JP3076740B2 - 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. Brushes for rotating electrical machines with protective measures to prevent overheating
Related to the device.

[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 that can be protected with high reliabilityBushing for rotating electric machine
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, comprising: a cylindrical brush holder fixed to holder insulation; In a brush device for a rotating electrical machine provided with a brush that is elastically pressed, a terminal fitting having a first fusing body connection portion at a commutator side end disposed near the commutator ; A brush holder having a second fusible member connecting portion disposed close to and in a non-contact with the first fusible member connecting portion; and a brush holder provided between the two fusible member connecting portions and electrically connected at a predetermined temperature or lower. A connection is made with a heat-sensitive fusing body which cuts off the connection at a predetermined temperature or higher, and further comprises protection switch means provided electrically connected to a current path flowing through the armature, and the protection switch means comprises: The terminal metal Those having a suppressing heat conduction suppressing means heat conduction from the thermal fusing member for metal parts other than the first fusing member connection portion of the terminal fitting at the side. In carrying out the present invention, the heat conduction of the terminal fittings
The restraining means may be configured to connect the first blown body as in the invention of claim 2.
It is provided so as to separate the continuation part and other metal parts.
May be formed by one or more holes or slits or grooves.
It is also possible to provide the heat-sensitive blown body as in the invention of claim 3.
Connecting the first fused body connection portion of the terminal fitting to the
Heat conduction suppressing means may be formed.

In the first to third aspects of the present invention, the terminal fitting of the protection switch means and the brush holder 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. Further, when the protection switch means is heated by the abnormal spark and is heated to a predetermined temperature or higher, the heat-sensitive fusing body is melted, so that the melting cuts off the electrical connection between the terminal fitting as a switch contact piece and the brush holder , In other words, the switch is open. Thus, 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 heat conduction suppressing means provided on the terminal fitting side of the protection switch means suppresses heat conduction from the heat-sensitive fusing body to a metal fitting portion other than the first fusing body connection portion of the terminal fitting.
Reduce the heat radiation from the thermal fuse to the terminal fittings. Thus, when an abnormal spark occurs, the temperature of the heat-sensitive blown body heated by the spark can be quickly increased. It can be bigger with time.

[0014] In order to solve the same problem, according
Item 4. The brush device for a rotating electric machine according to the invention of Item 4 , wherein in the brush device for a rotating electric machine, a brush that is elastically pressed against a commutator of an armature is provided in a cylindrical brush holder fixed to holder insulation. Commutator placed near child
A terminal fitting having a first fusing body connection at a side end ; and a brush tool having a second fusing body connection proximate to the first fusing body connection and non-contacting in the vicinity of the commutator.
And holder, together with the connecting those provided between the fusing body connecting portion electrically at a predetermined temperature or less, made of a thermal fusing member sever blown this connection at a predetermined temperature or higher, flows into the armature A protection switch means electrically connected to the current path, wherein the heat-sensitive fusing body is a block preformed in a predetermined shape, and the insertion ends provided at both ends thereof are cut off by the both fusing; These are inserted into fitting portions provided respectively in the body connecting portions and fixed to these fused body connecting portions.

[0015] In the invention as claimed in claim 4, functions as a switch contact piece and the terminal fitting and the brush holder of the protective switch means. 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. Further, when the protection switch means is heated by the abnormal spark and is heated to a predetermined temperature or higher, the heat-sensitive fusing body is melted, so that the melting cuts off the electrical connection between the terminal fitting as a switch contact piece and the brush holder , In other words, the switch is open. Thus, the current is cut off in the brush device, and the operation of the rotating electric machine including the brush device is stopped.

Since the heat-sensitive fusing body is made of a block preformed in a predetermined shape, the quantity can be easily and reliably controlled, and the quantification of the heat-fusing body can reduce the variation in the fusing of the heat-sensitive fusing body. Further, since both ends of the heat-sensitive fusing body are inserted into and fixed to the connection parts of the fusing body of the terminal fitting and the brush holder , the heat-sensitive fusing body is crushed by the terminal fitting as the temperature rises and softens. Then, even if the heat-sensitive fusing body holds the collapsed posture due to a subsequent temperature drop, the first fusing body connection portion of the terminal fitting can follow the height displacement. As a result, no gap is formed between the first fusing body connection portion and the heat-sensitive fusing body, and poor contact between the first fusing body connection portion and the heat-sensitive fusing body can be prevented.

Further, in order to solve the same problem, in order to further improve the reliability of the protection operation against abnormal spark, the brush device for a rotating electric machine according to the invention of claim 5 is characterized in that the terminal fitting or the brush holder is provided. At least one of the surfaces on the heat-sensitive fusing body side, and at least the periphery of the fusing body connecting portion is covered with a plating layer.

In the fifth aspect of the present invention, the plating layer prevents rusting at a connection portion between the heat-sensitive fusing body and the first and second fusing body connecting portions. Further, since the plating layer has good wettability with the heat-sensitive fusing body, when the heat-sensitive fusing body is melted to perform a protective operation, the melted heat-sensitive fusing body is easily flowed, and the heat-sensitive fusing body is easily made into the first heat fusing body. , And is discharged from between the second fused body connection portions.

[0019]

[0020]

[0021]

[0022]

[0023]

[0024]

[0025]

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 front wheel 5 which can be turned and a rear wheel 6 having a large diameter, 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 which partitions the rear end of the dust collecting chamber 3, and a filter 8 is supported on the front face. 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 accommodated in the cleaner body 1 between the suction grid 7 and the exhaust hole 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. 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 which surrounds the commutator motor 13 once 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 between the bearings 22 and 24, and the above-mentioned centrifugal fan (not shown) is attached to the 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) discharge ports 38 are provided in a 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 attached, 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 attached to 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 has, for example, a melting point.
It is formed of a synthetic resin such as nylon with glass having an electrical insulation of 210 ° C. The holder insulation 42 has a holder insulation main body 42a penetrating the peripheral wall of the frame 21 and a mounting flange 42b. Mounting flange 42
b overlaps the outer peripheral surface of the peripheral wall of the frame 21, and the holder insulation 42 is detachably fixed to the frame 21 by tightening a screw 48 passing therethrough and screwing to the peripheral wall.

As shown in FIGS. 3 and 4, the holder insulating main body 42a is provided with a terminal mounting hole 49 and a holder mounting hole 42e which are parallel to each other. As shown in FIGS.
A plurality of ribs 42d are provided on the inner surface of 2e along the axial direction thereof in parallel with each other, and the ribs 42d support the brush holder 43 by floating from the inner surface of the holder mounting hole 42e. . These ribs 42d
Accordingly, the resistance when the brush holder 43 is inserted into the holder mounting hole 42e is reduced, and the work is facilitated.

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 tubular 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 brush holder 43 is entirely plated. FIGS. 4 and 9 only show the plating layer 43h as a representative. This plating layer 43
h can be solder plating, tin plating, gold plating, nickel plating, silver plating, or the like. In particular, employing solder plating or tin plating is excellent in that it is inexpensive and easy to implement.

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. Heat conduction suppressing 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 the tip end portion on the wall portion 43c side of the tip end portion defined by the slit 55, for example. 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 binder made of a synthetic resin and solidifying it in a prismatic shape is used. 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 these are electrically connected. 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 its both ends in contact with the brush 44 and the end wall 43e, and the spring force of the spring 46 causes the brush 44 to protrude from the open end of the brush holder 43. 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 in the vicinity of the part, and a conductive heat-sensitive fusing body 51. I have.

As shown in FIGS. 3, 13, and 14 and the like, the terminal fitting 50 is formed of an elastic spring plate, and has a saw-toothed engagement with each side edge of the flat main body 50c in the width direction. The projection 50c1 is provided. Furthermore, the terminal fitting 5
Reference numeral 0 has a mounting portion 50a that is raised from one end of the main body 50c and bent into a substantially rectangular shape, and has a spring portion 50b that protrudes from the other end of the main body 50c.

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 in close contact with the opposing inner surfaces of the terminal mounting holes 49. Terminal mounting hole 49
The flat terminal plate portion of the connection terminal 34 is inserted with the attachment of the brush device 41 as described above, whereby the stator coil 31a and the terminal fitting 5 are connected via the connection terminal 34.
0 is 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 connection portion 56 which is arranged in close contact with the second fusing body connection portion 52 in a non-contact manner. Connection hole 56a
Is provided.

The spring portion 50b includes a first fused body connecting portion 56.
And a hole 57 is formed as a heat conduction suppressing means. The hole 57 is preferably made as large as possible without impairing the resiliency required for the spring portion 50b in order to suppress heat conduction, and is formed by providing one or more small holes or slits. You may. This heat conduction suppressing means 5
Numeral 7 prevents heat transfer in the terminal fitting 50 from the first fusing connection portion 56 to the main body portion 50c. In the case of this embodiment, this is realized by increasing the thermal resistance in the spring portion 50b. are doing.

The terminal fitting 50 having the above-described structure is entirely plated. Only the plating layer 50h is shown in FIGS.
Are shown as representatives. For the plating layer 50h, solder plating, tin plating, gold plating, nickel plating, silver plating, or the like can be employed. In particular, employing solder plating or tin plating is excellent in that it is inexpensive and easy to implement. .

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 (210 ° C.) of the holder insulation 42, for example, 180 ° C. 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 melt the brush holder 4.
3 is provided for disconnecting the electrical connection between the terminal 3 and the terminal fitting 50.

The heat-sensitive fusing body 51 is formed by inserting a predetermined amount of heat-sensitive fusing material in advance into insertion ends 51a and 51b formed of, for example, projections at both ends of a main portion having a short cylindrical shape as shown in FIG. Is formed in advance in a shape protruding. The insertion ends 51a and 51b are connected to the connection holes 52.
The holes 52a and 56a correspond to the shapes of the holes 52a and 56a, for example.

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. Further, the other connection shaft 51b is inserted through the connection hole 56a and inserted, and for example, a solder 58 (shown only in FIG. 4) is provided from the outside so as to cover the insertion end, so that the heat-sensitive melt 5
Numeral 1 is electrically connected to the first fusing body connection portion 56 and is thermally conductively fixed. Thus, the heat-sensitive fusing body 51
FIG. 4 shows a state in which is inserted into and fixed to both fused body connection portions 52 and 56.

By the fixing, the distal end portion of the spring portion 50 b of the terminal fitting 50 (the fusion member connection portion 5) with respect to the thermal fusion member 51.
6) is pressed tightly by the spring force of the metal fitting 50, and the heat-sensitive fusing body 51 and the terminal metal fitting 50 are also electrically connected at this portion. Note that 2 in FIG.
The dotted line 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 is provided so as not to contact the brush holder wall 43c.

The electric blower 11 provided with the brush device 41 having the above-described configuration is arranged in such a manner that the connection portions 52 and 56 of the fusing body of the protection switch means 47 are vertical as shown in FIGS. . It should be noted that, instead of this position, the connection portions 52 and 56 of the fusing body are inclined (in this case also, the oblique posture close to vertical), the molten heat-sensitive fusing body 51, that is, the melted solder flows down. Both fused body connection parts 52, 56
It is excellent in that it can be easily drained from ), And if necessary, the electric blower 11 may be arranged in a posture in which both the fusing body connection portions 52 and 56 are non-horizontal.

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 lower, 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.

Thus, 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.

Incidentally, 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 heat-sensitive fusing member 51 of the protection switch means 47 is affected by the heat.
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 electrical connection between the wall 43c of the brush holder 43 and the terminal fitting 50 is established by soldering between them. As compared with the case where the heat-fusing member 51 is provided in a pile, the amount of the heat-sensitive fusing body 51 can be easily and reliably controlled, and the mass productivity can be improved.

Further, according to the above configuration, since the heat-sensitive fusing body 51 provided in the protection switch means 47 is made of a block formed in a predetermined shape by solder or the like, the amount of the solder or the like can be made 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.

Further, the quantified heat-sensitive fusing body 51 is
Fused body connecting portion 52 between brush holder 43 and terminal fitting 50,
Since they were respectively inserted into the fixing members 56 and fixed by caulking, press-fitting, soldering or other fixing means, they are excellent in the following points. That is, one end of the heat-sensitive fusing body 51 is fixed,
When the other end is pressed (unfixed) to the brush holder 43 or the terminal fitting 50, for example, when the spring portion 50b of the terminal fitting 50 is pressed to the heat-sensitive fusing body 51 as shown in FIG. There are the following problems: When FIG. 16A shows the initial state, the heat-sensitive fusing body 51 formed of a solder block expands while softening due to resistance heat generated by energization. This expanded state is shown in FIG. 16 (B), and the two-dot chain line in the figure is a line showing the initial state for comparison. At this time, the heat-sensitive fusing body 51 softened by the elastic force of the spring portion 50b is squashed and swelled while expanding so as to be thick like a sawdust. The phenomenon associated with the softening is the same even in a state where the spring portion 50b has no resilience (therefore, a state where there is no crushing action). Next, when the energization is stopped, the thermal cut-off body 51 is naturally cooled, but has no restoring force itself.
As shown in (C), the state is contracted from the crushed state, and the initial state for the next energization is obtained. Since such expansion and contraction phenomena are repeated each time the power is supplied and stopped, a gap g is finally formed between the unfixed end face of the heat-sensitive fusing body 51 and the terminal fitting 50 therewith. Will be done. As a result, particularly when the use environment has a high humidity, rust is easily generated in the gap. When rust is generated in this way, the contact between the heat-sensitive fusing body 51 and the spring portion 50b of the terminal fitting 50 becomes defective, and the electrical connection therebetween is reduced or impaired, and the thermal resistance also greatly varies. As a result, the intended protection switch function cannot easily be maintained.

However, as described above, the brush device 41 fixes both ends of the heat-sensitive fusing body 51 to the brush holder 43 and the terminal fitting 50, respectively, and integrally connects these three members. It can be held regardless of the expansion and contraction of the heat-sensitive fusing body 51. Therefore, no gap is generated between the fusing body 51 and the brush holder 43 and the terminal fitting 50 due to the deformation of the thermal fusing body 51, and the heat-sensitive fusing body 51 and the terminal fitting 50 and Poor contact with the brush holder 43 can be prevented. As a result, there is no reduction or loss of the electrical connection therebetween, and there is no variation in the thermal resistance, and the variation in the temperature at which the heat-sensitive fusing body 51 melts can be reduced. Therefore, the protection switch means 47 can maintain the desired protection switch function, and can reliably perform the protection operation at the desired temperature with high reliability.

When both ends of the heat-sensitive fusing member 51 are fixed to the brush holder 43 and the terminal fitting 50 as described above, the brush holder 43 for the heat-sensitive fusing member 51 is fixed.
In addition, the electrical connection of the terminal fitting 50 can secure a large contact area instead of a point contact, and the contact resistance can be reduced. As a result, it is possible to prevent the current from flowing intensively at one point when the commutator motor 13 is turned on and off.
1 can be prevented from being inadvertently blown.

Further, 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 formed of solder or the like has a small heat capacity, it can quickly follow the temperature rise of the brush 44 while having a small number of components and a simple structure. Therefore, the brush 44
Protection switch means 4 in response to abnormal temperature rise
7 can be opened.

Further, since the brush device 41 has the hole 57 as a heat conduction suppressing means of the terminal fitting 50, the heat resistance in the hole 57 increases, so that the first fused member connecting portion 56 Heat conduction of the terminal fitting 50 to the main body 50c side can be suppressed. Thereby, the heat of the heat-sensitive fusing body 51 can be reduced from escaping to the terminal fitting 50 through the first fusing body connecting portion 56, and the first fusing body connecting portion 56 can be reduced by the heat of the abnormal spark.
And the temperature of the heat-sensitive fusing body 51 can be quickly raised. As described above, the performance of detecting the abnormal spark heat of the heat-sensitive fusing body 51 can be improved, so that the reliability of the protection operation of the protection switch means 47 can be improved.

Further, since a gap 53 is ensured between the fused body connecting portion 52 of the brush holder 43 and the tip of the brush 44, the thermal resistance of the brush 44 increases the temperature due to the resistance heating and the steady spark. of the tip portion of the heat, to prevent the heat conduction directly fusing body connecting part 52, fusing member contacting
The temperature of the connecting portion 52 can be lower than the temperature of the brush 44.
However, when an abnormal spark occurs, the fusing body connecting portion 52
As described above, the temperature is increased under the influence of the abnormal spark. Therefore, it is possible to increase the difference between the temperature at the time of occurrence of the steady spark and the temperature at the time of occurrence of the abnormal spark of the fusing body connection portion 52 and the thermal fusing body 51 disposed therein.

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 at the connecting portion 52 is provided.
Temperature difference can be increased.

Therefore, the malfunction of the protection switch means 47 performing the protection operation despite the occurrence of the normal spark is prevented, and the proper protection operation can be performed only when the abnormal spark occurs. The reliability of the protection operation of the switch means 47 can be improved.

The brush holder 43 and the terminal fitting 50 of the protection switch means 47 are connected to at least the first and second fusing body connection portions 52, 5 to which the heat-sensitive fusing body 51 is connected.
6 has plating layers 43e and 50e. Since these plating layers 43e and 50e have good wettability with the solder forming the heat-sensitive fusing body 51, the heat-sensitive fusing body 51 is abnormally sparked.
When is melted, the melted heat-sensitive fusing body 51 can be quickly flowed and smoothly discharged from the first and second fusing body connecting portions 52 and 56. Thus, the protection operation of the protection switch means 47 can be promptly performed with the occurrence of the abnormal spark.

Further, in the first embodiment, the plating layer 4
Since 3e and 50e are provided on the entire brush holder 43 and the terminal fitting 50, the rust prevention performance of these components can be improved. Then, in particular, the first and second blown body connection portions 52, 5
6, the heat-sensitive fusing body 51, the terminal fitting 50 and the brush holder 4 can be prevented.
3 can prevent poor contact. As a result, there is no reduction or loss of electrical connection between them, and there is no variation in thermal resistance.
Can be reduced. Therefore, the protection switch means 47 can maintain the intended protection switch function, and can reliably perform the protection operation properly at the desired temperature with high reliability.

Further, the electric blower 11 having the brush device 41 is arranged in such a manner that the first and second fusible member connecting portions 52 and 56 of the protection switch means 47 are vertically (or obliquely). When the heat-sensitive blown body 51 melted by the abnormal spark flows out, neither the first nor the second blown body connection portions 52, 56 hinder the flow. Therefore, the melted heat-sensitive fusing body 51 quickly flows downward due to its own weight, and the first and second fusing body connecting portions 5 are connected.
It can be discharged smoothly from 2,56. Thus, the protection operation of the protection switch means 47 accompanying the occurrence of the abnormal spark can be promptly performed.

As described above, according to the commutator motor 13 including the brush device 41 having the above-described configuration, when the brush 44 reaches a predetermined temperature or more due to the occurrence of abnormal spark, the protection switch means 47 quickly switches the brush device 41. 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 danger 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.

Further, 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.

In the configuration of the brush device 41, a pair of switch contact pieces provided in the protection switch means 47, that is, the brush holder 43 and the terminal fitting 50 are provided.
Are mounted on the same holder insulation 42.
Therefore, since the reference of the mounting position of the brush holder 43 and the terminal fitting 50 is the same, the brush holder 43
And the terminal fitting 50 can easily determine the mutual positional relationship. Therefore, it is possible to improve the reliability of the brush 44 for preventing the temperature from excessively rising. In addition, since there is no need to find another mounting structure for supporting the terminal fitting 50, the structure is simple and easy to manufacture.

Further, since the melting point of the holder insulation 42 is higher than the melting point of the heat-sensitive fusing member 51, the holder insulation 42 is heated.
The current path can be opened by fusing the heat-sensitive fusing body 51 before deformation occurs. Thereby, since the mutual positional relationship of the respective parts of the protection switch means 47 does not deviate from an appropriate state due to the deformation of the holder insulation 42 so as to be melted by the influence of heat, the protection operation of the protection switch means 47 is surely performed. Can be run.

FIG. 17 shows a second embodiment of the present invention. This second embodiment is different from the first embodiment only in the structure for fixing the heat-sensitive fusing body to the first and second fusing body connecting portions. Other configurations are the same as or similar to those of the rotary electric machine brush device and the vacuum cleaner according to the first embodiment shown in FIGS. 1 to 16 including portions not shown in FIG. 1 to 16 are substituted for the components that are not shown, and the same or similar components shown in the drawings are denoted by the same reference numerals as those in the first embodiment. Although the description 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, burring portions 52a1 and 56a1 are formed at the edges of the connection holes 52a and 56a of the connection portions 52 and 56, respectively. One end 51a of the thermal cutoff 51 is inserted without penetrating into the connection hole 52a whose length is extended by the burring portion 52a1, and the other end 51b is similarly extended by the burring portion 52b1. Is inserted without penetrating into the extended connection hole 56a. These insertions may or may not be press fits. And both burring parts 52
Solder 58 as a fixing means is provided on the outside of each of a1 and 56a1.
The ends 51 a and 51 b of the heat-sensitive fusing body 51 are separately fixed to the ends 56. The configuration other than the above is the same as that of the first embodiment.

In the second embodiment as well, 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. Moreover, according to the second embodiment, the burring portion 52
By inserting the heat-sensitive fusing body 51 into the a1 and 56a1, the mounting posture of the fusing body 51 can be easily made constant, and the contact area between the fusing body connecting portions 52 and 56 and the heat-sensitive fusing body 51 can be increased to rectify the flow. This is excellent in that the concentration of current can be reduced as the slave motor 13 is turned on and off.

FIGS. 18 and 19 show a third embodiment of the present invention. The third embodiment differs from the first embodiment in the configuration of the heat conduction suppressing means on the terminal fitting side of the thermal switch means. Other configurations include those not shown in FIGS. 18 and 19 and FIGS.
Since the configuration is the same or similar to that of the rotary electric machine brush device and the vacuum cleaner of the first embodiment shown in FIG. 16, the configurations not shown are shown in FIGS. The same or similar components are denoted by the same reference numerals as in the first embodiment,
Although the description of those configurations and the description of the operation and effects based on them are omitted, these same or similar parts also form part of the rotating electrical machine brush device and the vacuum cleaner according to the third embodiment. It is.

The heat conduction suppressing means in the third embodiment is formed by a concave groove 157 provided at the root of the spring portion 50b of the terminal fitting 50, and the concave groove 157 blows the root of the spring portion 50b. It is thinner than the body connection part 56.
Thereby, the concave groove 157 increases the thermal resistance of the terminal fitting 50 against heat transfer from the fusing body connection portion 56 to the main body portion 50c side, and the fusing body connection portion 56 and the heat-sensitive material thermally fixed thereto. The temperature of the fusing body 51 is easily increased quickly due to the abnormal spark. 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.

FIGS. 20 and 21 show a fourth embodiment of the present invention. The fourth embodiment is different from the first embodiment in the configuration of the heat-sensitive fusing body of the thermal switch means and the configuration of the heat conduction suppressing means on the terminal fitting side. Other configurations are the same as 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. 20 and 21. Therefore, 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 fourth embodiment.

Heat-sensitive fusing body 15 in the fourth embodiment
In 1, the end face 151 a on the terminal fitting 50 side is formed in a plane, and the connection hole of the fused body connection portion 56 of the terminal fitting 50 is omitted correspondingly. Then, the heat-sensitive fusing body 151 has its end face 151a connected to the fusing body connecting portion 56.
Is provided so as to protrude about half from the front end surface of. The structure provides a means for suppressing heat conduction for such attachment.

According to this suppressing means, the heat-sensitive fusing body 151
Since the heat transfer area from the wire to the fused body connection portion 56 is reduced,
The amount of heat that escapes from the heat-sensitive fusing body 151 to the terminal fitting 50 can be reduced, thereby easily raising the temperature of the heat-sensitive fusing body 151 due to abnormal spark. The end surface 151a and the fused body connection portion 56 are fixed by welding such as ultrasonic welding, but may be simply in close contact with each other without being fixed, but the configuration for fixing as described above is as described above. This is excellent in that the generation of a gap due to the softening of the thermal cutoff 151 can be prevented. The configuration other than the above is the same as that of the first embodiment.

In the fourth embodiment as well, 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.

FIGS. 22 and 23 show a fifth embodiment of the present invention. The fifth embodiment differs from the first embodiment in the configuration of the heat-sensitive fusing body of the thermal switch means and the configuration of the heat conduction suppressing means on the terminal fitting side. Other configurations are the same as or similar to 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. 23 and 23. Therefore, 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 fifth embodiment.

[0094] Heat-sensitive fusing body 25 in the fifth embodiment
1 has a flat end face on the terminal fitting 50 side. A fusing body connecting portion 56 is provided at a spring portion 50 b of the terminal fitting 50.
Is formed instead of the connection hole. The width of the long groove 256a is a cylindrical heat-sensitive fusing body 2
It is slightly smaller than the diameter of 51. Then, the heat-sensitive fusing body 251
Is press-fitted into the long groove 256a at the end having the plane, and is provided so as to penetrate the long groove 256a. The structure provides a means for suppressing heat conduction for such attachment.

This attachment is performed by inserting the brush holder 43 in which the heat-sensitive fusing body 251 is fixed in advance in the holder insulator 42 in which the terminal fitting 50 is fixed in advance in the direction of the arrow in FIG. As a result, as shown in FIG. 22, opposing groove edges of the long groove 256 a bite into the solder-made heat-sensitive fusing body 251 that is softer than the terminal fitting 50, and the heat-sensitive fusing body 251 is thermally connected to the terminal fitting 50. Both are fixed and are electrically connected. Therefore, the terminal fitting 50 and the heat-sensitive fusing body 251
This eliminates the need to specially connect the two by ultrasonic welding or the like, and can be easily manufactured.

According to the heat conduction suppressing means, the heat transfer area from the heat-sensitive fusing body 151 to the fusing body connecting portion 56 is reduced, and the spring portion 50b is substantially narrowed by the long groove 256a. And the thermal resistance can be increased, so that the amount of heat escaping from the heat-sensitive fusing body 151 to the terminal fitting 50 can be reduced,
Thereby, the temperature of the heat-sensitive fusing body 151 is easily increased quickly due to the abnormal spark. The configuration other than the above is the same as that of the first embodiment.

In the fifth 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.

FIGS. 24 and 25 show a sixth embodiment of the present invention. The sixth embodiment is different from the first embodiment in the arrangement of an electric blower including a brush device. Other configurations include the first part shown in FIGS. 1 to 16 including parts not shown in FIGS. 24 and 25.
Since the configuration is the same or similar to that of the rotary electric machine brush device of the embodiment, the configuration not shown in FIG.
16 and the same or similar components shown in the drawings are denoted by the same reference numerals as those in the first embodiment, and the description of those components and the description of the operation and effect based thereon are omitted. However, these same or similar parts also form part of the present embodiment.

In the sixth embodiment, a pair of brush devices 41 are attached to the commutator motor 13 of the electric blower 11 with a 90 ° orientation in comparison with the first embodiment. Therefore, as shown in FIG. 25, the electric blower 11
2, 56 are arranged in a horizontal posture. The configuration other than the above is the same as that of the first embodiment.

Also in the sixth 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. Further, in the sixth embodiment, the horizontal first fusing body connection portion 56 of the terminal fitting 50 located below the thermal fusing body 51.
However, this obstructs the flow of the heat-sensitive fusing body 51 melted by the abnormal spark. However, the terminal fitting 50 has a plating layer 50e as a whole, so that the wettability with the molten solder is improved, and the terminal fitting 50 is always kept completely horizontal due to the use conditions of the vacuum cleaner and the like. When the heat-sensitive fusing body 51 is melted due to abnormal spark, the melted heat-sensitive fusing body 51 is caused to flow quickly and discharged from the first and second fusing body connecting portions 52 and 56. Can be done. Thus, the protection operation of the protection switch means 47 can be promptly performed with the occurrence of the abnormal spark.

In the sixth embodiment, a plating layer is provided only on other electric conductors, such as the terminal fitting 50 or the brush holder 43, which are horizontally arranged below the heat-sensitive fusing body 51. Alternatively, a plating layer may be provided only at least around the fused body connection part. 26 to 28 show a seventh embodiment of the present invention. The seventh embodiment is different from the first embodiment in that the protection switch means is not related to the brush holder but is formed outside the holder. Other configurations are the same as or similar to those of the rotary electric machine brush device of the first embodiment shown in FIGS. 1 to 16 including portions not shown in FIGS. 1 to 16, the same or similar components shown in the drawings are denoted by the same reference numerals as those in the first embodiment, and the description of those components and the operation and effect based on them are given. Although the description is omitted, these same or similar parts also form part of the present embodiment.

In the seventh embodiment, as shown in FIG. 26, the stator 3
A winding holder 33 made of synthetic resin for electrical insulation is attached to one end, and a terminal coil 71 as an electric conductor is connected to the stator coil 31a supported by the holder 33. The distal end of the terminal fitting 71 is disposed near the commutator 29 and on the side where a spark generated between the commutator 29 and the brush 44 is generated. A plating layer is provided on the entire terminal fitting 71.

Next, the brush device 41 will be described.
A pair of brush devices 41 is attached to the peripheral wall of the frame 21 so as to penetrate the frame 21 in the radial direction. As shown in FIGS. 27 and 28, these brush devices 41 include a holder insulator 42, a brush holder 43, a brush 44,
The pigtail 45 includes a coil-shaped spring 46, a terminal fitting 72, and a conductive heat-sensitive fusing body 51.

More specifically, the holder insulation 42 made of synthetic resin such as glass-containing nylon having electrical insulation 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. 28, a holder mounting hole 7 penetrating in the axial direction of the holder insulating body 42a.
3 and a terminal mounting hole 74 are provided.

The brush holder 43 is made of metal such as brass or galvanized steel plate or copper plate, and has a pair of flat wall portions 43a and 43b opposed to each other.
a and 43b, each of which has a pair of opposite wall portions 43c and 43d connected to each other, and is formed in a rectangular cylindrical shape having both ends opened.

The brush holder 43 has a holder insulation 42
Is inserted from the commutator 29 side into the holder mounting hole 73 and is mounted on the holder insulation 42 so as not to move in the axial direction. Note that 43f in FIGS. 27 and 28 is cut and raised from the brush holder 43 to form the holder insulating body 42a.
It is a stopper that is hooked on.

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 these are electrically connected.

As shown in FIG. 28, the terminal fitting 72 is
The commutator 2 is inserted into the terminal mounting hole 74 of the holder insulating body 42a.
9 and inserted from the opening on the opposite side. The terminal fitting 72 is provided with a plating layer on the whole thereof and has a frame 21 in a holder mounting hole 73.
And a terminal main portion 76 which is bent from the receiving portion 75 and inserted into the terminal mounting hole 74 so as to close the opening. It should be noted that 76a in FIG.
And 76b are a first press contact portion and a second press contact portion which are pressed against the inner surface of the terminal mounting hole 74 by the resiliency of the terminal main portion 76. Raised stopper tongues, which keep the terminal fitting 72 inserted into the holder insulation 42.

The other end of the pig tail 45 is fixed to the receiving portion 75 by spot welding or the like, and 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 its both ends in contact with the brush 44 and the receiving portion 75.
The brush 44 is moved by the spring force of the spring 46 to the brush holder 43.
Are biased so as to protrude from the open end. Therefore, in the free state of the brush device 41, most of the brush 44 projects from the brush holder 43, and the brush device 4
In a state where 1 is fixed to the frame 21, as shown in FIG. 28, the brush 44 hits the outer peripheral surface of the commutator 29 and is pushed into the brush holder 43, and is elastically pressed and held against the outer peripheral surface.

The terminal fitting 72 electrically connected to the brush 44 as described above has a tip portion (first fusing body connection portion 72b) of the terminal main portion 76 on the opposite side to the receiving portion 75, and the commutator 29. It is provided in the vicinity and on the side where a spark generated between the commutator 29 and the brush 44 is generated. One end of a heat-sensitive fusing body 51 formed by inserting the solder into the first fusing body connecting portion 72b and forming it in a block shape in advance is fixed by caulking. The other end of the melted body 51 is inserted into and fixed to the distal end of the terminal fitting 71 (the second melted body connection portion 71b, which is disposed close to and in contact with the connection portion 72b). ing. The fixation of both the fusing body connection portions 71b, 72b of these terminal fittings 71, 72 and the heat-sensitive fusing body 51 and the configuration of electrical and heat conductive connection based thereon are the same as those of the first embodiment. .

By these electrical connections, the heat-sensitive fusing body 5
1 is inserted in the current path flowing through the armature 25. The switch means 47 closes the current path at a temperature lower than a predetermined temperature, and cuts off the current path at a temperature higher than the predetermined temperature. It has become. The configuration other than the above is the same as or similar to the first embodiment.

In the seventh embodiment, the stator coil 31a of the stator 31 of the commutator motor 13 and the commutator 29
The brush 44 elastically pressed against the heat-sensitive fusing body 5 is electrically connected to the brush 44 via the pigtail 45, the terminal fitting 72, the thermal fusing body 51, and the terminal fitting 71.
1 is near the commutator 29 and the brush 44
And the commutator 29 are disposed on the side where sparks are generated.

Therefore, below a predetermined temperature (the melting point of the heat-sensitive fusing body 51), the current path through which the heat-sensitive fusing body 51 flows through the armature 13 is closed. Thus, when the commutator motor 13 is energized, the current supplied from the power supply flows through the brush device 41 on the positive electrode side to the armature coil 28 from the commutator 29 in which the brush 44 is in sliding contact. Then, a current is returned from the commutator 29 to the negative brush device 41, so that the commutator motor 13 is operated.

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. Note that the temperature of the brush 44 also rises due to resistance heat generated by energizing the brush 44.

The temperature of the brush 44 is transmitted to the brush holder 43 with which the brush 44 is in contact due to the temperature rise. However, the terminal fittings 34 electrically connected to the brushes 44 are connected to the holder insulation body 42 of the holder insulation 42.
a (ther is thermally insulated by the partition wall portion 42c separating the holder mounting hole 73 and the terminal mounting hole 74 of the main body 42a), so that the heat of the brush 44 and the brush holder 43 is transferred to the terminal fitting 72. Transmission is prevented. In addition, since the heat-sensitive fusing body 51 is not in contact with the brush holder 43, it is not affected by the heat of the brush 44 via the brush holder 43, and is located at a point where a steady spark occurs (a point at which the short-circuit current is cut off). On the other hand, since the heat-sensitive fusing body 51 is arranged at a distance so as not to be exposed to the steady spark, the temperature rise of the heat-sensitive fusing body 51 does not become so large. Therefore, the temperature difference of the heat-sensitive fusing body 51 at the time of the steady spark and at the time of the abnormal spark can be increased, whereby the reliability of fusing the heat-sensitive fusing body 51 at a predetermined temperature can be improved.

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 greatly and abnormally occurs, and naturally, the thermal influence on the surrounding parts such as the brush 44 becomes enormous.

Due to such a situation, the heat-sensitive fusing body 51 located closest to the commutator 29 on the spark generating side, which is the place where the temperature of the brush device 41 rises faster, follows the outer peripheral surface of the commutator 29. Effectively exposed to the abnormally extending abnormal spark, and the temperature quickly rises.

As a result, when the temperature of the heat-sensitive fusing body 51 becomes equal to or higher than the predetermined temperature, it melts, so that the electrical connection between the two terminal fittings 71 and 72 is cut off. In other words, the current path flowing through the armature 25 in the heat-sensitive fusing body 51 is cut off, so that the switch is opened.

As described above, with the occurrence of abnormal spark,
By this spark, the current path flowing to the armature 25 can be quickly cut by the heat-sensitive fusing body 51 to stop the further operation of the commutator motor 13, so that an abnormal spark between the commutator 29 and the brush 44 is prevented. As a cause, the temperature of the brush 44 does not rise abnormally and is not burned.

Further, also in the seventh embodiment,
The same effect as that of the first embodiment can be obtained to solve the problem to be solved by the present invention.

The present invention is not limited to the above embodiments. For example, in practicing the present invention, the components of each of the above embodiments are arbitrarily and selectively combined, whereby
A brush device having a function equivalent to or different from that of each of the above embodiments may be formed, and this may be a new embodiment.

[0123]

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

[0124] According to a brush device for a rotating electrical machine according to the invention of claims 1 to 3, holds the brush holder and the terminal fitting by a protective switch means to switch contact piece, the equivalent state and closed switch at a predetermined temperature or less However, 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, so that abnormal temperature rise of the brush due to abnormal spark between the commutator and the brush may occur. On the other hand, the rotating electric machine can be protected. In addition, the need for a temperature sensor and a signal processing circuit that is used in conjunction with the sensor and that has a large number of parts is eliminated, so that the number of parts is small and the structure is simple. In addition to the fact that the number of parts can be reduced as in
In addition, since the temperature of the heat-sensitive fusing body can be quickly increased when an abnormal spark is generated by the heat conduction suppressing means provided on the terminal fitting side, the reliability of the protection operation against the abnormal spark can be improved.

According to the brush device for a rotating electric machine according to the fourth aspect of the present invention, the protection switch means using the brush holder and the terminal fitting as switch contacts holds the switch at a predetermined temperature or less at a state equivalent to closing the switch. 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, so that an abnormal temperature rise of the brush caused by an abnormal spark between the commutator and the brush is prevented. The rotating electric machine can be protected. In addition, the need for a temperature sensor and a signal processing circuit that is used in conjunction with the sensor and that has a large number of parts is eliminated, so that the number of parts is small and the structure is simple. In addition to the fact that the number of parts can be reduced as described above, there is little variation in fusing of the heat-sensitive fusing body, and there is no gap between the connection part of the heat-fusing body and the heat-sensitive fusing body. Therefore, 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 fifth aspect of the present invention, rust is prevented by the plating layer provided around the connection portion of the fusing body, and the heat-sensitive fusing body is melted based on its wettability. Since the heat-sensitive blown body melted during the protection operation can be easily discharged from between the first and second blown body connection portions,
The reliability of the protection operation against abnormal spark can be improved .

[0127]

[0128]

[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 the configuration of a commutator side end of the 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 plan view showing a configuration of a terminal fitting included 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 diagram showing a configuration of an electric circuit of the commutator motor shown in FIG. 2;

FIG. 16A is a cross-sectional view showing a configuration around the heat-sensitive fusing body before energization in a structure in which the heat-sensitive fusing body of the heat-sensitive switch means and the terminal fitting are not fixed. FIG. 3B is a cross-sectional view showing a configuration around the heat-sensitive fusing body in a state where the heat-sensitive fusing body of the heat-sensitive switch means is not fixed to the terminal fitting in an energized state.
(C) is a cross-sectional view showing the configuration around the heat-sensitive fusing body in a state where the heat-sensitive fusing body of the heat-sensitive switch means and the terminal fitting are not fixed after the energization is completed.

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

FIG. 18 is a perspective view showing a partial configuration of a brush device according to a third embodiment of the present invention.

FIG. 19 is a plan view showing a configuration of a terminal fitting included in the brush device shown in FIG. 18;

FIG. 20 is a perspective view showing a configuration of a part of a brush device according to a fourth embodiment of the present invention.

FIG. 21 is a plan view showing a configuration of a terminal fitting included in the brush device shown in FIG. 20;

FIG. 22 is a perspective view showing a configuration of a part of a brush device according to a fifth embodiment of the present invention.

FIG. 23 is a plan view showing a configuration of a terminal fitting included in the brush device shown in FIG. 22;

FIG. 24 is a side view showing a partially sectioned configuration of a vacuum cleaner provided with a brush device according to a sixth embodiment of the present invention.

FIG. 25 is a sectional view showing a relationship between a brush device and a commutator according to a sixth embodiment.

FIG. 26 is a side view showing a cross section of a configuration of a commutator motor including a brush device according to a seventh embodiment of the present invention;

FIG. 27 is a front view showing the brush device shown in FIG. 26 as viewed from the commutator side.

FIG. 28 is a sectional view around the brush device shown in FIG. 26 along the line YY.

[Explanation of symbols]

 13: Commutator motor (rotating electric machine), 25: Armature, 29: Commutator, 31: Stator, 41: Brush device, 42: Holder insulation, 43: Brush holder, 43h: Plating layer, 44: Brush, 45 ... pigtail, 47 ... protection switch means, 50 ... terminal fittings, 50a, 50b ... insertion end of the terminal fittings, 50h ... plating layer, 51 ... heat-sensitive fusing body, 52 ... second fusing body connecting part, 52a ... connection hole ( (Fitting portion), 56: first fusing body connection portion, 56a: connection hole (fitting portion), 57: hole (heat conduction suppressing means), 71a: first fusing body connection portion, 71b: second fusing body connection Reference numeral 151: heat-sensitive fusing body, 157: concave groove (heat conduction suppressing means), 251: heat-sensitive fusing body, 256a: long groove (heat conduction suppressing means, fitting part).

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-U 1-90264 (JP, U) (58) Field surveyed (Int. Cl. ⁷ , DB name) H02K 13/00 H02K 23/00

Claims (5)

(57) [Claims] 1. A brush device for a rotating electric machine, wherein a brush that is elastically pressed against a commutator of an armature is provided in a cylindrical brush holder fixed to holder insulation, wherein a rectifier disposed near the commutator. A terminal fitting having a first fusing body connection portion at a child side end portion, and a second fusing body connection portion disposed near the commutator and close to the first fusing body connection portion in a non-contact manner. A brush holder and a heat-sensitive fusing body provided between the fusing body connection portions and electrically connecting them at a predetermined temperature or lower, and fusing and cutting the connection at a predetermined temperature or higher. A protection switch means electrically connected to a flowing current path; and a heat conduction suppressing means for suppressing heat conduction from the heat-sensitive fusing body to a metal part other than the first fusing body connection part in the terminal fitting. provided things Brush device for a rotating electrical machine according to claim. 2. The heat conduction suppressing means of the terminal fitting, wherein
(1) To separate the fused body connection part and other metal parts
One or more holes or slits provided in the
The brush device for a rotating electric machine according to claim 1, wherein
Place. 3. A part of said heat-sensitive fusing body,
The first fused body connection portion was connected to serve as the heat conduction suppressing means.
The brush device for a rotating electric machine according to claim 1, wherein
Place. 4. A cylindrical brush holder fixed to holder insulation.
Inside, a brush elastically pressed against the commutator of the armature
In the brush device for a rotating electrical machine provided with a first blowout at a commutator side end disposed near the commutator.
A terminal fitting having a body connection portion;
And is arranged in a non-contact manner close to the first fusing body connection portion.
A brush holder having a second fused body connection portion,
It is provided between the disconnection connection parts and these
Connection, and this connection is blown at a predetermined temperature or higher.
And a thermal fuse which cuts off
Protection switch means electrically connected to the flow path
And a pre-formed blown heat-fused body having a predetermined shape.
As well as the insertion ends provided at both ends,
Inserting into the fitting parts provided in each of the fusing body connection parts
A circuit characterized by being fixed to each of these fused body connection portions.
Brush device for converter. 5. The terminal fitting or the brush holder.
At least one of the surfaces on the heat-sensitive fusing body side,
It is necessary to cover the periphery of the fused body with a plating layer
The brush device for a rotating electric machine according to any one of claims 1 to 4, characterized in that: