JP6697904B2 - Method of manufacturing cast aluminum products - Google Patents

Description

  The present invention relates to a method for manufacturing a cast aluminum product.

  The components of the electric pump (for example, components called a pump casing or a pump cover) are cast products of aluminum or aluminum alloy (in the present specification, both aluminum and aluminum alloy) from the viewpoint of weight reduction and workability. It is often used to include aluminum cast products). Many of this type of aluminum cast products are subjected to a surface treatment called alumite treatment from the viewpoint of corrosion resistance and durability.

  When the alumite treatment is applied to the surface of aluminum, the longer the treatment time, the larger the film thickness and the better the corrosion resistance and durability. However, on the other hand, there is a problem that the surface becomes rough. Generally, when an aluminum casting processed product is used as a pump part, it is necessary to have high dimensional accuracy on the fitting surface of the parts, the sealing surface, the mounting surface of the bearing, etc., and the corresponding part is cut. However, when performing alumite treatment on cast products, especially when trying to provide a sufficient film thickness on the casting surface where alumite is difficult to ride, the cut surface will have an unnecessarily large film thickness and the surface will be rough. Will end up.

  Therefore, conventionally, a masking process is performed on the cut surface and then the alumite treatment is performed (for example, refer to Patent Document 1). A thin (non-coarse) alumite layer is required on the machined surface that requires such high dimensional accuracy, and after removing the masking member, the alumite treatment is performed again to make a thin alumite layer. ..

JP-A-2000-104680

  However, the use of a masking member is troublesome to manage, and sometimes the masking member may fall off during processing, resulting in poor workability.

  Therefore, the present invention has been made in view of the above-mentioned circumstances, and an aluminum casting process capable of making a difference in the surface roughness of the alumite layer depending on a required portion without using a masking member. An object is to provide a method for manufacturing a product.

In order to solve the above problems, a method for manufacturing an aluminum cast product according to the present invention includes a motor section, a pump mechanism driven by the motor section, and a pump section having a pump casing coupled to the motor section. A manufacturing method of an electric pump in which the pump casing and the motor unit are fitted to each other on a sealing surface of the pump casing so as to have the pump mechanism inside thereof. And a pump assembly step of assembling the pump casing, the motor portion, and the pump mechanism, and the manufacturing step of the pump casing includes an aluminum casting step of casting an aluminum cast product body in the shape of the pump casing. , forming a first alumite layer on the casting surface by applying a first alumite treatment on the entire surface of the aluminum casting body, after the step of the aluminum casting body from above the first alumite layer Among them, a step of forming a cutting surface by cutting at least a predetermined portion including the sealing surface of the pump casing , and after the step, a second alumite treatment is applied to the entire surface of the aluminum cast product body. Thereby forming a second alumite layer only on the cut surface, wherein the second alumite layer is formed as a surface treatment layer having a surface roughness smaller than that of the first alumite layer. And

By adopting such a method, it is possible to easily make the surface roughness of the alumite layer different depending on a required portion without using a masking member. That is, a thick alumite layer can be formed on the casting surface, and a thin alumite layer with small surface roughness can be formed on the cutting surface.
Further, by utilizing the insulating property of the first alumite layer formed on the casting surface, it is possible to efficiently form the second alumite layer whose surface roughness is suppressed only on the machined surface. Therefore, the alumite treatment can be easily performed without using a masking member. In this case, the cutting process for ensuring the accuracy of the finished surface (cutting surface) also serves as the preparation process for the second alumite treatment.

  In the method for producing an aluminum cast product according to the present invention, the first alumite layer is composed of alumite sulfate.

  By adopting such a method, the film thickness on the casting surface can be set thick and the durability can be enhanced.

  In the method for producing an aluminum cast product according to the present invention, the second alumite layer is composed of alumite oxalate.

  By adopting such a method, the durability of the cut surface can be maintained high.

  According to the present invention, it is possible to easily apply a plurality of alumite treatment conditions to one aluminum cast product without using a masking member. For example, a sufficient film thickness can be applied to a portion requiring corrosion resistance, and a minimum necessary film thickness can be applied to a cut surface (sealing surface or the like) requiring surface roughness.

It is the whole electric pump perspective view in the embodiment of the present invention. It is an exploded perspective view of the electric pump in the embodiment of the present invention. It is a longitudinal cross-sectional view of the electric pump in the embodiment of the present invention. FIG. 3 is a cross-sectional view showing a motor main body of a motor section of the electric pump according to the embodiment of the present invention. It is a front view showing arrangement of a stator unit and other parts in an embodiment of the present invention. It is a front view of the motor body of the electric pump in the embodiment of the present invention. It is an explanatory view for explaining a manufacturing process of a stator unit of a motor part of an electric pump in an embodiment of the present invention. It is an explanatory view for explaining a manufacturing process of a stator unit of a motor part of an electric pump in an embodiment of the present invention. It is an explanatory view for explaining a manufacturing process of a stator unit of a motor part of an electric pump in an embodiment of the present invention. It is an explanatory view for explaining a manufacturing process of a stator unit of a motor part of an electric pump in an embodiment of the present invention. It is an explanatory view for explaining a manufacturing process of a motor body of a motor part of an electric pump in an embodiment of the present invention. It is an explanatory view for explaining a manufacturing process of a motor body of a motor part of an electric pump in an embodiment of the present invention. It is an explanatory view for explaining a manufacturing process of a motor body of a motor part of an electric pump in an embodiment of the present invention. It is an explanatory view for explaining a manufacturing process of a motor body of a motor part of an electric pump in an embodiment of the present invention. It is a perspective view which shows the relationship between the punching hole of a positioning pin and silicon|silicone in embodiment of this invention. FIG. 4 is a perspective view showing a state in which silicon in the embodiment of the present invention is injected into a positioning pin hole of a stator core and is cured by heating. It is a perspective view which takes out and shows the rotor of the motor part of the electric pump in the embodiment of the present invention. It is an exploded perspective view of the rotor of the motor part of the electric pump in the embodiment of the present invention. It is explanatory drawing of the manufacturing method of the rotor of the motor part of the electric pump in embodiment of this invention. It is explanatory drawing of the manufacturing method of the rotor of the motor part of the electric pump in embodiment of this invention. It is explanatory drawing of the manufacturing method of the rotor of the motor part of the electric pump in embodiment of this invention. It is explanatory drawing of the manufacturing method of the pump casing of the electric pump in embodiment of this invention, (a) is a figure which shows the state of the casting surface surface cast by aluminum, (b) is a 1st alumite layer after that on the casting surface. Is a diagram showing a state in which the second alumite layer is formed, FIG. 7C is a diagram showing a state in which necessary processing is subsequently performed, and FIG. 8D is a diagram showing a state in which a second alumite layer is subsequently formed on the cut surface. . It is a detailed explanatory view of the state of (d) of FIG.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
The embodiment described here is an example in which the present invention is applied to an electric pump for sending a combustible gas (hydrogen gas, propane gas, vaporized gasoline, etc.).

  1 is an overall perspective view of the electric pump 1 of the embodiment, FIG. 2 is an exploded perspective view of the electric pump 1 of the embodiment, FIG. 3 is a vertical sectional view of the electric pump 1 of the embodiment, and FIG. FIG. 3 is a cross-sectional view showing a motor main body 120 of the motor unit 100 of the pump 1 taken out and shown.

(Electric pump)
As shown in FIGS. 1 and 2, the electric pump 1 includes a motor unit 100 configured by a brushless motor (electric motor), and a pump unit 200 integrally connected to a front portion of the motor unit 100. .. The motor unit 100 and the pump unit 200 are coaxially arranged. The pump unit 200 is driven by the motor unit 100 to discharge the combustible gas under pressure.

  As shown in FIG. 3, the motor unit 100 includes a motor main body 120 molded by mold resins (mold resin units) 122 and 132 so as to cover the cylindrical stator 140, and a rotor 110 integrated with the shaft 101. It consists of and. Inside the motor body 120, a rotor housing space 121, which is a cylindrical cavity for housing the rotor 110, is provided. The rotor housing space 121 has a rear end sealed with a resin wall and a front end opened.

  As shown in FIGS. 2 and 3, the pump unit 200 includes a pump casing 210 and an impeller 220. The impeller 220 is rotationally driven by the shaft 101 of the motor unit 100, and cooperates with the pump casing 210 to suck and compress the combustible gas.

Here, the impeller type pump unit 200 is illustrated, but the type of pump does not matter.
The motor unit 100 and the pump unit 200 are integrated by a plurality of connecting bolts 104 in a state where fitting portions 124 and 214 provided on the outer peripheral portion in the radial direction are fitted to each other and an O-ring 105 is interposed on the fitting surface. Is bound to. The fitting surface is formed as a cylindrical surface, and corresponds to a fitting inner peripheral surface 214a on the pump unit 200 side and a fitting outer peripheral surface 124a on the motor unit 100 side, which will be described later.

  The shaft 101 of the motor unit 100 has a front end side protruding from a front end opening of the rotor housing space 121 of the motor main body 120 toward the pump unit 200 side, and the front end thereof is rotatable with respect to the pump casing 210 via the front side bearing 102. Supported by. The rear end side is housed inside the rotor housing space 121 of the motor body 120, and the rear end is rotatably supported by the motor body 120 via the rear bearing 103.

  In the description of the present embodiment, the axial direction of the shaft 101 of the motor unit 100 is simply referred to as the axial direction, the pump unit 200 side is referred to as the front side, and the non-pump unit 200 side is referred to as the rear side. Further, the direction orthogonal to the axial direction and being the radial direction of the shaft 101 is simply referred to as the radial direction, and the circumference of the shaft 101 is simply referred to as the circumferential direction.

(Pump casing)
The pump casing 210 is made of a cast aluminum product having a substantially disk shape. An alumite layer is formed on the outer surface of the pump casing 210 (the surface exposed to the outside exposed to air or gas) in order to improve corrosion resistance and durability. This point will be described in detail later. The pump casing 210 has a front surface 210A that is an outer side and a back surface 210B that is an inner side when the pump unit 200 is coupled to the motor unit 100.

  A boss portion 213 that accommodates the front bearing 102 is provided at the center of the pump casing 210 in the radial direction. A suction port 211 and a discharge port 212 are provided at positions slightly inward of the outer peripheral portion on the surface 210A side of the pump casing 210 and are circumferentially separated from each other. Further, an arcuate pump flow path 215 communicating with the suction port 211 and the discharge port 212 is provided at a position slightly inside the outer peripheral portion on the back surface 210B side of the pump casing 210.

  Further, a cylindrical fitting portion 214 protruding toward the motor unit 100 side is provided on the outer peripheral portion of the pump casing 210. The fitting portion 214 is a portion that is fitted with the fitting portion 124 on the side of the motor portion 100 in a spigot fitting manner. Therefore, the fitting portion 124 is provided with a fitting inner peripheral surface 214a formed of a cylindrical surface parallel to the axial direction and an abutting surface 214b formed of an annular flat surface orthogonal to the axial direction.

  The fitting inner peripheral surface 214a is provided on the inner peripheral side of the abutting surface 214b. The fitting inner peripheral surface 214a is a spigot fitting with the fitting outer peripheral surface 124a on the motor unit 100 side when the motor unit 100 and the pump unit 200 are coupled to each other. It exerts the function as a sealing surface that secures the matching function and hermeticity. The abutment surface 214b abuts the abutment surface 124b on the side of the motor unit 100 when the motor unit 100 and the pump unit 200 are coupled to each other, thereby exerting an axial positioning function of the motor unit 100 and the pump unit 200.

  Further, on the outer peripheral side of the fitting portion 214 on the outer periphery of the pump casing 210, the ear portions 216 with screw holes for coupling with the motor portion 100 are provided at appropriate intervals in the circumferential direction, and the electric pump 1 itself. And an ear portion 219 for fixing the pump, which is used to attach the pump to any member. The pump part 200 is coupled to the motor body 120 of the motor part 100 by screwing the connecting bolt 104 into the screw hole of the ear part 216 having the screw hole from the motor part 100 side.

(Impeller)
The impeller 220, which is another component of the pump unit 200, is provided with a boss portion 221 having a shaft hole 223 at the center in the radial direction. The impeller 220 has a row of blades 222 arranged in the circumferential direction on the front surface of the outer peripheral portion in the radial direction. The blade row 222 is provided corresponding to the pump passage 215 on the back surface 210B side of the pump casing 210. When the impeller 220 rotates in a certain direction, the pump section 200 sucks gas from the suction port 211, compresses the gas in the pump flow path 215, and discharges the gas from the discharge port 212.

(Motor part)
Next, the motor section 100 will be described in detail.
The motor unit 100 is composed of a motor main body 120 having a structure in which almost the entire stator unit 130 is embedded inside an overmold resin (mold resin unit) 122, and a rotor 110 including a shaft 101. As shown in FIG. 3, the motor body 120 is provided with a connector portion 160 formed during molding (overmolding described later). Except for the terminals of the connector portion 160 and a part of the outer peripheral portion of the stator core 141 described later, almost the entire stator unit 130 is covered with the overmold resin 122.

  In this way, the stator unit 130 is embedded in the overmold resin 122 so that even if the combustible gas enters the product, the combustible gas may be generated in a portion (mainly the stator 140) where a spark may be generated. This is to prevent contact.

Here, as apparent from FIG. 4, the molding is performed in two stages.
The first stage process is a first mold forming process (premold forming process) for embedding the stator 140, the bus bar 153 (described later), and the like inside the premold resin (mold resin portion) 132. The stator unit 130 is obtained by this pre-molding process.

  The second step is a second molding step (overmolding step) for embedding the stator unit 130 obtained in the first step inside the overmolding resin (molding resin portion) 122. By this overmolding step, the motor main body 120 as shown in FIG. 4 is obtained.

  In addition, as shown in FIGS. 3 and 4, a resin wall that closes the rear end surface of the rotor housing space 121 of the motor body 120 has a radially inner center surface that is made of metal (eg, non-magnetic) that houses the rear bearing 103. A bearing holder 123 made of SUS) is provided. The bearing holder 123 is provided integrally with the resin portion (overmold resin 122) of the motor body 120 by insert molding. The bearing holder 123 is an annular body having a peripheral side wall with an L-shaped cross section, and has a fitting inner peripheral wall 123 a that receives the outer periphery of the rear bearing 103 and an abutting wall 123 b that receives the end face of the rear bearing 103. is doing.

(Stator unit)
As shown in FIG. 4, the stator unit 130 is one in which a stator 140, a bus bar unit 155 (described later), and the like are embedded in the premolded resin 132.

FIG. 5 is a front view showing the arrangement of the stator unit 130 and other components at the pre-stage of making the motor body 120 of the electric pump 1, and FIG. 6 is a front view of the motor body of the electric pump 1.
As shown in FIG. 5, the motor unit 120 as shown in FIG. 6 can be obtained by performing overmolding while combining the stator unit 130, which is a premolded body, with the bearing holder 123 and the collar 127. it can. Here, as shown in FIG. 4, the collar 127 is a small-diameter metal cylindrical member for securing the bolt through hole 128 when the motor body 120 is coupled to the pump casing 210.

  Next, a detailed configuration of the stator 140, the stator unit 130, and the motor body 120 will be described while describing a method of manufacturing the stator unit 130 and the motor body 120.

  7 to 10 are explanatory views of the steps until the stator unit 130 is obtained. 7 is a perspective view showing the configuration of the stator core 141 alone, and FIG. 8 is a perspective view showing the stator 140 formed by winding the coil 150 around the teeth 143 of the stator core 141 of FIG. 7 via the insulator 151. 9 is a perspective view showing a state in which a bus bar unit 155 pre-molded with a bus bar 153 (a member also called a terminal plate) is arranged on the stator unit 130 shown in FIG. 8, and FIG. 10 shows the assembly shown in FIG. FIG. 6 is a perspective view showing a stator unit 130 configured by performing resin molding (premolding).

(Stator core)
As shown in FIG. 7, the stator core 141 is formed by stacking a plurality of electromagnetic steel plates that are press-formed into the same shape in the axial direction. And a plurality of teeth 143 protruding. In this embodiment, six teeth 143 are provided at regular intervals in the circumferential direction. The tips of the teeth 143 are T-shaped when viewed in the axial direction, and the inner peripheral surface of the tips is formed by arcuate surfaces arranged on the same circumference.

  On the outer circumference of the cylindrical portion 142 of the stator core 141, an ear portion 144 protruding outward in the radial direction is provided. These ears 144 are arranged in correspondence with the teeth 143 adjacent to each other and the intermediate position between the teeth 143. Each ear portion 144 is provided with a through hole 146 penetrating in the axial direction. The through holes 146 of each ear portion 144 are arranged at equal intervals in the circumferential direction on the same circle concentric with the center of the stator core 141.

  Of these six through holes 146 formed in each ear portion 144, the connecting pin 148 is inserted into every other three through holes 146 in the circumferential direction. The stacked electromagnetic steel plates are integrally joined by the inserted connecting pins 148. A cover member 149 is attached to both ends of the through hole 146 into which the connecting pin 148 is inserted.

  In addition, the three through holes 146, in which the connecting pin 148 is not inserted and which remain every other one in the circumferential direction, are left as holes as the positioning holes 147 used for positioning in the subsequent process. Therefore, three positioning holes 147 are provided on the outer circumference of the stator core 141 at equal intervals in the circumferential direction.

  The six ears 144 are set so as not to be embedded inside the resin (premold resin 132, overmold resin 122) but to be exposed outside during premolding or overmolding described later. It corresponds to the department. That is, three positioning holes 147 penetrating along the axial direction are arranged in these externally exposed portions. It is preferable that a plurality of positioning holes 147 are provided, and at least three or more are provided as in the present embodiment.

  A coil 150 is wound around each tooth 143 of the stator core 141 thus configured as shown in FIG. 8 by an automatic winding device (not shown) in the next winding step. The coil 150 is wound via the insulator 151. For example, the coils 150 for three phases of U, V, and W phases are wound around the six teeth 143. Thereby, the stator 140 is formed. In this winding step, by inserting a positioning pin (not shown) into the positioning hole 147 of the stator core 141, the stator core 141 can be correctly positioned and fixed to the automatic winding device, which improves workability in the winding step. The winding quality can be improved.

  In the next step, as shown in FIG. 9, a bus bar (also called a terminal plate) 153 that energizes the coil 150 is attached to the rear end surface side of the stator 140. The bus bar 153 is annularly arranged along the ring shape of the stator 140. The terminals of the predetermined bus bar 153 are arranged in a fixed relationship so as to be used as terminals of the connector unit 160 (see FIG. 3 ). Such a bus bar 153 is pre-molded with an annular resin in advance to form a bus bar unit 155. The bus bar unit 155 is attached to the stator 140 by being locked to the engaging portion provided on the insulator 151.

  In the next step, as shown in FIG. 10, premolding is performed with the premolding resin 132 so as to cover the main part of the stator 140. The molded body obtained by the pre-molding is the stator unit 130. In this stator unit 130, the ear portion 144 of the stator core 141 is exposed from the premolded resin 132 to the outside. In addition, a terminal portion of the predetermined bus bar 153 projects outward from the premolded resin 132 as a terminal.

(Pre-molding process)
11 is a schematic cross-sectional view showing a state in which the assembly shown in FIG. 9 is being pre-molded (first molding) by a pre-molding die while positioning using the positioning pins, and FIG. FIG. 12 is a cross-sectional view showing the stator unit (premolded body) obtained in the premolding step shown in FIG. 11 taken out from the mold.

  In the pre-molding step, as shown in FIG. 11, the assembly shown in FIG. 9, that is, the assembly in which the bus bar unit 155 is assembled to the stator 140 is used for pre-molding (first molding die) 501. , 502. At that time, by inserting the positioning pin 505 into the positioning hole 147 formed in the stator core 141, the assembled stator 140 such as the bus bar 153 is positioned and fixed to the molds 501 and 502. In this case, since the three positioning holes 147 are provided in parallel with each other, the positioning pins 505 can be inserted in parallel from the same direction.

  Then, in that state, a molten resin is injected into the cavities of the molds 501 and 502 to mold the main part of the stator 140, the bus bar unit 155 and the like with the pre-molding resin 132. As a result, the stator unit 130 as shown in FIGS. 12 and 10 is obtained. In the stator unit 130, which is a molded body of this resin, the positioning holes 147 (ears 144) of the stator core 141 are exposed to the outside of the resin.

(Overmolding process)
FIG. 13 is a schematic cross-sectional view showing a state in which the stator unit shown in FIG. 12 is being over-molded (second molding) by an over-molding die while positioning using the positioning pins.

  In the overmolding step, the stator unit 130 obtained in the premolding step is set in overmolding dies (second molding dies) 511 and 513 as shown in FIG. At that time, by inserting the positioning pin 515 into the positioning hole 147 formed in the stator core 141, the stator unit 130 is positioned and fixed to the molds 511 and 513. Further, the bearing holder 123 and the collar 127 are set in a predetermined die 513 so that insert molding can be performed.

  Then, in this state, the molten resin is injected into the cavities of the molds 511 and 513, and the stator unit 130 is molded with the overmold resin 122. As a result, the motor body 120 is obtained. By this overmolding, the motor main body 120 is formed with the connector portion 160 having the terminal portion of the predetermined bus bar 153 as a terminal. In the motor body 120, which is a molded body of this resin, the positioning hole 147 of the stator core 141 is still in a state in which the positioning pin can be inserted from the outside.

(Cutting process)
FIG. 14 is a schematic cross-sectional view showing a state in which the molded product (motor main body) after overmolding shown in FIG. 13 is set in the cutting machine while positioning is being performed using the positioning pin and is about to be cut.

  In the motor body 120 obtained by overmolding, there are portions where the processing accuracy is insufficient as it is. Here, as the location where the machining accuracy is insufficient, the fitting portion 124 (fitting outer peripheral surface 124a, abutting surface 124b) on the outer periphery of the motor main body 120 and the bearing fitting portion (bearing inner peripheral wall 123a and the fitting inner peripheral wall 123a of the bearing holder 123 are projected. The wall 123b) is mentioned. In order to improve the accuracy of these parts, the molded product (motor main body 120) after overmolding is subjected to machining, that is, cutting. Finished surfaces obtained by cutting are shown by reference numerals K1 to K4 in FIG.

  The finishing surface K1 and the finishing surface K2 are the fitting outer peripheral surface 124a and the abutting surface 124b of the fitting portion 124 on the outer circumference of the motor body 120. The finished surfaces K3 and K4 are the fitting inner peripheral wall 123a and the abutting wall 123b of the bearing holder 123. The finished surfaces K1 and K3 are finished as cylindrical surfaces parallel to the axial direction of the motor body 120. Further, the finished surfaces K2 and K4 are finished as planes orthogonal to the axial direction of the motor body 120.

  In this cutting process, when the motor body 120 is set on the cutting machine, the positioning hole 147 formed in the stator core 141 is used for positioning. That is, when setting the work (motor main body 120) held by the suction chuck 551 to the processing jig 550 of the cutting machine (not shown), the positioning pin 555 protruding from the processing jig 550 is attached to the motor main body 120. It is inserted into the positioning hole 147 of the stator core 141 buried in the. Thereby, the motor body 120 can be correctly positioned and set on the cutting machine. In that state, the finished product can be obtained by cutting the motor body 120 at a predetermined position.

  As described above, by inserting the positioning pins 505, 515, 555 into the positioning holes 147 of the stator core 141, the work (stator core 141, stator 140, stator unit 130) can be used in the winding process, the molding process, and the cutting process. The motor body 120) can be reliably and accurately positioned and fixed. Therefore, it is possible to improve workability and product quality and accuracy. Further, since the same positioning hole is used in the cutting process and the molding process, the accuracy can be further improved. Therefore, it is possible to prevent the axis of the motor unit (electric motor) 100 from tilting or being misaligned, and improve the accuracy of the axis to improve the performance of the electric pump 1.

  Further, by providing a plurality of positioning holes 147, particularly three or more, it is possible to position and support the stator core 141, the stator 140, the stator unit 130, and the motor body 120 in a well-balanced manner. Further, since the positioning hole 147 is formed along the axial direction, the radial position of the work (stator core 141, stator 140, stator unit 130, motor main body 120) is determined by the position of the positioning pins 505, 515, 555. It can be easily and accurately managed.

  As shown in FIG. 15, the motor body 120 manufactured as described above has holes 614 for the positioning pins 515 (see FIG. 13) formed after overmolding. 615 (see FIG. 16) is injected, and the silicon 615 is cured by heating. At that time, as shown in FIG. 16, the silicon 615 is also injected into the positioning hole 147 of the stator core 141. That is, since the positioning hole 147 and the removal hole 614 are located on the same plane and formed along the same direction, the silicon 615 can be easily injected into the positioning hole 147 and the removal hole 614.

(Rotor)
Next, the rotor 110 inserted into the motor body 120 manufactured as described above will be described.
As shown in FIG. 3, the rotor 110 is rotatably provided on the inner peripheral side of the stator 140 of the motor body 120. Further, a uniform air gap is secured in the circumferential direction between the outer peripheral surface of the rotor 110 and the inner peripheral surface of the stator 140.

  17 is a perspective view showing the rotor 110 taken out, and FIG. 18 is an exploded perspective view of the rotor 110. 19 to 21 are explanatory views of the manufacturing method of the rotor 110. 19 is a cross-sectional view showing a step of press-fitting the shaft into the rotor core arranged inside the magnet cover, and FIG. 20 is a sectional view showing the magnet in the annular space between the magnet cover and the rotor core after the step shown in FIG. FIG. 21 is a cross-sectional view showing the state of the step of inserting the magnet, and FIG. 21 is a cross-sectional view showing the state of the step of curing the adhesive disposed between the magnet cover and the rotor core and the magnet after the step shown in FIG. ..

  As shown in FIGS. 17 and 18, the rotor 110 includes a shaft 101, a rotor core 111 arranged on the outer periphery of the shaft 101, and a plurality of rotors 110 arranged on the outer periphery of the rotor core 111 along the circumferential direction (4 Individual magnets 112, a cylindrical magnet cover 113 that covers the outer periphery of the magnets 112, and side plates 114 and 115 that are arranged on both axial end surfaces of the rotor core 111. The rotor core 111 is made of a magnetic material, and the magnet cover 113 is made of a non-magnetic metal such as stainless steel or aluminum as a thin member. The side plates 114 and 115 are made of non-magnetic metal or resin.

  The rotor core 111 is made of a laminated body of magnetic steel plates, and is provided with four magnet positioning protrusions 111a extending along the axial direction on the outer peripheral surface at regular intervals in the circumferential direction. Each of the magnets 112 is formed in a quarter-arc cylindrical shape so that a combination of four magnets forms a cylindrical ring magnet. The axial length of the magnet 112 is slightly shorter than the axial length of the rotor core 111. These magnets 112 are prepared such that two magnets each have an NS pole toward the inside and the outside in the radial direction of the rotor 110, and two magnets each have an SN pole on the contrary. They are arranged alternately in the direction. That is, it has a four-pole structure. The magnetic pole of each magnet 112 extends parallel to the axis of the rotor 110.

  As shown in FIGS. 19 to 21, the magnet cover 113 is provided with a cylindrical peripheral wall 113a that covers the outer periphery of the magnet 112, and is connected to one axial end of the cylindrical peripheral wall 113a so as to extend radially inward and to have a central opening 113c. Has an annular inner flange 113b whose diameter (inner diameter) is smaller than the outer diameter of the rotor core 111. The inner flange 113b has a flat plate ring shape orthogonal to the axis of the cylindrical peripheral wall 113a. The magnet cover 113 is manufactured by, for example, drawing.

  Further, the one side plate 114 is arranged on the one axial end surface side of the rotor core 111, and is press-fitted onto the shaft 101 so that the inner flange of the magnet cover 113 is formed between the one side plate 114 and the axial one end surface of the rotor core 101. It holds 113b. The magnet 112 is inserted in an annular space secured between the cylindrical peripheral wall 113 a of the magnet cover 113 and the outer peripheral surface of the rotor core 111 while being in contact with the outer peripheral surface of the rotor core 111.

  Bonding between the opposing peripheral surfaces is performed between the inner peripheral surface of the magnet 112 and the outer peripheral surface of the rotor core 111, and between the outer peripheral surface of the magnet 112 and the inner peripheral surface of the cylindrical peripheral wall 113a of the magnet cover 113. Adhesive layers m1 and m2 of the agent G are provided.

(Method of manufacturing rotor)
The rotor 110 is manufactured by mounting the magnet cover 113 before the magnet 112, so that the rotor 110 is manufactured in the following process sequence.

  In the first step, as shown in FIG. 19, the rotor core 111 is concentrically arranged inside the magnet cover 113, and an opening on the one end side in the axial direction is provided between the magnet cover 113 and the rotor core 111. An annular space 117 closed by the inner flange 113b of 113 is secured. In addition, the shaft 101 is press-fitted into the rotor core 111, and the magnet cover 113 is provided between the side plate 114 and the axially one end face of the rotor core 111, which are separately press-fitted to the shaft 101, on the axially one end face side of the rotor core 111. The inner flange 113b is clamped.

  In the next step, as shown in FIG. 20, the shaft 101 is arranged with the inner flange 113b facing downward and the opening on the other end side in the axial direction of the magnet cover 113 facing upward. Then, with the adhesive G applied to the outer peripheral surface of the rotor core 111 and the inner peripheral surface of the cylindrical peripheral wall 113a of the magnet cover 113, the magnet 112 is applied to the outer peripheral surface of the rotor core 111 and the inner peripheral surface of the cylindrical peripheral wall 113a of the magnet cover 113. It is inserted from above relative to the annular space 117 secured between and.

  In the next step, as shown in FIG. 21, the other side plate 115 is press-fitted onto the shaft 101 to heat and cure the adhesive G (see FIG. 20). As a result, the magnet 112 is integrally fixed to the rotor core 111 and the magnet cover 113 by the adhesive layers m1 and m2.

  As described above, since the inner flange 113b is provided at one end of the magnet cover 113, it is possible to prevent the adhesive G from dripping onto the outer surface of the component. That is, the lower end of the annular space 117 between the magnet cover 113 and the rotor core 111 is closed by the inner flange 113b of the magnet cover 113, so that the adhesive G is applied to the outer peripheral surface of the rotor core 111 and the inner peripheral surface of the magnet cover 113. When the magnet 112 is inserted into the annular space 117, even if the adhesive 112 applied to the outer peripheral surface of the rotor core 111 and the inner peripheral surface of the magnet cover 113 is scraped off by the magnet 112, it drips. It is possible to prevent the adhesive G from leaking to the outer surface. Further, even when the adhesive G is cured by heating, it is possible to prevent the adhesive G from leaking to the outer surface. Therefore, the work of wiping off the dripping adhesive is unnecessary, and the workability of assembly can be improved. Further, since the side plates 114, 115 are arranged on both end surfaces of the rotor core 111 in the axial direction, it is possible to easily prevent the magnet 112 from falling off in the axial direction.

(Assembling the electric pump)
The rotor 110 manufactured as described above is housed inside the motor body 120, the impeller 220 is attached to the front end of the shaft 101, and then the motor body 120 is coupled to the pump casing 210. At that time, the front end and the rear end of the shaft 101 are supported by the motor main body 120 and the pump casing 210 by the front bearing 102 and the rear bearing 103. By doing so, the electric pump 1 is completed.

(Alumite treatment of pump casing)
Next, the surface treatment of the pump casing 210 will be described.
As described above, the pump casing 210 is made of a cast aluminum product and is subjected to alumite treatment as a surface treatment for ensuring corrosion resistance and durability. Particularly, on the outer surface of the pump casing 210 in the present embodiment, the first alumite layer formed by subjecting the casting surface to the first alumite treatment, and the casting surface is subjected to the cutting processing, and the cutting surface is provided with the second alumite. The second alumite layer formed by performing the treatment is provided. The second alumite layer is formed as a surface treatment layer having a surface roughness smaller than that of the first alumite layer.

FIG. 22 is an explanatory diagram of a method for manufacturing the pump casing 210.
In order to obtain the pump casing 210 of this embodiment, the process proceeds in the order of the steps of FIGS. In each of FIGS. (a) to (d), the upper drawing shows the front surface 210A of the pump casing 210, and the lower drawing shows the back surface 210B of the pump casing 210.

  At the beginning of the manufacturing process, first, the pump casing 210 is made by casting aluminum. FIG. 22(a) shows a state of casting after casting with aluminum. That is, the outer surface of the pump casing 210, which is the main body of the aluminum casting, is in the state of the casting surface S1.

  Next, sulfuric acid alumite treatment (first alumite treatment) is applied to the entire surface of the pump casing 210 (aluminum cast product body). FIG. 22B shows a state in which a sulfated alumite layer (first alumite layer) S2 having a large film thickness is formed on the entire casting surface S1. In this sulfate alumite treatment, a sulfate alumite layer (first alumite layer) S2 having a required film thickness is formed on the entire casting surface S1 on which the alumite layer is difficult to attach. Since the casting surface S1 is subjected to the alumite treatment for a long time, the sulfate alumite layer S2 has a large surface roughness.

  Next, a cutting process is performed on a required portion (a predetermined portion). For example, the periphery of the suction port and the discharge port on the front surface 210A side of the pump casing 210 and almost the entire back surface 210B are cut. As shown in FIG. 22(c), in the cut portion, the sulfated alumite layer S2 and the casting surface S1 are removed, and the newly cut surface S3 is exposed.

  Next, the entire pump casing 210 is subjected to oxalic acid alumite treatment (second alumite treatment). Then, since the portion having the sulfate alumite layer S2 is an insulating surface, the portion is not coated with alumite, and only the cut surface S3 is formed, as shown in FIG. 22(d), as shown in FIG. 22(d). Is formed. Therefore, the oxalic acid alumite layer S4 on the cut surface S3 can be a surface treatment layer having a small film thickness and a small surface roughness. In other words, this is a surface-treated surface that is advantageous when ensuring sealing performance on the cut surface.

  As described above, the cutting process is performed after the first alumite layer is formed, and the second alumite treatment (oxalic acid alumite treatment) is performed after the cutting process. Therefore, it is possible to easily perform only the machining surface without using a masking member. A second alumite layer (oxalic acid alumite layer) can be formed on the second layer. That is, at the time of the second alumite treatment, the insulating property of the first alumite layer previously formed on the casting surface is utilized to form the second alumite layer whose surface roughness is efficiently suppressed only on the machined surface. be able to. Therefore, the surface roughness of the second alumite layer can be suppressed, which is advantageous in the case of ensuring the sealing property on the cut surface. The cutting process also serves as a preparation process for the second alumite treatment.

  Further, since the sulfated alumite layer S2, which is the first alumite layer, can be formed with a sufficient film thickness with respect to the casting surface S1, the durability can be improved. Further, since the oxalic acid alumite layer S4 is formed on the second alumite layer, the durability of the cut surface S3 can be maintained high.

As a result, the electric pump 1 having both corrosion resistance and good sealability can be assembled.
When there is a particularly high dimensional accuracy (for example, a sealing surface) in the machined surface, such as the location indicated by S5 in FIG. 23, the alumite layer at that location has a surface roughness corresponding to the underlying surface. Is processed.

  The method of performing the alumite treatment twice with the cutting process interposed is not limited to the pump casing but can be widely applied to aluminum cast products.

The present invention is not limited to the above-described embodiments, and includes various modifications of the above-described embodiments without departing from the spirit of the present invention.
For example, in the above-described embodiment, the case where the pump unit 200 of the electric pump 1 is driven by the motor unit 100 to discharge the combustible gas under pressure has been described. However, the present invention is not limited to this, and a pump that pressurizes and discharges oil may be adopted instead of the pump unit 200. In addition to the pump unit 200, the configuration of the motor unit 100 as described above can be applied to various electric motors.

  Further, in the above-described embodiment, the case where the side plates 114 and 115 are press-fitted to the shaft 101 has been described. However, the present invention is not limited to this, and the side plates 114 and 115 may be externally fitted and fixed to the shaft 101.

  Moreover, in the above-mentioned embodiment, the case where sulfuric acid alumite was used as the first alumite treatment was described. However, the present invention is not limited to this, and oxalic acid alumite may be appropriately added to the sulfuric acid alumite which is the main component according to the object to be treated.

1... Electric pump 100... Motor part 101... Shaft 110... Rotor 111... Rotor core 112... Magnet 113... Magnet cover 113a... Cylindrical peripheral wall 113b... Inner flange 114... Side plate 115... Side plate 120... Motor body 122... Pre-molded resin ( Mold resin part)
123... Bearing holder 123a... Fitting inner peripheral wall 123b... Abutting wall 124... Fitting portion 124a... Fitting outer peripheral surface 124b... Abutting surface 126... Ear 127... Collar 128... Bolt through hole 130... Stator unit 132... Overmolding Resin (molded resin part)
140... Stator 141... Stator core 142... Cylindrical part 143... Teeth 144... Ear part 146... Through hole 147... Positioning hole 148... Connecting pin 149... Cover member 150... Coil 151... Insulator 153... Bus bar 155... Bus bar unit 160... Connector part 200... Pump part 210... Pump casing 210A... Front surface 210B... Back surface 211... Suction port 212... Discharge port 213... Boss part 214... Fitting part 214a... Fitting inner peripheral surface (sealing surface)
214b... Abutting surface 215... Pump channel 216... Ear portion 219... Ear portion 220... Impeller (pump mechanism)
221... Boss portion 222... Blade row 223... Shaft hole 501... Mold 502... Mold 505... Positioning pin 511... Mold 513... Mold 515... Positioning pin 550... Cutting jig 551... Suction device 555... Positioning pin 615 … Silicon K1… Cutting surface (fitting outer peripheral surface 124a)
K2... Cutting surface (fitting abutting surface 124b)
K3... Cutting surface (fitting inner peripheral surface 123a of bearing holder)
K4... Cutting surface (fitting abutting surface 123b of bearing holder)
S1... Cast surface S2... Sulfate alumite layer (first alumite layer)
S3... Cutting surface S4... Oxalic acid alumite layer (second alumite layer)
S5...High precision machining surface

Claims (3)

The motor part,
A pump mechanism driven by the motor unit, and a pump unit having a pump casing coupled to the motor unit;
Equipped with
A method of manufacturing an electric pump, wherein the pump casing and the motor portion are fitted together at a sealing surface of the pump casing so as to have the pump mechanism inside,
A manufacturing process of the pump casing,
A pump assembly step of assembling the pump casing, the motor section, and the pump mechanism;
Have
The manufacturing process of the pump casing is
An aluminum casting step of casting an aluminum cast body into the shape of the pump casing;
Forming a first alumite layer on the casting surface by applying a first alumite treatment on the entire surface of the aluminum casting body,
After the step, a step of forming a cutting surface by performing a cutting process on at least a predetermined part of the aluminum casting body from above the first alumite layer , including at least the sealing surface of the pump casing ,
After the step, a step of forming a second alumite layer only on the cut surface by performing a second alumite treatment on the entire surface of the aluminum cast product body,
The method for producing an aluminum cast product, wherein the second alumite layer is formed as a surface treatment layer having a surface roughness smaller than that of the first alumite layer.   The method for manufacturing an aluminum cast product according to claim 1, wherein the first alumite layer is composed of alumite sulfate.   The said 2nd alumite layer is comprised by the oxalic acid alumite, The manufacturing method of the aluminum casting process product of Claim 1 or Claim 2 characterized by the above-mentioned.

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