JP4105024B2 - DC motor and fuel pump using this DC motor - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a DC motor used for home appliances or automotive electrical components, and a fuel pump configured using the DC motor.
[0002]
[Prior art]
Small DC motors used for home appliances or automotive electrical components generally have many excellent characteristics such as high output and easy control of rotational speed by using an electronic control circuit. ing. On the other hand, since the commutator rotates in a sliding state with respect to the brush, there is a problem that the brush and the commutator wear against each other. This wear problem is largely due to the occurrence of sparks between the brush and the commutator. Therefore, conventionally, in order to reduce the occurrence of sparks between the brush and the commutator, a DC motor including a spark erasing element such as a capacitor has been proposed (for example, see Patent Document 1).
[0003]
[Patent Document 1]
Utility Model Registration Publication No. 2510549 Publication (FIGS. 1, 2, and 3)
[0004]
[Problems to be solved by the invention]
Conventionally, in a DC motor, in order to suppress a spark generated between a commutator and a brush, it is widely known to provide a spark erasing element in the vicinity of the commutator. However, since the commutator and the spark erasing element are generally configured to be mounted on the armature shaft as separate parts, it is difficult to mount or in the case of a DC motor used for an in-tank fuel pump. However, it was difficult to solve various problems. Furthermore, since it is difficult to install, it has also caused a decrease in mass productivity.
[0005]
In order to solve the above-mentioned problems, the present invention is a unit that includes a commutator and a spark erasing element, is easy to manufacture, and facilitates mounting on an armature shaft, An object is to obtain a highly safe DC motor and a fuel pump using the DC motor.
[0006]
[Means for Solving the Problems]
To achieve the above object, a DC motor according to the present invention includes a commutator device installed at one end of an armature, connected to an armature winding, and slidably in contact with a brush. The commutator device is fixed to a commutator piece arranged radially and in a disc shape around the axis of the armature, and to the back side of the commutator piece, and the armature. A conductive terminal piece adapted to be connected to the winding; and an insulating holder molded so that the commutator piece can be in contact with the brush while holding the commutator piece to which the conductive terminal piece is fixed; It said the concave plant arranged such that adjacent conductive terminal piece in the back side of the insulating holding member is exposed to each other, is connected between the exposed conductive terminal piece within the recess across the conductive terminal piece to the adjacent Fire It is obtained by a deletion device.
[0007]
A fuel pump according to the present invention includes a commutator device in which a commutator and a spark erasing element are unitized, a DC motor configured by molding the outer periphery of an armature winding with a thermoplastic resin material, and the DC motor. The pump is configured to be driven by an electric motor, and a pump unit configured to discharge the fuel sucked by the rotational driving through the DC motor.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows an example of a fuel supply device for an automobile equipped with a commutator device, where M is a part of a DC motor, a fixed magnetic pole 2 is disposed on the inner periphery of a housing 1, and an armature is provided on the inner side 3 is supported by a bearing 4 so that it can rotate. Reference numeral 3 a denotes an armature 3 axis. The bearing 4 is held by a bracket 5 fitted to one end of the housing 1. A planar commutator device 10 is configured such that the brush 6 held by the bracket 5 is in sliding contact with the commutator surface. Details of the commutator device 10 will be described later with reference to FIGS. P is a pump unit that is rotated by a DC motor M to function as a pump. This fuel pump is used by being installed in a fuel tank of an automobile, for example, and the sucked fuel passes through the DC motor M and is discharged from a discharge port 5 a provided in the bracket 5. It is comprised so that.
[0009]
Embodiment 1 FIG.
2A and 2B show a commutator device 10 for a DC motor M according to Embodiment 1 of the present invention, in which FIG. 2A is a front view, FIG. 2B is a side sectional view taken along line AA, and FIG. FIG. 4D is a cross-sectional view taken along line BB. In the figure, the commutator pieces 12 are arranged in a radial and disc shape around a shaft hole 13 fitted to the shaft 3a of the armature. The commutator piece 12 is made of, for example, a carbon fired material, and is manufactured by a manufacturing method as described below. Conductive terminal pieces 14 are fixed to the back side of the commutator piece 12. The conductive terminal piece 14 is made of a copper alloy material, and a hook-like terminal 14a for connecting to an armature winding (not shown) is provided at the outer peripheral tip.
[0010]
The insulating holding body 15 holds the state where the commutator pieces 12 to which the conductive terminal pieces 14 are fixed are arranged radially through the slits 16 having a predetermined width, and is a thermosetting resin material (for example, phenol resin). Material). A shaft hole 13 is formed at the center of the insulating holder 15, and a recess 17 is formed on the back surface so as to expose the conductive terminal piece 14 across the slit 16. A spark erasing element 18 configured using a capacitor, for example, a chip capacitor, is fitted in the recess 17 and connected to the straddling conductive terminal piece 14. This connection is made by soldering, bonding with a conductive adhesive, or fusing depending on the configuration of the spark erasing element 18. The size of the recess 17 can be increased by drilling at a position away from the shaft hole 13, so that the spark erasing element 18 can be easily fitted,
Since it is away from the shaft hole 13, the mechanical strength of the insulating holder 15 is also increased.
[0011]
In the commutator device 10 of the DC motor M, it goes without saying that the slits 16 are required between the individual commutator pieces 12 and the conductive terminal pieces 14. Therefore, although the commutator piece 12 and the conductive terminal piece 14 may be individually manufactured and arranged, the commutator device 10 according to the present invention includes the commutator piece 12 and the conductive terminal piece 14 as follows. It is desirable to form.
[0012]
That is, first, as shown in FIG. 4, a disc-shaped commutator piece 22 is made of a carbon fired material, and a conductive terminal piece 24 is made of a conductive material such as a copper plate. Then, the conductive terminal piece 24 is fixed to the back surface of the disc-shaped commutator piece 22. In this case, the protrusion 22a is provided on the back surface of the commutator piece member 22, the fitting hole 24a is provided in the conductive terminal piece member 24 so as to correspond to the position of the protrusion 22a, and the protrusion 22a is fitted in the fitting hole 24a. Thus, the mechanically and electrically joined state is obtained. This bonding can be further ensured if the bonding surfaces of the commutator piece material 22 and the conductive terminal piece material 24 are tin-plated and soldered. Note that a hook-shaped terminal 14a for connecting a lead wire of an armature winding is provided at the outer peripheral tip of the conductive terminal piece 24 as will be described later.
[0013]
Next, as shown in FIG. 2, an insulating holder 15 made of a thermosetting resin material (for example, a phenol resin material) is molded around the commutator piece material 22 and the conductive terminal piece material 24. The outer peripheral portion of the conductive terminal piece 24 is molded so as to be exposed on the outer peripheral surface of the insulating holder 15 as shown in FIG. If the slit 16 is formed by cutting after molding as described above, the commutator piece 12 and the conductive terminal piece 14 can be easily configured. The surface of the commutator piece 12 is also cut before or after the slit 16 is cut to form an accurate flat surface. The slit 16 is cut to line K in FIG. 2 to divide the commutator piece 22 and the conductive terminal piece 24 to form the commutator piece 12 and the conductive terminal piece 14. The spark erasing element 18 is connected to the recess 17 via the conductive terminal piece 14 as described above.
[0014]
As described above, the unitized commutator device 10 is configured as shown in FIG. 3 by bending the hook-shaped terminal 14a as shown by a one-dot chain line in FIG. This is fitted to the shaft 3 a of the armature 3 to constitute a DC motor M.
[0015]
Embodiment 2. FIG.
In the DC motor M according to the first embodiment, the spark erasing element 18 is fitted in the recess 17 formed in the back surface of the insulating holding body 15 of the commutator device 10 as shown in FIG. The spark erasing element 18 may be connected to the outer peripheral tip of the conductive terminal piece 14. That is, in the figure, the commutator piece 12, the conductive terminal piece 14, and the insulation holder 15 are configured in the same manner as in the first embodiment (shown in FIG. 2). However, the recess 17 on the back surface of the insulating holder 15 may be omitted. In this configuration, since the insulating holding body 15 is formed so that the outer peripheral tip of the conductive terminal piece 14 is exposed as described above, the spark erasing element 18 is electrically conductive adjacent to the outer peripheral tip of the conductive terminal piece 14. It is connected between the terminal pieces 14. According to this configuration, it is easier to connect the spark erasing element 18 than the commutator device of the first embodiment, and a large-sized spark erasing element 18 can also be connected.
[0016]
Embodiment 3 FIG.
In the first or second embodiment, the spark erasing element 18 is individually connected. However, as shown in FIG. 7, the spark erasing element 18 is connected in advance by a connecting conductor 19 to form a necklace shape. In this case, the spark erasing elements 18 can be connected together as shown in FIG. In this case, the connecting conductor 19 may be a thin plate or a conductive wire knitted in a net shape. When this configuration is used, connection is facilitated by connecting the conductive terminal piece 14 at the portion of the connecting conductor 19. 8A, at least one set of adjacent spark erasing elements is connected by a connecting conductor 19, and the spark erasing element 18 is connected to the conductive terminal via the connecting conductor 19. It may be connected to the piece 14. Further, as shown in FIG. 8B, three sets of spark erasing elements may be connected by a connecting conductor 19. Since the lead wire of the armature winding is connected to the hook-shaped terminal 14a, the connecting conductor 19 can be connected if the lead wire of the armature winding is connected via the hook-shaped terminal 14a at the same time. Will improve.
[0017]
Embodiment 4 FIG.
As described above, the commutator device unitized with the spark erasing element 18 is easy to mount on the armature shaft, but the armature winding and the circumferential surface (side surface) portion of the commutator device are made of resin. A better DC motor can be obtained by molding with a material. That is, if this DC motor is used in an in-tank type fuel pump as shown in FIG. 1, the spark erasing element 18 is securely held, and the spark erasing fuel pump is obtained.
Further, it is preferable that the spark erasing element 18 is also encapsulated with resin for molding the armature winding and the circumferential portion of the commutator device. In this case, the fuel pump through which the fuel such as gasoline passes through the DC motor M has a characteristic of the fuel flow that causes the capacitor to drop off from the commutator, disconnection of the capacitor connection, disconnection of the joint, and gasoline It is possible to prevent the capacitor from deteriorating due to the above.
[0018]
【The invention's effect】
Since the present invention is configured as described above, the following effects can be obtained.
[0019]
Since the commutator and the spark erasing element are unitized, it is easy to attach the spark erasing element or to fit the armature on the shaft, thereby improving mass productivity. In addition, since the wear of the brush and the commutator is suppressed by the spark erasing element, a DC motor that can be used stably for a long period of time is obtained.
[0020]
Further, since the spark erasing element is connected between the adjacent conductive terminal pieces at the outer peripheral tip of the conductive terminal piece, it is easy to select the spark erasing element to be used, and the connection to the conductive terminal piece is also simple. .
[0021]
In addition, since the spark erasing element is connected in a necklace shape and connected to the conductive terminal piece via the connecting conductor portion, the spark erasing element can be easily attached and connected.
[0022]
Furthermore, when the spark erasing element is configured in a necklace shape and the connecting conductor is connected to the conductive terminal piece, the lead wire of the armature winding can be simultaneously connected by means such as fusing, According to this method, the connection of the lead wire of the armature winding together with the spark erasing element is further facilitated.
[0023]
Since the commutator device has a configuration in which the commutator and the spark erasing element are unitized, it can be easily fitted to the shaft of the armature, and the exterior mold applied to the armature can also be applied to the commutator device. Therefore, for example, a safe DC motor can be obtained even when implemented in an in-tank fuel pump.
[Brief description of the drawings]
FIG. 1 is a cutaway side view of a fuel pump in which a commutator device of the present invention is implemented.
FIG. 2 is a detailed view showing a commutator device of the present invention.
FIG. 3 is a perspective view showing the commutator device of the first embodiment.
FIG. 4 is a part diagram for explaining a method of manufacturing the commutator device.
FIG. 5 is a perspective view showing a commutator device according to a second embodiment.
FIG. 6 is a perspective view showing a commutator device according to a third embodiment. FIG. 7 is a component diagram of a necklace-like spark erasing element.
FIG. 8 is a component diagram of a spark erasing element connected in a strip shape.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Commutator apparatus, 12 Commutator piece, 14 Conductive terminal piece, 15 Insulation holding body, 16 Slit, 17 Recessed part, 18 Spark elimination element.

Claims (5)

In a DC motor having a commutator device installed at one end of an armature and connected to an armature winding and in sliding contact with a brush, the commutator device is centered on the axis of the armature. A commutator piece arranged radially and in a disk shape, a conductive terminal piece fixed to the back side of the commutator piece and connected to the armature winding, and the conductive An insulating holder molded to hold the commutator piece to which the terminal piece is fixed and the commutator piece can come into contact with the brush, and an adjacent conductive terminal piece on the back side of the insulating holder are exposed to each other. concave plant is arranged so as to be characterized in that with a connected spark quenching element between the exposed conductive terminal piece in the recess across the conductive terminal piece to the adjacent DC motor . In a DC motor having a commutator device installed at one end of the armature and connected to the armature winding, and in contact with the brush,
The commutator device includes a commutator piece arranged radially and in a disk shape around the axis of the armature, and fixed to the back side of the commutator piece, and the armature winding A conductive terminal piece adapted to be connected to the conductive terminal piece, a commutator piece to which the conductive terminal piece is fixed, and the commutator piece can be brought into contact with the brush; comprising an insulating holding member which is molded as part are exposed, and connected spark quenching element between the conductive terminal piece adjacent the outer peripheral distal end of the conductive terminal strip, at least one pair of adjacent spark quenching A direct current motor characterized in that the elements are connected by a connecting conductor formed by conducting wires knitted in a thin plate shape or a net shape, and are connected to the conductive terminal piece via the connecting conductor . The conductive terminal piece of the commutator device is provided with a hook-shaped terminal, and the connecting conductor of the spark erasing element and the lead wire of the armature winding are connected to the conductive terminal piece via the hook-shaped terminal. The DC motor according to claim 2 . The DC motor according to any one of claims 1 to 3 , wherein the outer periphery of the commutator device and the armature winding is molded with a resin material. 5. A DC motor according to claim 4 , and a pump unit that is rotationally driven by the DC motor and in which the fuel sucked by the rotational driving is discharged through the DC motor. Fuel pump.

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