peripheral portion of the main plate 2 and the outer peripheral portion of the side plate 3 are fixed by the fixing jig 7. The fixing jig 7 is strip-shaped and plate-shaped, and the fixing jig 7 fixes the outer peripheral side of the main plate 2 and the outer peripheral side of the side plate 3 over the entire periphery. At the same time, as shown by the fixing weld 11, the welding material is poured from the hole 9 provided in the groove 5, the main plate 2 and the blade 4 are temporarily fixed by welding, and the fixing jig 7 and the main plate 2 are welded. The fixing jig 7 and the side plate 3 are temporarily fixed by welding.

Next, as shown in step 6 of FIG. 9, electric welding is performed along the groove 5. Specifically, for example, slot welding is performed with a current of 60 A to 190 A from the inner peripheral side to the outer peripheral side of the groove 5. At this time, the welding material is poured from the welding hole 9 shown in FIG. 7C to weld the main plate 2 and the blade 4. The structure shown in FIG. 7C is obtained by welding. As shown in FIG. 7C, there is a deformation in which the main plate 2 hangs down to the side plate 3 side between the blades 4 in the cross section taken along the line CC ′ in FIG. 6.

Next, as shown in step 7 of FIG. 10, annealing is performed for removing strain at 500 to 600 ° C. for about 3 hours. Next, as shown in step 8 of FIG. 10, the portion fixed by the fixing jig 7 or the like is deleted, and surface processing is performed according to the design dimension. Thereby, the impeller 21 which concerns on a comparative example is completed, and the impeller which has the cross section shown to FIG 7 (D) is obtained.

As shown in FIG. 7D, there is a deformation in which the main plate 2 hangs down to the side plate 3 side between the blades 4 in the cross section taken along the line CC ′ of FIG. FIG. 11 is a diagram for explaining the amount of contraction of the impeller 21 according to the comparative example. Since the outer peripheral side is fixed and the inner peripheral side is welded in a free end state, as shown in FIG. 11, the inner peripheral side is more contracted than the outer peripheral side, so the inner peripheral side is more than the outer peripheral side. Deformation increases.

<Embodiment of the present invention>
On the other hand, in the embodiment of the present invention, when welding, the core is sandwiched between the main plate 2 and the side plate 3 and the main plate 2 hangs down to the side plate 3 between the blade 4 and the blade 4. Is physically suppressed. Hereinafter, a method for manufacturing the impeller 1 of the rotary machine according to the present embodiment will be described with reference to FIGS. Here, the rotating machine is, for example, a pump, a turbine, a compressor, or a blower.

FIG. 1 is a perspective view showing an outline of the manufacturing process of the impeller 1 according to the present embodiment. FIG. 2 is a cross-sectional view showing details of the manufacturing process of the impeller 1 according to the present embodiment. FIG. 3 is a cross-sectional view showing a continuation of the manufacturing process of FIG. FIG. 4 is a sectional view showing a continuation of the manufacturing process of FIG. FIG. 5A is a top view of the impeller at the time of FIG. FIG. 5B is a cross-sectional view taken along the line BB ′ in FIG.

First, the side plate 3 provided with the blades 4 is formed. Specifically, the side plate 3 is cut out from the forged material by machining so that the blades 4 are integrally cut out. As shown in FIG. 1A, the side plate 3 has a disc shape. As shown in step 1 of FIG. 2, the side plate 3 is installed. Next, as shown in step 2 of FIG. 1B and FIG. 2, a centering jig 8 is attached to the center of the side plate 3.

Next, as shown in Step 3 of FIG. 1C and FIG. 2, the core 10 is arranged on the side plate 3 so that the core 10 is sandwiched between the blade 4 and the blade 4. Here, the core 10 has a disk shape, and a through hole (slit) 14 that matches the shape of the blade 4 is formed in the core 10 so that the blade 4 can be accommodated in the core 10 when the core 10 is arranged. Is provided. Further, the same number of through holes 14 of the core 10 as the number of blades 4 are provided.
A specific arrangement method is as follows. The core 10 is placed by placing the core 10 on the side plate 3 so that the horizontal positions of the corresponding through holes 14 substantially coincide with the horizontal positions of the plurality of blades 4. At this time, the core 10 is arranged so that the central axis of the core 10 and the central axis of the side plate 3 substantially coincide. In the present embodiment, the through hole 14 of the core 10 has a shape similar to the shape of the blade 4, and the width in the circumferential direction is wider than that of the blade 4. As a result, the blade 4 is accommodated in the core 10.

Further, as shown in FIGS. 1 (C) and 5 (B), the core 10 is provided with a vent hole 15. The ventilation hole 15 is for back shield gas, and is a hole for flowing an inert gas such as nitrogen (N2) or argon (Ar) for the purpose of preventing oxidation of the weld metal. Here, the weld metal is a metal that melts and solidifies during welding when welding is performed.

Since the core 10 is exposed to a high temperature during welding, it is preferably a high temperature resistant material. The core 10 is formed using a material used for precision casting. Here, in precision casting, there are few unevenness | corrugations, such as a casting surface. Thereby, the unevenness | corrugation of the surface of the core 10 can be decreased. For this reason, even if unevenness corresponding to the shape of the surface of the core 10 is formed on the surface of the main plate 2 in contact with the core 10 by welding, the unevenness of the surface of the core 10 is small. Can be reduced.
Moreover, since the core 10 must be removed after welding, it is preferably a material that can be physically broken easily. In the present embodiment, as an example, the core 10 is formed using the material described in Patent Document 1. By using such a material, physical removal of the core 10 is facilitated.

Next, as shown in step 4 of FIG. 1 (D) and FIG. 2, the main plate 2 is disposed on the blade 4. As shown in FIG. 1 (D), the main plate 2 is formed with a groove 5 in accordance with the shape of the blade, and the groove 5 has a welding hole 9 indicated by a broken line in step 4 of FIG. A plurality are provided. Further, the main plate 2 has a disk shape, and in the step of arranging the main plate 2 on the blades 4, the main plate 2 is arranged so that the central axis of the main plate 2 and the central axis of the side plate 3 substantially coincide with each other.

As shown in FIG. 5B, the core 10 is inserted between the main plate 2 and the side plate 3. Thereby, the deformation | transformation of the main plate 2 by the solidification shrinkage of the molten metal by welding can be suppressed physically. Further, the inner peripheral portion 17 of the main plate 2 is supported by the centering jig 8 and the core 10. Thereby, the deformation | transformation of the inner peripheral part 17 by the solidification shrinkage | contraction of the molten metal by welding can be suppressed physically.

As shown in step 5 of FIG. 3, tape 16 is applied to the gap between the main plate 2 and the core 10, and inert gas is passed through the vent holes 15 (see FIG. 5B) between the main plate 2, the side plate 3, and the core 10. Fill the space between. Here, the tape 16 has heat resistance. By sticking the tape 16, it is possible to prevent the inert gas from leaking through the gaps between the main plate 2, the side plate 3 and the core 10, so that oxidation of the weld metal can be reliably prevented. Thereafter, the ends of the blades 4 and the grooves 5 of the main plate 2 are fixed by welding (see step 5 in FIG. 3). Thereby, the welding part 11 for fixation is formed.
Thereafter, as shown in Step 6 of FIG. 3, the main plate 2 and the blade 4 are welded by pouring the welding material through the plurality of welding holes 9. As a result, the main plate and the blade can be welded even in an impeller having a narrow space where the welding rod is difficult to enter. This welding is so-called slot welding. The welding current at this time is, for example, 60 A to 190 A. By this welding, the welded portion 12 is formed. Thereafter, as shown in step 7 of FIG. 3, the tape 16 is peeled off after the step 6 of welding shown in FIG.

Next, as shown in step 7 of FIG. 3, the welded impeller is annealed. The annealing conditions vary depending on the plate thickness and the like. In the present embodiment, annealing is performed at 500 to 600 ° C. for about 3 hours as an example. After annealing, as shown in step 8 of FIG. 4, the centering jig 8 that has played the role of positioning is removed. Next, as shown in step 9 of FIG. 4, when the main plate 2 becomes lower than a predetermined temperature, the core 10 is physically destroyed and removed. Thereby, since the core is destroyed when contraction force acts on the main plate, a structure in which a space is provided between the main plate and the side plate can be manufactured without deforming the main plate. Next, as shown in step 10 of FIG. 4, the outer peripheral portion 19 shown in step 9 of FIG. Thereby, the impeller 1 which concerns on this embodiment is completed.

As a result of measuring with a precision measuring instrument, in the comparative example, a concave deformation of about 0.5 to 1 mm was observed at the most severely deformed portion on the inner peripheral side. On the other hand, in the present embodiment, almost no deformation is observed at the corresponding inner peripheral side, or even if there is a deformation, it is an extremely small deformation of about 0.1 mm.

As shown in FIG. 11, in the comparative example, the main plate 2 had a large amount of shrinkage and a large amount of deformation in the direction from the outer peripheral side to the inner peripheral side boss portion 18. In particular, since the boss portion 18 of the main plate 2 becomes a free end, a large contraction occurs and the deformation is large. On the other hand, in this embodiment, the core 10 is physically suppressed from being deformed by the contraction force during natural cooling after welding by inserting the core 10 between the main plate 2 and the side plate 3 of the impeller 1. Therefore, an impeller with a small deformation amount of the main plate 2 can be manufactured. Thereby, the yield can be improved, the production efficiency can be remarkably improved, and the manufacturing cost can be reduced.

In addition, although this embodiment demonstrated the manufacturing method of the impeller 1 of a rotary machine, it is not restricted to this, Using a core is applicable also to the manufacturing method of another structure. In particular, it is preferable to adapt to a structure having a narrow space where a welding rod is difficult to enter.

In addition, in this embodiment, although the blade | wing was provided in the side plate, you may provide a blade | wing not only in this but a main plate. In either case, one impeller can be manufactured from two materials. Further, since the blades can be cut out by machining, the flow path can be formed more accurately than the casting. Specifically, the manufacturing method of the impeller includes a step of forming a main plate provided with a plurality of blades, and a step of arranging the core on the main plate so that the core is sandwiched between the blades and the blades. And a step of arranging a side plate on which a groove matching the shape of the blade is formed on the blade, and a step of welding the side plate and the blade. The core is provided with a through-hole that matches the shape of the blade so that the blade can be accommodated in the core when the core is disposed.

<Second Embodiment>
In the first embodiment, it is a large disk-shaped core, which is approximately the same size as the main plate of the impeller. This core is resistant to compression but has a brittle nature, and the thin outer peripheral portion is liable to collapse due to lack of corners or its own weight. The core needs to be hardened after molding. However, deformation such as warpage is likely to occur at this time, and this deformation is particularly large in a single disk-shaped core. It becomes difficult to attach the core, and it is easy to damage the core if it is forcibly installed.

Moreover, when manufacturing an impeller using a big disk core like 1st Embodiment, if a disk core has a partial defect | deletion, the disk core will become unusable. . Although the core raw material is relatively inexpensive, the production cost of the core is expensive. If the disk core becomes unusable, the cost is greatly affected. In the core according to the first embodiment, a small ventilation hole is provided in order to secure the air permeability of the back seal gas. However, since there is a high risk of damaging the core at this time, it is necessary to be careful and troublesome. It was an expensive work.

On the other hand, in the second embodiment, a split core obtained by dividing the disk-shaped core along the shape of the blade is used instead of the disk-shaped core. Here, there are a plurality of split cores, and as an example, the split angles with the impeller central axis as the center are substantially the same. By using the split core in which the core is divided in this way, the weight of the single split core is suppressed, and the collapse of the split core due to its own weight can be avoided.

Since the split core has a small size, the amount of deformation during the curing process can be reduced, and combined with the split structure, the mounting (assembly) workability to the impeller is extremely high. Even if the split core becomes unusable due to deformation or damage, since it has a split structure, it is only necessary to replace one of the split cores, thereby reducing the influence on the production cost. Further, as shown in FIG. 14 to be described later, by providing an inner circumferential spacer between the split core and providing a gap between the split core and the split core, air permeability of the back seal gas is ensured. This makes it possible to avoid the work of creating a vent hole with a high risk of damaging the core.

Subsequently, the manufacturing method of the impeller will be described along the flowchart of FIG. 19 with reference to FIGS. FIG. 12 is a perspective view of the main plate before and after mounting of the centering jig. FIG. 13 is a perspective view of the main plate before and after the arrangement of the split cores. FIG. 14 is a perspective view when one split core is viewed from the back surface. FIG. 15 is an exploded perspective view when the split core is viewed from the back in order to explain the inner peripheral spacer and the outer peripheral spacer. FIG. 16 is a perspective view of the main plate when the inner circumferential spacer, the outer circumferential spacer, and the split core are disposed. FIG. 17 is a partial perspective view of the main plate when cut along the polygonal line L1 and the straight line L2 of FIG. However, in FIG. 17, the inner circumferential spacers 34-1 to 34-13 and the outer circumferential spacers 35-1 to 35-13 are omitted. FIG. 18 is a perspective view of the main plate before and after the side plates are arranged. FIG. 19 is a flowchart illustrating an example of a manufacturing method of an impeller according to the second embodiment.

Hereinafter, a description will be given along the flowchart of FIG.
(Step S101) First, the main plate 31 provided with a plurality of blades 41-1 to 41-13 is formed. Specifically, the main plate 31 is cut out from the forged material by machining, so that the blades 41-1 to 41-13 are cut out integrally. As shown in FIG. 12, the main plate 31 has a disk shape, and the main plate 31 has a cavity formed in the center. The plurality of blades 41-1 to 41-13 are provided at equal angular intervals from the center of the main plate 31, and the shapes of the blades 41-1 to 41-13 are substantially the same.

(Step S102) Next, as shown in FIG. 12, a centering jig 32 is mounted in the cavity formed in the main plate 31.

(Step S103) Next, the split cores 33-1 to 33-13, the inner circumferential spacers 34-1 to 34-13, and the outer circumferential spacers 35-1 to 35-13 are arranged. Specifically, as shown in FIG. 13, a plurality of split cores 33-1 to 33-33 are arranged on the main plate 31 so that the split cores 33-1 to 33-13 are arranged between adjacent blades. Place -13. As shown in FIGS. 13 and 17, the split cores 33-1 to 33-13 protrude to the inner peripheral side from the main plate 31.

The split cores 33-1 have substantially the same shape as the split cores, and each split core has a shape as shown in FIG. With this configuration, the wooden molds for molding the split cores 33-1 to 33-13 need only be one small set, and can be formed from the same wooden mold. In addition, the wooden molds for molding the split cores 33-1 to 33-13 are smaller, and it is possible to use a small and inexpensive 3D printer for resin molding for the production of the wooden molds. Since it is possible to manufacture a wooden mold (resin mold) with high target shape accuracy, the split cores 33-1 to 33-13 can be created in a short time and at low cost. Alternatively, the same split core can be mass-produced by a 3D printer based on the same 3D data.

As shown in FIG. 15 and FIG. 16, in the step of arranging the split cores 33-1 to 33-13, the inner periphery is disposed between the adjacent split cores 33-1 to 33-13 on the inner peripheral side. Spacers 34-1 to 34-13 are provided. With this configuration, the positions of the split cores 33-1 to 33-13 can be determined.

As shown in FIG. 16, the height of the inner peripheral spacers 34-1 to 34-13 when the inner peripheral spacers 34-1 to 34-13 are provided is equal to the height of the split cores 33-1 to 33-13. Less than that. And in the process of welding mentioned later, an inert gas is supplied from the inner peripheral side so that an inert gas may flow through the flow path formed between the main plate 31 and the side plate 36. With this configuration, a slight gap can be provided on the surface of the split core and the split core, and the inert gas can be supplied from this gap. For this reason, it is possible to avoid a vent hole forming operation with a high risk of damaging the core.

Further, as shown in FIGS. 15 and 16, in the step of arranging the split cores 33-1 to 33-13, the adjacent blades 41- on the outer peripheral side of the split cores 33-1 to 33-13 are arranged. Outer spacers 35-1 to 35-13 are arranged between 1 to 41-13, respectively.

As shown in FIG. 17, in the step of placing the split core, the back surface on the inner peripheral side of the split core is placed in contact with the surface of the centering jig 32. With this configuration, since the split core supports the inner peripheral side of the side plate, the inner peripheral side of the side plate provided on the core can be prevented from falling down by welding.

As shown in FIG. 17, the thickness of the split cores 33-1 to 33-13 is thinner by a predetermined length than the height of the blades relative to the surface of the main plate 31. The predetermined length is a length corresponding to the amount by which the blade is contracted and the height of the blade is lowered by melting the end face of the blade by welding. As a result, the end face of the blade is melted by welding, so that the blade contracts and becomes approximately the same height as the thickness of the split cores 33-1 to 33-13. Can be prevented from applying excessive force.

Further, since the split cores 33-1 to 33-13 must be removed after welding, it is preferable to use a material that can be physically easily broken. In the present embodiment, as an example, the split cores 33-1 to 33-13 are formed using the material described in Patent Document 1. By using such a material, physical removal of the split cores 33-1 to 33-13 is facilitated.

(Step S104) Next, as shown in FIG. 18, on the main plate 31 and the split cores 33-1 to 33-13, grooves 37-1 to 37 matched with the shapes of the blades 41-1 to 41-13 are formed. A side plate 36 on which −13 is formed is disposed.

(Step S105) Next, the side plate 36 and the blades 41-1 to 41-13 are welded while supplying the inert gas from the inner peripheral side. In this welding process, the inert gas is supplied from the inner peripheral side so that the inert gas flows through the flow path formed between the main plate 31 and the side plate 36. Thus, the presence of the outer peripheral spacers 35-1 to 35-13 makes it difficult for the inert gas to leak out. It is possible to make the inert gas impinge on the lining produced during the welding of the blade, and to prevent the lining from being oxidized.

(Step S106) Next, heat treatment is performed. For example, after slowly raising the temperature, cool slowly. Thereby, the residual stress can be released.

(Step S107) Next, the outer peripheral portion is cut out. As a result, the outer peripheral spacers 35-1 to 35-13 are removed.

(Step S108) Next, the split cores 33-1 to 33-13 are physically destroyed with a wire or the like.

(Step S109) Next, a desired shape is finished by machining. Thereby, an impeller is completed.

As described above, the manufacturing method of the impeller according to the second embodiment includes the step of forming the main plate 31 provided with the plurality of blades 41-1 to 41-13 and the arrangement of the split cores between the adjacent blades. As described above, a step of disposing a plurality of split cores 33-1 to 33-13 on the main plate 31, and a step of disposing a side plate 36 on the main plate 31 and the split cores 33-1 to 33-13. And welding the side plate 36 and the blades 41-1 to 41-13.

With this configuration, by using the split cores 33-1 to 33-13, the weight of each of the split cores 33-1 to 33-13 can be reduced, and collapse due to its own weight can be avoided. Further, by lifting the split cores 33-1 to 33-13, the bending moment generated in the split cores 33-1 to 33-13 is reduced, and the split cores 33-1 to 33-13 are manufactured and welded ( It is possible to ensure strength that can withstand work such as assembling the split core. Since the split cores 33-1 to 33-13 have a small size, the amount of deformation during the curing process can be reduced, and the mounting (assembly) workability to the impeller can be improved in combination with the split structure. Further, even if the split cores 33-1 to 33-13 become unusable due to deformation or damage, it is possible to replace one of the split cores 33-1 to 33-13 because of the split structure. , The impact on production costs will be reduced.

In the present embodiment, the blades 41-1 to 41-13 are formed on the main plate 31, but the present invention is not limited to this, and the blades 41-1 to 41-13 may be formed on the side plate 36. In that case, the manufacturing method of the impeller includes a step of forming a side plate provided with a plurality of blades and a plurality of divided cores on the side plate so that the divided cores are arranged between adjacent blades. What is necessary is just to make it have the process of arrange | positioning, the process of arrange | positioning a main plate on a side plate and a division | segmentation core, and the process of welding a main plate and a blade | wing.

As described above, the present invention is not limited to the above-described embodiment as it is, and can be embodied by modifying the constituent elements without departing from the scope of the invention in the implementation stage. In addition, various inventions can be formed by appropriately combining a plurality of components disclosed in the embodiment. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, constituent elements over different embodiments may be appropriately combined.

1, 2: Impeller 2, 31: Main plate 3, 36: Side plate 4, 41-1 to 41-13: Blade, 5, 37-1 to 37-13: Groove, 7: Fixing jig, 8 32: Centering jig, 9: Hole, 10: Core, 11: Welding part for fixing, 12: Welded part, 14: Through hole, 15: Vent hole, 16: Tape, 17: Inner peripheral part, 18: Boss portion, 19: outer peripheral portion, 33-1 to 33-13: split core, 34-1 to 34-13: inner peripheral spacer, 35-1 to 35-13: outer peripheral spacer

Claims

Forming a side plate provided with a plurality of blades;
Placing the core on the side plate such that the core is sandwiched between the blade and the blade; and
Disposing a main plate on which the grooves according to the shape of the blade are formed on the blade;
Welding the main plate and the blade;
Have
A manufacturing method of an impeller, wherein a through-hole matching the shape of the blade is provided in the core so that the blade is accommodated in the core when the core is disposed.
The impeller manufacturing method according to claim 1, further comprising: a step of destroying and removing the core when the main plate becomes lower than a predetermined temperature after the welding step.
The core is provided with a vent hole,
Prior to the welding step, the method further includes a step of attaching a tape to a gap between the main plate and the core, and filling an inert gas into the space between the main plate, the side plate, and the core through the vent hole. Item 3. A method for producing an impeller according to Item 1 or 2.
The impeller manufacturing method according to any one of claims 1 to 3, wherein the through hole of the core has a shape similar to the shape of the blade, and has a circumferential width wider than that of the blade.
The number of through-holes in the core is the same as the number of blades,
In the step of arranging the core, the core is arranged by placing the core on the side plate so that the horizontal position of the corresponding through hole substantially coincides with the horizontal position of the plurality of blades. The manufacturing method of the impeller as described in any one of 1-4.
The side plate and the core are disk-shaped,
In the step of arranging the core on the side plate, the core is arranged so that a central axis of the core and a central axis of the side plate substantially coincide with each other. The manufacturing method of the impeller as described in a term.
The main plate and the core are disk-shaped,
The process of arrange | positioning the said main board on the said blade | wing WHEREIN: The said main board is arrange | positioned so that the central axis of the said main board and the central axis of the said side plate may correspond substantially. The manufacturing method of an impeller.
The impeller manufacturing method according to any one of claims 1 to 7, wherein the core is formed using a material used for precision casting.
The impeller manufacturing method according to any one of claims 1 to 8, wherein the side plate is a side plate formed by machining the blades integrally.
A groove for welding is provided in the groove of the main plate,
10. The impeller according to claim 1, wherein in the step of welding the main plate and the blade, a welding material is poured through the welding hole to weld the main plate and the blade. Production method.
The manufacturing method of the impeller according to any one of claims 1 to 10, wherein the impeller is an impeller of a rotary machine.
Forming a main plate provided with a plurality of blades;
Placing the core on the main plate such that the core is sandwiched between the blade and the blade; and
A step of placing a side plate on which the groove according to the shape of the blade is formed on the blade;
Welding the side plate and the blade;
Have
A manufacturing method of an impeller, wherein a through-hole matching the shape of the blade is provided in the core so that the blade is accommodated in the core when the core is disposed.
Forming a main plate provided with a plurality of blades;
Disposing a plurality of split cores on the main plate such that split cores are respectively disposed between the adjacent blades;
Placing a side plate on the main plate and the split core;
Welding the side plate and the blade;
The manufacturing method of the impeller which has.
A hollow is formed in the center of the main plate,
The split core protrudes to the inner peripheral side from the main plate,
The method for manufacturing an impeller according to claim 13, further comprising a step of providing an inner peripheral spacer between adjacent split cores on an inner peripheral side in the step of arranging the split core.
The height of the inner circumferential spacer when the inner circumferential spacer is provided is lower than the height of the split core,
The impeller according to claim 14, wherein an inert gas is supplied from an inner peripheral side so that the inert gas flows through a flow path formed between the main plate and the side plate during the welding process. Manufacturing method.
A hollow is formed in the center of the main plate,
After the step of forming the main plate, before placing the split core, further comprising the step of mounting a centering jig in the cavity formed in the main plate,
16. The impeller according to claim 13, wherein, in the step of arranging the split core, the back surface on the inner peripheral side of the split core is disposed so as to contact the surface of the centering jig. Production method.
In the step of disposing the split core, it further includes a step of disposing outer peripheral spacers on the outer peripheral side of the split core and between the adjacent blades.
17. The inert gas is supplied from the inner peripheral side so that the inert gas flows through a flow path formed between the main plate and the side plate during the welding step. An impeller manufacturing method according to one item.
The plurality of blades are provided at equal angular intervals from the center of the main plate, and the shapes of the blades are substantially the same.
The impeller manufacturing method according to any one of claims 13 to 17, wherein the divided cores have substantially the same shape.
The method of manufacturing an impeller according to any one of claims 13 to 18, wherein the thickness of the split core is thinner by a predetermined length than the height of the blades relative to the surface of the main plate.
Forming a side plate provided with a plurality of blades;
Arranging a plurality of split cores on the side plate such that split cores are respectively disposed between the adjacent blades;
Arranging a main plate on the side plate and the split core;
Welding the main plate and the blade;
The manufacturing method of the impeller which has.