JPS6143941B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of manufacturing a molded commutator used in a rotating electric machine.

FIG. 1 is an upper half vertical sectional view showing the general structure of a molded commutator.

In the figure, 1 is a commutator cylinder constituted by alternately arranging a predetermined number of commutator pieces 2 and inter-piece mica 3, and 4 and 4' are U formed on both end faces of this commutator cylinder 1, respectively. An annular groove with a letter-shaped cross section, 5 a commutator spider arranged concentrically with the commutator cylinder 1 with an air gap between it and the inner periphery of the commutator cylinder 1, and 6 and 6' insulating materials at multiple locations on the cylinder, respectively. A plurality of reinforcing rings made of iron, 8 partially covered with binders 7 and 7' consisting of is filled in the gap between the commutator cylinder 1 and the commutator spider 5 as well as the annular grooves 4 and 4' of the commutator cylinder 1 so as to cover both end faces of the commutator cylinder 1. It is a thermosetting resin that is bonded together. The reinforcing rings 6 and 6' that are fitted into the annular grooves 4 and 4' of the commutator cylinder 1 are inserted into the annular grooves 4 and 4' of the commutator cylinder 1 as the rotating electric machine rotates.
It is used to support the centrifugal force that occurs in
Used for medium and large commutators with an outer diameter of approximately 50 mm or more. On the other hand, in the case of a small commutator with an outer diameter of 50 mm or less, the centrifugal force generated in the commutator cylinder 1 can be sufficiently supported by the resin 8 alone, so from the viewpoint of manufacturing cost, such reinforcement is not necessary. Rings 6 and 6' are not used.

A molded commutator generally has such a structure, and a riser portion 9 into which a rotor coil is normally inserted and connected is formed at the rear end portion. Conventionally, in manufacturing such molded commutators,
The method roughly shown in Figure 2 was adopted.
That is, a clamp that also serves as a molding jig is attached to the outer periphery of the commutator cylinder 1, which is constructed by alternately arranging a predetermined number of commutator pieces 2 and mica 3 between the pieces, with the sliding surface 10 in contact with the brush left unprocessed. After fitting the cylinder 11 with the cylinder 11 and tightening the commutator cylinder 1 from the periphery using appropriate means (not shown) applied to the tightening cylinder 11, and applying a predetermined seasoning to the mica 3 between the pieces, The commutator cylinder 1 tightened by the tightening cylinder 11 is machined,
Annular grooves 4 and 4' having a U-shaped cross section are formed on both end surfaces thereof, and a plurality of reinforcing rings 6 and 6' are respectively fitted into these annular grooves 4 and 4' via a binder (not shown). Thereafter, by suitably constructed means (not shown) in connection with the clamping cylinder 11, a commutator spider (not shown) is arranged concentrically with the commutator cylinder 1, and the outer periphery of this commutator spider is This commutator spider and the commutator cylinder 1 cover both end surfaces of the commutator cylinder 1 from the side.
The gap between the commutator spiders and the annular grooves 4 and 4' of the commutator cylinder 1 are filled with a resin (not shown), and the resin is thermoset to join the commutator spider and the commutator cylinder 1 together. Then, the commutator in which the commutator spider and the commutator cylinder 1 are integrally combined is taken out from the tightening cylinder 11, and the sliding surface 10 with the brush is machined on the commutator cylinder 1. By this, the riser portion 9 was formed. Generally, when manufacturing commutators,
In order to make the commutator strong enough to prevent phenomena such as high bars from occurring, the commutator cylinder is tightened from the circumference, heated, and seasoned several times to dry the resin component contained in the mica. By repeating this process, sufficient surface pressure is applied between the commutator pieces and the mica pieces.
In the conventional method for manufacturing a molded commutator, as described above, after the commutator spider and the commutator cylinder 1 are integrally joined with resin, the sliding contact surface 10 with the brush is machined on the commutator cylinder 1. By doing so, the riser portion 9 is formed.
After the riser portion 9 is formed, the contact area between the commutator pieces 2 and the inter-piece mica 3 becomes significantly smaller compared to the state after seasoning, and even though the commutator pieces 2 and inter-piece mica 3 have been sufficiently seasoned, The mutual surface pressure between the commutator pieces 2 and the mica pieces 3 is insufficient,
As a result, during the rotation of the rotating electric machine, a hyperbar phenomenon occurs partially in the commutator pieces 2 that make up the commutator cylinder 1, which can cause poor commutation or breakage of brushes. I couldn't escape it. Such a tendency becomes more pronounced as the height of the riser portion 9 formed at the rear end portion of the molded commutator increases. In addition, in the conventional method for manufacturing a molded commutator, as described above, the commutator cylinder 1 has an unprocessed sliding surface 10 that contacts the brush.
A tightening cylinder 11 is fitted onto the outer periphery of the commutator spider, and with the commutator cylinder 1 being tightened by the tightening cylinder 11, the resin is filled from the outer periphery of the commutator spider, and the tightening cylinder 11 is used as a molding jig. Since it also serves as an envelope for the commutator, the mold jig not only becomes large, but also becomes complicated in order to properly fill the resin, which increases the manufacturing cost of the molded commutator. The more expensive it was, the more disadvantages came.

The present invention was made to eliminate these drawbacks found in the conventional molded commutator manufacturing method, and uses a small, simple molding jig with good workability, so that phenomena such as high bar do not occur. The present invention provides a novel method for manufacturing a molded commutator that provides a strong molded commutator.

The details of the present invention will be explained below based on FIGS. 3 and 4.

In the present invention, as shown in the figure, at least one or more radial notch grooves 12 are formed in the tip portion to communicate the inner periphery and the outer periphery, and the pedestal 13 of the mold jig is formed in the axial direction from both end surfaces. A rotor of a rotating electrical machine is formed with a plurality of screw holes (not shown) for fastening the upper cover 14 or 15, respectively, and is fitted with a piston 16 operated by fluid pressure so as to be slidable in the axial direction. A commutator spider 17 is used in which the inner periphery of the shaft hole into which the shaft is fitted is precisely finished by grinding or the like. However, the shapes of the rear end portions of the commutator spider 17 used in the embodiment shown in FIG. 3 and the commutator spider 17 used in the embodiment shown in FIG. 4 are different.

FIG. 3 is a longitudinal sectional view showing an embodiment of the method for manufacturing a molded commutator according to the present invention.

In this embodiment, as shown in the figure, a predetermined number of commutators are cut off with a cutter or the like up to nearly 10 of the sliding contact surface with the brush, leaving a slight finishing margin, and a riser portion 9 is formed at the rear end portion. A tightening ring 18 is fitted onto the outer periphery of the sliding surface 10 of the commutator cylinder 1, which is constructed by alternately arranging pieces 2 and inter-piece mica 3, and which is in sliding contact with the brush. After tightening the commutator cylinder 1 from the periphery by a means (not shown) and applying a predetermined seasoning to the mica 3 between the pieces, the tightening ring 1 is
The commutator cylinder 1 tightened by the screws 8 is machined to form annular grooves 4 and 4' with a U-shaped cross section on both end faces thereof, and a binder (Fig. A plurality of reinforcing rings 6 and 6' are respectively fitted through the metal fittings (not shown), and then the tip of the brush-sliding surface 10 of the commutator cylinder 1 is formed on the pedestal 13 of the molding jig. By fitting into the fitting part 19, the commutator cylinder 1 is held downward by the pedestal 13 while being tightened by the tightening ring 18, and a radial direction is formed on the upper surface of the pedestal 13. Commutator spider 1 with cutout grooves 12 formed
A plurality of screw holes are formed in the pedestal 13 along a circumference concentric with the pilot part 19 so as to be in contact with the tip surfaces of the commutator spiders 17 and facing the screw holes formed in the tip surfaces of the commutator spiders 17. By inserting the reamer bolts 20 into the respective reamer holes (not shown) and screwing them into the threaded holes of the commutator spider 17, and tightening these reamer bolts 20, the commutator spider 17 is connected to the commutator cylinder 1. Hold concentrically. Next, a hole 21 that is precisely finished by grinding or the like is formed in the center with the same diameter as the shaft hole of the commutator spider 17, and an axial protrusion 22 is formed on the periphery, and the inner part of this protrusion 22 is formed on the lower surface. The lower surface of the upper lid 14 of the molding jig is formed with an annular groove 24 along the circumference in which the seal ring 23 is slidably fitted in the axial direction. , commutator spider 1
7, and a commutator spider 17 is attached to the upper cover 14 along a circumference concentric with the hole 21.
The reamer bolts 25 are inserted into a plurality of reamer holes (not shown) drilled to face the screw holes formed on the rear end surface, and are screwed into the screw holes of the commutator spider 17. 25
By tightening the upper cover 14, the upper cover 14 is tightly secured to the rear end surface of the commutator spider 17, and the set screws 26 are respectively screwed into the plurality of screw holes formed in the upper cover 14 along the annular groove 24. Then, the tips of each are brought into contact with the upper surface of the seal ring 23 fitted in this annular groove 24, and these set screws 2 are
6 in the tightening direction, the lower surface of this seal ring 23 is brought into close contact with the rear end surface of the commutator cylinder 1. As a result, a sealed space 27 into which resin, which will be described later, is injected from the annular grooves 4 and 4' of the commutator cylinder 1 to the outer periphery of the commutator spider 17 is formed by the pedestal 13, upper lid 14, and seal ring 23 of these molding jigs. is formed. The seal ring 23 is for compensating for dimensional errors in the axial direction between the commutator cylinder 1 and the commutator spider 17, and is designed to adjust the protrusion length of the axial protrusion 22 of the upper cover 14 when it is held by the pedestal 13. Commutator spider 17
The length of the seal ring 23 protruding from the rear end surface of the commutator cylinder 1 is made somewhat shorter than the length of the projection from the rear end surface of the commutator cylinder 1, and the seal ring 23 is brought into close contact with the rear end surface of the commutator cylinder 1 by the set screw 26 as described above. It is possible to effectively prevent the resin from leaking to the outside when the resin is injected. Once the pedestal 13, upper cover 14, and seal ring 23 of the molding jig have been set to the commutator cylinder 1 and commutator spider 17 in this way, after sufficiently preheating the whole, the hole 21 of the upper cover 14
A specified amount of thermosetting resin 8 is injected into the shaft hole of the commutator spider 17 from the hole 2 of the upper cover 14.
1 and the shaft hole of the commutator spider 17, and the piston 16 is slid in the direction of the arrow by fluid pressure, using the hole 21 of the upper cover 14 and the shaft hole of the commutator spider 17 as a cylinder. As a result, the resin 8 injected into the shaft hole of the commutator spider 17 is compressed under pressure. As a result, the resin 8 injected into the shaft hole of the commutator spider 17 flows from the radial notch groove 12 formed at the tip of the commutator spider 17 to the receiving part of the mold jig as shown by the arrow. It flows into the closed space 27 formed by the base 13, the upper lid 14, and the seal ring 23, and the air gap between the commutator cylinder 1 and the commutator spider 17 and the annular shape of the commutator cylinder 1 flow so as to cover both end faces of the commutator cylinder 1. Grooves 4 and 4' are densely filled. Under this pressurized state by the piston 16,
By heating the resin 8 at an optimal temperature for a predetermined period of time, the resin 8 is thermosetted, and the commutator cylinder 1 and the commutator spider 17 are firmly joined together. In this way, once the resin 8 is thermoset, the commutator cylinder 1 and the commutator spider 17 are integrally joined, and the molding work for the commutator is completed, the pedestal 13, upper cover 14, and seal of the molding jig are After removing the ring 23, piston 16, and tightening ring 18, press-fitting the molded commutator onto the rotor shaft, and inserting and connecting the rotor wire to the riser portion 9,
Machining is performed to finish the sliding contact surface 10 with the brush to regular dimensions. In this embodiment, the molding operation for the commutator is performed in this manner.

FIG. 4 is a longitudinal sectional view partially showing another embodiment of the method for manufacturing a molded commutator according to the present invention.

In the molding operation for the commutator as described above, the air flows from the shaft hole of the commutator spider through the radial notch groove into the sealed space formed by the molding jig and fills the air gap between the commutator cylinder and the commutator spider. Also, the volume of the resin filled in the annular grooves on both end faces of the commutator cylinder after thermosetting is apparently smaller than that of the resin before thermosetting that is injected into the shaft hole of the commutator spider. , in order to inject enough resin to join the commutator cylinder and commutator spider together, the volume of the shaft hole of the commutator spider must be
It needs to be about 2.5 times larger than that of the sealed space formed by the mold jig. Therefore,
In the embodiment shown in FIG. 3, the prescribed amount of resin may not be fully injected due to insufficient volume of the shaft hole of the commutator spider.

The present embodiment is designed to deal with such a case, and a pilot part 28 is formed on the rear end surface of the commutator spider 17 concentrically with the shaft hole thereof, and a pilot part 28 is formed in the molding jig at the center of the lower surface. A protrusion 29 that fits into the brazing part 28 is formed, and the protrusion 29 protrudes from the upper surface concentrically with the protrusion 29, and the center of the protrusion 29 is precision-finished by grinding to a diameter equal to that of the shaft hole of the commutator spider 17. An upper lid 15 is used in which a cylindrical protrusion 31 with a hole 30 extending up to the protrusion 29 is formed therein. When performing molding work on the commutator, use the cradle (not shown) of a molding jig that is exactly the same as in the embodiment in FIG.
The protrusion 2 of the upper cover 15 is attached to the spigot part 28 of the commutator spider 17 which is held concentrically with the commutator cylinder 1 which is tightened by a tightening ring (not shown).
At the same time, the commutator spider 17 is inserted along a circumference concentric with the hole 30 from the end surface of the cylindrical projection 31 of the upper lid 15 to the end surface of the projection 29.
Bolts 32 are inserted into a plurality of holes (not shown) drilled to face the screw holes formed on the rear end surface, and are screwed into the screw holes of the commutator spider 17. By tightening the upper lid 15, the upper cover 15 is tightly secured to the rear end surface of the commutator spider 17. At the same time, set screws 26 are respectively screwed into a plurality of screw holes formed along an annular groove 24 formed on the lower surface of the upper lid 15, which is exactly the same as that in the embodiment shown in FIG. These set screws 2
6 in the tightening direction, the lower surface of this seal ring 23 is brought into close contact with the rear end surface of the commutator cylinder 1. As a result, a sealed space 27 in which resin is injected from the annular groove 4 (not shown) and 4' of the commutator cylinder 1 to the outer periphery of the commutator spider 17 is formed by the pedestal/upper lid 15 and seal ring 23 of the molding jig. is formed. Once the molding jig's pedestal/upper cover 15 and seal ring 23 have been set to the commutator cylinder 1 and commutator spider 17 in this way, after sufficiently preheating the whole, insert the upper cover from the shaft hole of the commutator spider 17. A prescribed amount of thermosetting resin 8 is injected into the hole 30 of the cylindrical projection 31 of 15, and the piston 16 is fitted into the hole 30 of the upper lid 15.
The resin 8 injected from the shaft hole of the commutator spider 17 to the hole 30 of the upper cover 15 is pressurized and compressed by sliding it in the direction of the arrow by fluid pressure along the hole 30 of the commutator spider 17 and the shaft hole of the commutator spider 17. . As a result, the resin 8 injected from the shaft hole of the commutator spider 17 to the hole 30 of the upper cover 15 is transferred from the radial notch groove (not shown) formed at the tip of the commutator spider 17 to the mold jig. The gap between the commutator cylinder 1 and the commutator spider 17 and the commutator cylinder 1 flow into the closed space 27 formed by the cradle/upper lid 15 and the seal ring 23 and cover both end surfaces of the commutator cylinder 1. annular groove 4
and 4' are densely packed. By heating the resin 8 at an optimal temperature for a predetermined time under such pressurized state by the piston 16, the resin 8 is thermosetted, and the commutator cylinder 1 and commutator spider 17 are firmly integrated into one body. be combined. In this example,
In this way, the molding work for the commutator is performed, and in this embodiment, as described above, a molding jig is formed in the rear end surface of the commutator spider 17 at the center of the lower surface concentrically with the shaft hole thereof. Tainro Club 2
A protruding part 29 is formed to fit into the protruding part 8, and a hole 30 that protrudes concentrically with the protruding part 29 on the upper surface and reaches the protruding part 29 with the same diameter as the shaft hole of the commutator spider 17 extends through the center of the protruding part 29. Using the upper lid 15 in which the cylindrical protrusion 31 is formed, the upper lid 15 is attached to the spigot part 28 of the commutator spider 17.
At the same time, the upper cover 15 is fastened to the rear end surface of the commutator spider 17 with bolts 32, and the hole 30 of the cylindrical protrusion 31 of the upper cover 15 is inserted from the shaft hole of the commutator spider 17. Since the volume of the hole into which the resin 8 is injected is considerably larger than that in the embodiment shown in FIG. 3, there is no shortage of hole volume, and the rectification is Child cylinder 1 and commutator spider 1
Sufficient resin 8 can be injected to bond 7 together.

In this embodiment, as described above, the pilot part 28 is formed on the rear end surface of the commutator spider 17 concentrically with the shaft hole thereof, and the protruding part 29 is formed at the center of the lower surface of the upper lid 15 of the molding jig. form,
This protrusion 29 is fitted into the spigot part 28 of the commutator spider 17, and the upper cover 15 is fastened to the rear end surface of the commutator spider 17 with bolts 32. Part 28
As in the embodiment shown in FIG. 3, the lower surface of the upper lid 15 on which the protrusion 29 is not formed is brought into contact with the rear end surface of the commutator spider 17 on which the spigot part 28 is not formed. In addition, a screw hole is bored in the axial direction from the end surface of the cylindrical protrusion 31 of the upper cover 15 along a circumference concentric with the hole 30 so as to face a screw hole formed in the rear end surface of the commutator spider 17. By inserting the reamer bolts into the plurality of reamed holes, screwing them into the threaded holes of the commutator spider 17, and tightening these reamer bolts, the upper cover 15 is attached to the commutator spider 17.
It may also be fastened to the rear end surface of. However, in this embodiment, since the length in the axial direction of the cylindrical protrusion 31 formed on the upper surface of the upper lid 15 is considerably long, the upper lid 15 is fastened to the rear end surface of the commutator spider 17 with a reamer bolt. Therefore, the plurality of reamer holes drilled in the axial direction from the end surface of the cylindrical protrusion 31 of the upper cover 15 and the reamer bolts inserted into these reamer holes are quite long. Not only is it difficult and workability is significantly impaired, but the manufacturing cost of the molding jig is also high because the reamed hole is machined using a jig borer. Therefore, as in this embodiment, the lower surface of the upper lid 15 of the molding jig and the rear end surface of the commutator spider 17 are pin-fitted, and the upper lid 15 is fastened to the rear end surface of the commutator spider 17 with bolts 32. The workability will be improved and the production cost of the molding jig will be lower if the molding tool is placed in the molded area.

On the other hand, in the embodiment shown in FIG. If leakage of the resin 8 can be prevented, as in the embodiment shown in FIG. This protrusion is fitted into the spigot part of the commutator spider 17, and a screw is formed on the rear end surface of the commutator spider 17 along a circumference concentric with the hole 21 in the upper cover 14. The upper cover 14 is attached to the back of the commutator spider 17 by inserting bolts into a plurality of holes drilled opposite the holes, screwing them into the threaded holes of the commutator spider 17, and tightening these bolts. It may be fastened to the end face. As a result,
Workability is improved, and the manufacturing cost of the molding jig is also reduced.

In this way, the present invention has a radial notch groove that communicates the inner circumference and outer circumference formed in the tip portion, and the piston is fitted onto the rotor shaft of a rotating electrical machine so as to be slidable in the axial direction. Using a commutator spider whose inner periphery of the shaft hole is precision-finished, the commutator cylinder tightened by a tightening ring and this commutator spider are concentrically held by a holder of a molding jig, and the center The upper cover of a molding jig in which a precision-finished hole with the same diameter as the shaft hole of the commutator spider is formed is tightly coupled to the rear end surface of the commutator spider, and between the upper cover and the commutator cylinder. By bringing the intervening seal ring into close contact with the rear end surface of the commutator cylinder, the annular grooves with a U-shaped cross section formed on both end surfaces of the commutator cylinder by the pedestal/top cover of the molding jig and the seal ring, respectively. A sealed space is formed from the part to the outer periphery of the commutator spider, and then a specified amount of thermosetting resin is injected into the hole in the top cover of the molding jig and the shaft hole of the commutator spider, and the piston is inserted into the hole in the top cover. , use the hole in the top cover and the shaft hole of the commutator spider as a cylinder, slide this piston along the hole in the top cover and the shaft hole of the commutator spider, and connect the hole in the top cover and the shaft hole of the commutator spider. By pressurizing and compressing the resin injected into the shaft hole, this resin is transferred from the radial notch groove formed at the tip of the commutator spider to the mold jig's pedestal, top cover, and seal ring. The resin flows into a sealed space to fill the gap between the commutator cylinder and the commutator spider as well as the annular groove of the commutator cylinder, and is heated at a predetermined temperature for a predetermined time to thermoset the resin. By doing so, the commutator cylinder and commutator spider are integrally connected, and the commutator spider is used in place of the cylinder, and the commutator spider itself is part of the mold jig. The fixture's pedestal, top cover, and seal ring are independent of the clamping ring of the commutator cylinder, so the clamping cylinder of the commutator cylinder is connected to the molding jig's envelope. Compared to the conventional method for manufacturing a molded commutator, the molding jig is smaller and simpler, which not only lowers the manufacturing cost of the molded commutator but also improves workability. As mentioned above, the molding jig is independent of the clamping ring of the commutator cylinder, so that the sliding surface of the commutator cylinder with the brush is The present invention is also applicable to a molded commutator in which the shaft holes of the commutator spider fitted to the rotor shaft of a rotating electrical machine have the same diameter and different axial lengths. A tightening ring is attached to the outer periphery of the commutator cylinder, which is constructed by alternately arranging a predetermined number of commutator pieces that have been cut off to near the sliding surface with the brush, leaving a slight finishing margin, and mica between the pieces. After fitting and tightening this commutator cylinder from the periphery with this tightening ring and applying a predetermined seasoning to the mica on one side, annular grooves are formed on both end faces of this commutator cylinder, and then this commutator cylinder is tightened from the circumference. While the child cylinder is still being tightened by the tightening ring, it is set in the molding jig together with the commutator spider, and the molding work is performed.After the molding work is completed, the sliding surface with the brush is finished to the regular dimensions. Since the depth of cut during this finishing is very small, the surfaces between the commutator piece and the mica piece are carefully seasoned before and after the molding process. There is almost no change in the pressure, and therefore, according to the present invention, an extremely strong molded commutator is obtained, and the commutator pieces do not cause a hyperbar phenomenon during rotation of the rotating electric machine. The present invention has many excellent effects as described above, and its value is extremely large.

[Brief explanation of the drawing]

FIG. 1 is an upper half vertical cross-sectional view showing the general structure of a molded commutator, FIG. 2 is a vertical cross-sectional view schematically showing a conventional manufacturing method of a molded commutator, and FIG. 3 is a molded commutator according to the present invention. FIG. 4 is a vertical sectional view partially showing another embodiment of the method for manufacturing a molded commutator according to the present invention. 1... Commutator cylinder, 2... Commutator piece, 3... Mica between pieces, 4, 4', 24... Annular groove, 5, 17
...Commutator spider, 6,6'...Reinforcement ring,
7, 7′...Binder, 8...Thermosetting resin,
9... Riser part, 10... Sliding surface with the brush, 11
... tightening cylinder, 12 ... notch groove, 13 ... pedestal,
14, 15...Top lid, 16...Piston, 18...
...Tightening ring, 20, 25...Reamer bolt, 23...
... Seal ring, 26 ... Pressure screw, 27 ... Sealed space, 31 ... Cylindrical protrusion, 32 ... Bolt.

Claims (1)

[Scope of Claims] 1. A rotor of a rotating electrical machine, in which at least one or more radial notch grooves communicating between the inner periphery and the outer periphery are formed in the tip portion, and the piston is fitted to be slidable in the axial direction. In addition to using a commutator spider with a precisely finished inner circumference of the shaft hole that fits into the shaft,
A tightening ring is attached to the outer periphery of the commutator cylinder, which is constructed by alternately arranging a predetermined number of commutator pieces that have been cut off to near the sliding surface with the brush, leaving a slight finishing margin, and mica between the pieces. Fit it in and tighten this commutator cylinder from the periphery using this tightening ring,
After applying a predetermined seasoning to the mica, annular grooves are formed on both end faces of the commutator cylinder, and the commutator cylinder tightened by the tightening ring and the tip of the commutator spider are molded. By closely connecting the upper surface of the pedestal of the jig, the commutator cylinder and the commutator spider are held concentrically by this pedestal, and a precision hole of the same diameter as the shaft hole of this commutator spider is formed in the center. A top cover of a molding jig with a finished hole formed therein is tightly coupled to the rear end surface of the commutator spider so that the hole is aligned with the shaft hole of the commutator spider, and the top cover and the top cover of the commutator cylinder are closely connected to each other. By bringing the intervening seal ring into close contact with the rear end face of the commutator cylinder, the annular grooves formed on both end faces of the commutator cylinder by the pedestal/upper cover of the mold jig and the seal ring, respectively. A sealed space is formed around the outer circumference of the commutator spider, and then a specified amount of thermosetting resin is injected into the hole in the upper lid of the molding jig and the shaft hole of the commutator spider,
Fit the piston into the hole in the top cover, use the hole in the top cover and the shaft hole of the commutator spider as a cylinder, and slide the piston along the hole in the top cover and the shaft hole of the commutator spider. By processing and compressing the resin injected into the hole in the upper cover and the shaft hole of the commutator spider, this resin is passed through the radial notch groove formed at the tip of the commutator spider to the pedestal of the mold jig. The resin flows into the sealed space formed by the upper lid and the seal ring, and fills the gap between the commutator cylinder and the commutator spider and the annular groove of the commutator cylinder so as to cover both end surfaces of the commutator cylinder. manufacturing a molded commutator characterized in that the commutator cylinder and the commutator spider are integrally joined by heating the resin at a predetermined temperature for a predetermined time to thermoset the resin; Method. 2. The molded commutator according to claim 1, wherein the hole in the upper lid of the molding jig into which the piston is fitted is a cylindrical protrusion that projects in the axial direction from the upper surface of the upper lid. manufacturing method.