JP2013249778A

JP2013249778A - Impeller

Info

Publication number: JP2013249778A
Application number: JP2012125356A
Authority: JP
Inventors: Toru Goto; 透後藤; Koji Toyoda; 耕司豊田; Kazuma Iimi; 一真飯見; Toshizo Takahashi; 利造高橋
Original assignee: Kawamoto Pump Mfg Co Ltd
Current assignee: Kawamoto Pump Mfg Co Ltd
Priority date: 2012-05-31
Filing date: 2012-05-31
Publication date: 2013-12-12
Anticipated expiration: 2032-05-31
Also published as: JP6006987B2

Abstract

PROBLEM TO BE SOLVED: To provide an impeller capable of preventing deterioration in pump efficiency.SOLUTION: An impeller 1 includes: an impeller body 3 including a disk-like back shroud 11 and a plurality of blades 12 integrally formed on one main surface of the back shroud 11; an impeller cover 4 having an opening for sucking liquid at its center and covering the impeller body 3; an engaging part 13 provided in an end surface 12a facing the impeller cover 4 of the blades 12; and an engaged part 33 provided in the impeller cover 4 facing the engaging part 13, formed so that it can insert the blades 12 and can engage with the engaging part 13 and welded with the engaging part 13 after the engagement.

Description

本発明は、ポンプに用いられるインペラに関する。 The present invention relates to an impeller used for a pump.

現在、その二次側に水等の液体を供給するポンプに用いられるインペラとして、周方向に沿って複数枚配置されるとともに、軸心線に対して傾斜を有する羽根を、軸心方向に円板状の一対のシュラウドで挟み込む形状に一体成型されたものが知られている。 Currently, a plurality of impellers used in a pump for supplying a liquid such as water to the secondary side thereof are arranged along the circumferential direction, and blades that are inclined with respect to the axial center line are circular in the axial direction. What was integrally molded by the shape pinched | interposed with a pair of plate-shaped shrouds is known.

このようなインペラは、その製造方法として、羽根形状及びシュラウド形状の型として、主型及び中子を用いて一体成型する技術が知られている。このような一体成型によりインペラを形成すると、羽根が軸心方向に対して傾斜している部分があり、さらに羽根とシュラウドとが一体に形成されているため、中子は、軸心線方向には取り外せない。また、インペラは一体成型されている形状であるため、外周方向からであっても中子は取り出し難い。 As such an impeller, as a manufacturing method thereof, a technique of integrally molding using a main mold and a core as a blade-shaped mold and a shroud-shaped mold is known. When the impeller is formed by such integral molding, there is a portion where the blade is inclined with respect to the axial direction, and the blade and the shroud are integrally formed, so the core is in the axial direction. Cannot be removed. In addition, since the impeller has an integrally molded shape, it is difficult to take out the core even from the outer peripheral direction.

このような問題を解決するために、中子を水溶性の樹脂材により形成し、インペラ成型後に中子を水溶させることで、インペラから中子を除去する技術が知られている。また、インペラの製造方法として、インペラ内の流路を形成する型をスライドさせることで成型する技術が知られている。 In order to solve such a problem, a technique is known in which a core is formed from a water-soluble resin material, and the core is removed from the impeller by making the core water-soluble after impeller molding. In addition, as an impeller manufacturing method, a technique is known in which molding is performed by sliding a mold that forms a flow path in the impeller.

また、表シュラウド及び複数の羽根が形成された裏シュラウドを別々に成型するとともに、表シュラウド及び裏シュラウドを機械的に固定する技術も知られている。この機械的にシュラウドを固定する方法としては、表シュラウド及び裏シュラウドにねじを形成し、互いに締結する技術や、ボルト等により表シュラウド及び裏シュラウドを締結する構成等が知られている。 A technique is also known in which a front shroud and a back shroud formed with a plurality of blades are separately molded, and the front shroud and the back shroud are mechanically fixed. As a method for mechanically fixing the shroud, there are known a technique in which screws are formed on the front shroud and the back shroud and fastened to each other, a structure in which the front shroud and the back shroud are fastened by bolts or the like.

さらに、インペラの製造方法として、合成樹脂を射出成型により形成した表シュラウド及び裏シュラウドの羽根を溶着することで、表シュラウド及び裏シュラウドを固定する技術も知られている。（例えば特許文献１参照）。 Furthermore, as a method for manufacturing an impeller, a technique is also known in which a front shroud and a back shroud are fixed by welding a front shroud formed by injection molding of a synthetic resin and a blade of the back shroud. (For example, refer to Patent Document 1).

特開２００８−３０３７４０号公報JP 2008-303740 A

上述したようなインペラでは、次のような問題があった。即ち、中子に水溶性の樹脂材料を用いたインペラの製造方法では、中子をインペラの製造毎に水溶させて除去する必要がある。また、中子は、一度水溶させると再利用することができない。このように、中子に水溶性の樹脂材料を用いたインペラの製造方法では、中子の製造コストが高くなる。 The impeller as described above has the following problems. That is, in the impeller manufacturing method using a water-soluble resin material for the core, it is necessary to remove the core by making it water-soluble every time the impeller is manufactured. In addition, the core cannot be reused once it is dissolved in water. Thus, in the impeller manufacturing method using a water-soluble resin material for the core, the manufacturing cost of the core increases.

また、流路を形成する型をスライドさせるインペラの製造方法では、成型可能な流路の形状が限定される。 Moreover, in the manufacturing method of the impeller which slides the type | mold which forms a flow path, the shape of the flow path which can be shape | molded is limited.

さらに、表シュラウド及び裏シュラウドを別体とするインペラの製造方法では、機械的に接続すると、インペラ内部にて、シュラウド及び羽根により形成される一の流路から他の流路への漏れが発生する虞がある。インペラは、その内部に漏れが発生すると、ポンプ効率が低下する、という問題がある。 Furthermore, in the impeller manufacturing method in which the front shroud and the back shroud are separated, when mechanically connected, leakage from one flow path formed by the shroud and the blades to the other flow path occurs inside the impeller. There is a risk of doing. The impeller has a problem that the pump efficiency decreases when a leak occurs in the impeller.

例えば、表シュラウドを羽根に溶着により接続すると、当該溶着部が密着することから、インペラ内部での漏れを防止することが可能となる。しかし、羽根は、インペラの中心側から外周側に向かって傾斜するとともに、インペラの中心側でその傾斜角度が大きくなる構成である。 For example, when the front shroud is connected to the blade by welding, the welded portion comes into close contact with each other, so that leakage inside the impeller can be prevented. However, the blades are inclined from the center side of the impeller toward the outer peripheral side, and the inclination angle is increased on the center side of the impeller.

このため、表シュラウド及び羽根を溶着すると、インペラの中心側の溶着が難しく、インペラ中心側において、インペラ内部での漏れの発生となる未溶着部及び溶着不足の発生や、溶着時に樹脂の一部が流路上に流れる虞がある。この未溶着部は、インペラ内部での漏れの要因となる。また、流路上に樹脂が流れ、当該樹脂が硬化すると、流路上の液体の流れの障害となり、ポンプ効率が低下する虞がある。 For this reason, if the front shroud and blades are welded, it is difficult to weld the center side of the impeller, and on the impeller center side, unwelded portions that cause leakage inside the impeller, occurrence of insufficient welding, and part of the resin during welding May flow on the flow path. This unwelded portion becomes a cause of leakage inside the impeller. Further, when the resin flows on the flow path and the resin is cured, the liquid flow on the flow path may be obstructed, and the pump efficiency may be reduced.

そこで本発明は、ポンプ効率の低下を防止可能なインペラを提供することを目的としている。 Accordingly, an object of the present invention is to provide an impeller capable of preventing a reduction in pump efficiency.

前記課題を解決し目的を達成するために、本発明のインペラは、次のように構成されている。 In order to solve the above problems and achieve the object, the impeller of the present invention is configured as follows.

本発明の一態様として、円板状の裏シュラウド、及び、前記裏シュラウドの一方の主面に一体に形成された複数の羽根を具備するインペラ本体と、その中心に液体を吸い込む開口を有し、前記インペラ本体を覆うインペラカバーと、前記羽根の前記インペラカバーと対向する端面に設けられた係合部と、前記インペラカバーに前記係合部と対向して設けられ、前記羽根を挿入可能、且つ、前記係合部と係合可能に形成され、前記係合部と係合後に溶着される被係合部と、を備える。 As one aspect of the present invention, a disk-shaped back shroud, an impeller body including a plurality of blades integrally formed on one main surface of the back shroud, and an opening for sucking liquid at the center thereof , An impeller cover that covers the impeller body, an engagement portion provided on an end surface of the blade facing the impeller cover, and provided on the impeller cover facing the engagement portion so that the blade can be inserted. And an engaged portion that is formed so as to be engageable with the engaging portion and is welded after engaging with the engaging portion.

本発明によれば、ポンプ効率の低下を防止可能なインペラを提供することが可能となる。 ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to provide the impeller which can prevent the fall of pump efficiency.

本発明の一実施形態に係るインペラの構成を示す平面図。The top view which shows the structure of the impeller which concerns on one Embodiment of this invention. 同インペラの構成を分解して示す断面図。Sectional drawing which decomposes | disassembles and shows the structure of the impeller. 同インペラの要部構成を分解して模式的に示す断面図。Sectional drawing which decomposes | disassembles and shows typically the principal part structure of the impeller. 同インペラの要部構成を分解して模式的に示す断面図。Sectional drawing which decomposes | disassembles and shows typically the principal part structure of the impeller. 同インペラに用いられるインペラ本体部の構成を示す平面図。The top view which shows the structure of the impeller main-body part used for the impeller. 同インペラに用いられるインペラカバーの構成を示す平面図。The top view which shows the structure of the impeller cover used for the impeller. 同インペラに用いられるインペラカバーの構成を示す平面図。The top view which shows the structure of the impeller cover used for the impeller.

以下、本発明の一実施の形態に係るインペラ１を、図１乃至図７を用いて説明する。
図１は本発明の一実施形態に係るインペラ１の構成を示す平面図、図２はインペラ１の構成を分解して示す断面図、図３は図２中ＩＩＩ−ＩＩＩ断面であって、インペラ１の要部構成を分解して模式的に示す断面図、図４は図２中ＩＶ−ＩＶ断面であって、インペラ１の要部構成を分解して模式的に示す断面図、図５はインペラ１に用いられるインペラ本体部３の構成を示す平面図、図６はインペラ１に用いられるインペラカバー４の構成を示す平面図、図７はインペラ１に用いられるインペラカバー４の構成を示す平面図である。 Hereinafter, an impeller 1 according to an embodiment of the present invention will be described with reference to FIGS. 1 to 7.
1 is a plan view showing a configuration of an impeller 1 according to an embodiment of the present invention, FIG. 2 is an exploded cross-sectional view showing the configuration of the impeller 1, and FIG. 3 is a cross-sectional view taken along the line III-III in FIG. FIG. 4 is a cross-sectional view schematically showing an essential part configuration of 1, FIG. 4 is a cross-sectional view taken along the line IV-IV in FIG. 2, and a cross-sectional view schematically showing an essential part configuration of the impeller 1, FIG. FIG. 6 is a plan view showing the configuration of the impeller cover 4 used for the impeller 1, and FIG. 7 is a plan view showing the configuration of the impeller cover 4 used for the impeller 1. FIG.

図１及び図２に示すように、インペラ１は、樹脂材料で形成されたインペラ本体３と、樹脂材料で形成されたインペラカバー４と、を備えている。インペラ１は、インペラ本体３及びインペラカバー４が別体に形成されるとともに、溶着部５において溶着されることで、一体に形成される。 As shown in FIGS. 1 and 2, the impeller 1 includes an impeller body 3 formed of a resin material and an impeller cover 4 formed of a resin material. The impeller 1 is integrally formed by the impeller body 3 and the impeller cover 4 being formed separately and being welded at the weld portion 5.

このようなインペラ１は、その外周側に吐出口が、インペラカバー４の中心部に吸込口が形成される。インペラ１は、ポンプに用いられる。例えば、インペラ１は、ポンプのポンプケーシング内に配置されるとともに、モータに接続された回転軸に固定される。このようなインペラ１は、回転軸がモータにより回転することで、その吸込口から水等の液体を吸込むとともに、その内部を通過する水を増圧して吐出口から吐出することで、二次側へ圧送することが可能に形成されている。 Such an impeller 1 has a discharge port on the outer peripheral side and a suction port in the center of the impeller cover 4. The impeller 1 is used for a pump. For example, the impeller 1 is disposed in a pump casing of a pump and is fixed to a rotating shaft connected to a motor. Such an impeller 1 has a rotating shaft that is rotated by a motor so as to suck in liquid such as water from the suction port and increase the pressure of water passing through the suction port and discharge it from the discharge port. It is formed so that it can be pumped to.

インペラ本体３は、裏シュラウド１１と、裏シュラウド１１の一方の主面に設けられ、複数、例えば５枚が一定間隔で配置された羽根１２と、これら羽根１２のインペラカバー４と対向する端面１２ａにそれぞれ設けられた係合部１３と、を備えている。インペラ本体３は、裏シュラウド１１、羽根１２及び係合部１３が、射出成型により、一体に形成されている。 The impeller body 3 is provided on the back shroud 11 and one main surface of the back shroud 11, and a plurality of, for example, five blades 12 arranged at regular intervals, and an end surface 12a of the blades 12 facing the impeller cover 4. And engaging portions 13 provided respectively. In the impeller body 3, a back shroud 11, a blade 12 and an engaging portion 13 are integrally formed by injection molding.

裏シュラウド１１は、円板状に形成されたベース部１４と、ベース部１４の一方の主面の中央に形成され、その先端に向かって漸次縮径するとともに、その中心が開口する、略円錐台形状の突起部１５と、突起部１５の内周面に嵌合されたインサート１６と、を備えている。 The back shroud 11 is formed in the center of one base surface of the base part 14 formed in a disk shape and one of the base parts 14, gradually reducing its diameter toward the tip, and having a substantially conical opening. A trapezoidal protrusion 15 and an insert 16 fitted to the inner peripheral surface of the protrusion 15 are provided.

インサート１６は、金属材料により形成されている。インサート１６は、その中心に孔部１７が形成されている。孔部１７は、ポンプの回転軸を挿入可能に形成されている。 The insert 16 is made of a metal material. The insert 16 has a hole 17 formed at the center thereof. The hole 17 is formed so that the rotation shaft of the pump can be inserted.

羽根１２は、裏シュラウド１１の一方の主面に等間隔に複数（５枚）配置される。羽根１２は、裏シュラウド１１の外周縁及び裏シュラウド１１の中心側に渡って、円弧状に湾曲して延設される。 Plural (five) blades 12 are arranged on one main surface of the back shroud 11 at equal intervals. The blades 12 are curved and extended in an arc shape over the outer peripheral edge of the back shroud 11 and the center side of the back shroud 11.

羽根１２は、裏シュラウド１１の外周側から中心側に向かってその高さが前記高くなるように傾斜して形成されている。羽根１２は、裏シュラウド１１の中心側に位置する端部が、他部よりも傾斜角度が大きく形成される。また、羽根１２は、その厚みが略同一又は中心側から外周側につれて漸次厚くなるように形成されている。 The blades 12 are formed to be inclined so that the height increases from the outer peripheral side of the back shroud 11 toward the center side. The blade 12 is formed such that the end portion located on the center side of the back shroud 11 has a larger inclination angle than the other portions. Further, the blades 12 are formed so that the thickness thereof is substantially the same or gradually increases from the center side toward the outer peripheral side.

図２乃至図４に示すように、係合部１３は、羽根１２の端面１２ａに形成された第１係合部２１、第２係合部２２及び第３係合部２３を備えている。係合部１３は、第１係合部２２、第２、第２係合部２２及び第３係合部２３が、後述する被係合部３３と係合可能に形成されるとともに、被係合部３３と溶着することで、溶着部５を構成する。 As shown in FIGS. 2 to 4, the engaging portion 13 includes a first engaging portion 21, a second engaging portion 22, and a third engaging portion 23 formed on the end surface 12 a of the blade 12. The engaging portion 13 is formed so that the first engaging portion 22, the second, second engaging portion 22, and the third engaging portion 23 can be engaged with an engaged portion 33 described later. The welded portion 5 is formed by welding with the joint portion 33.

図２、図３及び図５に示すように、第１係合部２１は、羽根１２の端面１２ａに設けられ、羽根１２の両端部側間であって、羽根１２の延設方向の略中心に沿って延設された溝部である。図３に示すように、第１係合部２１は、その長手方向に直交する方向の断面視で円弧状に形成されている。換言すると、第１係合部２１は、湾曲する半円柱状に形成された溝部である。 As shown in FIGS. 2, 3, and 5, the first engagement portion 21 is provided on the end surface 12 a of the blade 12, between both end portions of the blade 12, and approximately at the center in the extending direction of the blade 12. It is the groove part extended along. As shown in FIG. 3, the first engagement portion 21 is formed in an arc shape in a sectional view in a direction orthogonal to the longitudinal direction. In other words, the first engaging portion 21 is a groove portion formed in a curved semi-cylindrical shape.

図２、図４及び図５に示すように、第２係合部２２は、羽根１２の端面１２ａに設けられ、羽根１２の一方の端部側、具体的には、裏シュラウド１１の中心側に位置する羽根１２の端部側に、羽根１２の延設方向の略中心に沿って延設された湾曲する方体状の溝部である。第２係合部２２は、第１係合部２１よりもその深さが深く形成されている。 As shown in FIGS. 2, 4, and 5, the second engagement portion 22 is provided on the end surface 12 a of the blade 12, and is one end side of the blade 12, specifically, the center side of the back shroud 11. A curved rectangular groove extending along the approximate center of the extending direction of the blade 12 on the end portion side of the blade 12 positioned at the center. The second engaging portion 22 is formed deeper than the first engaging portion 21.

第２係合部２２は、裏シュラウド１１の中心側の端部の内面が円弧状に形成されるとともに、裏シュラウド１１の外周側の端部の内面が、羽根１２の延設方向の中心に対して傾斜する平面状に形成されている。また、第２係合部２２は、図４に示すように、その側面と下面との稜部が曲面状に面取りされて形成されている。 The second engaging portion 22 has an inner surface of the end portion on the center side of the back shroud 11 formed in an arc shape, and an inner surface of the end portion on the outer peripheral side of the back shroud 11 is in the center in the extending direction of the blades 12. It is formed in a flat shape that is inclined with respect to it. Moreover, as shown in FIG. 4, the 2nd engaging part 22 is formed by chamfering the ridge part of the side surface and a lower surface in the shape of a curved surface.

図２及び図５に示すように、第３係合部２３は、羽根１２の端面１２ａに設けられ、羽根１２の中央側であって、羽根１２の延設方向の略中心に沿って等間隔に複数、本実施形態においては３つ配置された円柱状の突起である。 As shown in FIGS. 2 and 5, the third engaging portion 23 is provided on the end surface 12 a of the blade 12, and is equidistant along the center side of the blade 12 and substantially along the extending direction of the blade 12. In addition, a plurality of cylindrical protrusions are arranged in the present embodiment.

インペラカバー４は、表シュラウド３１と、表シュラウド３１の一方の主面、具体的にはインペラ本体３と対向する主面に設けられた被係合部３３と、を備えている。インペラカバー４は、表シュラウド３１及び被係合部３３が射出成型により一体に形成されている。 The impeller cover 4 includes a front shroud 31 and an engaged portion 33 provided on one main surface of the front shroud 31, specifically, a main surface facing the impeller body 3. In the impeller cover 4, the front shroud 31 and the engaged portion 33 are integrally formed by injection molding.

表シュラウド３１は、円板状に形成されたベース部３４と、ベース部３４の他方の主面の中央に形成され、その中心が開口する円筒状の突起部３５と、を備えている。表シュラウド３１は、その一方の主面が、外周側から中心側に向かって、対向する裏シュラウド１１から離間する方向に漸次傾斜して形成されている。突起部３５は、その開口がインペラ１の吸込口を構成する。 The front shroud 31 includes a base portion 34 formed in a disc shape, and a cylindrical projection portion 35 formed at the center of the other main surface of the base portion 34 and having an open center. The front shroud 31 is formed such that one main surface thereof is gradually inclined in a direction away from the opposite back shroud 11 from the outer peripheral side toward the center side. The opening of the protrusion 35 constitutes the suction port of the impeller 1.

図２乃至図４、図６及び図７に示すように、被係合部３３は、表シュラウド３１の一方の主面に形成された、案内部４０、第１被係合部４１、第２被係合部４２及び第３被係合部４３を備えている。被係合部３３は、案内部４０が羽根１２と係合可能、且つ、第１被係合部４１、第２被係合部４２及び第３被係合部４３が第１係合部２２、第２、第２係合部２２及び第３係合部２３と係合可能に形成される。また、被係合部３３は、係合部１３と溶着することで、溶着部５を構成する。 As shown in FIGS. 2 to 4, 6, and 7, the engaged portion 33 is formed on one main surface of the front shroud 31, the guide portion 40, the first engaged portion 41, and the second engaged portion. An engaged portion 42 and a third engaged portion 43 are provided. In the engaged portion 33, the guide portion 40 can engage with the blade 12, and the first engaged portion 41, the second engaged portion 42, and the third engaged portion 43 are in the first engaging portion 22. The second engagement portion 22 and the third engagement portion 23 are formed to be engageable with each other. Further, the engaged portion 33 constitutes the welded portion 5 by welding with the engaging portion 13.

図２乃至図４及び図６に示すように、案内部４０は、表シュラウド３１の一方の主面に形成された羽根１２の端面１２ａと略同一形状の溝部である。図３及び図４に示すように、案内部４０は、その幅が、羽根１２と所定の隙間を形成可能に、羽根１２の幅よりも若干長く形成されている。案内部４０は、ベース部３４の一方の主面であって、突起部３５の下方が、他部よりも傾斜角度が大きく形成される。 As shown in FIGS. 2 to 4 and 6, the guide portion 40 is a groove portion having substantially the same shape as the end surface 12 a of the blade 12 formed on one main surface of the front shroud 31. As shown in FIGS. 3 and 4, the width of the guide portion 40 is slightly longer than the width of the blade 12 so that a predetermined gap can be formed with the blade 12. The guide portion 40 is one main surface of the base portion 34, and the lower portion of the projection portion 35 is formed with a larger inclination angle than the other portions.

なお、羽根１２及び案内部４０により形成される所定の隙間は、羽根１２及び案内部４０の延設方向に対して直交する方向に形成される隙間である。この所定の隙間は、溶融した第１被係合部４１、第２被係合部４２及び第３係合部２３のうち、第１係合部２１、第２係合部２２及び第３被係合部４３から移動した第１被係合部４１、第２被係合部４２及び第３係合部２３を配置可能な容積に形成される。 Note that the predetermined gap formed by the blade 12 and the guide portion 40 is a gap formed in a direction orthogonal to the extending direction of the blade 12 and the guide portion 40. The predetermined gap is the first engaged portion 21, the second engaged portion 22, and the third engaged portion of the melted first engaged portion 41, second engaged portion 42, and third engaged portion 23. The first engaged portion 41, the second engaged portion 42, and the third engaged portion 23 that have moved from the engaging portion 43 are formed in a volume that can be arranged.

図２、図３及び図６に示すように、第１被係合部４１は、表シュラウド３１の一方の主面であって、且つ、案内部４０の主面、換言すると、案内部４０の羽根１２の端面１２ａと対向する面に形成され第１係合部２１の形状に沿って延設された突起部である。第１被係合部４１は、案内部４０の延設方向の略中心に沿って延設される。図３に示すように、第１被係合部４１は、その長手方向に直交する方向の断面視でその先端が円弧状に形成されている。 As shown in FIGS. 2, 3 and 6, the first engaged portion 41 is one main surface of the front shroud 31 and the main surface of the guide portion 40, in other words, the guide portion 40. It is a projection formed on the surface facing the end surface 12 a of the blade 12 and extending along the shape of the first engagement portion 21. The first engaged portion 41 is extended along substantially the center in the extending direction of the guide portion 40. As shown in FIG. 3, the tip of the first engaged portion 41 is formed in an arc shape in a sectional view in a direction orthogonal to the longitudinal direction.

図３に示すように、第１被係合部４１は、その幅が、第１係合部２１の幅よりも小さく形成されている。また、図３に示すように、第１被係合部４１は、その案内部４０の主面からの高さが、第１係合部２１の羽根１２の端面１２ａからの深さよりも長く形成されている。さらに、図３に示すように、第１被係合部４１は、その体積が、第１係合部２１の容積よりも大きく形成されている。 As shown in FIG. 3, the first engaged portion 41 is formed with a width smaller than that of the first engaging portion 21. As shown in FIG. 3, the first engaged portion 41 is formed such that the height from the main surface of the guide portion 40 is longer than the depth from the end surface 12 a of the blade 12 of the first engaging portion 21. Has been. Furthermore, as shown in FIG. 3, the volume of the first engaged portion 41 is larger than the volume of the first engaging portion 21.

図２、図４及び図６に示すように、第２被係合部４２は、表シュラウド３１の一方の主面であって、且つ、案内部４０の主面に形成され、第２係合部２１の形状に沿って延設される。第２被係合部４２は、案内部４０の延設方向の略中心に沿って延設される。 As shown in FIGS. 2, 4, and 6, the second engaged portion 42 is formed on one main surface of the front shroud 31 and the main surface of the guide portion 40, and the second engaging portion 42 It extends along the shape of the portion 21. The second engaged portion 42 extends along substantially the center in the extending direction of the guide portion 40.

また、第２被係合部４２は、案内部４０の表シュラウド３１の中心側から外周側に向かって漸次高さが低くなる形状に形成された方体状の突起である。具体的には、第２被係合部４２は、その第２係合部２２と対向する面が、インペラ１の軸心方向と直交する方向に延設されて形成される。 The second engaged portion 42 is a cuboid protrusion formed in a shape in which the height gradually decreases from the center side of the front shroud 31 of the guide portion 40 toward the outer peripheral side. Specifically, the second engaged portion 42 is formed such that a surface facing the second engaging portion 22 extends in a direction orthogonal to the axial direction of the impeller 1.

図４に示すように、第２被係合部４２は、その幅が、第２係合部２２の幅よりも小さく形成されている。図４に示すように、第２被係合部４２は、その第２係合部２２と対向する主面及びその側面の稜部が、断面視で直角状に形成されている。第２被係合部４２は、第２係合部２２の側面及び下面の曲面状の稜部に線で、さらに言えば、その長手方向に直交する方向の断面視で点により接触可能に形成されている。 As shown in FIG. 4, the second engaged portion 42 has a width smaller than that of the second engaging portion 22. As shown in FIG. 4, the second engaged portion 42 has a main surface facing the second engaging portion 22 and a ridge portion on the side surface formed in a right angle shape in a cross-sectional view. The second engaged portion 42 is formed so that it can be contacted by a point in a cross-sectional view in a direction orthogonal to the longitudinal direction thereof, with a line on the curved ridges on the side surface and the lower surface of the second engaging portion 22. Has been.

この第２係合部２２との接触により、第２被係合部４２の稜部は、第２係合部２２の曲面状の稜部に当接することで変形可能、換言すると、第２係合部２２の稜部に当接することで、第２係合部２２の稜部の幅と同一幅につぶれることが可能に形成されている。第２被係合部２２は、第２係合部２２との接触による変形によって、第２係合部２２と嵌合可能に形成されている。 Due to the contact with the second engagement portion 22, the ridge portion of the second engaged portion 42 can be deformed by contacting the curved ridge portion of the second engagement portion 22, in other words, the second engagement portion 22. By abutting on the ridge portion of the joint portion 22, it is formed so as to be crushed to the same width as the width of the ridge portion of the second engagement portion 22. The second engaged portion 22 is formed to be able to be fitted to the second engaging portion 22 by deformation due to contact with the second engaging portion 22.

また、図４に示すように、第２被係合部４２は、その案内部４０の主面からの高さが、第２係合部２２の羽根１２の端面１２ａからの深さよりも短く形成されている。さらに、図４に示すように、第２被係合部４２は、その体積が、第２係合部２２の容積よりも小さく形成されている。 As shown in FIG. 4, the second engaged portion 42 is formed such that the height from the main surface of the guide portion 40 is shorter than the depth from the end surface 12 a of the blade 12 of the second engaging portion 22. Has been. Furthermore, as shown in FIG. 4, the second engaged portion 42 is formed so that the volume thereof is smaller than the volume of the second engaging portion 22.

また、第２被係合部４２は、第２係合部２２と形成される幅方向の隙間が、第１係合部２１及び第１被係合部４１による幅方向の隙間よりも小さく形成される。換言すると、第２係合部２２及び第２被係合部４２は、第１係合部２１及び第１被係合部４１よりも、そのクリアランスが小さく形成されている。 Further, the second engaged portion 42 is formed such that the widthwise gap formed with the second engaging portion 22 is smaller than the widthwise gap between the first engaging portion 21 and the first engaged portion 41. Is done. In other words, the clearance between the second engaging portion 22 and the second engaged portion 42 is smaller than that of the first engaging portion 21 and the first engaged portion 41.

図２、図６及び図７に示すように、第３被係合部４３は、表シュラウド３１であって、且つ、案内部４０の主面に形成され、第３係合部２３の形状に沿って形成された円筒状の開口である。第３被係合部４３は、表シュラウド３１が、裏シュラウド１１に組み合わされた際に、第３係合部２３と対向する位置、具体的には、案内部４０の中心側であって、案内部４０の延設方向の略中心に沿って等間隔に複数、本実施形態においては３つ配置される。 As shown in FIGS. 2, 6, and 7, the third engaged portion 43 is the front shroud 31 and is formed on the main surface of the guide portion 40, and has the shape of the third engaging portion 23. It is a cylindrical opening formed along. The third engaged portion 43 is a position facing the third engaging portion 23 when the front shroud 31 is combined with the back shroud 11, specifically, the center side of the guide portion 40, A plurality, three in this embodiment, are arranged at equal intervals along the approximate center of the extending direction of the guide portion 40.

図２、図６及び図７に示すように、第３係合部２３は、表シュラウド３１の一方の主面から他方の主面に向かって、２つの異なる内径の円筒状の開口により形成される。 As shown in FIGS. 2, 6, and 7, the third engaging portion 23 is formed by a cylindrical opening having two different inner diameters from one main surface of the front shroud 31 toward the other main surface. The

具体的には、第３係合部２３は、表シュラウド３１の一方の主面側、且つ、案内部４０の主面側に形成された第１開口部４６と、表シュラウド３１の他方の主面側、且つ、ベース部３４の他方の主面に形成され、第１開口部４６と連続して形成された第２開口部４７と、を備えている。 Specifically, the third engagement portion 23 includes a first opening 46 formed on one main surface side of the front shroud 31 and the main surface side of the guide portion 40, and the other main surface of the front shroud 31. And a second opening 47 formed on the surface side and on the other main surface of the base portion 34 and formed continuously with the first opening 46.

第３被係合部４３は、第１開口部４６及び第２開口部４７の容積が、第３係合部２３の体積と略同一、又は、大きく形成されている。第１開口部４６は、その内径が、第２開口部４７の内径よりも小径に形成されている。第１開口部４６は、その内径が、第３係合部２３の外径よりも大径に形成され、第３係合部２３を挿入可能に形成されている。また、第１開口部４６は、その容積が、第１係合部２３の体積よりも小さく形成されている。 The third engaged portion 43 is formed such that the volumes of the first opening 46 and the second opening 47 are substantially the same as or larger than the volume of the third engaging portion 23. The first opening 46 has an inner diameter smaller than the inner diameter of the second opening 47. The first opening 46 is formed so that the inner diameter thereof is larger than the outer diameter of the third engagement portion 23 so that the third engagement portion 23 can be inserted. Further, the volume of the first opening 46 is smaller than the volume of the first engaging portion 23.

このように構成されたインペラ１は、インペラ本体３及びインペラカバー４を組み合わせ、係合部１３及び被係合部３３を係合させて溶着させることで形成される。具体的には、先ず、インペラ本体３及びインペラカバー４を対向させるとともに、各羽根１２の端面１２ａを案内部４０内にそれぞれ配置させて係合させる。 The impeller 1 configured as described above is formed by combining the impeller body 3 and the impeller cover 4, and engaging and welding the engaging portion 13 and the engaged portion 33. Specifically, first, the impeller body 3 and the impeller cover 4 are made to face each other, and the end surfaces 12a of the blades 12 are arranged in the guide portions 40 and engaged with each other.

また、第１係合部２１及び第１被係合部４１、第２係合部２２及び第２被係合部４２、並びに、第３係合部２３及び第３被係合部４３をそれぞれ係合させる。これらの係合により、インペラ本体３及びインペラカバー４は、羽根１２の端面１２ａと、案内部４０の主面とが、若干離間した状態で一体に組み合わせる。 Further, the first engaging portion 21 and the first engaged portion 41, the second engaging portion 22 and the second engaged portion 42, and the third engaging portion 23 and the third engaged portion 43 are respectively provided. Engage. By these engagements, the impeller body 3 and the impeller cover 4 are combined together with the end surface 12a of the blade 12 and the main surface of the guide portion 40 being slightly separated.

この状態で、係合部１３及び被係合部３３を溶融し、固着させる。具体的には、係合部１３及び被係合部３３を、超音波加熱により加熱させる。この加熱により、第１被係合部４１が溶融し、当該溶融した第１被係合部４１が第１係合部２１に移動し、第１係合部２２を充填する。同加熱により、第２被係合部４２が溶融し、当該溶融した第２被係合部４２が第２係合部２２に移動し、第２係合部２２を充填する。同加熱により、第３係合部２３が溶融し、当該溶融した第３係合部２３が第３被係合部４３に移動し、第３被係合部４３を充填する。 In this state, the engaging portion 13 and the engaged portion 33 are melted and fixed. Specifically, the engaging part 13 and the engaged part 33 are heated by ultrasonic heating. By this heating, the first engaged portion 41 is melted, and the melted first engaged portion 41 moves to the first engaging portion 21 and fills the first engaging portion 22. Due to the heating, the second engaged portion 42 is melted, and the melted second engaged portion 42 moves to the second engaging portion 22 to fill the second engaging portion 22. By the same heating, the third engaging portion 23 is melted, and the melted third engaging portion 23 moves to the third engaged portion 43 and fills the third engaged portion 43.

また、第１係合部２１及び第２係合部２２が溶融することで、羽根１２の端面１２ａ及び案内部４０の主面が当接する。また、第１係合部２１は、その体積が、第１被係合部４１の容積よりも大きく形成されていることから、溶融した第１係合部２１の一部は、羽根１２の端面１２ａ及び案内部４０の主面間、及び、羽根１２の側面及び案内部４０の側面間に移動する。 Moreover, the end surface 12a of the blade | wing 12 and the main surface of the guide part 40 contact | abut because the 1st engaging part 21 and the 2nd engaging part 22 fuse | melt. Further, since the volume of the first engaging portion 21 is larger than the volume of the first engaged portion 41, a part of the melted first engaging portion 21 is the end face of the blade 12. It moves between the main surfaces of 12a and the guide part 40, and between the side surface of the blade 12 and the side surface of the guide part 40.

また、第３係合部２３は、その体積が、第３被係合部４３の容積と同一又は小さく形成されていることから、溶融した第３係合部２３が、第３被係合部４３内に移動し、第３被係合部４３を充填することとなる。具体的には、第３被係合部４３は、二つの異なる内径の第１開口部４６及び第２開口部４７を有する構成であり、第１開口部４６の容積が、第３係合部２３の体積よりも小さく形成されている。このため、溶融した第３係合部２３は、第１開口部４６に充填されるとともに、第２開口部４７の全部又は少なくとも一部に充填される。これにより、溶融した第３係合部２３は、その一部が、第２開口部４７の主面と当接する。 Further, since the volume of the third engaging portion 23 is the same as or smaller than the volume of the third engaged portion 43, the melted third engaging portion 23 becomes the third engaged portion. 43, and the third engaged portion 43 is filled. Specifically, the third engaged portion 43 includes a first opening 46 and a second opening 47 having two different inner diameters, and the volume of the first opening 46 is the third engaging portion. It is formed smaller than the volume of 23. For this reason, the melted third engagement portion 23 is filled in the first opening 46 and filled in all or at least a part of the second opening 47. Thereby, a part of the melted third engaging portion 23 comes into contact with the main surface of the second opening 47.

このように、係合部１３及び被係合部３３が溶着されることで、インペラ本体３及びインペラカバー４が一体に固定されたインペラ１が形成される。 Thus, the impeller 1 in which the impeller body 3 and the impeller cover 4 are integrally fixed is formed by welding the engaging portion 13 and the engaged portion 33.

このように構成されたインペラ１によれば、係合部１３及び被係合部３３を係合させて溶着させることで、インペラ本体３及びインペラカバー４を一体に固定することが可能となる。また、インペラ１は、羽根１２及び係合部１３と、被係合部３３とを係合させることで位置合わせが可能となり、インペラ本体３及びインペラカバー４の溶着時における位置精度を向上させることが可能となる。 According to the impeller 1 configured in this manner, the impeller body 3 and the impeller cover 4 can be integrally fixed by engaging and welding the engaging portion 13 and the engaged portion 33. Further, the impeller 1 can be aligned by engaging the blade 12 and the engaging portion 13 with the engaged portion 33, and the positional accuracy when the impeller body 3 and the impeller cover 4 are welded is improved. Is possible.

また、インペラ１は、第１係合部２１、第２係合部２２及び第３係合部２３、並びに、第１被係合部４１、第２被係合部４２及び第３被係合部４３が、それぞれ羽根１２及び案内部４０に沿って配置される。この構成により、係合部１３及び被係合部３３は、いずれかで溶融した第１被係合部４１、第２被係合部４２及び第３係合部２３が、第１係合部２１、第２係合部２２及び第３被係合部４３から移動したとしても、羽根１２及び案内部４０間に形成される隙間に移動する。 Further, the impeller 1 includes a first engaging portion 21, a second engaging portion 22, and a third engaging portion 23, as well as a first engaged portion 41, a second engaged portion 42, and a third engaged portion. The parts 43 are arranged along the blades 12 and the guide part 40, respectively. With this configuration, the engaging portion 13 and the engaged portion 33 are either the first engaged portion 41, the second engaged portion 42, or the third engaging portion 23 that is melted in any one of the first engaging portions. 21, even if moved from the second engaging portion 22 and the third engaged portion 43, it moves to the gap formed between the blade 12 and the guide portion 40.

特に、第１係合部２１、第２係合部２２及び第３係合部２３、並びに、第１被係合部４１、第２被係合部４２及び第３被係合部４３は、それぞれ羽根１２及び案内部４０の延設方向の略中心に配置されることから、溶融して移動した場合に、羽根１２及び案内部４０間に、当該延設方向の中心から均一に移動する。 In particular, the first engaging part 21, the second engaging part 22 and the third engaging part 23, and the first engaged part 41, the second engaged part 42 and the third engaged part 43 are: Since each of the blades 12 and the guide portion 40 is disposed at the approximate center in the extending direction, when the melted and moved, the blade 12 and the guide portion 40 move uniformly from the center in the extending direction.

このため、インペラ１は、羽根１２及び案内部４０間の隙間により、溶融した第１被係合部４１、第２被係合部４２及び第３係合部２３が、裏シュラウド１１、羽根１２及び表シュラウド３１により形成される液体の流路上に移動することを防止できる。これにより、インペラ１は、当該裏シュラウド１１、羽根１２及び表シュラウド３１により形成される流路上に移動することで、流路上の水の流れを阻害し、又は、流路抵抗となる障害物となることを防止可能となる。 For this reason, the impeller 1 has a melted first engaged portion 41, second engaged portion 42, and third engaging portion 23 due to a gap between the blade 12 and the guide portion 40. And it can prevent moving on the flow path of the liquid formed by the front shroud 31. Thereby, the impeller 1 moves on the flow path formed by the back shroud 11, the blades 12 and the front shroud 31, thereby obstructing the flow of water on the flow path or obstructing the flow path resistance. Can be prevented.

このように、インペラ１は、当該裏シュラウド１１、羽根１２及び表シュラウド３１により形成される流路上に、障害物が発生することを防止可能となり、ポンプ効率の低下を防止可能、且つ、インペラ本体３及びインペラカバー４の溶着後の修正作業である、流路上の障害物の除去作業が不要となる。 Thus, the impeller 1 can prevent the occurrence of an obstacle on the flow path formed by the back shroud 11, the blades 12 and the front shroud 31, can prevent the pump efficiency from being lowered, and the impeller body. 3 and the removal operation of the obstacle on the flow path, which is a correction operation after the impeller cover 4 is welded, becomes unnecessary.

また、第２係合部２２及び第２被係合部４２は、互いに嵌合可能な構成とすることで、第２係合部２２及び第２被係合部４２の溶着不足が発生しても、当該嵌合により、インペラ１の性能の低下を防止することが可能となる。 Further, the second engaging portion 22 and the second engaged portion 42 are configured to be fitted to each other, so that the second engaging portion 22 and the second engaged portion 42 are insufficiently welded. Moreover, it becomes possible to prevent the performance of the impeller 1 from being deteriorated by the fitting.

具体的に説明すると、第２係合部２２及び第２被係合部４２は、溶着だけでなく、第２係合部２２の曲面状に形成された稜部と、第２被係合部４２の稜部とが嵌合することにより係合させる構成であることから、強固にインペラ本体３及びインペラカバー４を固定することが可能となる。また、当該第２係合部２２及び第２被係合部４２は、嵌合による係合を行うことで、溶着時間を短縮することも可能となる。 Specifically, the second engaging portion 22 and the second engaged portion 42 are not only welded, but also a ridge portion formed in a curved shape of the second engaging portion 22 and the second engaged portion. Since it is the structure which engages by fitting with the ridge part of 42, it becomes possible to fix the impeller main body 3 and the impeller cover 4 firmly. Further, the second engaging portion 22 and the second engaged portion 42 can be shortened by performing engagement by fitting.

これらのように、インペラ１は、溶着後の修正作業の低減、及び、溶着時間の短縮により、製造コストを低減することも可能となる。 As described above, the impeller 1 can also reduce the manufacturing cost by reducing the correction work after welding and shortening the welding time.

さらに、第３係合部２３は、第３被係合部４３に溶着すると、その一部が第３被係合部４３の第２開口部４７の主面と係合することで、インペラ本体３及びインペラカバー４が離間する方向に力が印加されても、当該係合により、強固にインペラ本体３及びインペラカバー４を固定することが可能となる。 Further, when the third engaging portion 23 is welded to the third engaged portion 43, a part of the third engaging portion 23 engages with the main surface of the second opening 47 of the third engaged portion 43, so that the impeller body Even if a force is applied in a direction in which the 3 and the impeller cover 4 are separated, the impeller body 3 and the impeller cover 4 can be firmly fixed by the engagement.

上述したように、本発明の一実施の形態に係るインペラ１によれば、係合部１３及び被係合部３３を係合させてインペラ本体３及びインペラカバー４を溶着させることで、確実にインペラ本体３及びインペラカバー４を溶着し、ポンプ効率の低下を防止することが可能となる。 As described above, according to the impeller 1 according to the embodiment of the present invention, the impeller body 3 and the impeller cover 4 are welded by engaging the engaging portion 13 and the engaged portion 33, thereby reliably. It is possible to weld the impeller body 3 and the impeller cover 4 to prevent a decrease in pump efficiency.

なお、本発明は前記実施の形態に限定されるものではない。例えば、上述したインペラ１は、羽根１２の端面１２ａの中央側に３つの第３係合部２３を設ける構成を説明したがこれに限定されない。第３係合部２３は、１又は２つ設ける構成であってもよく、また、羽根１２の延設方向に沿って、等間隔に３以上設けられる構成であってもよく、設けられる位置は、羽根１２の中央側だけでなくてもよい。この他、本発明の要旨を逸脱しない範囲で種々変形実施可能である。 The present invention is not limited to the above embodiment. For example, although the above-described impeller 1 has been described with the configuration in which the three third engaging portions 23 are provided on the center side of the end surface 12a of the blade 12, the invention is not limited thereto. One or two third engagement portions 23 may be provided, or three or more may be provided at equal intervals along the extending direction of the blades 12. , Not only the center side of the blade 12. In addition, various modifications can be made without departing from the scope of the present invention.

１…インペラ、３…インペラ本体、４…インペラカバー、５…溶着部、１１…裏シュラウド、１２…羽根、１２ａ…端面、１３…係合部、１４…ベース部、１５…突起部、１６…インサート、１７…孔部、２１…第１係合部、２２…第２係合部、２３…第３係合部、３１…表シュラウド、３３…被係合部、３４…ベース部、３５…突起部、４０…案内部、４１…第１被係合部、４２…第２被係合部、４３…第３被係合部、４６…第１開口部、４７…第２開口部。 DESCRIPTION OF SYMBOLS 1 ... Impeller, 3 ... Impeller main body, 4 ... Impeller cover, 5 ... Welding part, 11 ... Back shroud, 12 ... Blade | wing, 12a ... End surface, 13 ... Engagement part, 14 ... Base part, 15 ... Protrusion part, 16 ... Insert, 17 ... hole, 21 ... first engaging portion, 22 ... second engaging portion, 23 ... third engaging portion, 31 ... front shroud, 33 ... engaged portion, 34 ... base portion, 35 ... Projection part, 40 ... guide part, 41 ... first engaged part, 42 ... second engaged part, 43 ... third engaged part, 46 ... first opening part, 47 ... second opening part.

Claims

A disc-shaped back shroud, and an impeller body including a plurality of blades integrally formed on one main surface of the back shroud;
An impeller cover having an opening for sucking liquid at the center thereof and covering the impeller body;
An engagement portion provided on an end surface of the blade facing the impeller cover;
An engaged portion that is provided on the impeller cover so as to face the engaging portion, can be inserted into the blade, can be engaged with the engaging portion, and is welded after engaging with the engaging portion. When,
An impeller characterized by comprising:

The engagement portion is a first engagement portion formed on the end surface of the blade along the extending direction of the blade, and a second engagement portion formed on the center side of the back shroud on the end surface of the blade. An engagement portion, and a plurality of third engagement portions formed to protrude from the end face of the blade,
The engaged portion is formed so as to be able to insert the blade, and is provided in the guide portion formed in a width capable of forming a predetermined gap with a side surface of the blade, the first engaging portion, A first engaged portion that engages, a second engaged portion that engages with the second engaging portion, and a third engaged portion that engages with the third engaging portion. The impeller according to claim 1.

The first engagement portion is a groove formed in the end surface of the blade along the extending direction of the blade,
The impeller according to claim 2, wherein the first engaged portion is a protrusion that is formed on the guide portion and can be disposed on the first engaging portion.

The first engaging portion is formed so that the width thereof is larger than the width of the first engaged portion, and the volume thereof is smaller than the volume of the first engaged portion. The impeller according to claim 3.

The predetermined gap includes the first engaged portion that has moved from the first engaged portion of the melted first engaged portion when the engaging portion and the engaged portion are welded. The impeller according to claim 4, wherein the impeller is formed in a displaceable volume.

The second engaging portion is a groove formed on the end surface of the blade along the extending direction of the blade,
The impeller according to claim 2, wherein the second engaged portion is a protrusion that is formed on the guide portion and can be disposed on the second engaging portion.

The second engaging portion has a width larger than that of the second engaged portion, and a volume larger than that of the second engaged portion. The impeller according to claim 6.

The second engaging portion has a width that is the same as or smaller than a width of the second engaged portion, and a volume that is larger than a volume of the second engaged portion, The impeller according to claim 6, wherein the impeller is formed so as to be able to fit into the engaged portion.

The second engaging portion has a ridge formed in a curved shape,
The impeller according to claim 8, wherein the second engaged portion is formed such that a ridge portion thereof can be fitted to the ridge portion of the second engagement portion.

The third engaging portion is a columnar protrusion provided on the end face of the blade,
The impeller according to claim 2, wherein the third engaged portion is an opening into which the third engaging portion can be inserted.

The third engaged portion is provided on the impeller cover, has an inner diameter larger than an outer diameter of the third engaging portion, and has a volume larger than a volume of the third engaging portion. And a second opening formed continuously with the first opening and having an inner diameter larger than that of the first opening. The impeller according to claim 10.

The first engagement portion is a groove formed in the end surface of the blade along the extending direction of the blade,
The first engaged portion is a protrusion that is formed on the guide portion and can be disposed on the first engaging portion.
The second engaging portion is a groove formed on the end surface of the blade along the extending direction of the blade,
The second engaged portion is a protrusion that is formed on the guide portion and can be disposed on the second engaging portion.
The third engaging portion is a columnar protrusion provided on the end face of the blade,
The impeller according to claim 2, wherein the third engaged portion is an opening into which the third engaging portion can be inserted.

The first engaging portion is formed with a width larger than a width of the first engaged portion and a volume smaller than a volume of the first engaged portion,
The second engaging portion is formed with a width larger than the width of the second engaged portion, and has a volume larger than the volume of the second engaged portion,
The third engaged portion is provided on the impeller cover, has an inner diameter larger than an outer diameter of the third engaging portion, and has a volume larger than a volume of the third engaging portion. And a second opening formed continuously with the first opening and having an inner diameter larger than that of the first opening. The impeller according to claim 12.

The first engaging portion is formed with a width larger than a width of the first engaged portion and a volume smaller than a volume of the first engaged portion,
The second engaging portion has a width that is the same as or smaller than a width of the second engaged portion, and a volume that is larger than a volume of the second engaged portion, It is formed so that it can be engaged with the engaged part,
The third engaged portion is provided on the impeller cover, has an inner diameter larger than an outer diameter of the third engaging portion, and has a volume larger than a volume of the third engaging portion. And a second opening formed continuously with the first opening and having an inner diameter larger than that of the first opening. The impeller according to claim 12.

The predetermined gap is the first of the melted first engaged portion, the second engaged portion, and the third engaged portion at the time of welding the engaging portion and the engaged portion. The first engaging portion moved from the first engaging portion, the second engaging portion, and the third engaged portion, the second engaged portion, and the third engaging portion in a volume that can be disposed. The impeller according to claim 13 or 14, wherein the impeller is formed.

The first engagement portion, the second engagement portion, and the third engagement portion are provided on the center in the extending direction of the blade,
The impeller according to claim 15, wherein the first engaged portion, the second engaged portion, and the third engaged portion are provided on a center in an extending direction of the guide portion. .