JP2018189042A - Motor pump - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the diameter of a pump case in a configuration in which a pump case having a spiral chamber formed by a flow path whose width changes in the radial direction and the axial direction of an impeller and a motor case are joined by laser welding. SOLUTION: In an electric pump 10, a pump case 20 in which a spiral chamber 34 is formed by a flow path whose width changes in the radial direction and the axial direction of an impeller 50, and a pump case 20 provided on one side in the axial direction with respect to the pump case 20. The motor case 60 is joined by laser welding at the joining portion 70. The pump case 20 is formed with a flat surface portion 42 having a plane orthogonal to the axial direction in a region on the other side of the spiral chamber 34 in the axial direction and overlapping the joint portion 70 in the axial direction. Therefore, at the time of laser welding, a jig can be applied to the flat surface portion 42 to pressurize the pump case 20 toward the motor case 60, so that the jig is applied radially outside the spiral chamber 34 in the pump case 20. It is not necessary to form a flange surface for the purpose. [Selection diagram] Fig. 1

Description

  The present invention relates to an electric pump.

  In a water pump (electric pump) described in Patent Document 1 below, a spiral chamber is formed in a casing (pump case) that houses an impeller. This spiral chamber is configured by a flow channel having a rectangular cross section in which the width in the radial direction of the impeller changes while the width in the axial direction of the impeller does not change. The pump case and the body (motor case) are welded (joined) to each other at ring-shaped flange portions formed at the respective open ends.

  In the electric pump described in Patent Document 2 below, a spiral chamber is formed in a pump case that houses the impeller. This spiral chamber is configured by a flow path (three-dimensional flow path) whose width changes both in the radial direction and the axial direction of the impeller. And the taper part provided in this pump case and the taper part provided in the motor case are comprised by the taper fitting in the axial direction of an impeller, and joining by laser welding. Thereby, the diameter of the joint portion between the pump case and the motor case is reduced.

JP 2004-124840 A JP 2013-72344 A

  In the electric pumps described in each of the above patent documents, when the weld of the joint between the pump case and the motor case is insufficient, the liquid flowing in the pump case leaks from the joint. In order to secure the sealing performance of the welded portion, it is necessary to weld the joint surfaces of the pump case and the motor case in close contact with each other. For this reason, during welding, the pump case is pressurized toward the motor case. At the time of this pressurization, it is necessary to apply a jig to the end surface of the pump case opposite to the motor case.

  In this regard, in the electric pump described in Patent Document 1, an annular flat surface is formed on the pump case on the side opposite to the motor case via a channel having a rectangular cross section. For this reason, the joining surfaces of the pump case and the motor case can be brought into close contact with each other by applying a pressure to the annular flat surface with a jig having an annular opening end. However, this electric pump has a problem in that the efficiency of the pump is lowered because the spiral chamber is constituted by a flow channel having a rectangular cross section in which the width of the impeller in the axial direction does not change.

  On the other hand, in the electric pump described in Patent Document 2, the spiral chamber is constituted by a three-dimensional flow path whose width changes both in the radial direction and the axial direction of the impeller, so that the pump efficiency can be increased. However, in the pump case, the end surface on the side opposite to the motor case via the spiral chamber (three-dimensional flow path) has a complex bulge shape, so that the above jig cannot be applied. . For this reason, an annular flat surface (flange surface) is formed on the radially outer side of the spiral chamber in the pump case, and the diameter of the pump case is increased by an amount corresponding to the flange surface.

  In consideration of the above facts, the present invention provides a pump case in which a spiral chamber is constituted by a flow path whose width varies in the radial direction and the axial direction of the impeller, and a motor case joined by laser welding. An object is to provide an electric pump capable of reducing the diameter.

  The electric pump of the present invention accommodates an impeller, and a pump case in which a spiral chamber formed on the radially outer side of the impeller is configured by a flow path whose width changes in the radial direction and the axial direction of the impeller; A motor case that is provided on one side in the axial direction with respect to the pump case and houses a motor that rotates the impeller, and an outer peripheral wall portion of the pump case and an outer peripheral wall portion of the motor case are arranged in the axial direction. A joint that is taper-fitted and joined by laser welding, and the pump case overlaps the joint on the other side in the axial direction than the spiral chamber and when viewed from the axial direction. A planar portion having a plane orthogonal to the axial direction is formed in the region.

  According to the electric pump having the above configuration, the pump case in which the spiral chamber is configured by the flow path whose width varies in the radial direction and the axial direction of the impeller, and the pump case is provided on one side in the axial direction of the impeller. The motor case is joined at the joint. In this joint portion, the outer peripheral wall portion of the pump case and the outer peripheral wall portion of the motor case are taper-fitted in the axial direction of the impeller and are joined by laser welding. The pump case is orthogonal to the axial direction of the impeller in a region that is on the other side in the axial direction of the impeller from the spiral chamber (on the opposite side to the motor case) and overlaps the above-described joint as viewed from the axial direction of the impeller. A flat portion having a flat surface is formed. For this reason, at the time of the above laser welding, since the pump case can be pressurized to the motor case side by applying a jig to the above-mentioned flat portion, the jig is arranged radially outside the spiral chamber in the pump case. There is no need to form an annular flange surface for application. This makes it possible to reduce the diameter of the pump case.

  In the electric pump according to the present invention, the pump case is formed with a plurality of the flat portions arranged in the circumferential direction of the pump case.

  According to the electric pump having the above configuration, the pump case is formed with a plurality of flat portions arranged in the circumferential direction of the pump case. By applying a jig to the plurality of flat portions and pressurizing the pump case toward the motor case, it becomes easy to uniformly bring the pump case and the motor case into close contact over the entire circumference of the taper fitting portion.

  Moreover, in the electric pump of the present invention, the pump case is formed with a plurality of ribs extending radially in the radial direction, and the plurality of flat portions are formed on the plurality of ribs.

  According to the electric pump having the above configuration, the pump case is formed with a plurality of ribs extending radially in the radial direction of the impeller, and the plurality of flat portions described above are formed on the plurality of ribs. As described above, since the planar portion is formed on the plurality of ribs formed on the pump case, the material of the pump case is less than that in the case where the planar portion is formed by increasing the thickness of the pump case, for example. Become. Further, for example, when the pump case is molded by resin injection molding, molding sinks are less likely to occur.

  In the electric pump of the present invention, the plurality of planar portions are formed with planar protrusions that protrude to the other side in the axial direction and whose tip surface is a plane orthogonal to the axial direction.

  According to the electric pump having the above configuration, the plurality of flat portions formed in the pump case protrude to the other side in the axial direction of the impeller (the side opposite to the motor case), and the front end surface is orthogonal to the axial direction of the impeller. A planar protrusion made of a flat surface is formed. For this reason, when pressurizing a pump case to a motor case side with a jig, a jig can hit a plurality of plane projections. In that case, adjustment for making the contact force at the taper fitting portion between the pump case and the motor case uniform over the entire circumference can be easily performed by changing (adjusting) the protrusion heights of the plurality of planar protrusions.

1 is a perspective view showing an electric pump according to a first embodiment of the present invention. It is a fragmentary sectional view which shows the electric pump which concerns on 1st Embodiment, and is a figure corresponding to the cut surface along the F2-F2 line | wire of FIG. It is an expansion perspective view which expands and shows the area | region which attached | subjected the code | symbol C in FIG. It is an expanded sectional view which expands and shows a part of FIG. It is a perspective view which shows the electric pump which concerns on a 1st comparative example. It is a fragmentary sectional view showing the electric pump concerning the 1st comparative example. It is an expanded sectional view which expands and shows the cut surface along F6-F6 line of FIG. It is sectional drawing which shows the modification which formed the flange-shaped plane in the outer peripheral wall part of the pump case which concerns on a 1st comparative example. It is sectional drawing which shows the partial structure of the electric pump which concerns on a 2nd comparative example. It is sectional drawing which shows the partial structure of the electric pump which concerns on 2nd Embodiment of this invention.

<First Embodiment>
Hereinafter, the electric pump 10 according to the first embodiment of the present invention will be described with reference to FIGS. In each drawing, some symbols may be omitted for easy understanding of the drawing.

  The electric pump 10 according to the present embodiment is, for example, a water pump for pumping cooling water into the interior of a vehicle engine. 1 and 2, the electric pump 10 includes a pump case (casing) 20 that houses an impeller 50, a motor case (body pump) 60 that houses a motor 80 that rotates the impeller 50, a motor And a circuit cover 90 that houses a circuit unit (not shown) that controls 80. In the electric pump 10, the fixed shaft 82 of the motor 80 and the impeller 50 are disposed coaxially. First, a schematic overall configuration of the electric pump 10 will be described, and then a main part of the present embodiment will be described. In the following description, the axial direction of the impeller 50 may be simply referred to as “axial direction”, and the radial direction of the impeller 50 may be simply referred to as “radial direction”.

(Pump case)
The pump case 20 is an integral part formed of a thermoplastic resin, and is formed in a substantially bottomed cylindrical shape. An impeller 50 (see FIG. 2) is coaxially accommodated inside the pump case 20. The pump case 20 includes a bottom wall portion 22 formed in a substantially disk shape, and an outer peripheral wall portion 24 extending from the outer periphery of the bottom wall portion 22 to one side in the axial direction (arrow A direction side). Yes. The outer peripheral wall 24 is open on one side in the axial direction. The outer peripheral wall portion 24 is formed with a tapered portion 24A having an inner diameter that increases toward the opening side.

  An annular boss portion 26 protruding to the other side in the axial direction (arrow B direction side) is formed at the center portion of the bottom wall portion 22, and from the central portion of the boss portion 26 toward the other side in the axial direction. A tubular inlet tube 28 is extended. The inlet pipe 28 is configured to be connected to a coolant outlet in a vehicle radiator via a pipe such as a rubber hose.

  A bulging portion 30 (see FIG. 1) that bulges to the other side in the axial direction is formed on the outer peripheral side of the bottom wall portion 22. The bulging portion 30 is formed in a substantially annular shape (substantially spiral) when viewed from the axial direction of the impeller 50 (arrow A direction and arrow B direction). An outlet pipe 32 extends from one end in the circumferential direction of the bulging portion 30 in a direction orthogonal to the axial direction of the inlet pipe 28. The outlet pipe 32 is configured to be connected to a cooling water inlet in a vehicle engine via a pipe such as a rubber hose, for example.

  The bulging portion 30 forms a substantially annular (substantially spiral) spiral chamber 34 inside the pump case 20 and outside the impeller 50 in the radial direction. The spiral chamber 34 is configured by a substantially annular (substantially spiral) flow path (three-dimensional flow path) whose width changes both in the radial direction and the axial direction of the impeller 50. Specifically, the spiral chamber 34 (three-dimensional flow path) is formed such that the radial and axial widths of the impeller 50 increase from one circumferential end to the other circumferential end. The other end in the circumferential direction communicates with the outlet pipe 32.

  In the pump case 20 configured as described above, the liquid (in this case, the engine coolant) that has flowed into the pump case 20 from the inlet pipe 28 flows toward the spiral chamber 34 by the rotation of the impeller 50, and at the same time inside the spiral chamber 34. It is configured to flow in the rotation direction of 50 and to be pumped to the outlet pipe 32.

(Motor case)
The motor case 60 is an integral part formed of a thermoplastic resin, and is provided on one side in the axial direction with respect to the pump case 20. The motor case 60 is formed in a substantially cylindrical shape and is arranged coaxially with the pump case 20. Specifically, the motor case 60 includes a cylindrical outer peripheral wall portion 62, a cylindrical inner cylindrical portion 64 that is coaxially disposed inside the outer peripheral wall portion 62, and an inner cylindrical portion. 64, one end wall portion (not shown) that closes the opening on one side in the axial direction in 64, and the other end wall portion 66 that connects the other ends in the axial direction in the outer peripheral wall portion 62 and the inner cylindrical portion 64 in the radial direction. I have. A tapered portion 62A whose outer diameter decreases toward the other side in the axial direction is formed at the end of the outer peripheral wall 62 on the other side in the axial direction (on the pump case 20 side).

  A fixed shaft 82 and a rotor 84 constituting the motor 80 are accommodated coaxially inside the inner cylinder portion 64. The fixed shaft 82 is pivotally supported in a cantilevered manner on a pivotal support formed on the one end wall, and is disposed coaxially with the impeller 50. A rotor 84 is coaxially attached to the outer peripheral portion of the fixed shaft 82. The rotor 84 is formed integrally with the impeller 50. A plurality of magnets (reference numerals omitted) are attached inside the rotor 84.

  A stator 86 constituting the motor 80 is coaxially accommodated between the outer peripheral wall portion 62 and the inner cylinder portion 64. The stator 86 includes a yoke (not shown) formed in an annular shape and a conductive winding (not shown) wound around the yoke. The stator 86 is disposed so as to surround the rotor 84, and the rotor 84 rotates around the fixed shaft 82 as a center when receiving a magnetic field generated by the stator 86. Thereby, the impeller 50 is configured to rotate integrally with the rotor 84.

  A circuit portion (not shown) for controlling the motor 80 is accommodated in the motor case 60 on one side in the axial direction of the motor 80. This circuit part is covered with a bottomed cylindrical circuit cover 90 attached to the end of one side in the axial direction of the motor case 60 (the side opposite to the pump case 20). The circuit cover 90 is provided with an external power supply connecting portion 92 (see FIG. 1). The external power supply connecting portion 92 is configured to be connected to a connector provided in a harness (not shown) for supplying external power to the circuit portion.

(Main part of this embodiment)
Next, the main part of this embodiment will be described.
In the present embodiment, the pump case 20 and the motor case 60 described above are joined by welding. Specifically, as shown in FIGS. 2 and 3, a taper portion 24 </ b> A formed on the outer peripheral wall portion 24 of the pump case 20 and a taper portion 62 </ b> A formed on the outer peripheral wall portion 62 of the motor case 60 are provided. The taper is fitted in the axial direction. And the taper part 24A and the taper part 62A are joined by laser welding, so that a joint part 70 between the pump case 20 and the motor case 60 is formed.

  Supplementing the above laser welding, the pump case 20 is made of a laser-transmitting resin, and the motor case 60 is made of a laser-absorbing resin. For this reason, when the laser is irradiated from the radially outer side to the taper fitting portion between the taper portion 24A of the pump case 20 and the taper portion 62A of the motor case 60, the outer peripheral surface of the taper portion 62A of the motor case 60 (ie, the taper portion). 24A and the taper portion 62A), the laser is absorbed and generates heat. Due to this heat generation, a joining portion (welded portion) 70 is formed between the tapered portion 24A and the tapered portion 62A. Further, the joint portion 70 is continuously formed over the entire circumference of the tapered portion 24A and the tapered portion 62A. Thereby, the sealing performance at the joint 70 between the pump case 20 and the motor case 60 is ensured without providing a sealing material.

  However, when welding of the joint part 70 between the pump case 20 and the motor case 60 is insufficient, the coolant flowing in the pump case 20 leaks from the joint part 70. In order to ensure the sealing property of the joint portion 70, it is necessary to perform laser welding in a state where the resins of the pump case 20 and the motor case 60 are in close contact with each other over the entire circumference of the tapered portion 24A and the tapered portion 62A. For this reason, at the time of laser welding, the pump case 20 is configured to be pressurized toward the motor case 60 side.

  Here, in the present embodiment, the pump case 20 includes a plurality of (here, 12) ribs extending from the bottom wall portion 22 to the other side in the axial direction (the side opposite to the motor case 60) as shown in FIG. 40 is formed. These ribs 40 extend radially in the radial direction of the pump case 20, are arranged at equal intervals or substantially equal intervals in the circumferential direction of the pump case 20, and protrude from the bulging portion 30 to the other side in the axial direction. . These ribs 40 include a plurality of (four in this case) long ribs 40 </ b> L extending from the boss portion 26 formed at the center of the bottom wall portion 22 to the outer peripheral side of the bottom wall portion 22, and the bottom wall portion 22. A plurality of (here, eight) short ribs 40S formed only on the outer peripheral side. The four long ribs 40L extend in directions orthogonal to each other when viewed from the axial direction, and two short ribs 40S are disposed between a pair of adjacent long ribs 40L.

  The radially outer end surfaces of the plurality of ribs 40 are disposed on the same curved surface as the outer peripheral surface of the outer peripheral wall portion 24. Further, the end surface on the other side in the axial direction of the plurality of ribs 40 is a flat portion 42 having a plane PS1 orthogonal to the axial direction (arrow A direction and arrow B direction). That is, the pump case 20 is formed with a plurality of flat portions 42 arranged in the circumferential direction. These flat portions 42 extend in the radial direction on the other axial side (the side opposite to the motor case 60) from the spiral chamber 34 and the bulging portion 30. These flat portions 42 extend radially outward from the spiral chamber 34 and also exist in a region (a region indicated by an arrow E in FIG. 4) that overlaps the joint portion 70 when viewed from the axial direction.

  Further, in each planar portion 42, a planar protrusion 42 </ b> A projecting in a columnar shape toward the other side in the axial direction is formed in a region overlapping with the joint portion 70 when viewed from the axial direction. The front end surface 42A1 of each planar protrusion 42A is configured by a plane PS2 orthogonal to the axial direction (arrow A direction and arrow B direction). That is, in each plane portion 42, a portion other than the plane protrusion 42 </ b> A and the tip end surface 42 </ b> A <b> 1 of the plane protrusion 42 </ b> A are each configured by the planes PS <b> 1 and PS <b> 2 orthogonal to the axial direction.

  In the electric pump 10 having the above configuration, when the pump case 20 and the motor case 60 are laser-welded, the pump case 20 is pressurized toward the motor case 60 using the jig J shown in FIG. It has become. The jig J is formed in a bottomed cylindrical shape, and is configured such that the end surface on the opening side is pressed against the plurality of flat portions 42. At the time of this pressing, the tip surfaces 42A1 of the plurality of planar protrusions 42A are mainly configured to positively contact the end surfaces of the jig J. Thereby, the pressurizing force F1 (see FIG. 4) from the jig J mainly acts on the outer peripheral portion of the pump case 20 (that is, the region overlapping with the tapered portion 24A and the tapered portion 62A in the axial direction view). As a result, the contact forces F2 and F3 (see FIG. 4) that cause the taper portion 24A and the taper portion 62A to closely contact each other sufficiently operate.

  In the present embodiment, the flat surface portion 42 is formed to the region overlapping the bulging portion 30 in the axial direction view and to the center side of the pump case 20 from the region, but is not limited thereto. The part 42 should just be formed in the area | region which overlaps with respect to the outer peripheral wall part 24 of the pump case 20 at an axial direction view.

(Function and effect)
Next, the operation and effect of this embodiment will be described.

  In the electric pump 10 configured as described above, the pump case 20 in which the spiral chamber 34 is configured by a flow path whose width varies in the radial direction and the axial direction of the impeller 50, and one axial direction side of the impeller 50 with respect to the pump case 20 The motor case 60 provided in the joint is joined at the joint 70. In this joint portion 70, the outer peripheral wall portion 24 of the pump case 20 and the outer peripheral wall portion 62 of the motor case are taper-fitted in the axial direction of the impeller 50 and are joined by laser welding.

  Further, the pump case 20 has an impeller 50 in a region overlapping with the joint portion 70 when viewed from the axial direction of the impeller 50 on the other side in the axial direction of the impeller 50 from the spiral chamber 34 (on the side opposite to the motor case 60). A plurality of plane portions 42 having a plane orthogonal to the axial direction are formed. For this reason, at the time of the above laser welding, since the pump case 20 can be pressurized to the motor case 60 side by applying the jig J to the plurality of flat portions 42, the diameter of the pump case 20 is larger than that of the spiral chamber 34. There is no need to form a flange surface (flange-shaped plane) for applying the jig J on the outer side in the direction. Thereby, the diameter of the pump case 20 can be reduced.

  Regarding the above effect, the electric pump 100 shown in FIGS. 5 to 8 (hereinafter referred to as “first comparative example 100”) and the electric pump 110 shown in FIG. 9 (hereinafter referred to as “second comparative example 110”) Supplementary explanation will be given. In FIG. 5 to FIG. 9, the same reference numerals are given to basically the same configurations as in the present embodiment.

  In the first comparative example 100, as shown in FIGS. 5 and 6, the pump case 20 has a configuration in which the plurality of ribs 40 (the plurality of plane portions 42) according to the present embodiment are not provided. . In the pump case 20 according to the first comparative example 100, not only the radial width of the impeller 50 but also the flow path (see the arrow h in FIG. 6) in which the axial width of the impeller 50 changes constitutes the spiral chamber 34. Has been. For this reason, the area where the bulging part 30 is formed in the bottom wall part 22 has a three-dimensionally complicated shape, and the jig J cannot be applied to the area, but the diameter of the bulging part 30 A substantially flange-shaped flat surface 102 is formed on the outer side in the direction. For this reason, when laser welding the pump case 20 and the motor case 60, as shown by a two-dot chain line in FIG. It is conceivable to pressurize.

  However, in the pump case 20 according to the first comparative example 100, as shown in FIG. 7, there is a region 104 where the plane 102 does not exist in a part of the circumferential direction. For this reason, since the pressing force of the jig J cannot be applied to the region 104, the adhesion between the tapered portion 24A and the tapered portion 62A is insufficient around the region 104. That is, in the first comparative example 100, it is not possible to secure a flat surface (jig pressurizing surface) for uniformly applying a pressing force (adhesion force) over the entire circumference with respect to the tapered portion 24A and the tapered portion 62A.

  In this regard, for example, as in the electric pump 100 ′ shown in FIG. 8 (modified example of the first comparative example 100), the flange portion 106 is formed on the outer peripheral wall portion 24 of the pump case 20, and the motor case in the flange portion 106 is formed. It is conceivable that a jig J (not shown in FIG. 8) is applied to the end face 106A opposite to 60. However, in the electric pump 100 ′ according to this modification, the diameter of the pump case 20 is increased by the amount of the flange portion 106, and the flange portion 108 needs to be formed on the outer peripheral wall portion 62 of the motor case 60. The motor case 60 is also increased in diameter. As a result, there arises a problem that the size of the electric pump 100 'increases. 7 and 8, D1 represents the outer diameter of the spiral chamber 34, D2 represents the outer diameter of the pump case 20 according to the first comparative example 100, and D3 represents the electric pump of the above modification. The outer diameter of the pump case 20 according to 100 'is shown.

  On the other hand, the second comparative example 110 shown in FIG. 9 has the same configuration as the electric pump according to Patent Document 2 described in the background art section, and the radial width of the impeller 50 changes, while the impeller The spiral chamber 112 is constituted by a channel having a rectangular cross section in which the width in the axial direction of 50 does not change (see an area surrounded by a broken line in FIG. 9). In the second comparative example 110, an annular flat surface 114 is formed on the side opposite to the motor case 60 via the spiral chamber 112 (a channel having a rectangular cross section). For this reason, the jig | tool J (illustration omitted in FIG. 9) can be applied to the said plane 114, and the pump case 20 can be pressurized to the motor case 60 side. However, in the second comparative example 110, the spiral chamber 112 is constituted by a flow channel having a rectangular cross section in which the width of the impeller 50 in the axial direction does not change.

  On the other hand, in the present embodiment, it is possible to avoid an increase in size (increase in diameter) such as that of the modified example 100 ′ while improving the pump efficiency by the spiral chamber 34 configured by the three-dimensional flow path.

  Moreover, in the present embodiment, the pump case 20 is formed with a plurality of flat portions 42 aligned in the circumferential direction. By applying the jig J to the plurality of flat portions 42 and pressurizing the pump case 20 toward the motor case 60, pressure (contact force) is uniformly applied to the tapered portion 24A and the tapered portion 62A over the entire circumference. It becomes easy.

  Furthermore, in the present embodiment, the pump case 20 has the plurality of flat portions 42 formed on the plurality of ribs 40 extending radially in the radial direction of the impeller 50. For this reason, the material of a pump case decreases compared with the case where the bottom wall part 22 of the pump case 20 is thickened and the plane part 42 is formed, for example. Further, for example, when the pump case 20 is molded by resin injection molding, molding sinks are less likely to occur, so that the moldability of the pump case 20 can be easily ensured.

  Further, in the present embodiment, the plurality of planar portions 42 are formed with planar projections 42 </ b> A that project toward the other side in the axial direction of the impeller 50 (the side opposite to the motor case 60). These planar protrusions 42A are formed in regions overlapping the taper portions 24A and 62A when the impeller 50 is viewed in the axial direction, and the front end surface 42A1 is constituted by a plane PS2 orthogonal to the axial direction of the impeller 50. For this reason, when the pump case 20 is pressurized to the motor case 60 side by the jig J, the tip surfaces 42A1 of the plurality of planar protrusions 42A positively contact the jig J, thereby tapering the applied pressure of the jig J. It can be directly transmitted (concentrated) to the parts 24A and 62A. In addition, adjustment for making the adhesion of the tapered portions 24A and 62A uniform over the entire circumference can be easily performed by changing (adjusting) the protrusion heights of the plurality of planar protrusions 42A.

  From the above, according to the present embodiment, the strength of laser welding at the joint 70 between the pump case 20 and the motor case 60 is stabilized, and the sealing performance of the joint 70 can be easily ensured.

Second Embodiment
Next, a second embodiment of the present invention will be described. In addition, about the structure and effect | action similar to 1st Embodiment, the same code | symbol as 1st Embodiment is attached | subjected and the description is abbreviate | omitted. FIG. 10 is a sectional view showing a partial configuration of the electric pump 200 according to the second embodiment of the present invention. The electric pump 200 has a configuration similar to that of the first comparative example 100 described above, but is different from the first comparative example 100 in that the bottom wall portion 22 of the pump case 20 is formed thick. ing. In this electric pump 200, the pump case 20 is located on the other side in the axial direction from the spiral chamber 34 (arrow B direction side; opposite to the motor case 60) and in a region overlapping with the joint 70 when viewed from the axial direction. A plane portion 202 having a plane orthogonal to the axial direction is formed. The flat surface portion 202 is formed by forming the bottom wall portion 22 thick as described above. The flat portion 202 extends to the center side of the pump case 20 and is continuously formed over the entire circumference of the pump case 20.

  Also in this embodiment, the jig J can be applied to the flat portion 202 to pressurize the pump case 20 toward the motor case 60, so that the jig J is applied to the outer side of the spiral chamber 34 in the pump case 20 in the radial direction. There is no need to form a flange-like plane for the purpose. Thereby, the diameter of the pump case 20 can be reduced.

  Although one embodiment of the present invention has been described above, the present invention is not limited to the above, and various modifications other than the above can be implemented without departing from the spirit of the present invention. Of course.

DESCRIPTION OF SYMBOLS 10 ... Water pump (electric pump), 20 ... Pump case, 24 ... Outer peripheral wall part, 40 ... Rib, 42 ... Planar part, 42A ... Planar protrusion, 50 ... Impeller, 60 ... motor case, 62 ... outer peripheral wall part, 70 ... joint part, 200 ... electric pump, 202 ... flat part

Claims (4)

A pump case that houses an impeller, and a spiral chamber formed on the radially outer side of the impeller is configured by a flow path whose width changes in the radial direction and the axial direction of the impeller;
A motor case that is provided on one side in the axial direction with respect to the pump case and that houses a motor for rotating the impeller;
The outer peripheral wall portion of the pump case and the outer peripheral wall portion of the motor case are taper-fitted in the axial direction and joined by laser welding,
With
The pump case is formed with a plane portion having a plane perpendicular to the axial direction in a region overlapping the joint portion when viewed from the axial direction on the other side in the axial direction than the spiral chamber. pump.   The electric pump according to claim 1, wherein the pump case is formed with a plurality of the planar portions arranged in a circumferential direction of the pump case. The pump case has a plurality of ribs extending radially in the radial direction,
The electric pump according to claim 2, wherein the plurality of flat portions are formed on the plurality of ribs.   4. The electric pump according to claim 2, wherein the plurality of planar portions are formed with planar protrusions that protrude to the other side in the axial direction and whose tip surfaces are planes orthogonal to the axial direction. .