JP3177541B2 - Commutator manufacturing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a commutator mounted on an armature of a commutator motor.

[0002]

FIG. 13 shows, for example, Japanese Patent Publication No. 53-14725.
FIG. 1 is a view showing a conventional method of making a commutator by cutting a copper pipe disclosed in Japanese Patent Application Laid-Open Publication No. H10-207, in which 1 is a thick copper pipe, which is cut by a cutter 2 along a line 3 to form a ring body 4. .
The cutter 2 rotates around the shaft 5 and the pipe 1
Also rotate. FIG. 14 is a view showing an upsetting process for chamfering a corner portion so that the ring body 4 can be easily cold forged. In FIG. 14, reference numeral 6 denotes a lower die, and 7 denotes an upper die. Ring body 4 is lower mold 6
And press it with the upper die 7 to form a chamfer 8.

FIG. 15 is a view showing a known cold forging die which is described in detail in Japanese Patent Publication No. 58-5515. The left half of the drawing shows the state before cold forging, and the right half shows the state after cold forging. Indicates the status.
In the figure, 9 indicates a lower mold, 10 indicates an upper mold, and 11 indicates a core mold. When the ring 4 is placed on the lower die 9 and the upper die 10 is lowered, the ring 4 becomes a segment ring 12. Upper mold 1
0 is pressed against the ring body 4,
Is chamfered 8 to prevent the upper mold 10 from being damaged. The segment ring 12 is shown in FIG.
The shape shown in FIG. That is, the groove 14, the bridging piece 15, and the riser 16 are formed.

FIG. 17 is a view showing a conventional method of manufacturing a ring body 17 from a thick copper plate, which is disclosed in, for example, Japanese Patent Publication No. 58-5515. In this method, a copper plate 18 is punched,
The notches 19 and 20 are made by pressing. This is rolled into a ring as shown in FIG. The ring body 17 is placed in a cold forging die shown in FIG.

FIG. 19 shows a segment ring 12 made of a copper round bar.
Is a diagram showing a conventional method for producing
No. 761. In this method, a copper round bar 21
Is cut by a cutter 22 or a press to obtain a round bar tip 23 as shown in FIG. An annular body 24 as shown in FIG. 21 is obtained by pressing the chip 23 in two or three strokes. The ring 24 has a riser 25, a bottom plate 26, and an inner diameter 27. Bottom plate 2
6 is stamped out by a press and separated at the surface 28. Next, ring 2
By processing the inner diameter 27 of 4, the segment ring 12 shown in FIG. 16 is obtained.

[0006] The conventional method of manufacturing the segment ring 12 by cold forging is performed by the method described above. The riser 16 of the segment ring 12 cuts a riser groove (not shown) connected to the segment groove 14 and forms it with a molding material, and then cuts and removes the bridging pieces 15 to separate the segments into commutators. Get.

[0007]

When the above-described conventional method for manufacturing a commutator is classified according to the shape of the material used, the following three methods can be obtained.
Be kind. That is, it becomes a pipe material, a plate material, and a round bar. These methods have the following disadvantages. (1) The material is expensive. Assuming that the copper wire used in the present invention is 1, the material cost per commutator is 1.35 times for the pipe material and 1.2 for the plate material.
It is 7 times and 1.22 times for a bar, which is significantly more expensive. (2) Upsetting process is required. (3) Since the pipe material must be cut by rotating the cutter 2 as described in FIG. 13 (press cutting cannot be used), it takes time to cut. In addition, since the length of the material is relatively short for transporting the material, wasteful scrap is produced. If the outer diameter of the commutator changes, a pipe having an outer diameter corresponding to the outer diameter is required, and various types of pipes must be stocked.

(4) In the case of using a plate material, since a plate material used as a cold forging material has a thickness of 6 to 7 mm,
Punch out fixed-size items with a press. Therefore, there are many unusable offcuts. In addition, an operation for supplying the material to the cutting machine without interruption is required. (5) With a round bar, the round bar required for a large commutator has a large diameter, which makes press cutting difficult. Cutter cutting prolongs the time required for cutting, and is not suitable for mass production. Further, since the bottom plate 26 is punched by a press as shown in FIG. 21, the material in this portion is wasted.

The present invention has been made to solve the above problems, and has as its object to provide a method of manufacturing a commutator that is suitable for mass production and that can be manufactured at low cost.

[0010]

The method of manufacturing a commutator according to the present invention uses a copper wire having a substantially circular cross section.
This is processed by a roller or a press to create a parallel surface,
This copper wire is cut to a predetermined length, and the parallel surface is
Making a ring body that is rolled into a ring shape so as to form the inner and outer diameters, cold forging this ring body to make a segment ring with segments connected by a number of bridging pieces, and this segment ring with a molding material After molding, the bridging pieces are cut off and separated into segments to make commutators.

In the above method, when the copper wire is cut to a predetermined length, the cutting is performed in an oblique direction, and when the next cutting is performed, the oblique cutting is performed in a direction opposite to the previous oblique cutting. Make a ring body with things .

[0012] In the above method, the copper wire is formed into a cross-sectional shape having a pair of parallel surfaces perpendicular to each other and having a radius at a corner portion by a pair of rollers or presses which are perpendicular to each other, and is then reduced to a predetermined length.
I cut it. In the above method, in order to accurately detect the butted portion of the ring body, light is passed through the butted portion or a magnetic flux is passed to accurately fix the positional relationship between the cold forging die and the butted portion of the ring body. Then, the butted portion was made to come to the segment groove after cold forging. In the above method, the ring body is used as a secondary winding of a transformer, a short-circuit current is applied to weld the contact surface of the ring body, and the ring body is cold forged to form a segment ring.

[0013]

According to the present invention, copper having a substantially circular cross section is used.
Create a parallel surface on the wire with a roller or press, and then
This copper wire is cut to a predetermined length and the copper wire is made into a ring shape.
The ring body was made so that the parallel surfaces formed the inner and outer diameters of the ring, and this ring body was cold forged to make a segment ring, so the copper wire was made into a hoop shape and almost endless to the machine. It can be supplied, and the copper wire has no portion to be cut off, and is not only inexpensive, but also requires fewer processing steps than conventional manufacturing methods, so that commutators can be mass-produced at low cost.

[0014]

EXAMPLES Reference Example 1 FIG. A reference example of the present invention will be described with reference to FIGS. FIG.
FIG. 2 is a schematic view of the apparatus for explaining the method, FIG. 2 is a front view showing the hoop material of FIG. 1, FIG. 3 is a cross-sectional view taken along the line III-III of FIG. FIG. In the figure, reference numeral 29 denotes a copper wire which is supplied as a hoop material as shown in FIG. Reference numerals 30 and 31 denote cutting lines indicating the direction of cutting by a cutter or a press. When cut in this way, the cut surfaces match when bent into a ring shape as shown in FIG. Reference numeral 32 denotes a ring body formed by rolling a copper wire 29, 33
Is a cutting and bending machine for forming the copper wire 29 on the ring body 32.

FIG. 5 shows a conventionally known cold forging die, which is the same as that shown in FIG. When the upper body 10 of the ring body 32 produced as described above is lowered in the lower mold 9, the ring body 32 is cold forged to become the segment ring 12.
Since the core mold 11 has an uneven tooth shape, a segment groove 14 is formed as shown in FIG. The segment ring 12 produced in this manner is molded with a molding material in exactly the same manner as in the conventionally known example to produce a commutator.

In this reference example, 100% of the material can be used (there is no portion to be cut off and discarded), and the upsetting step required in the conventional manufacturing process is unnecessary (the wire is not required to be chamfered). Further, since the material can be supplied by a hoop material, it can be supplied almost endlessly. Since it is a wire, there is an advantage that cutting and bending are easy and the process is completed in a short time. Further, by changing the cutting length of the copper wire 29, it is possible to easily respond to a design change of the commutator outer diameter.

Embodiment 1 FIG . In the above Reference Example 1, the copper wire 29 was used as a round wire,
In the present invention , the round wire is processed into a shape that is easy to cold forge. FIG. 6 shows the method. Roller 3 with copper wire 29
4 and 35 to make a parallel plane to the copper wire 29.
This is put into a cutting and bending machine 33. FIG. 7 shows a cross-sectional shape of the ring body 36 processed by the cutting and bending machine 33.
The parallel surfaces 37 and 38 formed by the rollers 34 and 35 are set on the inner and outer diameter sides of the ring body 36. By doing so, the inner and outer diameters of the ring body 36 are accurately determined.
Insertion into the cold forging die becomes easier.

Embodiment 2 FIG . When a pair of rollers (not shown) is provided in addition to the rollers 34 and 35 shown in FIG. 6 so as to be orthogonal to the rollers 34 and 35, a ring body 39 shown in FIG. 8 is obtained. That is,
In FIG. 8, parallel planes 40 and 41 and parallel planes 42 and 43 orthogonal thereto are formed. At this time, the adjacent parallel surfaces must be connected by a radius 44 without fail. This is to omit the upsetting process.

Embodiment 3 FIG . Each of the ring bodies 32, 36, and 39 manufactured according to Reference Example 1 and Examples 1 and 2 described above has an abutting portion. Since the butted portion becomes a groove when cold forged, it must be aligned with the segment groove 14 when the segment ring 12 is formed. For this reason, when placing the ring body on the lower die 9 of the cold forging die, it is necessary to place the ring body at a position where the butted portion always matches the projection of the core die 11.

FIG. 9 shows a method for detecting abutting portions of the ring bodies 32, 36, and 39. In the figure, 32
A is a butted portion of the ring body 32, 45 is a light emitting element such as a light emitting diode, 46 is a light receiving element, 47 is an amplifier, and has a display mechanism. Reference numeral 48 denotes light emitted from the light emitting element 45. When the ring body 32 is rotated and the butted portion 32A comes directly below the light emitting element 45, the light 48 passes through the butted portion 32A, reaches the light receiving element 46, and sends a signal to the amplifier 47. If the rotation of the ring body 32 is stopped by the output signal of the amplifier 47, the butting position of the ring body 32 can be accurately detected.

FIG. 10 shows the detection of the butting portion 32A of the ring body 32 by magnetic flux. In the figure, reference numeral 49 denotes a ferrite core having an excitation coil 50. An oscillator 51 has a function of detecting an inductance inside. Oscillator 5
A magnetic flux φ is generated from the core 49 by the exciting current oscillated at 1. Since the ring body 32 is a good conductor, the inductance of the exciting winding 50 is small. When the ring body 32 is rotated and the butted portion 32A comes to a position facing the core 49, the short circuit of the ring body 32 is opened, and the inductance of the exciting coil 50 increases. The value of the inductance (or the value of the exciting current) is detected by the oscillator 51 and the ring 3
Stop rotation of 2.

Embodiment 4 FIG . As described above, the ring body 32 has the butted portion 32A. However, if this is welded to form an electrically integrated ring body, the detection of the butted portion 32A as described in FIG. 9 becomes unnecessary. . FIGS. 11 and 12 relate to a method for easily welding the butted portion 32A. In the figure, 52
Is a U-shaped iron core, and 53 is a strip-shaped iron core having a fulcrum 54 and a structure in which the ring body 32 can be inserted from below. 55 is an exciting coil, 56 is a power supply, and 57 is a switch.

When the switch 57 is closed, the exciting coil 55
However, normally, the butted portion 32A of the ring body 32 has a slight gap and is electrically open. When a force 58 is applied to the ring body 32 as shown in FIG. 12, the butting portions 32A come into contact with each other and a large current flows through the ring body 32. With this large current, the butted portion 32A is welded and the ring 3
2 are electrically connected instantaneously.

[0024]

As described above, according to the present invention, the following effects can be obtained. (1) Inexpensive materials can be used. The copper wire used for the commutator is 35% cheaper than the pipe material, 27% cheaper than the plate material, and 22% cheaper than the rod material when compared with the material cost required to make one commutator. Become cheap. (2) The utilization rate of the used materials is high. As shown in FIG.
Since there is no part to be discarded like the bottom plate 26 shown in 1,
The material utilization rate is high and there is no scrap material to be discarded.

(3) The material can be supplied to the machine almost endlessly. Pipes, plates and rods are of fixed size and must be constantly supplied to the processing machine. In this invention, however, the machine can be operated continuously for a long time to supply the copper wire in a hoop shape. Suitable for automatic driving. (4) There are few work processes. The chamfer 8 shown in FIG. 14 for extending the life of the cold forging die is unnecessary (because the material is rounded). In addition, since it is a wire, the number of working steps until cold forging is minimized.
That is, cutting and bending are easy and can be performed in a short time. (5) Compatible with various types of commutators with different dimensions. Since the commutator outer diameter can be changed by changing the cutting length of the copper wire, various types of commutators can be made of the same material.

(6) The abutting portion of the ring body can be automatically detected. Since detection is performed by light or magnetic flux, accurate position detection can be performed, and the cold forging process can be automated. (7) The butted portion of the ring body can be welded in a short time. Since the ring itself is used as the secondary coil of the transformer, the butted portion of the ring can be welded instantaneously. Also, since it is a transformer, it can be manufactured easily and inexpensively.
As described above, the method for manufacturing a commutator according to the present invention is suitable for mass production and can produce a commutator at low cost.

[Brief description of the drawings]

1 is a schematic view of a manufacturing apparatus showing a reference example 1 of the present invention.

FIG. 2 is a front view showing the hoop material of FIG. 1;

FIG. 3 is a sectional view taken along line III-III in FIG. 2;

FIG. 4 is a view showing a method of cutting the copper wire of FIG. 1;

FIG. 5 is a view showing a cold forging die conventionally used.

FIG. 6 is a schematic view of a manufacturing apparatus showing Embodiment 1 of the present invention.

FIG. 7 is a sectional view showing a ring body made according to FIG. 6;

FIG. 8 is a sectional view of a ring body according to a second embodiment of the present invention.

FIG. 9 is a principle diagram of detecting a butted portion of a ring body with light in a third embodiment of the present invention.

FIG. 10 is a principle diagram in which the configuration shown in FIG. 9 can be detected by magnetic flux.

FIG. 11 is a circuit diagram of a transformer used for welding a ring body in Embodiment 4 of the present invention.

FIG. 12 is a sectional view taken along line XII-XII in FIG. 11;

FIG. 13 is a view showing a method of making a ring body from a pipe material by a conventional method.

FIG. 14 is a cross-sectional view showing a conventional upsetting process.

FIG. 15 is a view showing a cold forging die conventionally used.

FIG. 16 is a front view showing the segment ring after cold forging.

FIG. 17 is a view showing a method of manufacturing a ring body from a plate material by a conventional method.

FIG. 18 is a perspective view showing a ring body made according to FIG. 17;

FIG. 19 is a diagram showing a method for producing a commutator from a bar in a conventional manner.

FIG. 20 is a view showing a round bar tip made according to FIG. 19;

FIG. 21 is a sectional view showing an annular body made from the round bar tip of FIG. 20;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 12 Segment ring 14 Segment groove 15 Bridge piece 29 Copper wire 30 Cutting line 31 Cutting line 32 Ring body 32A Butt joint 33 Cutting and bending machine 36 Ring body 37 Parallel plane 38 Parallel plane 40 Parallel plane 41 Parallel plane 42 Parallel plane 43 Parallel Surface 44 R 45 Light emitting element 46 Light receiving element 47 Amplifier 49 Core 50 Exciting coil 51 Oscillator 52 U-shaped iron core 53 Iron core 55 Exciting coil 56 Power supply

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Kiyotaka Yamane 640 Address, Funakazaka, Kamiguni-cho, Ako-gun, Hyogo Inside (72) Inventor Osamu Tokunaga 640 Funasaka, Kamigori-cho, Ako-gun, Hyogo Mitsui Electric Co., Ltd. (56) References JP-A-59-103542 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01R 43/08 H01R 43/06 H01R 39/04

Claims (5)

(57) [Claims] 1. A low copper wire cross-section forms a substantially circular
A parallel surface is created by lamination or pressing, and then this copper wire
Is cut to a predetermined length, and the parallel faces define the inner and outer diameters of the ring.
The ends of the cut are butted together to form a ring body, and the ring body is cold forged to form a segment ring having a plurality of bridging pieces. A method for manufacturing a commutator, wherein a bridging piece is removed and separated into segments. 2. The method for manufacturing a commutator according to claim 1, wherein when the copper wire is cut into a predetermined length, the cutting lines are slanted and the cutting lines are alternately slanted in opposite directions. . 3. The method according to claim 1 , further comprising the step of:
The method of manufacturing a commutator according to claim 1 or 2, wherein the commutator is formed into a copper wire and then cut into a predetermined length . By wherein sensing the butt position is passed through the optical or magnetic flux abutting portion of the ring body, according to claim 1 to 3, wherein the butt portion is such that exactly matches the segment groove after cold forging process The method for manufacturing a commutator according to any one of the above. By supplying a short-circuit current 5. A ring member as the secondary winding of the transformer, one of the claims 1-4 which is adapted to cold forging what was welded a contact surface of the ring body Commutator manufacturing method.