Impeller

Abstract

To provide an impeller made of resin formed by integrally molding a principal plate 1, a shroud 2, a plurality of blades and a reinforcing ring 4 straddling between radial direction outer edge parts of the blades and, in such blades that the long blade 31 whose radial inner edge part reaches the principal plate 1 and the short blades 32 whose radial inner edge part does not reach the principal plate 1 are alternately provided in circumferential directions, insufficient strength caused by weld of the final charging ring portion 4a as the portion to which the resin is finally charged upon molding, of the circumferential plurality of portions of the reinforcing ring 4 located between the blades adjoining in the circumferential direction can be solved.SOLUTION: The thickness of the final charging ring portion 4a is made to be larger than those of other ring portions. Further, the position of the final charging ring portion 4a can be offset to the shroud 2 side relative to the positions of other ring portions.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to an impeller for use in a centrifugal combustion fan or the like. [Background technology]

[0002] Conventionally, as an impeller of this kind, Patent Document 1 discloses a resin impeller including a main plate connected to a rotating shaft, an annular shroud spaced apart from the main plate in one axial direction and having an inner diameter equal to or larger than the outer diameter of the main plate, a plurality of blades arranged at circumferential intervals so as to protrude in the other axial direction from a side surface of the shroud facing the other axial direction and protruding radially outward from the outer circumferential edge of the shroud, and a reinforcing ring extending in an annular shape across between the radially outer ends of the side edges in the other axial direction of the blades, the main plate, the shroud, the plurality of blades, and the reinforcing ring being integrally molded. In this impeller, the side edges in the other axial direction of the portions of the blades near the radially inner ends are joined to the surface of the main plate facing the one axial direction, and the main plate and the shroud have marks of gates through which resin is injected during molding.

[0003] In the above conventional example, during molding, resin flows into the cavity for the blades from the cavity for the main plate and the cavity for the shroud, which may cause welds to form in the blades. Therefore, it is conceivable to provide a long blade in which the other axial side edge of the part close to the radial inner end is joined to the surface of the main plate facing one axial direction, and a short blade in which the radial inner end is located radially outward from the outer circumferential edge of the main plate, and further provide only the main plate with a gate trace for injecting resin during molding. According to this, during molding, resin flows from the cavity for the main plate into the cavity for the long blade, the cavity for the shroud, and the cavity for the short blade in that order, which can suppress the occurrence of welds in the long blade and the short blade.

[0004] However, in the portion of the reinforcing ring located between circumferentially adjacent blades, resin flows into the cavity for this ring portion from the cavity for one circumferentially adjacent blade and the cavity for the other blade during molding, resulting in the occurrence of a weld. Here, resin is not filled into all of the multiple circumferential portions of the reinforcing ring located between circumferentially adjacent blades at the same time, and one of the ring portions becomes the final filled ring portion into which resin is filled last during molding. In addition, the resin holding time that is useful for improving defects caused by welds becomes shorter in the final filled ring portion, resulting in insufficient strength. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2018-91199 A Summary of the Invention [Problem to be solved by the invention]

[0006] In view of the above, an object of the present invention is to provide an impeller capable of overcoming the lack of strength of the final packing ring portion. [Means for solving the problem]

[0007] The impeller is made of resin and includes a main plate connected to a rotating shaft, an annular shroud spaced apart from the main plate in one axial direction and having an inner diameter equal to or larger than the outer diameter of the main plate, a plurality of vanes provided at intervals in the circumferential direction so as to protrude in the other axial direction from a side surface of the shroud facing the other axial direction, the vanes protruding radially outward beyond the outer circumferential edge of the shroud, and a reinforcing ring extending annularly across between radially outer ends of the side edges in the other axial direction of the vanes, the main plate, the shroud, the vanes, and the reinforcing ring being integrally molded, the vanes including a long vane whose side edge in the other axial direction at a portion close to the radially inner end is joined to a surface of the main plate facing one axial direction, and a long vane whose radially inner end is joined to a surface of the main plate facing the one axial direction. In a reinforcing ring having a short blade located on the opposite side and a gate trace for injecting resin during molding provided only on the main plate, in order to solve the above-mentioned problem, the first invention of the present application is characterized in that the axial thickness of the final filling ring portion, which is the last to be filled with resin during molding among the multiple circumferential portions of the reinforcing ring located between circumferentially adjacent blades, is greater than that of the other ring portions, and the second invention of the present application is characterized in that the position of the final filling ring portion, which is the last to be filled with resin during molding among the multiple circumferential portions of the reinforcing ring located between circumferentially adjacent blades, is offset in one axial direction from the other ring portions.

[0008] According to the first invention, the strength deficiency of the final filling ring part can be eliminated by increasing the thickness of the final filling ring part. According to the second invention, the position of the final filling ring part is offset to one side in the axial direction, i.e., toward the shroud, so that resin is filled into the final filling ring part relatively quickly from the shroud side via the short blade. This ensures a pressure retention time for the resin in the final filling ring part, eliminating the strength deficiency of the final filling ring part.

[0009] According to the first aspect of the present invention, the dynamic balance of the impeller is lost by increasing the thickness of the final packed ring portion. Therefore, it is desirable to integrally mold a weight portion for ensuring dynamic balance in the portion of the shroud or the portion of the blade located circumferentially opposite the final packed ring portion. This makes it possible to ensure dynamic balance without increasing the number of parts. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a perspective view of an impeller according to a first embodiment of the present invention. [Diagram 2] FIG. 2 is a perspective view of the impeller of the first embodiment, seen from a different direction than that of FIG. [Diagram 3] FIG. 2 is a bottom view of the impeller of the first embodiment as viewed from the main plate side. [Figure 4] FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. [Diagram 5] FIG. 6 is a perspective view of an impeller according to a second embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] The impeller according to the embodiment of the present invention shown in Figures 1 to 4 is used in a centrifugal combustion fan, and includes a main plate 1 connected to a rotating shaft (not shown), and a shroud 2 spaced apart in one axial direction from the main plate 1. The shroud 2 is annular, more specifically, bell-mouth shaped, and has an opening 2a in the center, which serves as an intake port. The diameter of the opening 2a, i.e., the inner diameter of the shroud 2, is equal to or larger than the outer diameter of the main plate 1.

[0012] The impeller is provided at intervals in the circumferential direction so as to protrude in the other axial direction from the side surface of the shroud 2 facing the other axial direction, and includes long blades 3 (described later) protruding radially outward beyond the outer circumferential edge of the shroud 2. 1 and Short Feather 3 2 The impeller further comprises three blades. 1 , 3 2 The impeller is provided with a main plate 1, a shroud 2, and a plurality of blades 3. 1 , 3 2 and the reinforcing ring 4 are integrally molded from resin.

[0013] The blade is a long blade 3 whose other axial side edge at the radially inner end is joined to a side surface of the main plate 1 facing one axial direction. 1and short blade 3 whose radially inner end is located radially outward from the outer circumferential edge of the main plate 1. 2 And these three long blades are 1 and Short Feather 3 2 and are arranged alternately in the circumferential direction.

[0014] Here, one axial direction is the upper side and the other axial direction is the lower side. The impeller is made up of the main plate 1 and the underside of the shroud 2, and the long blade 3 located under the shroud 2. 1 and short feather 3 2 The lower mold forms the lower surface and both the inner and outer peripheral surfaces of the reinforcing ring 4, the upper surface of the main plate 1 and the shroud 2, and the long blade 3 that protrudes radially inward beyond the inner peripheral edge of the shroud 2. 1 and the long blade 3 which protrudes radially outward beyond the outer circumferential edge of the shroud 2. 1 and short feather 3 2 The mold is formed using a molding die consisting of an upper die for molding the upper surface of the main plate 1 and the upper surface of the reinforcing ring 4. The upper die is provided with a gate for injecting resin into the cavity for the main plate 1. Then, the long blade 3 is injected from the cavity for the main plate 1. 1 Cavity and shroud for 2 Cavity and short vane for 3 2 Resin flows into the cavity for the mold and the cavity for the mold in order, and finally into the long blade 3 1 and Short Feather 3 2 The cavity for the ring part located between the 1 Cavity and short blade for 3 2 In this case, the gate trace 5 for injecting the resin during molding is provided only on the main plate 1.

[0015] Between adjacent blades in the circumferential direction, i.e., between long blades 3 1 and Short Feather 3 2 In the portion of the reinforcing ring 4 located between the long blade 3 and the cavity for this ring portion, a long blade 3 is inserted into the cavity for this ring portion during molding. 1 Cavity and short blade for 3 2 Resin flows in through the cavity for the mold, causing a weld. 1 and Short Feather 3 2The resin is not filled into all of the circumferential portions of the reinforcing ring 4 located between the first and second portions at the same time, but one of the ring portions becomes the final filled ring portion 4a into which the resin is filled last during molding. In the final filled ring portion 4a, the resin pressure retention time, which is useful for improving defects caused by welding, becomes shorter, and if this continues, it will result in insufficient strength.

[0016] Therefore, in this embodiment, a molding test of the impeller is performed to identify the portion that will become the final filling ring portion 4a, and the axial thickness of this final filling ring portion 4a is made larger than that of the other ring portions. This makes it possible to eliminate the lack of strength of the final filling ring portion 4a.

[0017] However, simply increasing the thickness of the final packed ring portion 4a would destroy the dynamic balance of the impeller. Therefore, a weight portion 6 consisting of a cylindrical protrusion for ensuring dynamic balance is integrally formed with the portion of the shroud 2 located circumferentially opposite the final packed ring portion 4a. This makes it possible to ensure dynamic balance without increasing the number of parts. The weight portion 6 can be of any shape other than a cylindrical protrusion.

[0018] Next, a second embodiment shown in Fig. 5 will be described. The basic structure of the impeller of the second embodiment is not particularly different from that of the first embodiment, and the same members and parts as those of the first embodiment are given the same reference numerals. The difference between the second embodiment and the first embodiment is that, instead of increasing the thickness of the final packed ring portion 4a, the position of the final packed ring portion 4a is offset in one axial direction, i.e., toward the shroud 2, from the other ring portions.

[0019] According to this, during molding, the short blade 3 is inserted from the cavity for the shroud 2. 2 Therefore, the resin is filled relatively quickly into the final filling ring part 4a through the cavity for filling the resin. Therefore, the pressure retention time of the resin in the final filling ring part 4a can be secured, and the strength deficiency of the final filling ring part 4a can be eliminated.

[0020] Although the embodiment of the present invention has been described above with reference to the drawings, the present invention is not limited thereto. For example, in the first embodiment, the weight portion 6 for ensuring dynamic balance is integrally formed in the part of the shroud 2 located on the circumferentially opposite side to the final filling ring portion 4a. 1 Or short feather 3 2 It is also possible to integrally mold a weight portion 6 for ensuring dynamic balance in this portion. Specifically, the weight portion 6 is formed integrally with the long blade 3 located on the circumferential opposite side of the final filling ring portion 4a. 1 Or short feather 3 2 It is also possible to increase the thickness of the portion that protrudes from the outer circumferential edge of the shroud 2, or to increase the thickness of the portion in the other axial direction by increasing the draft angle of the portion, thereby forming this weight portion 6. Also, when there are a plurality of final filling ring portions 4a, it is only necessary to increase the thickness of each final filling ring portion 4a or to offset the position of each final filling ring portion 4a in one axial direction. 1 and Short Feather 3 2 The long blades are arranged alternately in the circumferential direction. 1 and Short Feather 3 2 and are arranged alternately in the circumferential direction, or 1 and Short Feather 3 2 Alternatively, a plurality of pieces of one type and one piece of the other may be arranged alternately in the circumferential direction. [Explanation of symbols]

[0021] 1...Main plate, 2...Shroud, 3 1 ...Long feather, 3 2 ...short blade, 4...reinforcement ring, 4a...final filling ring part, 5...gate trace, 6...weight part.

Claims

1. a main plate connected to a rotating shaft; an annular shroud spaced apart from the main plate in one axial direction and having an inner diameter equal to or larger than the outer diameter of the main plate; a plurality of vanes provided at intervals in the circumferential direction so as to protrude in the other axial direction from a side surface of the shroud facing the other axial direction, the vanes protruding radially outward beyond an outer circumferential edge of the shroud; and a reinforcing ring extending annularly across and between radially outer ends of the side edges in the other axial direction of the vanes, wherein the main plate, the shroud, the vanes, and the reinforcing ring are integrally molded, As the blades, a long blade is provided in which a side edge on the other axial direction of a portion close to a radial inner end is joined to a surface of the main plate facing one axial direction, and a short blade is provided in which a radial inner end is located radially outward from an outer circumferential edge of the main plate, In a case where the trace of the gate through which resin is injected during molding is provided only on the main plate, An impeller characterized in that the axial thickness of a final filled ring portion, which is the portion among multiple circumferential portions of a reinforcing ring located between circumferentially adjacent blades that is the last to be filled with resin during molding, is greater than that of other ring portions.

2. a main plate connected to a rotating shaft; an annular shroud spaced apart from the main plate in one axial direction and having an inner diameter equal to or larger than the outer diameter of the main plate; a plurality of vanes provided at intervals in the circumferential direction so as to protrude in the other axial direction from a side surface of the shroud facing the other axial direction, the vanes protruding radially outward beyond an outer circumferential edge of the shroud; and a reinforcing ring extending annularly across and between radially outer ends of the side edges in the other axial direction of the vanes, wherein the main plate, the shroud, the vanes, and the reinforcing ring are integrally molded, As the blades, a long blade is provided in which a side edge on the other axial direction of a portion close to a radial inner end is joined to a surface of the main plate facing one axial direction, and a short blade is provided in which a radial inner end is located radially outward from an outer circumferential edge of the main plate, In a case where the trace of the gate through which resin is injected during molding is provided only on the main plate, This impeller is characterized in that, among multiple circumferential portions of a reinforcing ring located between circumferentially adjacent blades, a final filled ring portion, which is the portion to be filled with resin last during molding, is offset in one axial direction from other ring portions.

3. 2. The impeller according to claim 1, wherein a weight portion for ensuring dynamic balance is integrally formed with a portion of the shroud or a portion of the blade located circumferentially opposite the final filling ring portion.

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