JP6361799B2 - Commutator - Google Patents

Description

  The present invention relates to a commutator.

  The commutator of a direct current motor has a cylindrical insulator fixed to the rotating shaft of the armature, and a plurality of conductive segments attached to the outer peripheral surface of the insulator. Each segment is provided with a riser to which ends of coils wound around the armature core are connected. The power supply brush is slidably contacted with the outer peripheral surface of the segment. DC power applied from the power supply brush is supplied to the coil of the armature through the segment.

  Such a commutator is manufactured as follows. That is, the previous insulator is formed by encapsulating a resin material inside the conductive cylindrical material arranged in the mold, and then the cylindrical material is cut along the axial direction to make a plurality of the above The segments are formed.

  By the way, as such a commutator, what is disclosed by patent document 1, for example is known. In patent document 1, in order to ensure the locking force of an insulator and each segment, the surface which contacts the insulator of a segment is roughened surface comprised by minute unevenness by being immersed in a roughening liquid. It is said that. Since the roughened surface is used, the locking area between the segment and the insulator is increased as compared with the case where the surface is smooth and smooth without unevenness, so that the locking force between the two increases.

JP 2002-51506 A

  In the segment of Patent Document 1, after forming a roughened surface, it is necessary to perform post-processing such as removing the roughening liquid on the surface. This is because when the post-treatment is not performed, the roughening of the roughened surface progresses and the unevenness changes, so that the locking force between the segment and the insulator decreases. That is, there are many man-hours for manufacturing a commutator.

  The present invention has been made in view of such a situation, and an object thereof is to provide a commutator having a high locking force between a segment and an insulator and a small number of manufacturing steps.

  In order to solve the above problems, a commutator includes a cylindrical insulator and a plurality of commutator pieces that are made of a conductive plate and are arranged in parallel in the circumferential direction on the outer peripheral surface of the insulator, The commutator piece extends toward the outer side in the radial direction of the insulator and is connected to the connection claw to which the armature winding is electrically connected, and extends toward the inner side in the radial direction of the insulator to engage the insulator. In the commutator provided with a locking claw for stopping, the radially inner surface of the insulator of the commutator piece includes a groove having an undercut, and the groove is a cross-sectional view along the axial direction of the insulator. A groove recessed obliquely from the radially inner surface of the commutator piece toward the one axial side, wherein both sides of the inner surface of the groove are defined as side surfaces in the axial direction of the groove. When the bottom surface is the surface that connects the deepest ends of the grooves on each side The both side surfaces are both inclined from the bottom surface side to the other axial direction side, the side surface on one axial side of the both side surfaces is an undercut surface, and passes through the tops where the side surfaces and the bottom surface intersect. And in the relationship between the two imaginary lines extending parallel to the axial direction, the imaginary line passing through the top of the side surface on the other side in the axial direction is more than the imaginary line passing through the top of the undercut surface. Is far from the radially inner surface.

  According to this configuration, the groove having an undercut can be formed by an easy molding method such as press molding. Further, the anchor effect is obtained by the engagement between the groove and the insulator. For this reason, according to the same structure, a commutator with few manufacturing steps can be provided. Further, even if the commutator rotates at high speed, the commutator piece is unlikely to be separated from the insulator.

  The commutator of the present invention has an effect that the number of manufacturing steps is small and the locking force between the segment and the insulator is high.

The perspective view which shows the commutator in 1st Embodiment. The perspective view which shows the raw material of the segment in 1st Embodiment. (A)-(c) is sectional drawing which shows the 1st-3rd groove | channel in 1st Embodiment. (A)-(c) is sectional drawing which shows the formation process of the groove | channel in 1st Embodiment. The perspective view which shows the raw material of the segment in 1st Embodiment. The perspective view which shows the cylindrical raw material in 1st Embodiment. The perspective view which shows the state which bent the riser and middle nail | claw of the cylindrical raw material in 1st Embodiment. (A)-(d) is sectional drawing which shows the formation process of another groove | channel. (A)-(c) is sectional drawing which shows the formation process of another groove | channel. The perspective view which shows the commutator in 2nd Embodiment. The perspective view which shows the raw material of the segment in 2nd Embodiment. The perspective view which shows the cut and raised punch in 2nd Embodiment. The perspective view which shows the scraping punch in 2nd Embodiment. The perspective view which shows the raw material of the segment in 2nd Embodiment. The perspective view which shows the cylindrical raw material in 2nd Embodiment. The perspective view which shows the state which bent the riser and 2nd middle nail | claw of the cylindrical material in 2nd Embodiment. (A) is a perspective view which shows the cylindrical raw material after inserting a cut and raised punch, (b) is sectional drawing which shows the cylindrical raw material of the state in which the cut and raised punch is inserted. (A) is a perspective view which shows the cylindrical raw material after inserting a scraping punch, (b) is sectional drawing which shows the cylindrical raw material of the state in which the scraping punch is inserted. The top view which looked at the cylindrical raw material after inserting the cut and raised punch from the axial direction. The top view which looked at the cylindrical raw material after inserting the rubbing punch from the axial direction. Sectional drawing which looked at the cylindrical raw material after inserting the rubbing punch from the axial direction. (A)-(c) is sectional drawing which shows the formation process of another groove | channel. (A)-(d) is sectional drawing which shows the formation process of another groove | channel.

<First Embodiment>
A first embodiment embodying the commutator of the present invention will be described below with reference to FIGS.
As shown in FIG. 1, the commutator 10 includes a cylindrical insulator 11 made of a thermosetting resin and ten segments 12 fixed to the outer peripheral surface of the insulator 11. A press-fit hole 11 a penetrating in the axial direction is provided at the radial center of the insulator 11. A rotary shaft of an armature (not shown) is press-fitted into the press-fitting hole 11a. Thereby, the commutator 10 rotates integrally with the rotating shaft of the armature.

  Each segment 12 is formed of a conductive metal plate material (for example, a copper plate). The ten segments 12 are arranged in parallel at equal angular intervals in the circumferential direction of the insulator 11 and are formed in a strip shape extending in the axial direction of the insulator 11. A dividing groove 13 extending in the axial direction of the insulator 11 is provided between the adjacent segments 12. The adjacent segments 12 are separated from each other by the dividing groove 13. That is, the ten segments 12 are electrically insulated from each other. Each dividing groove 13 is formed deeper inward in the radial direction than the thickness of each segment 12 (the radial thickness of the insulator 11). That is, each dividing groove 13 is formed up to the insulator 11.

  A riser 14 is provided at one end of each segment 12 in the axial direction (upper end in FIG. 1). The riser 14 is bent outward from the base end in the radial direction of the insulator 11. The riser 14 faces the radially outer surface of the segment 12. The riser 14 is connected to an armature coil that constitutes an armature (not shown). That is, the riser 14 corresponds to a connection claw.

  Two first middle claws 15 are provided at the end of each segment 12 on the riser 14 side. The two first middle claws 15 are provided so as to sandwich the riser 14. On the other hand, two second intermediate claws 16 are provided at the end of each segment 12 opposite to the end where the riser 14 is provided. The two second middle claws 16 are provided at positions that are paired with the two first middle claws 15 in the longitudinal direction of the segment 12. The first and second middle claws 15, 16 are bent from the base end to the side opposite to the riser 14, that is, radially inward of the insulator 11. The distal ends of the first and second middle claws 15 and 16 face the radially inner surface of the segment 12. The distal ends of the first and second middle claws 15 and 16 are embedded in the insulator 11. Thereby, each segment 12 is connected to the insulator 11. That is, the first and second middle claws 15 and 16 correspond to locking claws. In addition, as shown in FIG. 7, the notch 17 opened to the adjacent segment 12 side is provided in the side part of the 1st and 2nd middle nail | claws 15 and 16. As shown in FIG.

  As shown in FIG. 2, a groove 30 is provided on the surface of the segment 12 on the insulator 11 side. The groove portion 30 is constituted by two groove rows 31 provided along the longitudinal direction of the segment 12. Each of the two groove rows 31 includes eight first grooves 32, five second grooves 33, and three third grooves 34. The first to third grooves 32 to 34 are provided in this order from the end of the segment 12 on the side opposite to the riser 14. As shown in FIGS. 3A to 3C, the first to third grooves 32 to 34 are triangular grooves that become sharper as the distance from the contact surface with the insulator 11 increases.

  As shown in FIG. 3A, when the trough of the triangular groove is the apex, and the line extending to the longitudinal riser side of the segment 12 so as to pass through this apex is the reference line (0 °), the first groove 32 Is formed over 30 ° to 80 °. The surface along 80 ° of the first groove 32 is an undercut 32a. Undercut refers to a shape in which an opening protrudes above the bottom of a groove. The distance between the valley portion of the first groove 32 and the contact surface of the insulator 11, that is, the depth of the first groove 32 is 30% (0.3 t) of the plate thickness t.

  As shown in FIG.3 (b), the 2nd groove | channel 33 is formed over 100 degrees-150 degrees. The surface along 100 ° of the second groove 33 is an undercut 33a. The distance between the valley portion of the second groove 33 and the contact surface of the insulator 11 is 30% (0.3 t) of the plate thickness t.

  As shown in FIG.3 (c), the 3rd groove | channel 34 is formed over 100 degrees-150 degrees. The surface along the 100 ° of the third groove 34 is an undercut 34a. The distance between the valley of the third groove 34 and the contact surface of the insulator 11 is 50% (0.5 t) of the plate thickness t.

Next, the manufacturing process of the commutator 10 will be described.
As shown in FIGS. 4 (a) and 4 (b), first, the metal plate material 20 in a state where the wedge-shaped punch 9 having the tip portion angle of 50 ° and the plate surface has an angle of 30 °. Press against. Thereafter, as shown in FIG. 4C, the punch 9 is pulled out. Thereby, the first groove 32 is formed. Although not shown, the second and third grooves 33 and 34 are formed in the same manner as the first groove 32 only by changing the angle of the punch 9 from the plate surface to 150 °. . By repeating this, the metal plate material 20 becomes the metal plate material 20 in which the groove 30 shown in FIG. 5 is formed.

  Next, as shown in FIG. 5, a punching material 21 is punched from the metal plate material 20. The punching material 21 is formed in a substantially rectangular shape. Ten risers 14 and 20 first middle claws 15 are provided on one end surface of each punching material 21 in the short direction (a direction orthogonal to the longitudinal direction), and 20 second middle claws are provided on the other end surface. 16 are formed respectively. The risers 14 are formed at equal intervals in the longitudinal direction of the punched material 21. The first middle claw 15 is formed on both sides of the riser 14. The second middle claw 16 is formed at a position facing the first middle claw 15. Further, the first and second middle claws 15 and 16 are formed with notches 17.

  Next, the blanking material 21 is rounded so that the groove part 30 faces inward, and the cylindrical material 22 shown in FIG. 6 is formed. At this time, the riser 14 and the first and second middle claws 15, 16 have a linear shape parallel to the axis of the cylindrical material 22.

  After that, as shown in FIG. 7, each riser 14 is bent radially outward and shaped so that the tip thereof faces the axial center of the cylindrical material 22. Further, the first and second middle claws 15, 16 are bent inward in the radial direction, and are formed so that the front end portions thereof face the central portion in the axial direction of the cylindrical material 22.

Thereafter, a thermosetting resin is filled into the cylindrical material 22 using a mold (not shown). After filling, the resin is cured by a chemical reaction to form the insulator 11 shown in FIG.
Then, the dividing material 13 (refer FIG. 1) is shape | molded along the axial direction in the several places of the outer peripheral surface of the cylindrical raw material 22 integral with the insulator 11, and the cylindrical raw material 22 is cut | disconnected. Thereby, ten segments 12 electrically insulated from each other are formed, and the commutator 10 shown in FIG. 1 is completed.

Next, the operation of the commutator 10 will be described.
As shown in FIG. 2, the groove part 30 was provided in the contact surface with the insulator 11 of the segment 12. As shown in FIG. As shown in FIGS. 4A to 4C, the groove 30 is formed by press molding. That is, the number of manufacturing steps for forming the groove 30 is small. Since the groove portion 30 is formed, the engagement area between the segment 12 and the insulator 11 is increased as compared with the case where the groove portion 30 is not provided. For this reason, the locking force (hook) of both increases.

  As shown in FIG. 3A to FIG. 3C, the first to third grooves 32 to 34 constituting the groove part 30 are provided with undercuts 32 a to 34 a. The undercut 32a is provided along 80 °. The undercuts 33a and 34a are provided along 100 °. That is, the angle of the contact surface between the segment 12 and the insulator 11 in the undercut 32a and the undercuts 33a and 34a is different. When the commutator 10 rotates, a centrifugal force acting on the segment 12 radially outward (90 °) acts on the segment 12. When the segment 12 is about to be separated from the insulator 11, the segment 12 tends to be displaced along the undercuts 32a to 34a. That is, the contact portion with the undercut 32a tends to be displaced to the side where the riser 14 is formed, and the contact portion with the undercuts 33a and 34a tends to be displaced to the side opposite to the side where the riser 14 is formed. . Thus, even if a centrifugal force acts, the segment 12 tends to move in different directions in the longitudinal direction by the undercuts 32a to 34a. For this reason, forces acting in different directions in the longitudinal direction are canceled out. As a result, the locking force between the segment 12 and the insulator 11 is increased.

  As shown in FIGS. 3A to 3C, the depth of the third groove 34 is deeper than that of the first and second grooves 32 and 33. For this reason, the third groove 34 has a larger amount of locking between the segment 12 and the insulator 11 than the first and second grooves 32 and 33. In other words, the amount of resin of the insulator 11 locked to the undercut 34a is large. For this reason, the locking force between the segment 12 and the insulator 11 at the portion where the third groove 34 is provided increases. On the other hand, the part where the first and second grooves 32 and 33 are formed comes into sliding contact with a brush (not shown) as the commutator 10 rotates. Since the first and second grooves 32 and 33 are made shallower, the plate thickness is secured, so that the insulator 11 is not exposed even if the portion is worn slightly. For this reason, the function as the commutator 10 can be exhibited over a long period of time. As described above, the commutator 10 of the present example is configured so that the groove (the third groove 34) in the portion that does not wear is the same depth as the groove (the first and second grooves 32 and 33) in the portion that wears out. In comparison, the segment 12 is less likely to be separated from the insulator 11. Further, the life of the commutator 10 is ensured.

As described above in detail, according to the present embodiment, the following effects can be obtained.
(1) The groove part 30 which has the undercuts 32a-34a formed by the easy formation method called press molding in the segment 12 was provided. Thereby, compared with the case where a groove | channel is not provided, the latching force of the segment 12 and the insulator 11 becomes strong. Therefore, even if the commutator 10 rotates at a high speed, the segment 12 is unlikely to be separated from the insulator 11.

  (2) Undercuts 32 a to 34 a are provided in the first to third grooves 32 to 34 constituting the groove portion 30. Thereby, when the commutator 10 rotates, the centrifugal force acting on each segment 12 is decomposed into a direction along the undercuts 32a to 34a and a direction orthogonal to the undercuts 32a to 34a. The force in the direction along the undercuts 32a to 34a, which is a force for separating the segment 12 and the insulator 11, is obtained by resolving the centrifugal force. That is, it is smaller than the centrifugal force. Therefore, compared with the case where the undercuts 32a to 34a are not provided in the first to third grooves 32 to 34, the segment 12 is less likely to be separated from the insulator 11.

  (3) The groove portion 30 is provided between the first and second middle claws 15 and 16. Thereby, since the latching area of the segment 12 and the insulator 11 in the center part of the longitudinal direction of the segment 12 increases, the segment 12 is difficult to separate from the insulator 11.

  (4) It provided so that the inclination direction of the undercut 32a may differ from the inclination direction of the undercuts 33a and 34a. Thereby, when the commutator 10 rotates, the contact part with the undercut 32a in the segment 12 tends to be displaced in the inclination direction of the undercut 32a, and the contact part with the undercuts 33a and 34a is undercut 33a and 34a. Try to displace in the direction of the slope. For this reason, forces trying to move in different directions cancel each other. As a result, since the locking force between the segment 12 and the insulator 11 increases, the segment 12 is unlikely to be separated from the insulator 11.

  (5) The depth of the third groove 34 provided in the part facing the riser 14 is made deeper than the first and second grooves 32 and 33 provided in the other parts. Thereby, the latching area of the segment 12 and the insulator 11 increases compared with the case where the depth of a groove | channel is made uniform. For this reason, the segment 12 is difficult to be separated from the insulator 11. The part facing the riser 14 is not slidably contacted with the brush because the riser 14 is connected to the armature coil. Therefore, the part does not wear. That is, the plate thickness is not reduced. For this reason, the life of the commutator 10 is not shortened even if the depth of the third groove 34 of the part is deeper than the first and second grooves 32 and 33 of other parts.

<Second Embodiment>
Next, a second embodiment of the commutator will be described. The main difference between the second embodiment and the first embodiment is the first middle nail. For this reason, the same code | symbol shall be attached | subjected about the structure similar to 1st Embodiment, and the detailed description is omitted.

  As shown in FIG. 10, the commutator 101 includes a cylindrical insulator 11 and 18 segments 120 fixed to the outer peripheral surface of the insulator 11. Eighteen segments 120 are provided at equiangular intervals in the circumferential direction. Each segment 120 occupies an angle θ1. The 18 segments 120 have an overall inner diameter of φ1 and an outer diameter of φ2 excluding the riser 14, the second middle claw 16, and the first middle claw 121 described later.

  As shown in FIG. 11, two first middle claws 121 and a groove portion 130 are juxtaposed in the longitudinal direction of the segment 120 on the surface of each segment 120 on the insulator 11 side. The two first middle claws 121 are provided on the riser 14 side, and the groove 130 is provided on the second middle claw 16 side. The two first middle claws 121 are arranged side by side in the circumferential direction.

  The two first middle claws 121 are formed by being cut and raised from the radially inner surface of the segment 120 and bent from the base end portion to the second middle claws 16 side. For this reason, the front-end | tip part of the two 1st intermediate claws 121 opposes the surface inside the radial direction of the segment 120, and the groove part 130 correctly.

  Therefore, the two first middle claws 121 are embedded in the insulator 11 together with the tip portions of the two second middle claws 16. Accordingly, each segment 120 is connected to the insulator 11. That is, the first middle claw 121 corresponds to a locking claw.

  Note that, on the radially inner surface of each segment 120, two machining trace grooves 122 extending in the longitudinal direction of the segment 120 are formed as the two first middle claws 121 are cut and raised. The two processing trace grooves 122 are arranged side by side in the circumferential direction.

  As shown in FIGS. 20 and 21, undercuts 124 are formed on both sides of the opening 123 of the two processing trace grooves 122 so as to face each other. The direction in which each undercut 124 projects is the circumferential direction of the insulator 11.

  As shown in FIG. 11, the groove part 130 includes five first grooves 131 and five second grooves 132. The five first grooves 131 are provided on the second middle claw 16 side, and the five second grooves 132 are provided on the riser 14 side. As shown in FIGS. 3A and 3B, the first and second grooves 131 and 132 are the same as the first and second grooves 32 and 33 in the first embodiment. Since it is configured, its detailed description is omitted.

Next, the manufacturing process of the commutator 101 will be described.
Note that the commutator 101 is manufactured by using the cutting and raising punch 140 and the rubbing punch 150. First, the configuration of the cutting and raising punch 140 and the rubbing punch 150 will be described.

  As shown in FIG. 12, the cutting and raising punch 140 includes a cylindrical portion 141 and 36 cutting and raising blades 142 provided on the outer peripheral surface of the cylindrical portion 141 and extending in the coaxial direction with the cylindrical portion 141.

The outer diameter of the cylindrical portion 141 is a diameter φ6 (φ6 <φ1) smaller than the inner diameter φ1 of the 18 segments 120 as a whole.
The 36 cutting and raising blades 142 are made into a set of two. The 18 sets of cutting and raising blades 142 are arranged in parallel in an annular shape at equal intervals. The outer diameters of the 36 cutting and raising blades 142 are set to a diameter φ3 (φ1 <φ3 <φ2) that is larger than the inner diameter φ1 of the eighteen segments 120 and smaller than the outer diameter φ2.

  In the cut and raised punch 140, the end (the upper end in FIG. 12, the lower end in FIG. 17B) on the side to be inserted into a cylindrical material 161, which will be described later, is a mortar with a sharp outer diameter side. It is made into a shape.

  In addition, the two cutting and raising blades 142 that are paired are spaced apart from each other in the circumferential direction, and the surfaces that do not face each other have an angle θ2 (θ2 <θ1) smaller than the angle θ1 occupied by the segment 120. It is provided to become.

  As shown in FIG. 13, the rubbing punch 150 connects a columnar rubbing portion 151, a columnar pushing / bending portion 152 provided coaxially with the rubbing portion 151, and the rubbing portion 151 and the pushing / bending portion 152. Connecting portion 153.

  The rubbing portion 151 has an outer diameter φ5 that is larger than the overall inner diameter φ1 of the eighteen segments 120 and smaller than the outer diameter φ3 of the punch 140 (φ1 <φ5 <φ3). The rubbing portion 151 is provided with 18 relief grooves 154 extending in the axial direction at equal angular intervals.

The outer diameter of the push-bending portion 152 is a diameter φ4 (φ4 <φ1) smaller than the inner diameter φ1 of the 18 segments 120 as a whole.
The connecting portion 153 is tapered so that the outer diameter gradually decreases toward the bending portion 152 so that the outer surface of the rubbing portion 151 and the outer surface of the bending portion 152 are smoothly continuous.

Now, the manufacturing process of the commutator 101 will be described again. In addition, about the groove part 130, since it is the same as that of the manufacturing process of the groove part 30 of 1st Embodiment, the description is omitted.
As shown in FIG. 14, a punching material 160 is punched from the metal plate material 20. The blank material 160 is formed in a substantially rectangular shape. Eighteen risers 14 are formed on one end surface of each punching material 160 in the short direction (direction orthogonal to the longitudinal direction), and 36 second middle claws 16 are formed on the other end surface.

  The risers 14 are formed at equal intervals in the longitudinal direction of the punched material 160. The second middle claw 16 is formed so as to sandwich a position facing the riser 14. Further, a notch 17 is formed in the second middle nail 16.

  Next, the blank material 160 is rounded so that the groove portion 130 faces inward, and the cylindrical material 161 shown in FIG. 15 is formed. The riser 14 and the second middle claw 16 are in a straight line parallel to the axis of the cylindrical material 161.

  Next, as shown in FIG. 16, each riser 14 is bent radially outward. Further, the second middle claw 16 is bent inward in the radial direction so that the tip end portion faces the axial center of the cylindrical material 22.

  Next, as shown in FIG. 17B, the cut and raised punch 140 is inserted into the cylindrical material 161 from the riser 14 side. When viewed from the center of the cylindrical material 161, the cut and raised blades 142 are cut and raised so as to sandwich the riser 14 and the punch 140 is inserted.

  Then, as shown in FIGS. 17A and 17B, the inner surface of the cylindrical material 161 is cut and raised by the cutting and raising punch 140 to form 36 first intermediate claws 121. In addition, by forming 36 first middle claws 121, 36 machining trace grooves 122 are formed on the inner surface of the cylindrical material 161. Since the surface is cut and raised, as shown in FIG. 19, both sides of the opening 123 of the 20 machining trace grooves 122 rise.

  Next, the punch 140 is cut and raised from the cylindrical material 161, and the rubbing punch 150 is inserted into the cylindrical material 161 from the riser 14 side as shown in FIG. Note that the rubbing punch 150 is inserted so that the escape groove 154 (see FIG. 13) does not overlap the machining trace groove 122 when viewed from the cylindrical material 161. In the escape groove 154, the outer peripheral surface of the rubbing punch 150 and the inner peripheral surface of the cylindrical material 161 do not slide, that is, there is no sliding resistance for inserting the rubbing punch 150, so that the insertion is easy.

  Then, as shown in FIGS. 18A and 18B, the first middle claw 121 is bent radially inward by the push-bending portion 152 and the connecting portion 153. Further, the outer diameter φ5 of the rubbing portion 151 is larger than the inner diameter φ1 of the cylindrical material 161 and smaller than the entire outer diameter φ3 of the raising blade 142. Therefore, as shown in FIG. 20, the opening 123 of the machining groove 122, particularly the portion raised by the cut-and-punch 140 with the insertion of the rubbing portion 151 is narrowed, that is, in the circumferential direction. The undercut 124 is formed by falling so that both sides of the opening 123 facing each other approach.

  Next, the rubbing punch 150 is pulled out, and the inside of the cylindrical material 161 is filled with a thermosetting resin using a mold (not shown). Thereby, as shown in FIG. 21, the thermosetting resin flows into each groove including the machining trace groove 122. After filling, the resin is cured by a chemical reaction to form the insulator 11 shown in FIG.

  Then, the dividing material 13 (refer FIG. 10) is shape | molded along the axial direction in several places which avoid the process trace groove | channel 122 of the outer peripheral surface of the cylindrical material 161 integral with the insulator 11, and the cylindrical material 161 is cut | disconnected. Thereby, the 18 segments 120 electrically insulated from each other are formed, and the commutator 101 shown in FIG. 10 is completed.

Next, the operation of the commutator 10 will be described.
As shown in FIGS. 20 and 21, an undercut 124 is provided in the opening 123 of the machining trace groove 122. Since the insulator 11, which is a cured thermosetting resin, enters the processed trace groove 122, an anchor effect is obtained by the undercut 124. As a result, the locking force between the segment 120 and the insulator 11 is increased.

  Further, when the cylindrical material 161 was cut to form the segment 120, the dividing groove 13 was not overlapped with the processing trace groove 122. Therefore, as shown in FIG. 21, the opening of the machining trace groove 122 is not continuous with the edge of the segment 120 in the circumferential direction of the insulator 11. As a result, the undercuts 124 can be provided in both openings 123 of the machining trace groove 122 in the circumferential direction of the insulator 11. As a result, the locking force between the segment 120 and the insulator 11 is increased.

As described above in detail, according to the present embodiment, the following effects can be obtained in addition to the effects of the first embodiment described above.
(6) The surface on the insulator 11 side of the segment 120 was cut and raised to form the first middle claw 121. And the undercut 124 was provided in the opening part 123 of the process trace groove | channel 122 which cut and raised the surface by the side of the insulator 11. FIG. The insulator 11, which is a cured thermosetting resin, enters the processed trace groove 122. Thereby, since the anchor effect is obtained, the locking force between the segment 120 and the insulator 11 is increased.

  (7) When the cylindrical material 161 is cut to form the segment 120, the dividing groove 13 is not overlapped with the processing trace groove 122. Therefore, in the circumferential direction of the insulator 11, the opening portion of the processing trace groove 122 is not continuous with the edge portion of the segment 120. As a result, the undercuts 124 can be provided in both openings 123 of the machining trace groove 122 in the circumferential direction of the insulator 11, so that the segment 120 is insulated from the segment 120 as compared with the case where no undercut is provided in both openings. The locking force with the body 11 is increased.

In addition, you may change each said embodiment as follows.
-In each above-mentioned embodiment, you may form an undercut as follows. That is, as shown in FIG. 8A, the wedge-shaped punch 9 is pressed against the metal plate 20 in a state where the angle with the plate surface is 40 °. When the wedge-shaped punch 9 is pulled out, a groove 80 is formed and the periphery of the groove 80 is raised as shown in FIG. Next, as shown in FIG. 8C, a die-shaped punch 85 larger than the width of the groove 80 is pressed against the metal plate material 20 from the plate thickness direction. As a result, as shown in FIG. 8D, the raised portion around the groove 80 collapses, and the collapsed portion becomes an undercut 81.

  Moreover, you may form an undercut as follows. That is, as shown in FIG. 9A, a wedge-shaped punch 95 is pressed against the metal plate 20 in a state where the angle with the plate surface is a right angle. When the wedge-shaped punch 95 is pulled out, a groove 90 having a vertical surface 92 is formed as shown in FIG. Next, as shown in FIG. 9C, a portion adjacent to the vertical surface 92 side of the formed groove 90 is pressed with a punch 95. Then, as shown in FIG. 9C, the vertical surface 92 of the groove 90 falls, and the portion that was the vertical surface 92 becomes an undercut 91. Thus, even when the undercut is formed through the steps shown in FIGS. 8A to 8D and FIGS. 9A to 9C, the same effect as that of the above embodiment can be obtained.

  Moreover, you may form an undercut as follows. That is, using the wedge-shaped punch 95, two grooves 90 are formed so that the vertical surfaces 92 are adjacent to each other as shown in FIG. Next, as shown in FIG. 22 (b), a wedge-shaped punch 96 is pressed between the two grooves 90, that is, between the two vertical surfaces 92. At this time, the punch 96 is pressed so that the base end side is closer to the two vertical surfaces 92 than the front end side. Then, as shown in FIG. 22 (c), the vertical surfaces 92 of the two grooves 90 fall down, and the portion that was the vertical surface 92 becomes an undercut 91. When such a process is performed, a plurality of undercuts can be formed by a single operation.

  Moreover, you may form an undercut using the following punch 180. FIG. That is, as shown in FIG. 23A, the punch 180 includes a first machining surface 181, a second machining surface 182 that is continuous with the first machining surface 181, and a third machining surface 183 that is continuous with the second machining surface 182. Is provided. A top portion between the second machining surface 182 and the third machining surface 183 is defined as a machining tip 184. As a whole, the punch 180 is sharpened toward the processing tip 184.

First, as shown in FIG. 23A, the processing tip 184 of the punch 180 is pressed against the metal plate 20 so that the first processing surface 181 is perpendicular to the plate surface of the metal plate 20.
Then, a groove 190 is formed in the metal plate member 20 as shown in FIG. The groove 190 includes a first processed surface 191 processed by the first processed surface 181, a second processed surface 192 processed by the second processed surface 182, and a third processed surface processed by the third processed surface 183. And a processed surface 193. The first work surface 191 is a surface perpendicular to the plate surface. Further, the groove 190 is formed between the first workpiece top 194 that is the top between the first workpiece surface 191 and the second workpiece surface 192, and between the second workpiece surface 192 and the third workpiece surface 193. And a second work top 195 that is the top of the.

  Next, as shown in FIG. 23C, a portion adjacent to the first processed surface 191 side of the formed groove 190 is pressed with a punch 95. At this time, the punch 95 is pressed so that the distance between the tip of the punch 95 and the plate surface of the metal plate 20 is equal to the distance between the first workpiece top 194 and the plate surface of the metal plate 20. .

  Then, as shown in FIG. 23 (d), the first work surface 191 falls with the first work top 194 as a base point, and the first work surface 191 that was also a vertical surface becomes an undercut 196. When such a process is performed, since the amount of the plate material that tilts the vertical surface is smaller than the undercut formed through the steps shown in FIGS. 8A to 8C, the processing is easy.

  In the first embodiment, the groove portion 30 is constituted by the two groove rows 31. However, as shown in the second embodiment, the groove portion 30 may be a single groove row. Moreover, you may be 3 or more rows. Even when configured in this manner, the same effects as those of the first embodiment can be obtained.

In the first embodiment, the two groove rows 31 are provided along the longitudinal direction of the segment 12. However, the two groove rows 31 are not necessarily provided along the longitudinal direction.
In the first embodiment, the depth of the third groove 34 is greater than that of the first and second grooves 32 and 33, but may be the same depth. When configured in this manner, the same effects as the effects (1) to (4) of the first embodiment can be obtained.

  -In the said 1st Embodiment, it is good also considering the inclination direction of the undercuts 32a-34a as the same direction. When comprised in this way, the effect similar to the effect of (1)-(3), (5) of the said embodiment can be acquired. In the second embodiment, the inclination direction of the undercut in the groove 130 may be the same direction.

In the first and second embodiments, the groove portions 30 and 130 are composed of a plurality of grooves, but the number of grooves may be one or more.
In the first embodiment, two first and second middle claws 15 and 16 are provided, but one each may be provided. Further, the first and second middle claws 15 and 16 do not necessarily have to be paired in the longitudinal direction of the segment 12. Moreover, you may abbreviate | omit either the 1st and 2nd middle claws 15,16. Furthermore, in the said 2nd Embodiment, the 1st middle nail | claw 121 may be one and may be three or more.

-In the said 1st Embodiment, although the undercut was provided in all the 1st-3rd grooves 32-34, the groove | channel provided with an undercut should just be 1 or more.
In the first and second embodiments, the number of segments 12 is 10 and 18, respectively. However, the number is not limited to this number, and can be appropriately changed according to the configuration.

  In the first embodiment, the punching material 21 punched from the metal plate material 20 is rolled to form the cylindrical material 22, and then the segment 12 is formed by cutting. However, the segment 12 is directly formed from the metal plate material 20. You may punch it.

In the second embodiment, the escape groove 154 of the scraping punch 150 may be omitted.
The technical idea is described below.

A cylindrical insulator and a plurality of commutator pieces made of a conductive plate and arranged in parallel in the circumferential direction on the outer peripheral surface of the insulator, the commutator piece having a diameter of the insulator In a commutator comprising a connection claw that extends outward in the direction and to which an armature winding is electrically connected, and a locking claw that extends inward in the radial direction of the insulator and engages the insulator ,
On the radially inner surface of the insulator of the commutator piece, a groove having an undercut is provided,
The groove in the part facing the connection claw is characterized in that the depth of the groove is deeper than the groove provided in the other part.

  According to this configuration, the groove having an undercut can be formed by an easy molding method such as press molding. Further, the anchor effect is obtained by the engagement between the groove and the insulator. For this reason, according to the same structure, a commutator with few manufacturing steps can be provided. Further, even if the commutator rotates at high speed, the commutator piece is unlikely to be separated from the insulator.

  By the way, the commutator piece is in sliding contact with the brush, but the portion facing the connection claw is not in sliding contact with the brush because the connection claw is connected to the armature winding. For this reason, this part does not wear. That is, the plate thickness is not reduced. According to this structure, the groove | channel of the site | part where this board thickness does not become thin is deeper than the groove | channel of another site | part. For this reason, compared with the case where the groove | channel of the site | part which does not become thin plate thickness is made into the depth equivalent to the groove | channel of another site | part, a commutator piece is hard to isolate | separate from an insulator. In addition, the life of the commutator is not shortened.

The locking claws are provided at both ends of the commutator piece in the axial direction of the insulator;
The groove is provided between the two locking claws.
According to this configuration, even when the distance between the two locking claws is long, the groove provided between the two locking claws increases the locking area between the commutator piece and the insulator. Since the anchor effect is obtained, the commutator piece is difficult to be separated from the insulator.

・ A plurality of the grooves are provided,
The undercut is provided in at least two or more grooves,
At least one of the two or more undercuts has a different inclination direction.

  When an undercut is provided, the insulator and the commutator piece are separated from each other by displacing the commutator piece in the undercut inclination direction with respect to the insulator. In that respect, according to the same configuration, the inclination direction of the undercut is different. Therefore, even if the commutator piece is displaced in the inclination direction of one undercut relative to the insulator, the other undercut causes the commutator piece to be displaced. A force in the direction approaching the insulator acts on. That is, the force in the direction in which the insulator and the commutator piece are separated from each other is canceled by the force in the direction in which the insulator and the commutator piece are in proximity. For this reason, the commutator is difficult to be separated from the insulator.

-The locking claw is formed by cutting and raising the surface on the insulator side of the commutator piece,
The groove includes a processing trace groove provided by cutting and raising the locking claw.

  According to this configuration, since the undercut is provided in the machining trace groove, an anchor effect can be obtained. For this reason, compared with the case where an undercut is not provided, even if a commutator rotates at high speed, it is hard to separate a commutator piece from an insulator.

  -A plurality of the locking claws are provided in each of the plurality of commutator pieces at intervals in the circumferential direction of the insulator, and the edge of the commutator piece in the circumferential direction of the insulator It is formed by cutting and raising without containing.

  According to this configuration, the opening of the machining trace groove is not continuous with the edge of the commutator piece in the circumferential direction of the insulator. Therefore, it is possible to provide undercuts on both sides of the opening portion of the processing trace groove in the circumferential direction of the insulator. For this reason, compared with the case where an undercut is provided only on one side of the opening of the machining trace groove, the commutator piece is less likely to be separated from the insulator even if the commutator rotates at a high speed.

  DESCRIPTION OF SYMBOLS 10 ... Commutator, 11 ... Insulator, 11a ... Press-fit hole, 12, 120 ... Segment (commutator piece), 13 ... Dividing groove, 14 ... Riser (connecting nail), 15, 121 ... First middle nail (locking) Claw), 16 ... second middle claw (locking claw), 17 ... notch, 20 ... metal plate material, 21,160 ... punching material, 22,161 ... cylindrical material, 30,130 ... groove, 31 ... groove row, 32 ˜34, 80, 90, 131, 132... Groove, 32a to 34a, 81, 91, 124, 196... Undercut, 122.

Claims (1)

A cylindrical insulator and a plurality of commutator pieces that are made of a conductive plate material and are arranged in parallel in the circumferential direction on the outer peripheral surface of the insulator, the commutator piece being in the radial direction of the insulator In a commutator comprising a connection claw that extends outward and the armature winding is electrically connected, and a locking claw that extends radially inward of the insulator and locks the insulator.
On the radially inner surface of the insulator of the commutator piece, a groove having an undercut is provided,
The groove includes a groove that is obliquely recessed from the radially inner surface of the commutator piece toward the one axial side in a cross-sectional view along the axial direction of the insulator,
When the surfaces on both sides in the axial direction of the groove are the side surfaces of the inner surface of the groove, and the bottom surface is a surface connecting the innermost ends of the grooves on each side surface, both the side surfaces are It is inclined from the bottom side to the other side in the axial direction,
Of the both side surfaces, the side surface on one side in the axial direction is an undercut surface,
In the relationship between the imaginary lines that pass through the apexes where the side surfaces and the bottom surface intersect and extend parallel to the axial direction, the imaginary lines that pass through the apex portion on the other side surface in the axial direction are The commutator, wherein a distance from the radially inner surface of the commutator piece is farther than an imaginary line passing through the top.