JP6779818B2 - Commutator for DC motor and its manufacturing method - Google Patents

Description

The present invention relates to a commutator for a DC motor provided with a mold plate into which a rotating shaft is fitted and fixed, an annular varistor arranged on the mold plate, and a riser portion for connecting the annular varistor, and a method for manufacturing the same.

In the operation of a small DC motor, a sudden current change occurs by cutting off the current with a commutator, and a surge voltage is generated to generate a spark discharge. This spark discharge has a problem of shortening the life of the rectifier.
In order to absorb this surge voltage, a commutator for a DC motor in which a spark erasing element such as a varistor or a capacitor is connected between the commutators has been proposed (for example, Patent Document 1 and Patent Document 2).

Hereinafter, the configuration of the commutator for an electric motor of Patent Document 1 will be described. The corresponding part name of the present invention is described in parentheses after the part name of Patent Document 1.
In the commutator for electric motors of Patent Document 1, a flange portion is integrally formed on the bottom of a cylindrical holder (mold plate), and a plurality of segments (commutator pieces) are closely attached to the outer periphery of the cylindrical portion of the holder to form a synthetic resin or the like. It is fixed with an insulating washer made of the same material as the above material, and a riser (riser portion) is integrally formed and led out in the circumferential direction of the segment, and a coil outlet wire winding portion is provided on the tip side thereof.

A rotating shaft is fitted and fixed to the central hole of the cylindrical portion, a rotor core is fixed to the lower side of the collar portion, and a coil is wound around the rotor core.
A ring-shaped varistor (annular varistor) is placed on the flange portion, and the electrode portion having an electrode portion formed on the upper surface of the ring-shaped varistor with silver paste or the like is brought into contact with the back surface of the riser, and the coil outlet wire The coil (cup) lead wire (copper wire) is wound around the winding part and connected by soldering, and at the same time, the electrode part of the varistor and the riser are soldered.

According to the above configuration, with a simple configuration in which insulating washers and varistor are provided above and below the riser, the varistor and coil outlet wire need only be soldered once to the riser, and the inner diameter of the varistor can be reduced for commutation. It is stated that the maximum outer diameter of the child set can be reduced to reduce the size.

Further, in Patent Document 2, a ring varistor (annular varistor) is placed in a recess provided in a resin commutator base (mold plate), and this ring varistor is soldered to a riser portion mounted on the ring varistor. A commutator for a small motor is described.

Microfilm of Jitsugyo No. 61-97731 (Jitsukai Sho No. 63-7975) (pages 3 to 5, Fig. 2) Japanese Unexamined Patent Publication No. 63-138679 (pages 3 to 4, FIG. 2)

In the conventional rectifier for electric motor shown in Patent Document 1, a ring varistor (annular varistor) is placed on a flange (opening) provided in a holder (mold plate) as in the present application, and a segment (rectifier piece) is placed. The riser (riser part) provided at a right angle from) and the electrode of the ring varistor are soldered. However, in Patent Document 1, the problems and conditions regarding the case of soldering the riser and the electrode of the ring varistor and the case of soldering the coil lead wire and the riser are not examined at all.

That is, when soldering the riser and the electrode of the ring varistor, or when soldering the coil outlet wire and the riser with solder containing a resin, flux gas is generated and the components and cure of the DC motor There is a risk of soiling the jig and there is a risk of corrosion of parts due to flux residue.
Therefore, before assembling the DC motor, solder the riser and the ring varistor with solder containing resin and form a preliminary solder to the riser, and after assembling the DC motor, use a heating rod and use the preliminary solder of the riser. The coil outlet wire is soldered, but even in this case, the flux residue remains in the preliminary solder layer, so this flux residue may melt out due to the heating of the heating rod, which may adversely affect parts and jigs. There is.

Further, when soldering the coil outlet wire using a heating rod, the heating rod is pressed from the upper part of the riser to heat and pressurize, but the commutator described in Patent Document 1 and Patent Document 2 uses the commutator. In both cases, the ring varistor is sandwiched between the riser and the holder (mold plate) and brought into contact with each other, so the pressure of the heating rod is applied to the ring varistor via the riser, damaging the ceramic ring varistor. There is a risk of causing it.

An object of the present invention is to solve the above problems, to eliminate the adverse effect of flux, and to provide a commutator for a DC motor and a method for manufacturing the same, in which the annular varistor is not damaged by the heating rod.

In order to achieve the above object, the commutator for a DC motor in the present invention is in contact with both a mold plate in which a rotating shaft is fitted and fixed, an annular varistor arranged on the mold plate, and both the annular varistor and the mold plate. In the commutator for a DC motor provided with the riser portion arranged in the above direction, the region for joining the riser portion and the copper wire through which the current flows is the region where the riser portion and the mold plate are in contact with each other and the region where the riser portion and the annular varistor are in contact with each other. It is characterized by including.

According to the above configuration, it is possible to provide a commutator for a DC motor that eliminates the adverse effect of the flux residue of the preliminary solder layer and does not damage the annular varistor by the heating rod.

It is preferable that the mold plate has an opening for arranging the annular varistor, and a gap is provided on the surface of the annular varistor opposite to the joint surface between the annular varistor and the riser portion.

According to the above configuration, the voids provided on the lower surface of the annular varistor relax the pressing force by the heating rod transmitted to the annular varistor, and damage to the annular varistor can be prevented.

It is preferable to place the resin in the voids.

The riser portion may be provided so as to straddle the opening.

In the method for manufacturing a commutator for a DC motor of the present invention, a mold plate in which a rotating shaft is fitted and fixed, an annular varistor arranged on the mold plate, and a riser portion arranged in contact with both the annular varistor and the mold plate are provided. In the method for manufacturing a commutator for a DC motor provided, an annular varistor arrangement step of arranging an annular varistor on a mold plate, a riser portion arrangement step of arranging a riser portion on a mold plate and an annular varistor, and a riser portion and an annular shape. It has a riser part joining step for joining a varistor and a copper wire joining step for joining a copper wire for passing a current and a riser part, and the region for joining the riser part and the copper wire in the copper wire joining step is It is characterized by including a region where the riser portion and the mold plate are in contact with each other and a region where the riser portion and the annular varistor are in contact with each other.

According to the above manufacturing method, it is possible to provide a method for manufacturing a commutator for a DC motor, which eliminates the adverse effect of the flux residue of the preliminary solder layer and does not damage the annular varistor by the heating rod.

In the annular varistor arrangement step, it is preferable to arrange the annular varistor so as to provide a gap in the opening provided in the mold plate on the surface opposite to the joint surface between the annular varistor and the riser portion.

It is preferable to have a resin placement step of arranging the resin in the voids.

In the riser portion joining step, it is preferable to arrange the joining member between the riser portion and the annular varistor and on the surface of the riser portion.

It is preferable to have a residue cleaning step for cleaning and removing the residue after the riser joining step.

In the copper wire joining step, it is preferable to sandwich the copper wire, the riser portion and the mold plate between the heating rod and the pedestal, and pressurize and heat the copper wire.

As described above, in the present invention, it is possible to provide a commutator for a DC motor and a method for manufacturing the same, which eliminates the adverse effect of the flux residue of the preliminary solder layer and does not damage the annular varistor by the heating rod.

It is sectional drawing which shows the whole structure of the armature in 1st Embodiment of this invention. It is sectional drawing which shows the stator of the armature in 1st Embodiment of this invention. It is sectional drawing which shows the rotor of the armature in 1st Embodiment of this invention. It is sectional drawing which shows the brush part of the armature in 1st Embodiment of this invention. It is sectional drawing of the commutator mechanism (A1 part) in 1st Embodiment of this invention. It is sectional drawing which shows the commutator mechanism (A2 part) in 1st Embodiment of this invention. It is a process drawing which shows the manufacturing method of the commutator for a DC motor in 1st Embodiment of this invention. It is sectional drawing which shows the manufacturing method of the commutator for DC motors in 1st Embodiment of this invention. It is sectional drawing which shows the manufacturing method of the commutator for DC motors in 1st Embodiment of this invention. It is sectional drawing which shows the manufacturing method of the commutator for DC motors in 1st Embodiment of this invention. It is sectional drawing which shows the manufacturing method of the commutator for DC motors in 1st Embodiment of this invention. It is sectional drawing which shows the manufacturing method of the commutator for DC motors in 1st Embodiment of this invention. It is sectional drawing which shows the manufacturing method of the commutator for DC motors in 1st Embodiment of this invention. It is a top view which shows the commutator for a DC motor in the 2nd Embodiment of this invention. It is sectional drawing which shows the commutator for DC motors in 2nd Embodiment of this invention. It is sectional drawing which shows the commutator mechanism (A2 part) for DC motors in 3rd Embodiment of this invention. It is sectional drawing which shows the commutator mechanism (A2 part) for DC motors in 3rd Embodiment of this invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. However, the embodiments shown below exemplify a commutator for a DC motor for embodying the idea of the present invention, and the present invention is not limited to the following configurations. In particular, the dimensions, materials, shapes, relative arrangements, and the like of the components described in the embodiments are not intended to limit the scope of the present invention to the specific description unless otherwise specified, and are merely explanatory examples. Absent. In the following description, the same parts and components may be given the same name and reference numerals, and detailed description may be omitted as appropriate.

[First Embodiment]
The commutator for a DC motor according to the first embodiment of the present invention will be described with reference to FIGS. 1 to 6F. FIG. 1 is a cross-sectional view showing the overall configuration of the armature 1 of the first embodiment. 2 is an exploded cross-sectional view of the armature 1 shown in FIG. 1, FIG. 3 is an enlarged cross-sectional view of the commutator mechanism (A1 portion) of the armature 1 shown in FIG. 1, and FIG. 4 is a commutator mechanism (A2 portion) in FIG. ), FIGS. 5 to 6F are process diagrams and cross-sectional views showing the method for manufacturing the commutator for a DC motor of the present invention.

[Commutator configuration for DC motor]

The armature 1 shown in FIG. 1 is composed of three components, a stator 2, a rotor 3, and a brush unit 4. The stator 2 is shown in FIG. 2A, the rotor 3 is shown in FIG. 2B, and the brush unit 4 is shown. It is shown in FIG. 2C. As shown in FIG. 2A, the stator 2 includes a metal house 2a having a through hole for a rotating shaft, bearings 2b attached to both ends of the through hole of the metal house 2a, and a magnet 2c fixed to the outer circumference of the metal house 2a. It is composed of a housing 2d that protects the outer circumference.

As shown in FIG. 2B, the rotor 3 is composed of a rotating shaft 3a, a commutator mechanism 5 fixed to the rotating shaft 3a, and a cup 6 composed of a coil winding fixed to the outer peripheral wall of the commutator mechanism 5. .. The details of the commutator mechanism 5 will be described later.

As shown in FIG. 2C, the brush unit 4 is composed of a brush base 4a, a brush 4b attached to the brush base 4a, and a power supply terminal 4c.
As the brush 4b, a brush 4b in which metal wires are bundled or a metal plate formed in a comb-teeth shape can be used, and a precious metal or the like can be used as the material.
The brush 4b has a configuration in which a plurality of brush pieces having the same shape are arranged in parallel, and is arranged so that the plurality of brush pieces are in contact with each other at the same time following the shape of the commutator piece provided in the rotor 3 described later. There is. By simultaneously contacting a plurality of brush pieces with the commutator piece of the rotor, poor contact of the brush 4b with the commutator piece, which becomes unstable due to rotational contact, is prevented.

The armature 1 shown in FIG. 1 is arranged so that the magnet 2c of the stator 2 and the cup 6 of the rotor 3 face each other, and the drive voltage supplied from the power supply terminal 4c of the brush unit 4 via the brush 4b is applied to the rotor. The rotor 3 is supplied to the rectifier mechanism 5 of 3 and is coupled around the rotation shaft 3a by the action of attractive force and repulsive force due to the electromagnetic force generated by the current flowing through the cup 6 and the magnetic force of the magnet 2c of the stator 2. Rotates.

Next, the configuration of the commutator mechanism 5 of the rotor 3, which is the drive mechanism of the armature 1, and the brush unit 4 will be described with reference to FIG. FIG. 3 is an enlarged cross-sectional view of the A1 portion of FIG. 1, showing a detailed configuration of the drive mechanism of the armature 1 and an electrically connected state.
The structure of the rectifier mechanism 5 is formed on a mold plate 7 in which a base portion 7b is formed on the bottom of a cylindrical portion 7a in which a rotating shaft is fitted and fixed, and on the outer periphery of the cylindrical portion 7a of the mold plate 7. A plurality of attached rectifier pieces 8 and a riser portion 8a in which the rectifier piece 8 is bent in the circumferential direction at a position on the upper surface of a base portion 7b substantially orthogonal to the rectifier piece 8 are provided. Further, the rectifier piece 8 and the riser portion 8a are fixed by pushing the insulating washer 9. Further, an opening 7c for accommodating the annular varistor 10 is formed on the upper surface side of the mold plate 7, and a bush 11 is provided on the back surface side. That is, the annular varistor 10 arranged on the mold plate 7 and the riser portion 8a are arranged in contact with both the annular varistor 10 and the mold plate 7. Further, the cup 6 is positioned and fixed to the side wall 7d of the mold plate 7, and the drawn copper wire 6a drawn from the end of the cup 6 is soldered to the riser portion 8a. A current flows through the cup 6 and the riser portion 8a by the drawn copper wire 6a.

Next, the electrical connection between the commutator mechanism 5 constituting the drive mechanism and the brush unit 4 will be described.
The drive voltage supplied from the power supply terminal 4c of the brush unit 4 is intermittently supplied to the commutator piece 8 of the commutator mechanism 5 via the brush 4b. The drive voltage supplied to the rectifier piece 8 is supplied to the cup 6 via the riser portion 8a and the drawn copper wire 6a, and the rotor 3 rotates due to the electrokinetic action between the cup 6 and the magnet 2c.
The annular varistor 10 which is a spark erasing element is connected between the commutator pieces 8 to prevent the generation of sparks generated between the commutator piece 8 and the brush 4b, and prolong the life of the brush 4b. Can be done.

Next, the detailed configuration of the commutator mechanism 5 will be described with reference to FIG. FIG. 4 is an enlarged cross-sectional view of the A2 portion in FIG. 3, showing a detailed configuration of the commutator mechanism 5.
The commutator mechanism 5 shown in FIG. 4 is shown by rotating the A2 portion shown in FIG. 3 by 90 °.
The mold plate 7 has a cylindrical portion 7a and a base portion 7b in contact with the rotating shaft 3a, and an opening 7c is provided on the upper surface side of the base portion 7b. Further, on the lower side of the commutator piece 8 attached to the outer periphery of the cylindrical portion 7a, there is a positioning portion 8b inserted into the mold plate 7 and one of the commutator pieces 8 at the upper surface position of the base portion 7b of the mold plate 7. A riser portion 8a having a portion bent in the circumferential direction is provided, and a washer 9 is pushed in and fixed so that the commutator piece 8 does not come off from the mold plate 7. Further, the cup 6 is positioned and fixed to the side wall portion 7d of the mold plate 7.

An annular varistor 10 is arranged in the opening 7c of the mold plate 7, and the annular varistor 10 arranged on the lower surface side of the riser portion 8a and the riser portion 8a are fixed by soldering. A solder layer 12 is formed on the upper surface side of the riser portion 8a, and the drawn copper wire 6a drawn from the cup 6 fixed to the side wall portion 7d of the mold plate 7 is soldered to the solder layer 12. .. In this configuration, there is a gap t between the lower surface of the annular varistor 10 and the bottom surface of the opening 7c of the mold plate 7, that is, on the surface of the annular varistor 10 opposite to the joint surface between the annular varistor 10 and the riser portion 8a. The annular varistor 10 is formed, is fixed to the riser portion 8a, and is arranged with a space inside the opening 7c.

[Explanation of manufacturing method of commutator for DC motor]
Next, a method of manufacturing the commutator for a DC motor of the present invention will be described with reference to FIG. FIG. 5 is a process diagram showing a method for manufacturing a commutator for a DC motor. The annular varistor 10 is arranged in the opening 7c provided in the mold plate 7, and the annular varistor arrangement step S1 and the riser portion 8a are placed on the annular varistor 10. The riser portion arranging step S2 to be arranged, the riser portion joining step S3 for joining the riser portion 8a and the annular varistor 10, the residue cleaning step S4 for cleaning the residue generated in the riser portion joining step S3, and the mold plate 7 It is composed of a cup bonding step S5 for positioning and fixing the cup 6 to the side wall portion 7d of the cup 6, and a copper wire joining step S6 for joining the drawn copper wire 6a of the cup 6 to the solder layer 12 provided on the riser portion 8a.

Next, details of a method for manufacturing a commutator for a DC motor will be described with reference to FIGS. 6A to 6F.
6A to 6F are cross-sectional views showing each step of the manufacturing method of the commutator mechanism 5 (commutator for DC motor) shown in FIG. 4, and the first three steps are described with reference to FIGS. 6A to 6C. To do. FIG. 6A is a cross-sectional view showing the annular varistor arranging step S1 and the riser portion arranging step S2. The annular varistor 10 arranged inside the opening 7c of the mold plate 7, the base portion of the mold plate 7, and the annular varistor. The riser portion 8a is arranged above the 10 by press-fitting the washer 9. In this state, the cup 6 is not yet fixed to the side wall portion 7d of the mold plate 7, as shown by the dotted line.

FIG. 6B is a cross-sectional view showing the riser portion joining step S3, in which an electrode (not shown) provided on the upper surface of the annular varistor 10 and the lower surface side of the riser portion 8a are connected by solder containing a resin and at the same time the riser. A solder layer 12 which is a joining member is formed on the upper surface side of the portion 8a. At this time, it is necessary to join the annular varistor 10 and the riser portion 8a in contact with each other by using solder, and the commutator mechanism 5 shown in FIG. 6A is turned upside down so that the annular varistor 10 and the riser portion 8a are in contact with each other. By performing the riser portion joining step S3 in a state of being in contact with each other, it is possible to form a structure in which a gap is provided between the lower surface of the annular varistor 10 and the bottom surface of the opening 7c of the mold plate 7.

The method of providing a gap between the lower surface of the annular varistor 10 and the bottom surface of the opening 7c of the mold plate 7 described above is an example, and the annular varistor 10 and the commutator piece 8 (riser portion 8a) are soldered. By arranging the annular varistor 10 on the mold plate 7 after joining with the above, a structure in which a gap is provided between the lower surface of the annular varistor 10 and the bottom surface of the opening 7c of the mold plate 7 can be formed.

In the solder layer 12, the molten solder is brought into contact with the annular varistor 10 or the riser portion 8a, and the riser portion 8a in the region where the riser portion 8a and the annular varistor 10 are in contact and the region where the riser portion 8a and the mold plate 7 are in contact with each other. It is formed by the solder spreading over the entire upper surface of the solder.
When the solder layer 12 is formed by the solder containing the resin, the solder melts around the solder layer 12 and the residue 20 of the flux residue adheres to the solder layer 12, which may cause a problem in a later process.

FIG. 6C is a cross-sectional view showing the residue cleaning step S4, which is a step of cleaning the flux residue residue 20 generated around the solder layer 12 when the solder layer 12 is formed by the solder containing solder in the previous step. ..
The flux residue residue 20 is washed using a hydrocarbon-based cleaning liquid as a solvent for dissolving the flux residue. However, the cup 6 to be described later is configured by solidifying the wound copper wire with an adhesive, and when the cleaning liquid is a solution that dissolves the adhesive that solidifies the cup 6, the residue cleaning step S4 is a cup on the mold plate 7. It is necessary to do before fixing 6. If the cleaning liquid is a solution that does not dissolve the adhesive that hardens the cup 6, the residue cleaning step S4 can be performed after the cup 6 is fixed.
Further, the residue cleaning step S4 can be omitted as long as the flux residue is a component that is not likely to be corroded and the stains on the parts are not hindered.

Next, the latter three steps will be described with reference to FIGS. 6D to 6F. FIG. 6D is a cross-sectional view showing the cup bonding step S5, which is a step of positioning and fixing the cup 6 to the side wall portion 7d of the mold plate 7. The cup 6 is provided with a drawn copper wire 6a in which a thin copper wire is shaped into a cylindrical shape and hardened with an adhesive, and the end portion is solder-plated.
In the actual cup bonding step S5, the cup 6 is fixed with an adhesive while being heated using a cup bonding jig that positions the cup 6 and the commutator mechanism 5.

FIG. 6E is a cross-sectional view showing the copper wire joining step S6, which is a step of joining the drawn copper wire 6a of the cup 6 to the solder layer 12 provided in the riser portion 8a. This copper wire joining step S6 is performed using the solder layer 12 in which the solder layer 12 is formed and the residue 20 is washed by the solder containing the solder, which is the previous step, and the solder-plated drawn copper wire 6a. ..

As a joining method, as shown in FIG. 6E, the pedestal 15 is applied to the lower surface of the base portion 7b of the mold plate 7, and the solder layer 12 formed on the upper portion of the riser portion 8a corresponding to the position of the pedestal 15. The heating rod 16 is set above the above. In this state, the solder-plated tip portion of the drawn copper wire 6a drawn out from the cup 6 is set in the solder layer 12 formed on the upper portion of the riser portion 8a. In this state, the heating rod 16 is lowered to heat-bond the solder-plated tip portion of the drawn copper wire 6a to the solder layer 12.

In the copper wire joining step S6, the regions for joining the riser portion 8a and the drawn copper wire 6a are the region 8m where the riser portion 8a and the mold plate 7 are in contact with each other and the region 8n where the riser portion 8a and the annular varistor 10 are in contact with each other. The heating rod 16 is brought into contact with the position including both of the above regions 8m and 8n. FIG. 6F is a cross-sectional view showing a completed assembly state of the rotor 3, and the tip of the drawn copper wire 6a includes a region 8 m in contact with the riser portion 8a and the mold plate 7 and a region 8n in contact with the riser portion 8a and the annular varistor 10. Welded to the area.

According to the above joining method, the following effects are obtained. First, by applying pressure with the heating rod 16 at a position including the region 8m and the region 8n, the main pressure can be received by the base portion 7b of the mold plate 7, and further, by the gap provided in the lower part of the annular varistor 10. No pressure is applied to the portion of the annular varistor 10, and damage due to contact between the annular varistor 10 and the mold plate 7 can be prevented.
Further, as a soldering condition, after cleaning the residue formed on the upper portion of the riser portion 8a, the solder layer 12 and the lead copper wire 6a whose tip is solder-plated are heat-welded with a heating rod 16. Therefore, since the solder layer 12 and the solder plated on the end of the drawn copper wire 6a are fused and mixed to be joined, no flux gas is generated due to soldering, and the parts are contaminated by the flux residue. It is possible to prevent the occurrence of adverse effects such as corrosion.

By performing the cup bonding step S5 after the residue cleaning step S4, the cleaning liquid can be freely selected without dissolving the adhesive material of the cup 6.

[Second Embodiment]
Next, the rectifier for a DC motor according to the second embodiment of the present invention will be described with reference to FIG. 7.
FIG. 7 is a plan view and a cross-sectional view of the commutator mechanism 50 seen from the brush unit 4 side of the rotor 3 in the armature 1, and since the basic configuration is the same as that of the first embodiment, the same elements have the same number. The duplicate explanation is omitted.
The commutator mechanism 50 in the second embodiment is different from the commutator mechanism 5 in the first embodiment in that the riser portion 8a of the commutator piece extends long and is provided in a range straddling the opening 7c of the mold plate 7. That is to be done.

Next, the configuration of the rectifier mechanism 50 will be described in more detail with reference to FIG. 7.
7A is a plan view of the commutator mechanism 50, and FIG. 7B is a cross-sectional view taken along the line BB shown in FIG. 7A. In the plan view of the commutator mechanism 50 shown in FIG. 7A, a configuration in which the commutator pieces are divided into three pieces is illustrated, and the riser portions 81a, 82a, 83a are bent from the commutator pieces 81, 82, 83, respectively. Is growing. As a specific description of the configuration, the commutator piece 81 will be taken as an example, and the relationship between the riser portion 81a, the opening 7c of the mold plate 7, and the annular varistor 10 will be described with reference to FIGS. 7A and 7B.

The difference between the commutator mechanism 5 and the commutator mechanism 50 is that the riser portion 81a of the commutator piece 81 extends long and covers the range straddling the opening 7c of the mold plate 7 to the upper part of the side wall portion 7d of the mold plate 7. It is extending.
That is, the riser portion 81a that bends and extends from the commutator piece 81 extends long and covers the range that straddles the opening 7c of the mold plate 7 so that the portion hidden by the washer 9 is shown by the dotted line. It extends to the upper part of the side wall portion 7d of the.
Then, as described in the riser portion joining step S3, the connecting portion 12b that connects and fixes the electrode 10a provided on the upper surface of the annular varistor 10 and the riser portion 81a by forming the solder layer 12 with the solder containing the resin. Is formed, and at the same time, a solder layer 12a is formed on the upper surface side of the riser portion 81a. Further, the lead-out copper wire 6a of the cup 6 and the solder layer 12a are connected at the same position as the commutator mechanism 5 of the first embodiment.

In the configuration of the commutator mechanism 50 in the second embodiment, the riser portion 81a is supported by arranging the riser portion 81a on the base portion 7b and the side wall portion 7d of the mold plate 7 so as to straddle the opening 7c. Has the effect of stabilizing the positioning and holding of the fixed annular varistor 10.

[Third Embodiment]
Next, the commutator for a DC motor according to the third embodiment of the present invention will be described with reference to FIGS. 8A and 8B. 8A and 8B are cross-sectional views showing the same part as the commutator mechanism 5 (A2 part) of the armature 1 in the first embodiment, and since the basic configuration is the same as that of the first embodiment, they have the same elements. Are assigned the same number and duplicate explanations are omitted.
The feature of the commutator mechanism 60 in the third embodiment is that the filling resin 61 is filled inside the opening 7c of the mold plate 7 in which the annular varistor 10 is arranged.

In the configuration of FIG. 8A, the filling resin 61 is filled between the side surface of the annular varistor 10 and the side wall of the opening 7c inside the opening 7c in which the annular varistor 10 is arranged.
Further, in the configuration of FIG. 8B, the filling resin 61 is filled on the entire surface other than the upper surface of the annular varistor 10 in the opening 7c in which the annular varistor 10 is arranged.
Further, the solder layer 12 for forming the preliminary solder layer by fixing the annular varistor 10 to the riser portion 8a is provided at the same position as in the first embodiment, and the lead copper wire 6a of the cup 6 and the solder layer 12 are connected to each other. Is performed at the same position as in the first embodiment.

That is, the method of manufacturing the commutator mechanism 60 is a resin filling step of filling the opening 7c of the mold plate 7 in which the annular varistor 10 is arranged with the filling resin 61, as compared with the manufacturing process of the commutator mechanism 5 of the first embodiment. Will be added. As the filling resin 61, an epoxy resin, a urethane resin, or the like can be used.
According to the above configuration, the holding state of the annular varistor 10 arranged in the opening 7c of the mold plate 7 and joined to the riser portion 8a is stabilized, the strength of the mold plate 7 itself is improved, and the annular shape due to impact or the like is improved. Damage to the varistor 10 and the mold plate 7 can be prevented.

As described above, in the commutator for a DC motor provided with the annular varistor and the riser portion in the present invention, the structure can be configured such that no external force is applied to the annular varistor due to the voids provided around the annular varistor. A commutator for a DC motor capable of preventing damage to the varistor can be provided. Further, a stable manufacturing method can be provided by devising the assembly process of the rectifier for the DC motor.
Further, the above manufacturing method is not limited to the armature for a DC motor, and can be applied to any armature for an electric motor.

1 Armature 2 Stator 2a Metal house 2b Bearing 2c Magnet 2d Housing 3 Rotor 3a Rotating shaft 4 Brush unit 4a Brush stand 4b Brush 4c Power terminal 5, 50, 60 Commutator mechanism 6 Cup 6a Connecting copper wire 7 Mold plate 7a Cylindrical part 7b Base 7c Opening 7d Side wall 8, 80, 81, 82, 83 Commutator pieces 8a, 81a, 82a, 83a Riser 8m, 8n Area 9 Washer 10 Circular varistor 11 Bush 12, 12a Solder layer 12b Connection 15 pedestal 16 heating rod 20 residue

Claims (10)

A commutator for a DC motor including a mold plate with a rotating shaft fitted and fixed, an annular varistor arranged on the mold plate, and a riser portion arranged in contact with both the annular varistor and the mold plate.
The region for joining the riser portion and the copper wire through which the current flows includes a region where the riser portion and the mold plate are in contact with each other and a region where the riser portion and the annular varistor are in contact with each other. Child. The mold plate has an opening for arranging the annular varistor.
The commutator for a DC motor according to claim 1, wherein a gap is provided in a surface of the annular varistor on the side opposite to the joint surface between the annular varistor and the riser portion. The commutator for a DC motor according to claim 2, wherein the resin is arranged in the gap. The commutator for a DC motor according to claim 2 or 3, wherein the riser portion is provided so as to straddle the opening. A method for manufacturing a commutator for a DC motor, which includes a mold plate with a rotating shaft fitted and fixed, an annular varistor arranged on the mold plate, and a riser portion arranged in contact with both the annular varistor and the mold plate. In
An annular varistor arrangement step of arranging the annular varistor on the mold plate, and
A riser portion arranging step of arranging the riser portion on the mold plate and the annular varistor, and
The riser part joining step of joining the riser part and the annular varistor,
It has a copper wire joining step of joining a copper wire for passing an electric current and the riser portion.
The region for joining the riser portion and the copper wire in the copper wire joining step includes a region where the riser portion and the mold plate are in contact with each other and a region where the riser portion and the annular varistor are in contact with each other. Manufacturing method of rectifier for DC motor. The annular varistor arranging step is characterized in that the annular varistor is arranged so as to provide a gap in the opening provided in the mold plate on the surface opposite to the joint surface between the annular varistor and the riser portion. The method for manufacturing a commutator for a DC motor according to claim 5. The method for manufacturing a commutator for a DC motor according to claim 6, further comprising a resin arranging step of arranging the resin in the voids. The direct current according to any one of claims 5 to 7, wherein the riser portion joining step comprises arranging a joining member between the riser portion and the annular varistor and on the surface of the riser portion. Manufacturing method of commutator for motor. The method for manufacturing a commutator for a DC motor according to any one of claims 5 to 8, further comprising a residue cleaning step of cleaning and removing the residue after the riser joining step. Any of claims 5 to 9, wherein the copper wire joining step is performed by sandwiching the copper wire, the riser portion and the mold plate between the heating rod and the pedestal, and performing pressurization and heating. The method for manufacturing a commutator for a DC motor according to item 1.

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