Powder removal method

Abstract

To provide a powder removal method for efficiently removing powder adhered to an annular member with a simpler configuration.SOLUTION: In a powder removal method 1: each leg section 901 of a plurality of segment conductors 9 having two leg sections 901 is inserted into a slot 701 of a cylindrical stator core 70 having a plurality of slots 701, and protruded to the opposite side; and in a stator 7 of a rotary electric machine in which the leg section 901 is not joined yet, powder or foreign matters adhered to a section of a segment conductor 9 exposed to an outside of the slot 701 and its periphery are removed by air blow. The powder removal method 1 includes an inter-coil blowing step 11 and a conductor blowing step 13.SELECTED DRAWING: Figure 8

Description

[Technical field]

[0001] The present invention relates to a powder removal method. [Background technology]

[0002] In the stator manufacturing process, after the coil is placed in the slit, a varnish impregnation process and an excess varnish removal process are performed, but the removed varnish often adheres to the stator surface as foreign matter, making a foreign matter removal process necessary. For this reason, devices and methods for removing foreign matter adhered to the annular member have been conventionally known.

[0003] The foreign matter removal process is often performed by air blowing. For example, Patent Document 1 describes a foreign matter removal device and method having a central nozzle that blows air obliquely outward from the radial direction inside the annular workpiece and peripheral nozzles that blow air obliquely inward from the radial direction outside the annular workpiece. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2006-224067 A Summary of the Invention [Problem to be solved by the invention]

[0005] The above-mentioned prior art uses a nozzle that jets air diagonally outward and a nozzle that jets air diagonally inward in parallel to the radial direction to generate a swirling air flow. It also describes how the nozzle moves along the axial direction of the core, how the work area is shielded, and how a suction means is used in combination to enhance the effect of removing foreign matter.

[0006] However, this configuration is not efficient because the removed foreign matter has to travel a long distance before being sucked in, and there is a risk that it will float in the air and reattach to the workpiece.In addition, since the method involves blowing the entire circumference of the target part of the workpiece at the same time and shielding the entire work area, the device tends to become large.

[0007] The present invention has been made in consideration of this point, and an object of the present invention is to provide a powder removal method that can more efficiently remove powder adhering to an annular member with a simpler configuration. [Means for solving the problem]

[0008] The present invention relates to a powder removal method (1) for removing powder or foreign matter adhering to portions of the segment conductors exposed outside the slots and their surroundings by air blowing, for a rotating electric machine stator (7) in which two legs (901) of each of a plurality of segment conductors (9) are inserted into a plurality of slots (701) formed in a cylindrical stator core (70) and protrude to the opposite side, and the legs have not yet been joined.

[0009] The powder removal method according to one embodiment of the present invention includes an inter-coil blow step (11) and a conductor blow step (13). Here, the axial direction of the stator core is defined as the top-to-bottom direction, the cylindrical end face on the side where the legs are inserted into the slots is defined as the top surface (70A) of the stator core, and the cylindrical end face on the side where the legs protrude to the opposite side of the slots is defined as the bottom surface (70B) of the stator core.

[0010] At this time, in the inter-coil blowing step, the first air supply duct (33) blows air radially outward from the axial side of the stator core into multiple gaps (SA) formed between the top surface and the portions of the segment conductors exposed to the outside of adjacent slots, and the first suction duct (39) sucks the blown air radially outward, removing powder or foreign matter adhering to the gaps and their surroundings.

[0011] In the conductor blow step, the second blower duct (55) blows air along the axial direction of the stator core to the tips (SC) of the legs protruding from the slots at the bottom surface so that the blown air abuts the bottom of the tips, and the second suction duct (57) sucks the blown air on both sides of the tips, i.e., on the axial side and radially outside of the stator core, to remove powder or foreign matter adhering to the tips and their surroundings.

[0012] The inter-coil blow step and the conductor blow step are performed while rotating the stator core in the circumferential direction about the axis of the stator core, for each blow target location.

[0013] (Effects of one embodiment) According to one embodiment of the present invention, instead of blowing all the target locations in the circumferential direction at once, the blowing and suction means are individually arranged in close proximity to each target location, and the stator core is gradually rotated while removing and collecting the powder at each target location, which makes it possible to more reliably and efficiently remove the powder adhering to the annular member, and also effectively reduces the amount of powder that is missed. Furthermore, by arranging the suction means in close proximity to the blowing means, it is no longer necessary to shield the entire work area, and the device can be made more compact. [Brief description of the drawings]

[0014] [Figure 1] FIG. [Diagram 2] FIG. [Diagram 3] FIG. [Figure 4] FIG. 4 is a partial cross-sectional view (side view) showing a stator core and a main part of a blow device. [Diagram 5] A partially enlarged view of part V in Figure 4. [Figure 6] FIG. [Figure 7] FIG. 7 is a partially enlarged view of part VII in FIG. 4 . [Figure 8] FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0016] (One embodiment) One embodiment of the present invention is a powder removal method 1 for removing powder or foreign matter adhering to the outside of the slots 701 of the segment conductors 9, i.e., the exposed portions on the top surface 70A and bottom surface 70B sides of the stator core 7 and their surrounding areas, from a stator 7 of a rotating electric machine in which two legs 901 of each of a plurality of segment conductors 9 are inserted into a plurality of slots 701 formed in a cylindrical stator core 70 and protrude to the opposite side, and the legs 901 have not yet been joined. The method uses air blowing to remove powder or foreign matter adhering to the outside of the slots 701 of the segment conductors 9, i.e., the exposed portions on the top surface 70A and bottom surface 70B sides of the stator core 7 and their surrounding areas.

[0017] In this embodiment, the powder removal method includes an inter-coil blowing step 11, an upper surface blowing step 12, and a conductor blowing step 13. Each step is performed for each blow target location while gradually rotating the stator core 70 in the circumferential direction around the axis of the stator core 70.

[0018] 1 and 2 show a stator core 70 and a segment conductor 9 of the present invention. A plurality of slots 701 are formed in the stator core 70 radially from the axis. The segment conductor 9 has a head 900 and two legs 901. The axial direction of the stator core 70 is the top-to-bottom direction, and the cylindrical end face of the stator core 70 on the side where the legs 901 are inserted into the slots 701 is the top surface 70A of the stator core 70, and the cylindrical end face of the stator core 70 on the side where the legs 901 protrude to the opposite side of the slots 701 is the bottom surface 70B of the stator core 70.

[0019] Fig. 3 shows a combination of the stator core 70 and the segment conductors 9. The legs 901 are inserted into the slots 701 from the top surface 70A side (Fig. 3) and protrude toward the bottom surface 70B side (Fig. 4 shown later). On the top surface 70A side, many segment conductors 9 are densely inserted into the slots 701, and the portions of the segment conductors 9 exposed to the outside of adjacent slots 701 and the top surface 70A form multiple gaps SA as shown in Fig. 3. On the bottom surface 70B side, the legs 901 protrude continuously along the circumferential direction of the stator core 70 (also Fig. 4).

[0020] 4 shows the main part of the blowing device used in this embodiment. The stator core 70 is placed on a rotating device (not shown), and an inter-coil blowing step 11 and an upper surface blowing step 12 are performed above the stator core 70 (top surface 70A side, area V enclosed by dotted line), and a conductor blowing step 13 is performed below the stator core 70 (bottom surface 70B side, area VII enclosed by dotted line).

[0021] [Top air blower] Fig. 5 shows an enlarged view of the area V enclosed by the dotted line in Fig. 4. In the inter-coil blowing step 11, the first blower duct 33 blows air from the axial side of the stator core 70 toward the radially outward direction into the gaps SA formed by the portions of the segment conductors 9 on the top surface 70A that are exposed to the outside of the adjacent slots 701, and the first suction duct 39 sucks the blown air outward in the radial direction, removing powder or foreign matter adhering to the gaps SA and their periphery. At this time, the air is blown diagonally from above, weaving through the gaps SA, so that the varnish in the areas that do not need to be peeled off is not blown away and destroyed.

[0022] The inter-coil blowing step 11 is performed for each blow target location while gradually rotating the stator core 70 in the circumferential direction around the axis of the stator core 70. In this way, the insulating powder is reliably collected by blowing and sucking each part that may adhere to the workpiece (stator core 70) and affect its function.

[0023] This embodiment further includes an upper surface blowing step 12 performed in parallel with the inter-coil blowing step 11. In this upper surface blowing step 12, the third blower duct 36 blows air from one side to the other on the outer region SB of the top surface 70A that is radially outward of the gap SA. This removes powder or foreign matter adhering to the outer region SB and its periphery.

[0024] 6 shows the blow targets and blow directions in the inter-coil blow step 11 and the top surface blow step 12. The shaded areas are the outer areas SB that are the blow targets in the top surface blow step 12. In the inter-coil blow step 11, air is blown into the gaps SA from the axial side of the stator core 70 toward the radial outside, while in the top surface blow step 12, air is blown from one side to the other in the area radially outside the gaps SA.

[0025] 6 also illustrates the rotation direction of the workpiece, stator core 70. In this way, by rotating stator core 70 around the axis on a plane perpendicular to the axis in accordance with the position of the gap SA, each gap SA and its surroundings are reliably blown one by one (inter-coil blow step 11), and in parallel, the outer region SB is blown (upper surface blow step 12), removing powder or foreign matter while minimizing omissions.

[0026] [Bottom air blower] Fig. 7 shows an enlarged view of the area VII enclosed by the dotted line in Fig. 4. In the conductor blowing step 13, the second blowing duct 55 blows air along the axial direction of the stator core 70 to the tips SC of the legs 901 protruding from the slots 701 on the bottom surface 70B so that the blown air abuts against the bottom of the tips SC, and the second suction duct 57 sucks the blown air on both sides of the tips SC, i.e., on the axial side and the radial outside of the stator core 70, to remove powder or foreign matter adhering to the tips SC and their periphery. The tips SC are areas where it is not necessary to remove excess varnish, so the suction volume is set to be greater than the blown air volume.

[0027] 8 shows the powder removal method 1 according to one embodiment described above. In this embodiment, the inter-coil blow step 11, the upper surface blow step 12, and the conductor blow step 13 are all performed simultaneously on the top surface 70A and the bottom surface 70B of the stator core 70, thereby efficiently removing powder.

[0028] [Background to the invention] In recent years, in stator manufacturing, instead of the conventional insulating paper called paper insulator, a varnish impregnation process and excess varnish stripping process are carried out after the coil is installed in the slit. However, this method has resulted in the generation of a lot of insulating powder (stripped varnish) that was not generated with the insulating paper method. This adheres to the stator surface as foreign matter and causes production defects, so an effective method of removing the insulating powder was required.

[0029] However, (A) simply increasing the airflow to remove the powder would blow away and destroy the varnish in areas where the excess varnish does not need to be removed, while (B) decreasing the airflow would not remove the insulating powder well, and (C) too little airflow would cause the insulating powder to reattach to the product once it had been removed.

[0030] [Effects of the present invention] In response to these issues, in the present invention, instead of covering the entire work area as in Patent Document 1, a blowing device and a suction device are placed close to each area that needs removal and air is blown off and removed, and then the insulating powder is sucked and collected, making it possible to collect the insulating powder more efficiently. In addition, because the stator core is rotated so that the air hits only the areas that need it, the varnish in areas where the excess varnish does not need to be peeled off is not blown off and destroyed, and the insulating powder can be efficiently removed from the entire stator core.

[0031] (Other embodiments) The above embodiment has been described assuming a specific stator core, but the shape of the stator core and the number of slots, etc., that are the subject of the powder removal method of the present invention are not limited to the example in FIG.

[0032] In the above embodiment, each step is performed simultaneously, but the order of steps in the powder removal method is not limited to this example. Each step may be performed in order, or the upper surface blow step or the conductor blow step may be omitted as necessary. In addition, other blow removal patterns may be combined.

[0033] As described above, the present invention is not limited to the above-described embodiment, and can be embodied in various forms without departing from the spirit of the present invention. [Explanation of symbols]

[0034] 1 Powder removal method 11 Inter-coil blow step, 13 Conductor blow step 33 First ventilation duct, 39 First suction duct 55 Second ventilation duct, 57 Second suction duct 7 stator, 70 stator core, 701 slot, 70A top surface, 70B bottom surface 9 segment conductor, 901 legs SA gap, SC tip

Claims

1. A powder removal method (1) for a rotating electric machine stator (7) in which two legs (901) of a plurality of segment conductors (9) are inserted into a plurality of slots (701) formed in a cylindrical stator core (70) and protrude to opposite sides, and the legs have not yet been joined, the method removing powder or foreign matter adhering to portions of the segment conductors exposed outside the slots and their surroundings by air blowing, the method comprising the steps of: When the axial direction of the stator core is the top-bottom direction, the cylindrical end surface on the side where the leg is inserted into the slot is the top surface (70A) of the stator core, and the cylindrical end surface on the side where the leg protrudes to the opposite side of the slot is the bottom surface (70B) of the stator core, an inter-coil blowing step (11) in which a first blower duct (33) blows air from the axial side of the stator core toward the outside into a plurality of gaps (SA) formed between the top surface and portions of the segment conductors exposed to the outside of the adjacent slots, and a first suction duct (39) sucks the blown air outward in the radial direction, thereby removing powder or foreign matter adhering to the gaps and their peripheries; a conductor blowing step (13) in which a second blowing duct (55) blows air along the axial direction of the stator core to the tips (SC) of the legs protruding from the slots on the bottom surface so that the blown air abuts against the bottom of the tips, and a second suction duct (57) sucks the blown air on both sides of the tips, i.e., on the axial side and radially outside of the stator core, thereby removing powder or foreign matter adhering to the tips and their periphery, The powder removal method, wherein the inter-coil blowing step and the conductor blowing step are performed while rotating the stator core in a circumferential direction around an axis of the stator core for each blow target location.

2. The method further includes a top surface blowing step (12) in which a third blower duct (36) blows air from one side to the other of an outer region (SB) of the top surface that is radially outward from the gap, thereby removing powder or foreign matter adhering to the outer region and its periphery, The powder removal method of claim 1 , wherein the top surface blowing step is performed in parallel with or after the inter-coil blowing step.

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