JP3091827B2 - Brush device for rotating electric machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a brush device used for a rotating electric machine such as a DC commutator motor and an AC commutator motor or a generator, and more particularly to a brush device provided with a brush having an abnormal spark. TECHNICAL FIELD The present invention relates to a rotating electrical machine brush device provided with a protective measure for preventing overheating due to heat.

[0002]

2. Description of the Related Art When a commutator motor provided in a vacuum cleaner or the like is operated, a spark is inevitably generated between the commutator and the brush. However, the steady spark causes the motor to burn. Will not lead.

However, for example, even one armature coil is disconnected, the commutator is eccentric, and the brush does not properly contact the commutator piece, or the brush is chattered due to the missing or abnormal wear of the brush. If, for example, the current suddenly stops flowing during rotation, an abnormal spark is generated between the commutator and the brush. If the abnormal spark moves around the commutator, the brush may be burned.

In order to prevent the brush life from being abnormally shortened due to the heat of the abnormal spark, the temperature of the brush holder is detected by a temperature sensor, and the detection signal is processed by a signal processing circuit to detect the temperature sensor. A technique for stopping the rotation of the electric motor when the temperature rises is disclosed in
No. 93147.

[0005] In addition, in order to prevent abrasion due to excessive temperature rise of the brush and to prevent burnout of the motor, etc., the temperature of the brush or brush holder is detected by using a temperature sensor, and the temperature of the motor is determined based on the detected temperature. Japanese Patent Application Laid-Open Nos. 6-14501 and 2
-26253, JP-B-61-48359,
And JP-A-51-129601.

Further, in order to prevent the brush from being worn during the cooling operation, or to prevent the brush from being worn due to an excessive temperature rise, a heat responsive element made of a shape memory alloy is used to operate the brush. A technique for bringing a brush and a commutator into a non-contact state when a situation occurs is disclosed in Japanese Patent Application Laid-Open No. 5-30070.
No. 5, JP-A-2-177282, and the like.

[0007]

These various techniques are effective as protection measures for the electric motor.

However, the above-described various techniques for protecting the electric motor using the temperature sensor require a signal processing circuit in addition to the temperature sensor. Since this circuit is configured by combining a large number of circuit components, there is a problem that the number of components as a whole of the protection device is large and the cost is high. In addition, the operation reliability of the signal processing circuit decreases in accordance with the number of the circuit components, and in addition, there is a problem that it is difficult to provide a high-quality one because of the variation of the temperature sensor itself. Furthermore, since the temperature sensor has an insulating layer of glass or ceramics and has a considerable heat capacity, it is disadvantageous in protecting the motor by quickly following the rapid temperature rise of the brush due to the occurrence of abnormal spark. There is also a problem.

Further, in the technique using a shape memory alloy instead of a temperature sensor, there is a problem that the cost is high because the shape memory alloy itself is a rather expensive material. In the technology using bimetal instead of the temperature sensor,
Since there is a considerable heat capacity and the operation against temperature change is slow, it is disadvantageous in protecting the motor by quickly following the rapid temperature rise of the brush due to the occurrence of abnormal spark, and the reliability of the protection operation is poor. There is also a problem.

[0010] Therefore, the section to be solved by the present invention.
The title is the abnormal spark that occurs between the commutator and the brush.
Abnormal overheating of the brushRotating electric machine
Inexpensive motors that can protect
The object is to obtain a brush machine.

[0011]

According to a first aspect of the present invention, there is provided a brush device for a rotating electrical machine, wherein a commutator of an armature is provided in a cylindrical brush holder inserted in holder insulation. A brush unit for a rotating electric machine provided with a brush elastically pressed against the commutator, a terminal fitting inserted into the holder insulation having a first fusing body connecting portion disposed near the commutator; An electric conductor having a second fusing body connecting portion which is disposed in close proximity to the first fusing body connecting portion and in non-contact with the first fusing body connecting portion; And a protection switch means electrically connected to a current path flowing through the armature, the protection switch means comprising a heat-sensitive fusing body for fusing and cutting the connection at a predetermined temperature or higher. Of the fuse connection One end of the heat-sensitive fusing body is fixed to one of the fusing body connection portions, and the terminal fitting or the electric conductor having the other fusing body connection portion is formed of a harder material than the heat-sensitive fusing body, An uneven portion is provided on the other fused body connection portion pressed against the other end surface of the fused body, and a part of the other end surface of the heat-sensitive fusing body is inserted into a concave portion of the uneven portion, and a convex portion of the uneven portion is formed. It is made to bite into the other end face of the heat-sensitive fusing body.

In the first aspect of the present invention, the terminal fitting of the protection switch means and the electric conductor function as a switch contact piece. When the temperature is equal to or lower than the predetermined temperature, the heat-sensitive fusing body of the protection switch does not melt, so that the protection switch maintains a state equivalent to closing the switch.
In this state, the commutator is electrically connected to the current path flowing to the armature via the protection switch means and the brush which are electrically connected to each other. The protection switch means
When it is heated by abnormal spark and exceeds a predetermined temperature,
Since the heat-sensitive fusing body is melted, the melting cuts off the electrical connection between the terminal fitting as a switch contact piece and the electric conductor, so that the switch is opened. Thereby,
The current is cut off in the brush device, and the operation of the rotating electric machine including the brush device is stopped.

[0013] The terminal fitting or the electric conductor having the fusing body connection portion pressed against the other end face of the heat-sensitive fusing body that is not fixed is harder than the heat-sensitive fusing body and is provided at the fusing body connection portion. Of the concave and convex portions, the convex portion cuts into the other end surface, and the concave portion partially enters the other end surface,
The fusing body connection portion and the heat-sensitive fusing body pressed against the other end face are prevented from being electrically connected in a point contact state, and a large contact area between them is ensured, and the contact resistance therebetween is reduced. Can be smaller. Therefore, the heat conduction from the fusing body connection portion pressed into contact with the other end surface to the heat-sensitive fusing body becomes smooth,
Variations in fusing of the heat-sensitive fusing body can be reduced. Moreover,
As described above, by ensuring a large contact area between the heat-sensitive fusing body and the fusing body connection portion pressed against the other end face,
Since the variation of the thermal resistance between them is small, a large current flowing to the protection switch means is prevented from locally concentratedly flowing along with the turning on and off of the rotating electric machine, and thereby, it is possible to repeat the turning on and off. Accordingly, it is possible to eliminate the possibility that the heat-sensitive fusing body is inadvertently blown.

In order to solve the same problem without increasing the number of assembling steps, a brush device for a rotating electric machine according to a second aspect of the present invention is a method for inserting the electric conductor or the terminal fitting into the holder insulation. It is provided to extend in the wearing direction.

In the brush device for a rotating electric machine according to the present invention, one of the terminal fitting and the electric conductor is inserted into and attached to the holder insulation from the axial direction, and the other is inserted from the axial direction to the holder insulation. Then, the brush assembly is inserted into the brush holder and assembled. In this assembly, one end of the heat-sensitive fusing body is fixed in advance to one of the fusing body connection portions of the terminal fitting and the electric conductor, so that the terminal fitting and the electric conductor are attached to the holder insulation as described above. When the heat-sensitive fusing body is inserted, a fusing body connecting portion having an uneven portion is pressed against the other end surface of the heat-sensitive fusing body.

According to the second aspect of the present invention, since the uneven portion extends in the direction in which the terminal fitting or the electric conductor having the uneven portion is inserted into the holder insulation, there is little resistance to the insertion. With the insertion, the other end face of the heat-sensitive fusing body is rubbed against the uneven portion of the fusing body connecting portion pressed against the same. And since the uneven portion is harder than the heat-fused body, with the rubbing, the convex portion of the uneven portion bites into the other end surface, and a part of the other end surface that escapes enters the concave portion of the uneven portion. . Therefore, the pressing operation for pressing the fused body connection portion having the uneven portion against the other end surface of the heat-sensitive blown body is not particularly required, and simultaneously with the insertion of the terminal fittings and the electric conductor to the holder insulation, the uneven portion and the other end surface are used. Can be brought into a predetermined contact state.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to FIGS. FIG. 1 is a side view showing, in partial cross section, a configuration of a vacuum cleaner as an example of an electric appliance including a rotating electric machine, in which 1 is a lower case 1a.
A cleaner body formed by connecting the upper case 1b to the lower case 1a. A dust collecting chamber 3 is formed on the front of the lower case 1a. A lid 4 that opens and closes the upper surface opening of the camera is attached.

The cleaner body 1 is provided with a turnable front wheel 5 and a large-diameter rear wheel 6, and the cleaner body 1 can move through these rolling motions. The vacuum cleaner body 1
It is drawn through a dust suction hose (not shown) inserted and connected to a suction port (not shown) provided at the front end thereof.

In FIG. 1, reference numeral 7 denotes a suction grid for partitioning the rear end of the dust collection chamber 3, and a filter 8 is supported on the front surface. The grid 7 supports a dust bag 9 connected to the suction port from behind via a filter 8. Also, in FIG.
Is an exhaust hole.

An electric blower 11 is housed in the cleaner body 1 between the suction grid 7 and the exhaust holes 10. The electric blower 11 includes a fan unit 12 and a one-way rotating AC commutator motor 13. The fan unit 12 includes a centrifugal fan (not shown) rotated by the commutator motor 13, a fan cover that covers the centrifugal fan, and a rectifier plate that guides the air discharged from the centrifugal fan into the commutator motor 13 while giving a diffuser effect. Be prepared.

The electric blower 11 is supported by the blower supporting walls 14 and 15 of the cleaner body 1 via a first rubber packing 16 in a vibration-proof manner, and the other members of the cleaner body 1 are also provided. The second rubber packing 1 is attached to the blower support wall 17.
By being supported in a vibration-proof manner via 8, it is built in the cleaner body 1 with its axis horizontal. Note that the arrangement of the electric blower 11 is not limited to a horizontal position. For example, in the case of a pot-type electric vacuum cleaner, the electric blower 11 is built in the main body of the vacuum cleaner with the axis thereof being vertical. The first rubber packing 16 in the form of a ring is provided so as to fit around the periphery of the fan cover, and the second rubber packing 18 in the form of a cap is provided so as to fit over the rear end of the commutator motor 13. ing. The electric blower 11 sucks air in the dust collection chamber 3 and exhausts the air from the commutator motor 13 to the outside.

A cylindrical silencer 19 surrounding the commutator motor 13 is housed in the cleaner body 1. The silencer 19 is made of a breathable synthetic resin such as urethane foam and is flammable. The wind flowing out of the electric blower 11 flows through the rear part of the cleaner main body 1 through the silencer 19 and is discharged out of the cleaner main body 1 through the exhaust hole 10.

The configuration of the commutator motor 13 will be described with reference to FIG. In FIG. 2, reference numeral 21 denotes a substantially cylindrical frame with a bottom.
A bearing 22 is built in a bearing housing portion 21a projecting from the bottom wall and fitted with the second rubber packing 18. The fan cover is fitted and attached to the opening edge 21b of the frame 21 and the frame end plate 2
3 are attached. The end plate 23 is in the form of a strip crossing the opening of the frame 21 in the radial direction, and has a suction opening between both side edges and the opening edge 21b.
A bearing 24 is built in a bearing housing portion 23a formed at the center of the frame end plate 23.

The rotating shaft 26 of the armature 25 is supported over the bearings 22 and 24, and the centrifugal fan (not shown) is attached to an end of the shaft 26 that passes through the bearing 24. The armature 25 includes a rotating shaft 26, an armature core 27 fitted and fixed to the shaft 26, an armature coil 28 wound around the core 27, and a fixed commutator 29 fitted to the rotating shaft 26. The terminal portions of the armature coil 28 are connected to a plurality of commutator pieces 29 a arranged in parallel with each other on the periphery of the commutator 29 so as to be insulated from each other.

A plurality of (only one is shown in FIG. 2) outlets 38 are provided in the peripheral portion on the bottom side of the frame 21 and the like. Located between the outlet 38 and the opening edge 21b,
A stator 31 is built in the frame 21. This stator 31 has a substantially square outer shape when viewed from a plane,
The four corners are press-fitted into the inner peripheral surface of the frame 21 and provided.
A ventilation gap 32 (only one is shown in FIG. 2) is provided between the inner peripheral surface of the frame 21 and the side surface of the stator 31 opposed thereto.
Are formed.

At the end of the stator 31 located on the bottom side of the frame 21, a winding holder 33 made of synthetic resin for electrical insulation is mounted, and a pair of unillustrated integrally formed with the holder 33 is provided. The connection terminal 34 is attached to the terminal block. The terminal of the stator coil 31a is electrically connected to the connection terminal 34, and the connection terminal 3
Reference numeral 4 has a flat terminal plate portion extending so as to approach the inner peripheral surface of the frame 21.

A pair of brush devices 41 are mounted on the peripheral wall of the frame 21 so as to penetrate the frame 21 in the radial direction. As shown in FIGS. 3 to 7 except for FIG. 4, the brush device 41 includes a holder insulator 42 and a brush holder 43.
, A brush 44, a pigtail 45, a coiled spring 46, and protection switch means 47.

More specifically, the holder insulation 42 formed of a synthetic resin has a holder insulation body 42a penetrating the peripheral wall of the frame 21 and a mounting flange 42b. The mounting flange 42b overlaps the outer peripheral surface of the peripheral wall of the frame 21. The holder insulation 42 is detachably fixed to the frame 21 by penetrating the mounting flange 42b and tightening a screw 48 screwed to the peripheral wall.

As shown in FIG.
2a, a terminal mounting hole 49 and a holder mounting hole 42e parallel to each other are provided so as to penetrate therethrough. Figure 10
As shown in FIG. 12, a plurality of ribs 42d extending in the axial direction are provided on the inner surface of the holder mounting hole 42e in parallel with each other. The ribs 42d allow the brush holder to float from the inner surface of the holder mounting hole 42e. 43 are supported. The ribs 42d reduce the resistance when the brush holder 43 is inserted into the holder mounting holes 42e, thereby facilitating the work.

As shown in FIGS. 10 to 12, the holder mounting body 42a has a metal mounting surface 4 which is flush with the lower surface of the terminal mounting hole 49 (the surface on the side of the holder mounting hole 42e).
A terminal fitting supporting portion 42c having 2c1 is provided integrally. The support portion 42c extends from the entrance side of the terminal mounting hole 49 toward the commutator 29, and locking grooves 42c2 are formed on both sides in the width direction. These grooves 4
The lower surface of 2c2 and the mounting surface 42c1 are flush with each other.

The brush holder 43 as an electric conductor paired with a terminal fitting to be described later is made of a steel plate or a copper plate, and has a cylindrical shape having one end opened and the other end substantially closed by an end wall 43e. . As shown in FIGS. 5 to 9, the cylindrical portion of the brush holder 43 has a pair of flat walls 43 a and 43 b opposed to each other, and another pair of opposed walls which connect the two walls 43 a and 43 b respectively. A pair of wall portions 43c, 43
d and a cylindrical shape. The entire brush holder 43 is plated with solder, tin, or the like. FIG.
FIG. 9 only shows the plating layer 43h as a representative. The plating layer 43h is used for improving the wettability with the heat-sensitive fusing body 51 described later, for improving the discharge property when the fusing body 51 is melted, and for preventing rust.

A slit 55 is provided at the end of the brush holder 43 on the commutator 29 side. As shown in FIG. 4, FIG. 5, FIG. 8, etc., the slit 55 has a first slit portion 55a provided on the spark generating side wall portion 43a over a little more than half in the width direction thereof and a wall portion 43c connected thereto. And a third slit portion 55c provided from the second slit portion 55b to the commutator-side end of the wall portion 43a from the second slit portion 55b. . The continuous first to third slits 55a are provided so as to form a boundary between a tip portion between the slits and the commutator-side tip of the wall portions 43a and 43c and another portion of the brush holder 43. A thermal resistance increasing means for preventing heat transfer in the brush holder 43 from the tip portion toward the spring 46 is provided.

At the end of the brush holder 43 on the commutator 29 side, there is provided a second fusing body connection portion 52 comprising, for example, the front end portion on the wall 43c side among the front end portions defined by the slits 55. I have. The connecting portion 52 protrudes from the outer surface of the brush holder 43, and a gap 53 as a heat resistance means is provided between the inner surface and the brush 44. The second fusing body connection portion 52 is provided with a connection hole 52a as a fitting portion.

The brush holder 43 has a holder insulation 42
Is inserted from the commutator 29 side, and is attached to the holder insulator 42 so as not to move in the axial direction. The end wall 43e is disposed outside the frame 21. In FIG. 3, reference numeral 43f denotes a stopper which is cut and raised from the brush holder 43 and abuts against the tip of the holder insulating body 42a, and 43g which is cut and raised diagonally to hold the holder insulating body 4a.
2a, and the main body 42a is connected to the stopper 43f.
And the stopper piece 43g and the stopper piece 43g.
3 is positioned.

As the brush 44 made of an electric conductor, a carbon brush formed by binding carbon powder with a binder made of a synthetic resin binder and hardening it into a prismatic shape is employed. Brush 44
Is provided movably in the axial direction in the brush holder 43 using the holder 43 as a guide. One end of a pigtail 45 is embedded in the brush 44 and forms an electrically connected brush assembly. The other end of the pigtail 45 is fixed to the end wall 43e by spot welding or the like. Thus, the brush holder 43 and the brush 44 are electrically connected via the pick tail 45.

The spring 46 is housed in the brush holder 43 with both ends in contact with the brush 44 and the end wall 43e, and the spring 44 projects from the open end of the brush holder 43 by the spring force of the spring 46. Has been energized. Therefore, in the free state of the brush device 41, the brush 4
When the brush device 41 is fixed to the frame 21, the brush 44 hits the outer circumferential surface of the commutator 29 and is pushed into the brush holder 43 when the brush device 41 is fixed to the frame 21. And is pressed and held against the outer peripheral surface.

The protection switch means 47 is formed by including a part of the brush holder 43 as an electric conductor, a terminal fitting 50 arranged near the part, and a conductive heat-sensitive fusing body 51. I have.

As shown in FIGS. 3, 13 and 14, etc., the terminal fitting 50 is formed of a spring plate which is harder and more elastic than the heat-fused body 51, for example, a plate of brass or phosphor bronze. The use of brass is excellent in that the material cost is low, and the use of phosphor bronze is excellent in that processing is easy and hardness is high. Each of the terminal fittings 50 has a serrated locking projection 50c1 on each side edge of the flat main body 50c in the width direction. Further, the terminal fitting 50 has a mounting portion 50a raised from one end of the main body 50c and bent into a substantially rectangular shape, and has a spring portion 50b protruding from the other end of the main body 50c. I have.

The terminal fitting 50 is pressed into the locking groove 42c2 from the commutator 29 side so that the main body 50c is brought into close contact with the fitting mounting surface 42c1 and the mounting portion 50a is mounted on the terminal fitting 50a. It is inserted into the hole 49 and attached to the holder insulation 42. Thereby,
The terminal fitting 50 is arranged along the terminal supporting portion 42c of the brush holder 43.

The mounting portion 50a is elastically pressed against the opposing inner surfaces of the terminal mounting holes 49 and pressed against the inner surfaces. The flat terminal plate portion of the connection terminal 34 is inserted into the terminal mounting hole 49 along with the above-described mounting of the brush device 41, whereby the stator coil 31 is inserted through the connection terminal 34.
a and the terminal fitting 50 are electrically connected.

The spring 50 b of the terminal fitting 50 protruding out of the terminal mounting hole 49 toward the commutator 29 is
The spark in c is provided close to the generating side,
It can be elastically deformed around its root.
The spring portion 50 b is disposed substantially parallel to the wall portion 43 c and opposed to the wall portion 43 c, and has a length extending to a length reaching a tip portion of the brush holder 43.

The commutator-side tip of the spring portion 50b is used as a first fusing body connecting portion 56 which is disposed in close contact with the second fusing body connecting portion 52 in a non-contact manner. An uneven portion 57 that is in pressure contact with the fusing body 51 is provided by press working. As shown in FIGS. 9 and 15, the uneven portion 57 is configured by alternately arranging a plurality of parallel concave portions 57a and a plurality of parallel convex portions 57b. Moreover, in the present embodiment, the concave portion 57a is
6, and the convex portion 57a is protruded with respect to the pressing contact surface 56a. In addition, t in FIG. 15 has shown the notch depth of the recessed part 57a. The uneven portion 57 is provided so as to extend in the direction in which the terminal fitting 50 is inserted into the terminal mounting hole 49 of the holder insulation 42. The terminal fitting 50 having the above configuration is entirely plated. 4, 14, and 1
5 is representative of the plating layer 50h. The plating layer 50h is provided for the same purpose as the plating layer 43h.

The first and second fusing body connecting portions 56 and 52
They are electrically connected via a heat-sensitive fusing body 51 provided between them. The heat-sensitive fusing body 51 is made of, for example, a low-melting point metal such as solder (this embodiment), or a heat-fusible synthetic resin or synthetic rubber having conductivity.
The melting point of the heat-sensitive fusing body 51 made of solder or the like is lower than the melting point of the holder insulation 42. The heat-sensitive fusing body 51 is solidified below its melting point to electrically connect the brush holder 43 and the terminal fitting 50, and melts above the melting point to cut off the electrical connection between the brush holder 43 and the terminal fitting 50. It is provided for.

The heat-sensitive fusing body 51 is prepared by projecting a fixed amount of heat-sensitive fusing material in advance into one end of a main portion having a predetermined shape, for example, a short cylindrical shape as shown in FIG. It is formed in advance in the provided shape. The insertion end 51a corresponds to the shape of the connection hole 52a, and has, for example, a length penetrating the hole 52a. The other end surface 51b of the thermal fusing body 51 is a flat surface.

This fusing body 51 has one insertion end 5
By inserting and caulking 1a into the connection hole 52a, the brush holder 43 is electrically connected to the second blown body connection portion 52 of the brush holder 43 and fixed thermally. The other end surface 51b is also pressed against a concave / convex portion 57 formed at the distal end portion (fused body connection portion 56) of the spring portion 50b of the terminal fitting 50 by the spring force of the terminal fitting 50. The heat-sensitive fusing body 51 and the terminal fitting 50 are electrically connected. Then, as shown in FIG.
A part of the other end face 51b of the first part enters the concave part 57a of the uneven part 57, and the convex part 57b of the uneven part 57 cuts into the other end face 51b. Note that the two-dot chain line in FIG. 3 indicates the free state of the spring portion 50b. In this state, in other words, in the state where the heat-sensitive fusing body 51 is blown, the spring portion 50b does not contact the brush holder wall 43c. It is provided in.

The brush device 41 having the above structure is assembled as follows. First, the terminal fitting 50 is mounted in the terminal mounting hole 49 of the holder insulation 42 by inserting the mounting part 50a at the head thereof. In this way, the terminal fitting 50 is inserted into the holder insulation 42, and the spring portion 50 b is arranged to protrude outside the holder insulation 42. Next, the brush holder 43 is inserted into the holder mounting hole 42e of the holder insulation 42 by the end wall 43e.
Is inserted from the same direction as the insertion direction of the terminal fitting 50 and attached. In this case, the heat-sensitive fusing body 51 is fixed to the fusing body connecting portion 52 of the brush holder 43 in advance, and the end wall 43e extends in the longitudinal direction of the wall portion 43d as shown by a two-dot chain line in FIG. Is what it is.

In this manner, the brush holder 4 is
3 is inserted, the other end face 51 b of the heat-sensitive fusing body 51 fixed to the fusing body connecting portion 52 is provided with the irregularities formed on the fusing body connecting portion 56 of the terminal fitting 50 immediately before the completion of the insertion of the brush holder 43. It rubs against the part 57. In this rubbing, the uneven portion 57 extends in the insertion direction of the brush holder 43, so that there is no large resistance to the insertion work, and since the uneven portion 57 is harder than the heat-sensitive fusing body 51,
The convex portion 57b of the concave and convex portion 57 cuts into the other end surface 51b, and a portion protruding to the periphery (a part of the other end surface 51b) enters the concave portion 57a of the concave and convex portion 57.

Therefore, the other end face 51 of the heat-sensitive fusing body 51
Regardless of the accuracy of b, regardless of this, in the state where the brush holder 43 and the terminal fitting 50 are attached to the holder insulator 42, the uneven portion 57 of the terminal fitting 50 is large on the other end surface 51b of the heat-sensitive fusing body 51. It is possible to secure the contact area and perform the pressure contact.

In the assembly up to this stage, the brush holder 43 is first replaced with the holder insulating 4
2, the terminal fitting 50 may be inserted from the same direction as the insertion direction. In this case, similarly, the uneven portion 57 of the terminal fitting 50 is attached to the other end surface 51b of the heat-sensitive fusing body 51.
Can be pressed against each other while securing a large contact area.

Finally, the tip end of the pig tail 45 of the brush assembly is welded to the end wall 43e in a developed state, and then the brush assembly is moved from the end wall 43e side to the brush holder 43 with the brush 44 at the head. After that, the end wall 43e is bent as shown by a two-dot chain line arrow in FIG.
Close the opening on the e side. By the above procedure, the brush device 4
1 is assembled.

Therefore, the terminal fitting 5 having the uneven portion 57
0 is connected to the other end face 51 b of the heat-sensitive fusing body 51.
It is not necessary to perform a pressing operation for pressing the terminal fitting 50 on the holder insulating member 42, and the concave / convex portion 57 and the other end surface 51b can be brought into a predetermined contact state at the same time as the terminal fitting 50 is inserted into the holder insulation 42.

FIG. 16 is a diagram showing an electric circuit of the commutator motor 13. One of the brush devices 41 pressed against the commutator 29 is one of the stator coils 3 of the stator 31.
The other brush device 41 connected to one power supply terminal of the commercial AC power supply via 1a and pressed against the commutator 29 is connected to the other of the commercial AC power supply via the other stator coil 31a of the stator 31. Power supply terminal.
The electric motor 13 is configured such that the magnetic flux direction of the stator 31 according to the current direction passed through the stator coil 31a and the current direction of the armature 25 corresponding to the current direction passed through the stator coil 31a are switched in each half cycle of the alternating current. The rotation of the child 25 is continued in one direction. The direction of rotation is indicated by arrow A.

In the first embodiment, the stator coil 31a of the stator 31 of the commutator motor 13 and the brush 44 elastically pressed against the commutator 29 are composed of the protection switch means 47 and the pigtail 45. Are electrically connected via The protection switch means 47 has a configuration in which the terminal fitting 50 and the wall portion 43c, which is a part of the brush holder 43, are used as switch contact pieces, and a spark generated between the brush 44 and the commutator 29 is formed. It is arranged close to the generating side.

Therefore, at a predetermined temperature (the melting point of the heat-sensitive fusing body 51) or less, the heat-sensitive fusing body 51 provided between the wall 43c and the terminal fitting 50 is maintained in a pre-formed state, and both switches are connected. The wall 43 of the brush holder 43 forming a piece
c and the terminal fitting 50 are electrically connected. In other words, when the temperature is lower than the predetermined temperature, the protection switch 47
Is maintained in a state equivalent to closing the switch.

As a result, when the commutator motor 13 is energized, the current supplied from the power source is transferred from the commutator 29, whose brush 44 is in sliding contact with the armature coil, via the brush device 41 on the positive electrode side. Then, the current is returned from the commutator 29 to the negative-electrode-side brush device 41, so that the commutator motor 13 is operated.

Since the centrifugal fan rotates with the operation of the commutator motor 13, the blower operation by the electric blower 11 is performed. As a result, dust can be sucked into the cleaner body 1 of the vacuum cleaner, and the wind discharged from the centrifugal fan is
The frame 2 passes through a current plate and a suction opening (not shown).
1, the stator 31 in this frame 21
The air flows through the ventilation gap 32 while air-cooled, and further flows out of the commutator motor 13 through the outlet 38 after the brush device 41 is air-cooled. This wind sound is attenuated by passing through the silencer 19 surrounding the commutator motor 13. The wind exhausted as described above is exhausted through the exhaust hole 10 of the cleaner body 1. Therefore, it is possible to perform the cleaning by the vacuum cleaner under the above-described operation state.

In this operation, the short-circuit current flowing between the adjacent commutator pieces 29a of the commutator 29 via the brush 44 is cut off every time commutation is performed.
A steady spark is generated between the commutator 29 and the commutator 29, and accordingly, the commutator 29 and the brush 44 or the brush holder 4
The temperature of 3 rises.

By the way, for example, the armature coil 28
If one of the wires breaks for any reason, commutator 2
Since the value of the current to be cut with the rotation of 9 increases and the current ripple increases remarkably, the generated spark also becomes abnormally large, and of course, the thermal influence on the surrounding parts such as the brush 44 becomes significant.

Due to such a situation, the thermal cutoff 51 of the protection switch means 47 is affected by the thermal influence.
When the temperature becomes equal to or higher than the predetermined temperature, the heat-sensitive fusing body 51 is melted accordingly, so that the electrical connection between the wall 43c of the brush holder 43 and the terminal fitting 50 is cut off, and the protection switch is turned off. The means 47 is in a state where the switch is opened. Thus, the current path flowing through the armature 25 in the brush device 41 is cut off, and the operation of the commutator motor 13 can be stopped.

Since the heat-sensitive fusing body 51 of the protection switch means 47 employs a block formed in a predetermined shape in advance, the amount of solder or the like used can be kept constant. Accordingly, it is possible to reduce the variation in the temperature at which the heat-sensitive fusing body 51 melts, and to thereby make the protection switch means 47 perform the protection operation with high reliability. In addition, compared to the case where the electrical connection between the wall portion 43c of the brush holder 43 and the terminal fitting 50 is provided by laying solder therebetween, the amount of the heat-sensitive fusing body 51 can be easily and reliably controlled, and Mass productivity can be improved.

In the brush device 41 having the above-described configuration, as described above, of the uneven portions 57 provided on the fusing body connection portion 56 of the terminal fitting 50 that is harder than the heat-sensitive fusing body 51, the protruding portion 57b is Since the other end surface 51b bites into the concave portion 57a and a part of the other end surface 51b enters, the fusing body connection portion 56 pressed against the other end surface 51b and the heat-sensitive fusing body 51 are electrically connected in a point contact state. Are prevented from being connected to each other, and a large contact area between them can be secured, and the contact resistance between them can be reduced.

In other words, the other end face 5 of the heat-fused body 51
The variation in the thermal resistance between 1b and the fusing body connection portion 56 pressed against this is small. Therefore, the other end surface 51b
Since the heat conduction from the fusing body connecting portion 56 pressed to the heat-sensitive fusing body 51 is smooth, the variation in fusing of the heat-sensitive fusing body 51 can be reduced.

In addition to the fact that the contact resistance between the other end face 51b of the thermal fusing body 51 and the fusing body connecting portion 56 is small, one end of the thermal fusing body 51 has an insertion protrusion as described above. The heat-fused body 51 and the brush holder 43 are fixed by caulking to the brush holder 43 via a portion 51a.
The electrical connection with the semiconductor device can be made not by point contact but by securing a large contact area, so that these contact resistances can be reduced.

As described above, since the contact resistance between the heat-sensitive fusing bodies 51 and the brush holder 43 and the terminal fittings 50 sandwiching them is small, the ON / OFF of the rotating electric machine is reduced.
It is possible to prevent a large current flowing through the protection switch means from being locally concentrated due to turning off. This eliminates the risk that the heat-sensitive fusing body is inadvertently blown with the repetition of the on / off operation.

The tip side of the brush holder 43 is easily affected by the spark generated between the brush 44 and the commutator 29. In addition, the temperature of the spark generating side rises faster than the brush device 41. Location. Then, since the heat-sensitive fusing body 51 of the protection switch means 47 is provided near the place, the fusing body 51 can react sharply to the abnormal spark. In addition, since the heat-sensitive fusing body 51 made of solder or the like has a small heat capacity, the number of parts is small and the structure is simple, but the brush 4 is quickly moved.
4 can follow the temperature rise. Therefore, the protection switch means 47 responds quickly to an abnormal temperature rise of the brush 44.
Can be opened.

In addition, the slit 55 provided in the wall 43c of the brush holder 43 has the largest thermal resistance in the wall 43c, and constitutes a means for suppressing heat conduction on the brush holder 43 side. Therefore, at the time of occurrence of abnormal spark, the heat path which is to be conducted from the fusing body connection part 52 to the spring 46 side is interrupted by the slitch 55 in the wall part 43c whose temperature rises due to the influence of this spark, and the fusing body connection part 52 And the temperature of the heat-sensitive fusing body 51 fixed to the connecting portion 52 and the bottom can be quickly increased. Thereby, the temperature difference of the fusing body connection part 52 at the time of occurrence of a steady spark and at the time of occurrence of an abnormal spark,
Consequently, the heat-sensitive fusing body 51 provided in the mounting portion 52 is provided.
Temperature difference can be increased.

Therefore, even when a normal spark is generated, a malfunction in which the protection switch means 47 performs the protection operation is prevented, and an appropriate protection operation can be performed only when an abnormal spark occurs. The reliability of the protection operation of the switch means 47 can be improved.

As described above, according to the commutator motor 13 including the brush device 41 having the above-described structure, when the brush 44 reaches a predetermined temperature or higher due to the occurrence of abnormal spark, the brush switch 41 is quickly turned on by the protection switch means 47. Since the current can be cut off and the further operation of the commutator motor 13 can be stopped, the temperature of the brush 44 does not rise abnormally due to the abnormal spark between the commutator 29 and the brush 44. As a result, there is no possibility that the synthetic resin component forming the binder of the brush 44 will burn and emit smoke or fire. Therefore, the flame of the brush 44 does not spread to the combustible silencer 19 through the outlet 38. In other words, the protection switch means 47 protects the commutator motor 13 and the main body 1 of the cleaner with the protection operation for quickly coping with an abnormal temperature rise of the brush 44, thereby eliminating the risk of burning.

As described above, the protection switch means 47
Since the above-described protection operation is obtained by the brush device 41 having
There is no need for a temperature sensor for obtaining a similar protection operation and a signal processing circuit with a large number of components accompanying the temperature sensor. Moreover,
One of the switch contact pieces of the protection switch means 47 also serves as the brush holder 43. Therefore, the number of parts is small, the structure is simple, the device can be operated with high reliability, and the brush device 41 can be provided at a low cost because a high-cost shape memory alloy is not used to obtain the same protection operation as described above.

FIGS. 17 and 18 show a second embodiment of the present invention. This second embodiment is based on the first,
The connection structure of the heat-sensitive fusing body to the second fusing body connecting portion is different from that of the first embodiment. Other configurations are the same or similar to those of the rotary electric machine brush device and the vacuum cleaner of the first embodiment shown in FIGS. 1 to 16, including portions not shown in FIGS. 17 and 18. . Therefore, the components not shown are substituted with FIGS. 1 to 16, and the same or similar components shown are given the same reference numerals as those in the first embodiment, and the description of those components and the description thereof will be omitted. Although the description of the operation and effect based on this is omitted, these same or similar parts also constitute a part of the rotary electric machine brush device and the vacuum cleaner according to the second embodiment.

In the second embodiment, the outer surface of the fused body connecting portion 52 of the brush holder 43 as an electric conductor is
An uneven portion 57 is formed. A connection hole 56 a is formed in each of the fused body connection portions 56 of the terminal fitting 50. The heat-sensitive fusing body 51 has an insertion end 51a protruding from one end thereof.
Is fixed to the fusing body connection portion 56 of the terminal fitting 50 by inserting and caulking through the connection hole 56a. The heat-sensitive fusing body 51 fixed to the terminal fitting 50 is pressed against the uneven portion 57 of the fusing body connecting portion 52 of the brush holder 43 by the spring force of the spring portion 50b of the terminal fitting 50. The configuration other than the above is the same as that of the first embodiment.

The provision of the protection switch means 47 in the second embodiment also provides the same operation as in the first embodiment, and can solve the problem of the present invention.

FIGS. 19 to 21 show a third embodiment of the present invention. In the third embodiment, the uneven portion 57 is used.
Is different from the first embodiment. Other configurations are shown in FIG. 1 including portions not shown in FIGS.
16 to 16 are the same or similar to those of the rotary electric machine brush device and the vacuum cleaner according to the first embodiment shown in FIG. The same or similar components are denoted by the same reference numerals as those in the first embodiment, and the description of those configurations and the description of the operation and effect based on them will be omitted. Also forms part of the rotary electric machine brush device and the vacuum cleaner according to the third embodiment.

The concave and convex portion 57 in the third embodiment is tapered. This taper is
20 and FIG. 2 when the terminal fitting 50 is inserted first to the second and the brush holder 43 is inserted next.
As shown in FIG. 1, the spring portion 50b is formed with a slope that is lower toward the distal end side and higher toward the main body portion 50c.
When the brush holder 43 is first inserted into the holder insulation 42 and then the terminal fitting 50 is inserted,
It is only necessary to form the projection 57 with an inclination opposite to that of the projection 1, and the same applies to the case where the uneven portion 57 is provided on the fusing body connection portion 52 of the brush holder 43. The configuration other than the above is the same as that of the first embodiment.

In the third embodiment, the provision of the protection switch means 47 provides the same operation as in the first embodiment, and can solve the problem of the present invention. In addition, since the concave and convex portion 57 is tapered, it is advantageous in that the pressure contact between the concave and convex portion 57 and the other end surface 51b of the heat-sensitive fusing body 51 is easily performed when the brush device is assembled.

The present invention is not limited to the above embodiments. For example, the uneven portion 57 provided on the fusing body connection portion 56 or the like of the terminal fitting 50 or the electric conductor (such as the brush holder 43) adjacent to the terminal fitting 50 projects the convex portion 57a from the press contact surface 56a as shown in FIG. It may be formed without making it. In the present invention, the electric conductor may be a brush holder 43 as long as it is inserted into the holder insulation.
And other than the terminal fitting 50.

The present invention can be applied to a commutator motor driven by AC and capable of rotating forward and reverse, and can also be applied to a commutator motor driven by DC and capable of rotating in one direction or forward and reverse. The present invention can be applied to other electric devices including these electric motors. Further, in carrying out the present invention, the components of each of the above embodiments are arbitrarily and selectively combined, thereby forming a brush device having a function equivalent to or different from that of each of the above embodiments. An embodiment may be adopted.

[0078]

Since the present invention is configured as described above in detail, it has the following effects.

According to the brush device for a rotating electric machine according to the first aspect of the present invention, the protection switch means using the electric conductor and the terminal fitting inserted in the holder insulation as the switch contact pieces,
When the temperature is equal to or lower than the predetermined temperature, the switch is maintained in an equivalent state, and when the temperature is equal to or higher than the predetermined temperature, the switch is opened and the operation of the rotating electric machine including the brush device is stopped. The rotating electric machine can be protected against abnormal overheating of the brush caused by sparks. Moreover, the need for a temperature sensor and a signal processing circuit that is used in conjunction therewith and has a large number of parts is eliminated, so that the number of parts is small and the structure is simple, and since it does not use a shape memory alloy, it can be provided at low cost. In addition to the reduced number of parts as described above, in addition to the fact that there is little variation in fusing of the heat-sensitive fusing body, the contact resistance between the heat-sensitive fusing body and the fusing body connection part of the terminal fitting or electric conductor pressed against it Also, since the thermal resistance can be reduced, the reliability of the protection operation against abnormal spark can be improved.

According to the brush device for a rotating electric machine according to the second aspect of the present invention, the contact resistance and the thermal resistance between the heat-sensitive fusing body and the fusing body connection part of the terminal fitting or the electric conductor pressed against the heat fusing body are reduced. The pressing operation of pressing the uneven portion of the fused body having the uneven portion against the other end surface of the heat-sensitive fusing body is not particularly required, and therefore, the terminal fitting and the electrical connection to the holder insulation can be performed without increasing the number of assembling steps. Simultaneously with the insertion of the conductor, the uneven portion and the other end surface can be brought into a predetermined contact state.

[Brief description of the drawings]

FIG. 1 is a side view showing a partially sectioned configuration of a vacuum cleaner provided with a brush device according to a first embodiment of the present invention.

FIG. 2 is a side view showing a partial cross section of a configuration of a commutator motor of the electric blower provided in the electric vacuum cleaner shown in FIG. 1;

FIG. 3 is an enlarged cross-sectional view showing the periphery of the brush device according to the first embodiment;

FIG. 4 is an enlarged sectional view showing a main part of a protection switch means of the brush device according to the first embodiment;

FIG. 5 is a perspective view showing the configuration of the entire brush device according to the first embodiment.

6 is a front view showing the brush device shown in FIG. 5 viewed from a commutator side.

FIG. 7 is a rear view showing the brush device shown in FIG. 5 viewed from a side opposite to a commutator.

FIG. 8 is an exploded perspective view showing a configuration of a main part of a protection switch unit of the brush device according to the first embodiment.

FIG. 9 is a sectional view showing a configuration of a main part of a brush holder of the brush device according to the first embodiment.

FIG. 10 is a plan view showing the configuration of holder insulation provided in the brush device according to the first embodiment.

FIG. 11 is a sectional view showing the configuration of holder insulation provided in the brush device according to the first embodiment.

FIG. 12 is a front view showing a configuration of holder insulation provided in the brush device according to the first embodiment.

FIG. 13 is a bottom view showing the configuration of the terminal fitting provided in the brush device according to the first embodiment.

FIG. 14 is a sectional view of the terminal fitting taken along arrow ZZ in FIG. 13;

FIG. 15 is a sectional view of the terminal fitting taken along line YY in FIG. 14;

FIG. 16 is a diagram showing a configuration of an electric circuit of the commutator motor shown in FIG. 2;

FIG. 17 is an exploded perspective view showing a configuration of a main part of protection switch means of a brush device according to a second embodiment of the present invention.

FIG. 18 is a cross-sectional view illustrating a configuration of a brush holder of a brush device according to a second embodiment.

FIG. 19 is a bottom view showing a configuration of a terminal fitting included in a brush device according to a third embodiment of the present invention.

FIG. 20 is a sectional view of the terminal fitting taken along line ZZ in FIG. 19;

FIG. 21 is a side view showing a configuration around a spring portion of a terminal fitting of a brush device according to a third embodiment.

FIG. 22 is a cross-sectional view illustrating a configuration of a spring portion of a terminal fitting included in a brush device according to another embodiment of the present invention.

[Explanation of symbols]

 13: commutator motor (rotating electric machine), 25: armature, 29: commutator, 41: brush device, 42: holder insulation, 43: brush holder (electric conductor), 44: brush, 45: pigtail, 47: protection Switch means, 50: terminal fitting, 50b: spring part of terminal fitting, 51: heat-sensitive fusing body, 51a: insertion end of one end of heat-sensitive fusing body, 51b: other end face of heat-sensitive fusing body, 52: fusing body connecting part Reference numeral 52a: connection hole; 56, fused body connection portion; 57, uneven portion; 57a, concave portion of the uneven portion; 57b: convex portion of the uneven portion.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-59-111478 (JP, A) JP-A-61-65861 (JP, U) JP-A-3-39371 (JP, U) JP-A-1 90264 (JP, U) Hikaru 2-136470 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) H02K 13/00

Claims (2)

(57) [Claims] 1. A brush device for a rotating electrical machine, wherein a brush is elastically pressed against a commutator of an armature in a cylindrical brush holder inserted into a holder insulator, wherein the brush is arranged near the commutator. A terminal fitting having a first fusing body connection portion and inserted into the holder insulation, and a second fusing body connection proximate to the first fusing body connection portion and arranged in a non-contact manner near the commutator; An electrical conductor having a portion;
A heat-sensitive fusing body is provided between the fusing body connecting portions and electrically connects them at a predetermined temperature or lower, and cuts off the connection at a predetermined temperature or higher to cut off the connection. A protection switch provided electrically connected thereto, one end of the heat-sensitive fusing body being fixed to one of the fusing body connection portions, and the other fusing body connection portion being provided. The terminal fitting or the electric conductor is formed of a material harder than the heat-sensitive fusing body, and the other fusing body connection portion pressed against the other end surface of the heat-sensitive fusing body is provided with a concavo-convex portion. A part of the other end surface of the heat-sensitive fusing body, and a protrusion of the concave-convex portion is cut into the other end surface of the heat-sensitive fusing body. 2. The brush device for a rotating electric machine according to claim 1, wherein said uneven portion is provided so as to extend in a direction in which said electric conductor or terminal fitting is inserted into said holder insulation.