JP2013005705A - Dc motor for pump - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the productivity and the assemblability of a DC motor for a pump and prevent a brake oil from leaking from the pump side to the DC motor side.SOLUTION: A DC motor for a pump, having a brush, includes: a case 11 formed into a cup shape; a brush plate 17 covering an opening of the case; a rotor housed in the case and having an armature 43 and a commutator 22; a brush 21 pressure-welded to the commutator; and a rotation shaft 32 having one end part to which a first bearing 34 is attached and an intermediate part to which a second bearing 33 is attached and allowing the armature to be fixed and attached to an area between the first and second bearings. The brush plate is made of a resin, and the resin brush plate is integrally formed with multiple terminals 25a, 25b.

Description

  The present invention relates to a pump DC motor, and more particularly to a pump DC motor suitable for use in an antilock brake device.

  An example of a conventional DC motor is described in Patent Document 1. In the electric motor described in this publication, in order to easily and reliably connect the pigtail to the terminal, the brush holder that holds the brush connected to the commutator has a linear lead-out path from the outer peripheral edge to the power feeding terminal, And a holding portion that is disposed in the lead-out path and holds the pigtail detachably.

  Another example of a conventional DC motor is described in Patent Document 2. In the motor described in this publication, the brush holder that holds the brush is energized and accommodated in the axially formed plate thickness range so that the brush contacts the commutator. And the wiring path which electrically connects the electric power feeding path from the pump main body side and a brush is embed | buried integrally.

  Another example of a conventional DC motor is described in Patent Document 3. In the electric pump described in this publication, the pump housing is composed of the first and second housings for the purpose of downsizing and improvement in assembly workability, and the wiring combined plate is embedded in the first housing by insert molding and supported. A bearing is installed. This prevents parts from being arranged on the yoke bottom surface side of the rotor.

JP 2007-82314 A JP 2001-69725 A JP-A-5-288143

  In the electric motor described in Patent Document 1, a dedicated jig is prepared for assembling the brush and pigtail to the brush holder, and the holder main body, the rod-shaped body, and the pigtail are respectively attached to the three types of recesses formed in the jig. The brush attached to the side is inserted, and the middle part of the pigtail is held by the holding part of the holder body. Thereafter, the other end portion of the pigtail is welded to the terminal, the brush is removed from the concave portion of the jig, and the brush is accommodated in an accommodating portion formed on the holder body by bending the pigtail portion. According to the assembling method described in the cited document 1, there is an advantage that it is possible to avoid that the length of the pigtail is insufficient or too long, but the man-hours for bending and holding the pigtail increase. In addition, a dedicated jig is required, and a large number of jigs are required to cope with differences in model numbers. Further, no consideration is given to reducing the number of processing steps, reducing the weight, and improving the reliability of electrical insulation by converting the cover of the motor housing to resin.

  In the pump operating motor described in Patent Document 2, the brush holder that holds the brush that can supply power to the commutator is made of an insulating resin, and the power supply path and the brush from the pump body side are electrically connected to the brush holder. The wiring path to be connected is embedded by insert molding. In this motor, the wiring path is formed integrally with the brush holder, but the brake oil filled in the pump side is prevented from leaking from the gap formed as necessary for assembly between the power supply terminal portion and the cylindrical portion. Is not taken into consideration.

  Further, in the electric pump described in Patent Document 3, a folded wiring combined plate is embedded in the pump housing in the insert molding like the motor described in Patent Document 2. However, this pump does not take into consideration that brake oil may leak from the gap between the wiring dedicated plate and the grommet that are unavoidably formed in processing and assembly.

  The present invention has been made in view of the above-mentioned problems of the prior art, and in a DC motor for a pump with a brush, leakage of brake oil filled on the pump side to the motor side is improved while improving manufacturability and workability. It is to prevent. Another object of the present invention is to improve the hermeticity of a brushed pump DC motor while employing a resin brush plate to improve processing and assembly.

  A feature of the present invention that achieves the above object is that a case formed in a cup shape, a brush plate covering an opening of the case, a rotor housed in the case and having an armature and a commutator, and the rectifier A brush that is press-contacted to a child, a first bearing at one end, a second bearing at an intermediate portion thereof, and a rotary shaft that is fixedly mounted between the first and second bearings. In the DC motor for a pump with a brush, the brush plate is made of resin, and the resin brush plate is integrally formed with a plurality of terminals formed by bending a plate of a conductor that can be welded or fused. There is to be.

  In this feature, a protrusion is formed to expose one end side of the plurality of terminals from the brush plate, and a pigtail having one end connected to the brush can be attached to the protrusion by welding or fusing, and the other end side Is preferably a connection terminal connected to the power feeding portion of the pump, and the protrusion formed on one end side of the plurality of terminals is more preferably a protrusion formed by bending a flat plate. Further, a power cylindrical portion that holds the plurality of terminals that are electrically connected to the pump on the back side of the brush plate, and a plurality of box-like brushes that hold the brush on the front side of the brush plate More preferably, the holder is formed with a plurality of pigtail guides on the front side of the brush plate and in the vicinity of the protruding portion of the terminal.

  Further, in the above feature, the vicinity of the bent portion formed between the wiring portion and the straight portion of the plurality of terminals is integrated with an adhesive integrated member, and the brush plate is integrally molded with the integrated terminal with resin. A cylindrical protrusion is formed in the vicinity of the brush holder, a spring holder slit is formed on the upper surface of the cylindrical protrusion, and one end side of the coil spring having both ends extending linearly is connected to the spring holder slit. The coil spring may be wound around the columnar protrusion, and the other end of the coil spring may be pressed against the upper surface of the brush held by the brush holder.

  According to the present invention, since the power supply circuit to the brush can be integrally formed with the brush plate by insert molding, and the terminal of the power supply circuit is integrally formed with the resin on the brush plate, it is manufactured in a DC motor for a pump with a brush. As a result, the airtightness is increased and the reliability is improved. Further, since the resin brush plate is employed, the weight is reduced and the man-hours required for processing and assembly are reduced, thereby improving the workability.

It is the longitudinal cross-sectional view and side view of one Example of the direct current motor for pumps concerning this invention. FIG. 3 is a three-side view of a power supply terminal (left side) included in the pump DC motor shown in FIG. 1. FIG. 3 is a three-side view of a power supply terminal (right side) included in the pump DC motor shown in FIG. 1. It is a perspective view of the other Example of the electric power feeding terminal which concerns on this invention. It is a perspective view of the brush plate which concerns on this invention, and is a figure after integral molding.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1A is a longitudinal sectional view of an embodiment of a DC motor for a pump according to the present invention, and FIG. 1B is a side view thereof. The electric motor shown in FIG. 1 is used for an anti-lock brake system (ABS) provided in a vehicle, but the present invention is not limited to that used for ABS.

  The DC motor 100 according to this embodiment is a brushed DC motor. An annular permanent magnet 16 constituting a field of the electric motor 100 is fixed to a peripheral wall portion 12 of a case (yoke) 11 in which an iron plate is formed in a cup shape by pressing or the like. The case 11 and the permanent magnet 16 constitute a stator of the electric motor 100. An armature 43 is disposed so as to face the permanent magnet 16. The armature 43 includes a laminated steel plate (core) 41 formed by laminating die-cut silicon steel plates and the like, and a winding 42 wound around a convex pole formed on the laminated steel plate 41. . In addition, the outer surface side of the laminated steel plate 41 is molded with a mold resin to ensure insulation.

  The laminated steel plate 41 around which the winding 42 is wound is attached to the rotating shaft 32, and the pump 95 attached to one end side of the electric motor 100 is rotationally driven as the rotating shaft 32 rotates. The end portion of the rotating shaft 32 is supported by a rear side rolling bearing 34 held by a rear bearing holding portion 13 formed by pressing or the like at the center portion of the bottom portion (left end portion in FIG. 1A) of the case 11. Here, the rear bearing holding portion 13 is formed in a convex shape inside the case 11.

  In order to supply electric power to the winding 42, a commutator 22 is attached to the rotary shaft 32, and two brushes 21 are pressed against the commutator 22 by springs (see FIG. 5C). . The brush 21 is electrically connected to terminals 25a and 25b attached to a brush plate 17 described later in detail. The terminals 25 a and 25 b are protected from insulation by the cylindrical portion 83 of the brush plate 17.

  The opening of the case 11 is covered with a brush plate 17, and the brush plate 17 is fitted in the case 11 in an airtight manner. An opening for holding the front side rolling bearing 33 is formed at the center of the brush plate 17, and a part of the front side rolling bearing 33 fixed to the rotating shaft 32 is held. A flange 14 is formed on the outer periphery of the case 11, and a pump 95 is attached by inserting a bolt into a pump mounting hole 15 formed in the flange 14.

  Here, the brush plate 17 is made of resin and is integrally formed with the terminals 25a and 25b. Next, details of the terminals 25a and 25b formed integrally with the resin in the brush plate 17 will be described with reference to FIGS. The terminals 25a and 25b are integrated from the terminal protrusions 26a and 26b for attaching the pigtail 75 having one end attached to the brush 21 to the connector parts 29a and 29b connected to the power feeding part of the pump 95.

  2 and 3 are three views showing the shapes of the terminals 25a and 25b. The terminals 25a and 25b are formed by punching a steel plate or copper plate, which is a conductive material that can be spot welded, with a press or the like, and then forming a convex shape at the tip portion with a press or the like and a 90-degree bent shape at an intermediate portion. is there. FIG. 3 is a diagram of the terminal 25a on the left side, and is a terminal located on the upper side when protruding from the cylindrical portion 83. FIG. FIG. 4 is a diagram of the right terminal 25 b, which is a terminal located on the lower stage side when protruding from the cylindrical portion 83. Both terminals 25a and 25b have a rectangular shape at one end, and the rectangular portions are convex protrusions 26a and 26b.

  Subsequent to the projections 26a and 26b, portions that are flush with the projections 26a and 26b are formed as wiring portions 27a and 27b, respectively. The wiring portions 27a and 27b are shaped to fit within the ring portion of the brush plate 17 formed in a ring shape, and are formed in a shape that does not interfere with each other when the left and right terminals 25a and 25b are arranged. Linear portions 28a and 28b are formed in a shape bent 90 degrees from the wiring portions 27a and 27b. The straight portions 28a and 28b are provided for connection to the power supply portion of the pump 95, and the axial length thereof is determined according to the pump 95 to be driven. The front ends of the straight portions 28 a and 28 b are narrower than the straight portions 28 a and 28 b, and serve as connector portions 29 a and 29 b that connect to the power feeding portion of the pump 95. Except for the protrusions 26a and 26b of the terminals 25a and 25b, portions where the terminals 25a and 25b are disposed are flat portions. That is, in order to facilitate positioning when the terminals 25a and 25b are integrally molded with the resin, the wiring portions 27a and 27b are flat except for the protrusions 26a and 26b at the tips of the terminals 25a and 25b.

  As described above, the protruding portions (flat portions) 26a and 26b of the terminals 25a and 25b are higher than the wiring portions 27a and 27b by a predetermined amount. This is because the protrusions 26 a and 26 b of the terminals 25 a and 25 b are exposed from the brush plate 17 in order to attach the pigtail 75. That is, in the DC motor 100 of the present embodiment, the pigtail 75 is connected by welding such as spot welding or projection welding or fusing. For example, when spot welding is used, in addition to the place where the pigtail 75 is attached, a position for a welding terminal is required on the inner peripheral side, and the brush plate 17 has a long shape in the radial direction. At that time, since a large load is applied to the projections 26a and 26b, the convex shape increases the rigidity and avoids deformation of the terminals 25a and 25b and poor welding. Moreover, since the flat parts 26a and 26b which are welding parts are higher than a surrounding part, workability | operativity at the time of pressing an electrode improves.

  FIG. 4 is a perspective view showing another embodiment of the terminal according to the present invention. This embodiment differs from the above embodiment in that the two terminals 25a and 25b are integrated in advance with an integrated member 50 made of insulating resin, and the resin is integrally molded together with the integrated terminal 24. It is in. That is, the terminal 24 has a plurality of terminal materials 25a and 25b, and can be positioned by the integrated member 50 while ensuring airtightness. The material of the integrated member 50 is preferably an adhesive material having good airtightness and adhesiveness. According to this embodiment, in addition to the effects of the above embodiment, the mutual positional relationship between a plurality of (two in this embodiment) terminals 25a and 25b can be positioned in advance, so that positioning work during resin integral molding can be performed. It becomes easy and workability is improved.

  The terminals 25a and 25b thus molded are integrally molded with the resin using the protrusions 26a and 26b of the terminals 25a and 25b and the connector parts 29a and 29b of the terminals 25a and 25b as exposed parts. If these jigs are appropriately created using these exposed portions as a positioning reference, the positional accuracy in resin integral molding can be ensured.

  FIG. 5 is a perspective view (FIGS. 5A and 5B) and a front view (FIG. 5C) of the brush plate 17 formed through the integral molding process. There is no main structure other than the cylindrical part used when electrically connecting to the pump 95 on the connection side with the pump shown in FIG. ing. On the other hand, the flat surfaces of the projections 26a and 26b of the terminals 25a and 25b are exposed on the side facing the inside of the DC motor 100, and one end of the pigtail 75 is connected. The other end of the pigtail 75 is connected to the side surface of the brush 21 built in the brush holder 72. In order to guide the pigtail 75, a pair of pigtail guides 73 protrude from the integral mold, and the pigtail 75 is sandwiched between the two pigtail guides 73 and used to hold the position during spot welding. The coil spring 74 held by the spring holder 71 presses the head of the brush 21 held by the brush holder 72 inward in the radial direction.

  The brush 21 has a prismatic shape. The brush holder 72 is formed in a square box shape by integral molding, and a brush holder slit 77 is formed on the side surface so that the pigtail 75 attached to the brush 21 can move. Two brush holders 72 are formed at a pitch of 90 degrees, and a pair of spring holders 71 are formed between the brush holders 72. The spring holder 71 has a cylindrical shape, and a spring holder slit 76 is formed on the upper surface. A coil spring 74 is wound around the outer periphery of the spring holder 71. Both ends of the coil spring 74 extend linearly, and one end side is fitted into the spring holder slit 76. The other end of the coil spring 74 presses the head of the brush 21 held by the brush holder 72 as described above.

  According to the present embodiment configured as described above, since the brush holder and the terminal are integrally formed, the axial length of the DC motor can be reduced. Further, the brush plate can be integrated only through one step of resin integral molding, and the time required for assembly can be reduced. Furthermore, since positioning of each component is easy when integrating with resin, positional accuracy can be ensured.

  Although the two-brush structure has been described in the above embodiment, it is possible to change to a four-brush structure, or to freely change the arrangement of the brushes and the welding or fusing position of the pigtail 75. That is, since the power terminal and the pigtail connection terminal are integrated, and the power terminal has a role of a bus bar, the above-described change can be made only by changing the length and shape of the power terminal. Moreover, since the convex protrusion is formed on the terminal, the rigidity of the terminal can be increased, and the occurrence of problems due to welding or fusing can be reduced.

DESCRIPTION OF SYMBOLS 11 ... Case (yoke), 12 ... Peripheral wall part, 13 ... Rear bearing holding part, 14 ... Flange, 15 ... Pump attachment hole, 16 ... Permanent magnet, 17 ... Brush plate, 21 ... Brush, 22 ... Commutator, 24 ... Integrated terminal, 25a, 25b ... terminal, 26a, 26b ... (terminal) protrusion (flat part), 27a, 27b ... wiring part, 28a, 28b ... straight line part, 29a, 29b ... connector part (connection terminal part), 32 ... Rotating shaft, 33 ... Front side rolling bearing, 34 ... Rear side rolling bearing, 41 ... Laminated steel plate, 42 ... Winding, 43 ... Armature, 50 ... Integrated member, 71 ... Spring holder, 72 ... Brush holder, 73 ... Pigtail guide, 74 ... Coil spring, 75 ... Pigtail, 76 ... Spring holder slit, 77 ... Brush holder slit, 83 ... (Power supply) cylindrical part, 83a ... Circular hole part, 83b ... Gyoana portion, 83c ... void portion, 83d ... stepped bore portion, 95 ... pump, 100 ... DC motor.

Claims (6)

A case formed in a cup shape, a brush plate covering the opening of the case, a rotor having an armature and a commutator housed in the case, a brush pressed against the commutator, and one end In a DC motor for pumps with a brush having a first bearing, a second bearing attached to an intermediate portion thereof, and a rotating shaft having the armature fixed between the first and second bearings. ,
A DC motor for a pump, wherein the brush plate is made of resin, and the resin brush plate is integrally formed with a plurality of terminals formed by bending a plate of a conductor that can be welded or fused.   A protrusion that exposes one end of the plurality of terminals from the brush plate is formed, and a pigtail having one end connected to the brush can be attached to the protrusion by welding or fusing, and the other end is supplied with power from the pump. The direct current motor for pump according to claim 1, wherein the direct current motor is a connection terminal connected to the section.   3. The pump DC motor according to claim 2, wherein the projection formed on one end side of the plurality of terminals is a projection formed by bending a flat plate into a convex shape.   A power supply cylindrical portion that holds a plurality of the terminals that are electrically connected to the pump on the back side of the brush plate, and a plurality of box-shaped brush holders that hold the brush on the front side of the brush plate 4. The pump DC motor according to claim 3, wherein a plurality of pigtail guides are formed on the front side of the brush plate and in the vicinity of the protruding portion of the terminal. 5.   The vicinity of the bent portion formed between the wiring portion and the straight portion of the plurality of terminals is integrated with an adhesive integrated member, and the brush plate is integrally molded with the resin together with the integrated terminal. The direct current motor for pumps according to any one of claims 1 to 4.   A cylindrical protrusion is formed in the vicinity of the brush holder, a spring holder slit is formed on the upper surface of the cylindrical protrusion, and one end side of the coil spring having both ends extending linearly is held by the spring holder slit. 6. The coil spring is wound around the columnar protrusion, and the other end of the coil spring is pressed against the upper surface of the brush held by the brush holder. A direct-current motor for a pump according to the item.

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