JP3076735B2 - 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, a brush of the rotating electric machine is abnormal due to a spark. The present invention relates to a rotating electrical machine brush device provided with a protective measure when overheated.

[0002]

2. Description of the Related Art When a commutator motor is operated, a spark is inevitably generated between the commutator and the brush. However, the motor does not burn out due to the steady spark.

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, a spark is abnormally 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, and the operation of this element is used. 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. 5-300705.
And JP-A-2-177282.

[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 thermoresponsive element made of a shape memory alloy instead of the temperature sensor, there is a problem that the cost is high because the shape memory alloy itself is a considerably expensive material. In addition, since the heat responsive element has a considerable heat capacity, there is a problem that it is disadvantageous in protecting the motor by quickly following the rapid temperature rise of the brush due to the occurrence of abnormal spark.

SUMMARY OF THE INVENTION An object of the present invention is to provide an inexpensive rotating electric machine that can reliably and reliably protect a rotating electric machine against abnormal excessive temperature rise of a brush caused by abnormal spark generated between a commutator and a brush. It is to obtain a brush device.

[0011]

According to a first aspect of the present invention, there is provided a brush device for a rotating electric machine according to the present invention.
In a rotating electrical machine brush device provided with a brush which is urged by a spring and elastically pressed against a commutator in a cylindrical brush holder fixed to holder insulation, the brush and the brush holder are formed of an electric conductor. A terminal fitting provided in the vicinity of the brush holder by electrically connecting the brush holder and the brush, electrically connected to a current path flowing through the armature by being used as a switch contact piece together with the brush holder, The brush holder,
Each end of the brush holder and the terminal fitting on the commutator side
A protection switch means comprising a heat-sensitive fusing element for electrically connecting these at a predetermined temperature or lower, and fusing the connection at a predetermined temperature or higher, and wherein the brush holder has a commutator. A thermal resistance means is provided between the fusing body disposing portion at the side end and the brush so as to make them non-contact.

Further, in order to enable a quick protection operation to achieve the above object, a brush device for a rotating electric machine according to the present invention according to claim 2, wherein the brush holder comprises a pair of first walls opposed to each other. And a pair of second wall portions provided between the wall portions and opposed to each other, and at least one of these wall portions is protruded outwardly from the second A fusing body provided portion comprising a protruding portion forming a gap is provided therebetween, and the heat resistance means is formed by the gap.

[0013] Similarly, in order to enable a quick protection operation to achieve the above object, a brush device for a rotating electric machine according to the present invention according to claim 3 is characterized in that the fusing member disposing portion is formed by connecting the commutator to the commutator. The brush is formed on a wall of the brush holder, which is located on a side where a spark generated between the brush and the brush is generated.

Further, in a brush device for a rotating electric machine which is rotatable in a forward and reverse direction, a brush is provided in a cylindrical brush holder fixed to a holder insulation and is elastically pressed by a spring and pressed against a commutator. According to a fourth aspect of the present invention, in the brush device for a rotating electrical machine according to the present invention, the brush holders are provided to face each other with a pair of first wall portions facing each other and face each other. A pair of second wall portions, the brush holder and the brush are formed of an electric conductor, the brush holder and the brush are electrically connected, and the brush holder and the brush are used as a switch contact piece to be used as an electric switch. A terminal fitting which is electrically connected to a current path flowing through the brush and is provided in the vicinity of the brush holder; the brush holder; and each of the brush holder and the terminal fitting .
A protection switch means that is provided between the commutator-side end 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; Of the pair of first wall portions in the brush holder positioned on the front and rear sides in the rotation direction of the child.
Fusing body arrangement portions are provided at the commutator side end portions , respectively, and thermal resistance means for making them non-contact is provided between these arrangement portions and the brush.

According to another aspect of the present invention, there is provided a brush device for a rotating electric machine according to the present invention, wherein a commutator is urged by a spring into a cylindrical brush holder fixed to holder insulation. In a rotating electrical machine brush device provided with a brush that is elastically pressed against the brush holder,
A pair of first wall portions facing each other, and a pair of second wall portions provided between the wall portions and facing each other, and a spark generating side generated between the commutator and the brush; A protruding tip protruding toward the commutator side is extended at a tip of a wall portion of the brush holder located at a position where the brush and the brush holder are formed of an electric conductor, and the brush holder and the brush are electrically connected. The brush holder, the brush holder, and the protruding tip, which are electrically connected to a current path flowing through an armature together with the brush holder and electrically connected to a current path flowing through the armature. And provided between the tip of the wall of the brush holder and the tip of the terminal fitting, which is located on the spark generation side.
The protection switch means comprises a heat-sensitive fusible member which is electrically connected at a temperature lower than a predetermined temperature and cuts off the connection at a temperature higher than the predetermined temperature.

[0016]

According to the first aspect of the present invention, the brush holder and the terminal fitting are used as switch contact pieces , and these are connected to the commutator.
The protection switch means having the heat-sensitive fusing member provided between the end portions does not melt the heat-sensitive fusing member at a temperature lower than a predetermined temperature. A commutator is electrically connected to a current path flowing to the armature via the connected protection switch means and the brush. When the temperature reaches or exceeds a predetermined temperature, the protection switch means cuts off the electrical connection between the brush holder as a switch contact piece and the terminal fitting due to the melting of the heat-sensitive fusing body, so that the switch is opened.
Thus, the current is cut off in the brush device, and the operation of the rotating electric machine including the brush device is stopped.

[0017] The heat resistance means includes a brush holder.
The fusing body provided portion provided at the end of the splicer is held in non-contact with the brush to increase the thermal resistance therebetween.
This prevents the heat of the brush, which rises in temperature due to the resistance heat generation and the steady spark, from being directly supplied from the brush to the fusing body mounting portion, and keeps the temperature of this mounting portion low. However, the temperature of the fusing body disposition portion rises due to the influence of the abnormal spark. Therefore, the temperature difference of the fusing body arrangement part where the heat-sensitive fusing body is arranged,
It can be increased between when a steady spark occurs and when an abnormal spark occurs.

According to the second aspect of the present invention, since the fusing member mounting portion is formed by a protrusion provided on the wall of the brush holder so as to protrude to the outside thereof, the mounting portion is not in contact with the brush. In addition, a thermal resistance is secured between the two in the space between the fusing body step arrangement portion and the brush, and the temperature of the fusing body arrangement portion is kept low. Since the heat resistance means is an air gap, it is not necessary to use a special heat resistance member, and the heat resistance means can be implemented with a simple configuration.

According to the third aspect of the present invention, the spark generating side is a place where the temperature rises quickly in the brush device, which is most easily affected by the abnormal spark generated between the brush and the commutator. . Since the fusing body provided with the heat-sensitive fusing body of the protection switch means is provided therein, the temperature of the provided portion can be more sharply reacted to abnormal spark.

A fourth aspect is based on a brush device for a rotating electric machine that can be rotated forward and backward. In the configuration according to the fourth aspect, the brush holder and the terminal fitting are switch contact pieces , and
It has a heat-sensitive fusing body provided between these commutator side ends.
The protective switch means does not melt at a predetermined temperature or lower, so that the heat-sensitive blown body does not melt, and so to say, maintains a state equivalent to closing the switch, so that the protective switch means and the brush are electrically connected to each other. A commutator is electrically connected to a current path flowing through the armature. When the temperature of the protection switch exceeds a predetermined temperature, the electrical connection between the brush holder as a switch contact piece and the terminal fitting is cut off by melting of the heat-sensitive fusing body, so that the switch is opened. As a result, the current is cut off in the brush device, and the operation (forward rotation or reverse rotation) of the rotating electric machine including the brush device is stopped.

The heat resistance means is a phase of the brush holder.
A pair of opposing first walls are respectively provided at the commutator side ends.
The fusing body disposition portion is held in non-contact with the brush to ensure a large thermal resistance therebetween. This prevents the heat of the brush, whose temperature rises due to the resistance heat generation and the steady spark, from being directly supplied from the brush to the fusing body installation portion, and keeps the temperature of this installation portion low. However, the temperature of the fusing body disposition portion rises due to the influence of the abnormal spark. Therefore, the temperature difference of the fusing body disposition portion of the protection switch means where the heat-sensitive fusing body is disposed can be increased between the time of occurrence of a steady spark and the time of occurrence of an abnormal spark.

According to a fifth aspect of the present invention, the brush holder and the terminal fitting are used as switch contact pieces , and the end portions thereof are provided.
The protection switch means having the heat-sensitive fusing body provided between the parts is electrically connected to each other because the heat-sensitive fusing body does not melt at a predetermined temperature or less, so that a state equivalent to closing the switch is maintained. The commutator is electrically connected to a current path flowing to the armature via the protection switch means and the brush. When the temperature of the protection switch exceeds a predetermined temperature, the electrical connection between the brush holder as a switch contact piece and the terminal fitting is cut off by melting of the heat-sensitive fusing body, so that the switch is opened. Thus, the current is cut off in the brush device, and the operation of the rotating electric machine including the brush device is stopped.

In particular, the spark generating side of the tip of the brush holder is easily affected by sparks generated between the brush and the commutator, and is a place where the temperature of the brush device rises quickly. Since the heat-sensitive fusing body of the protection switch means is disposed at that position, the fusing body can react sharply to an abnormal spark.

Further, the tip of the wall portion of the brush holder located on the spark generating side has a protruding tip protruding toward the commutator, so that the protruding tip is more susceptible to abnormal sparks. Thus, the temperature of the heat-sensitive fusing body of the protection switch means can be quickly raised by the abnormal spark.

[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 a partial cross-section of the configuration of the electric vacuum cleaner. In FIG. 1, reference numeral 1 denotes a cleaner main body formed by connecting a lower case 1a and an upper case 1b, in front of the lower case 1a. A lid 4 is mounted on the upper side to open and close an upper opening of a dust collection chamber 3 formed at the front of the cleaner body 1 by rotating about a pivot 2.

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. Armature coil 28
Are connected to a plurality of commutator pieces 29a 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 30 are provided in the peripheral portion on the bottom side of the frame 21 and the like. Positioned between the outlet 30 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 terminal block has a connection terminal 34 (2 in FIG. 3).
(See dotted line). The terminal of the stator coil 31 a is electrically connected to the connection terminal 34, and the connection terminal 34 has a flat terminal plate portion extending 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 and 4, the brush device 41 includes a holder insulator 42, a brush holder 43, a brush 44, a pigtail 45, and a coil spring 46.
And protection switch means 47.

More specifically, the holder insulation 42 is made of a thermosetting synthetic resin such as a phenol resin having electric insulation.
It has a holder insulating 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.

The brush holder 43 is formed of an electric conductor such as a brass or galvanized steel plate or a copper plate, and has a cylindrical shape having one end opened and the other end closed by a bottom wall 43e. As shown in FIG. 5, the cylindrical portion of the brush holder 43 has a pair of opposed flat wall portions 43a and 43b.
And a pair of opposite wall portions 43c and 43d connecting these two wall portions 43a and 43b, respectively, and are formed in a rectangular cylindrical shape.

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 bottom wall 43e side is arranged outside the frame 21. In addition, 43f in FIG. 5 is a stopper cut and raised from the brush holder 43 and abutted on the tip of the holder insulating body 42a.

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 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 bottom 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 bottom wall 43e. The spring 44 projects the brush 44 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 terminal insulating hole 4 is formed in the holder insulating body 42a.
9 are provided. The protection switch means 47
Is formed with a part of the brush holder 43, a terminal fitting 50 arranged near the part, and a conductive heat-sensitive fusing body 51. The terminal fitting 50 is formed of a spring plate having elasticity, and the connecting portion 5 bent in a substantially rectangular shape.
0a. This connecting portion 50a is connected to the terminal mounting hole 4
9, the terminal fitting 50 is disposed near the outside of the wall 43 a of the brush holder 43.

The connecting portion 50a elastically closely contacts the opposing inner surfaces of the terminal mounting holes 49 to maintain the mounted state of the terminal fitting 50. 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 a and the terminal fitting 50 are connected via the connection terminal 34. Are electrically connected.

The protruding portion of the terminal fitting 50 protruding out of the terminal mounting hole 49 is provided with an insulating gap between the terminal fitting 50 and the wall 43a of the brush holder 43, and is disposed substantially parallel to the wall 43a. The tip of the brush holder 43 extends to reach the tip of the brush holder 43.

The wall 43a of the brush holder 43 is located on the front side in the direction of rotation of the commutator 29 (indicated by the arrow A in FIG. 3), in other words, on the side where sparks are generated between the commutator 29 and the brush 44. The wall to be located. A fusing body disposition portion 52 is provided at the end of the wall portion 43a on the commutator 29 side.

As shown in FIGS. 3 to 5, the disposing portion 52 comprises a projecting portion which forms a step portion projecting outside the brush holder 43 over the entire width of the wall portion 43a. A gap 53 is formed as a heat resistance means for increasing the heat resistance between the front end of the heat pipe 44 and the front end of the heat pipe 44. Since the fusing body arrangement portion 52 is bent, it is integrally connected to the wall 43a, and 43g in FIGS. 3 and 5 denotes a bent portion connected to the wall 43a.

The fusible member disposition portion 52 and the tip of the terminal fitting 50 are electrically connected via the thermal fusible member 51.
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 rubber having conductivity. The heat-sensitive fusing body 51 made of solder or the like is solidified at a predetermined temperature (for example, 160 ° C.) or less, and electrically connects the brush holder 43 and the terminal fitting 50. It is provided for disconnecting the electrical connection between the terminal and the terminal fitting 50.

It is to be noted that the heat-sensitive fusing body 51 is formed in a predetermined shape in advance, and is attached to the fusing body mounting portion 52 or the tip of the terminal fitting 50 by crimping or press fitting, or by spot welding or super welding. It is attached by welding such as sonic welding. Alternatively, a split mold (not shown) for regulating the shape having a predetermined cylindrical shape is arranged at the end of the fusing body arrangement part 52 or the terminal fitting 50, and a predetermined amount of the heat-sensitive fusing body 51 melted in the internal space of the mold. The mold is poured, and after curing, the mold is disassembled and removed, so that the mold is attached like soldering. Alternatively, the fusing body arrangement part 52 and the terminal fitting 5
It is provided so as to be sandwiched between the leading end of the zero.

The heat-sensitive fusing body 51 fixed to the fusing body disposition portion 52 or the distal end portion of the terminal fitting 50 is pressed against the distal end portion of the terminal filing 50 or the fusing body disposing portion 52 by the spring force of the terminal fitting 50. Thus, the brush holder 43 and the terminal fitting 50 are electrically connected. The terminal fitting 50
When the heat-sensitive fusing body 51 is blown, it is in a free state, or provided so as not to be in contact with the wall 43a by being restricted by the spring contact portion of the holder insulating body 42a.

FIG. 7 is a diagram showing an electric circuit of the commutator motor 13. One brush device 41 pressed against the commutator 29 is connected to one of the stator coils 31 a of the stator 31 via a stator coil 31 a. The other brush device 41 connected to one power supply terminal of the commercial AC power supply and pressed against the commutator 29 is connected to the other power supply terminal of the commercial AC power supply via the other stator coil 31a of the stator 31. It is connected. The electric motor 13 has a stator 31 corresponding to the direction of the current passed through the stator coil 31a every half cycle of the alternating current.
And the current direction of the armature 25 are switched correspondingly, so that the rotation of the armature 25 is continued in one direction.

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 combined with 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 43a which is a part of the brush holder 43 are used as switch contact pieces.

Therefore, at a temperature lower than a predetermined temperature (the melting point of the heat-sensitive fusing body 51), the heat-sensitive fusing body 51 provided between the wall 43a and the terminal fitting 50 is kept in a hardened state, and the two switches are connected to each other. The wall 43a and the terminal fitting 50 are electrically connected. In other words, when the temperature is equal to or lower than the predetermined temperature, the protection switch unit 47 is maintained in a state equivalent to a state in which the switch is closed.

As a result, when the commutator motor 13 is energized, the current supplied from the power source passes through the brush device 41 on the positive side from the commutator 29 in which the brush 44 is in sliding contact with the armature coil. Then, the current is returned from the commutator 29 to the negative 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 30 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, if the armature coil 28 is disconnected for any reason, the commutator 29
Since the value of the current cut off with the rotation of the motor increases, the current ripple increases remarkably, the generated spark also abnormally occurs, and the thermal influence on the peripheral parts such as the brush 44 becomes large.

Under such circumstances, 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 a predetermined temperature, the heat-sensitive fusing body 51 is melted accordingly, so that the electrical connection between the wall 43a 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.

Further, in this case, 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 spark generating side is the earliest in the brush device 41. It is a place where the temperature rises. Since the heat-sensitive fusing body 51 of the protection switch means 47 is provided at that location, the fusing body 51 can react sharply to the abnormal spark. In addition, since the heat-sensitive fusing body 51 formed of solder has a small heat capacity,
Although the number of parts is small and the structure is simple, the temperature of the brush 44 can be quickly followed. Therefore, brush 4
4, the protection switch means 47 can be opened quickly in response to the abnormal temperature rise.

By the way, between the brush 44 and the commutator 29, there is always a spark (steady spark or abnormal spark).
Is generated, which, in addition to heating the brush 44, generates heat based on a resistance proportional to the amount of current passing through the brush 44, so that the temperature of the brush 44 tends to rise. Since the brush 44 is in contact with the inner surface of the brush holder 43, the brush 44
Is transferred to the brush holder 43, and the brush holder 43
Temperature also rises.

However, the fusing body mounting portion 52 of the brush holder 43 in which the heat-sensitive fusing body 51 is provided is formed so as to protrude outward, and is provided in non-contact with the tip of the brush 44. Therefore, as shown in FIG. 6, the brush 44 is rotated with the rotation of the commutator 29 (the direction is indicated by an arrow A).
However, although the brush 44 is slightly inclined with respect to the brush holder 43 based on the clearance between the brush holder 43 and the brush holder 43, the brush 44 does not come into contact with the fusing body arrangement part 52, A gap 53 is provided between the brush 52 and the tip of the brush 44.

The gap 53 prevents the heat at the tip end of the brush 44, which becomes high in temperature due to the resistance heat generation and the steady spark, from being directly transmitted to the fusing body arrangement section 52 by heat conduction due to its thermal resistance. Therefore, the temperature of the fusing body arrangement part 52 can be lower than the temperature of the brush 44.

The brush 44 hits the bent portion 43g closest to the fusing body arrangement portion 52, and the inclination of the brush 44 is restricted. Therefore, the bent portion 43g is moved from the brush 44 to the wall portion 43a of the brush holder 43. Heat supply unit to the However, the fusing body arrangement part 5
2 are separated from each other, the temperature of the fusing body arrangement portion 52 can be made lower than that of the bent portion 43g in accordance with the heat radiation to the outside proportional to the distance. The temperature at 52 is kept low.

As described above, the fusing body arrangement part 52 and the brush 4
By increasing the thermal resistance between the tip end portion 4 and the gap 53 by the gap 53, the temperature of the fusing body arrangement portion 52 can be kept lower than the temperature of the brush 44. However, when an abnormal spark occurs, the temperature of the fusing body arrangement part 52 is increased by the influence of the abnormal spark as described above. Therefore, the difference between the temperature at the time of occurrence of a steady spark and the temperature at the time of occurrence of an abnormal spark of the fusing body disposition portion 52 and the heat-sensitive fusing member 51 disposed thereon can be increased.

For this reason, the heat-sensitive fusing body 51 caused by the variation in the amount of the heat-sensitive fusing body 51 and the variation in the contact between the fusing body 51 and the fusing body arrangement portion 52 or the terminal fitting 50, and the like.
Due to the slight variation in the melting characteristics of the above, it is possible to prevent the malfunction of the protection switch means 47 performing the protection operation despite the occurrence of the steady spark, and to perform the protection operation only when the abnormal spark occurs. Thus, the reliability of the protection operation by the protection switch means 47 can be improved.

Further, in the first embodiment, the thermal resistance means for securing the temperature difference is provided on the wall 43a of the brush holder 43, which is located on the spark generating side, by the fusing body disposing portion 52 comprising a projecting portion. Is formed, and the gap 53 is formed between the brush 44 and the tip of the brush 44, so that it is not necessary to use a special heat resistance material. Therefore, it can be implemented with a simple configuration.

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 more due to the occurrence of abnormal spark, the protection switch means 47 quickly switches the brush device 41 to 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 30. 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 the manufacturing is easy.

FIG. 8 shows a second embodiment of the present invention.
The second embodiment is different from the first embodiment only in the configuration of the fusing body provided on the brush holder. The remaining configuration is the same as or similar to that of the rotary electric machine brush device of the first embodiment shown in FIGS. 1 to 7 including portions not shown in FIG. 1 to 7, 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 configurations and the description of the functions and effects based on them will be omitted. The same or similar parts also form part of the apparatus of the present embodiment.

The brush-side wall 43a of the brush holder 43 of the second embodiment has a ridge 7 extending over its entire length in the longitudinal direction.
1 is provided. The ridge 71 projects outside the wall 43a, and its inner surface and the brush holder 4
Between the brush holder 4 and the brush 44 inserted therein.
3 form a gap 53 extending in the longitudinal direction. Ridge 7
1 is used as a fusing body arrangement part 52, and a heat-sensitive fusing body 51 is arranged on the outer surface of this part.

The gap 53 is formed between the fusing body arrangement portion 52 and the brush 4
4 is used as a ventilation path through which a part of the wind blown by the electric blower is passed, while the heat resistance means for increasing the heat resistance is formed between the tip end of the air blower 4 and the inside. The temperature rise of the brush device can be suppressed. The configuration other than the above points is the same as that of the first embodiment.
This is the same as the embodiment.

In the second embodiment as well, by providing the protection switch means, the same operation as in the first embodiment can be obtained, and the intended object of the present invention can be achieved.

FIG. 9 shows a third embodiment of the present invention.
The third embodiment is different from the first embodiment only in the configuration of the fusing body arrangement portion and the like formed on the brush holder. Other configurations are shown in FIGS. 1 to 7 including portions not shown in FIG.
Since the configuration is the same as or similar to that of the rotary electric machine brush device of the first embodiment shown in FIG. 1, the components not shown are substituted with FIGS. 1 to 7 and the same or similar components shown in FIG. The same reference numerals as in the first embodiment denote the same parts, and a description of those components and a description of the operation and effect based on them will be omitted. However, these same or similar parts also form part of the apparatus of the present embodiment. It is.

The wall 43 of the brush holder 43 of the third embodiment
On the spark side of d (or the wall 43c), a ridge 81 is provided over the entire length in the longitudinal direction. The protrusions 81 protrude outside the wall 43d, and form a gap 53 extending in the longitudinal direction of the brush holder 43 between the inner surface thereof and the brush 44 inserted into the brush holder 43. . The commutator-side tip of the ridge 81 is used as a fusing body arrangement part 52, and a heat-sensitive fusing body 51 is arranged on the outer surface of this part.

The gap 53 is formed between the fusing body arrangement portion 52 and the brush 4
4 is used as a ventilation path through which a part of the wind blown by the electric blower is passed, while the heat resistance means for increasing the heat resistance between the tip end of the air blower and the air blower is used. The temperature rise of the brush device can be suppressed. The configuration other than the above points is the same as that of the first embodiment.
This is the same as the embodiment.

In the third embodiment as well, by providing the protection switch means, the same operation as in the first embodiment can be obtained, and the intended object of the present invention can be achieved.

FIG. 10 shows a fourth embodiment of the present invention. The fourth embodiment differs from the first embodiment only in the configuration of the tubular portion of the brush holder and the configuration of the fusing body disposition portion formed thereon. Other configurations are the same or similar to those of the rotary electric machine brush device of the first embodiment shown in FIGS. 1 to 7 including portions not shown in FIG. 10. 7 to FIG. 7, 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 on them will be omitted. These same or similar parts also form part of the apparatus of this embodiment.

The cylindrical portion of the brush holder 43 of the fourth embodiment is located on the front side or the rear side in the rotation direction of the commutator, and is positioned between the pair of opposed wall portions 43a, 43b in the thrust direction of the commutator. And a pair of flat wall portions 43c and 4
3d and the walls 43a, 42b
Each has a convex ridge 91 which is formed in an arc shape and curved so as to protrude outward.

The protrusions 91 are formed over the entire length of the brush holder 43, and form a gap 53 extending in the longitudinal direction of the brush holder 43 between the inner surface thereof and the brush 44 inserted into the brush holder 43. doing. Ridges 91 formed on the wall 43a on the spark generation side
Of the commutator side is used as a fusing body arrangement part 52,
A heat-sensitive fusing body 51 is provided on the outer surface of this portion.

The gap 53 is formed between the fusing body arrangement portion 52 and the brush 4
4 is used as a ventilation path through which a part of the wind blown by the electric blower is passed, while the heat resistance means for increasing the heat resistance between the tip end of the air blower and the air blower is used. The temperature rise of the brush device can be suppressed. The configuration other than the above points is the same as that of the first embodiment.
This is the same as the embodiment.

In the fourth embodiment as well, by providing the protection switch means, the same effect as in the first embodiment can be obtained, and the intended object of the present invention can be achieved.

FIGS. 11 to 13 show a fifth embodiment of the present invention. The fifth embodiment is an example in which the present invention is applied to a commutator motor that can be rotated forward and backward. Only the circuit configuration and the configuration of a fusing body disposing portion formed at the end of the brush holder on the commutator side are the same as those of the first embodiment. Different from the embodiment. Other configurations are the same or similar to those of the first embodiment shown in FIGS. 1 to 6, including portions not shown in FIGS. 11 to 13. 6 are substituted for FIGS. 1 to 6, and the same or similar components shown in the drawings are denoted by the same reference numerals as in the first embodiment, and the description of those configurations and the description of the operation and effect based on them are omitted. However, these same or similar parts also form part of the apparatus of this embodiment.

FIG. 13 is a diagram showing an electric circuit of the commutator motor 13. One brush device 41 pressed against the commutator 29 is connected to the common terminal 1 of the first switch 101.
01a and the first switching terminal 101b and one stator coil 31a of the stator are connected in series to one power supply terminal of a commercial AC power supply. Similarly, the commutator 29
The other brush device 41 pressed against the other terminal of the commercial AC power supply via the common terminal 102a and the first switching terminal 102b of the second switching switch 102 and the other stator coil 31a of the stator in series. Connected to power supply terminal.

First and second changeover switches 101 and 10
Numeral 2 is switched in conjunction. The first switch terminal 101b of the first switch 101 is connected to the second switch terminal 102c of the second switch 102, and the second switch terminal 101c of the first switch 101 is connected.
c is the first switch terminal 102 of the second switch 102
a.

Therefore, in the commutator motor 13, the common terminal 101a of the first changeover switch 101 is connected to the first changeover terminal 101b and the common terminal 102a of the second changeover switch 102 is connected as shown by the solid line in FIG. When connected to the first switching terminal 102b, the direction of the magnetic flux of the stator corresponding to the direction of the current passed through the stator coil 31a and the current direction of the armature 25 are switched correspondingly every half cycle of AC. As a result, for example, FIG.
The rotation of the armature 25 can be continued in the counterclockwise direction indicated by the solid arrow. 13, the common terminal 101a of the first switch 101 is connected to the second switch 101.
c, and when the common terminal 102a of the second changeover switch 102 is connected to the second changeover terminal 102c, the stator coil 3 is switched every half cycle of AC.
1a, the direction of the magnetic flux of the stator according to the direction of the current passed through
The current direction of the armature 25 is switched correspondingly, so that the armature 25 moves clockwise as indicated by the dotted arrow in FIG.
Rotation can be continued.

Further, the fusing body arrangement part 52 of the fifth embodiment is provided.
A pair of wall portions of the brush holder 43 located on the front side and the rear side in the rotation direction of the commutator 29, that is, the side where a spark is generated when the commutator 29 is rotated in the direction indicated by the solid arrow A in FIG. 11 and a wall 43b located on the side where a spark is generated when the commutator 29 is rotated in the direction indicated by the dotted line B in FIG. 11, respectively.

The pair of fusing body arrangement portions 52 are
3a, 43b, a gap 5 serving as a thermal resistance means for increasing the thermal resistance between the brush 44 and the tip of the brush 44 without contact between the brush 44 and the fusing body disposing portion 52;
3 is formed. Then, the terminal fitting 50 is arranged only near the outside of the one fusing body disposition portion 52, and the heat-sensitive fusing body 51 is provided over the distal end portion and one of the fusing body disposition portions 52. Protection switch means 47 is formed. The configuration other than the above is the same as in the first embodiment.

In the fifth embodiment, the tip of the brush 44 and the brush holder 43 are separated by a pair of gaps 53.
Since the contact with the tip of the brush 44 is small, the temperature of the tip of the brush 44 heated by the occurrence of the steady spark is less transmitted to the tip of the brush holder 43, and the temperature of the fusing body arrangement part 52 is lowered. Can be held.

The commutator 29 is indicated by a solid arrow A in FIG.
When an abnormal spark is generated when rotating in the direction shown by the arrow, the temperature of one of the fusing body arrangement portions 52 provided on the wall portion 43a increases due to the abnormal spark. With the effect obtained, the protection switch means 47 can be operated.

If an abnormal spark occurs when the commutator 29 is rotated in the direction indicated by the dotted arrow B in FIG. 11, the other sparking member provided on the wall 43b is provided by the abnormal spark. Since the temperature of the portion 52 rises, this temperature spreads over the entire tip of the brush holder 43. Thereby, the temperature of the one fusing body disposing portion 52 in which the thermal fusing body 51 is disposed on the outer surface is also increased, so that the protection switch means 47 can be operated.

As described above, even if the rotation direction of the commutator 29 is switched, a large temperature difference of the heat-sensitive fusing body 51 between the occurrence of a steady spark and the occurrence of an abnormal spark is ensured.
The protection switch means 47 can work properly.

Therefore, in the fifth embodiment, the provision of the protection switch means 47 provides the same operation as that of the first embodiment, thereby achieving the intended object of the present invention.

In the fifth embodiment, a protection switch is provided also on the other fusing body disposition portion 52 side.
This may be provided in series with the protection switch means 47 on the side of the one fusing body disposing portion 52 on an electric circuit. In this case, the responsiveness of the protection operation by the protection switch means 47 against the occurrence of the abnormal spark can be further improved in both forward rotation and reverse rotation.

FIGS. 14 and 15 show a sixth embodiment of the present invention. The sixth embodiment differs from the first embodiment only in the configuration of the fusing body arrangement portion formed on the brush 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 7, including portions not shown in FIGS. 14 and 15. 1 to 7 are substituted, the same or similar components shown in the drawings are denoted by the same reference numerals as in the first embodiment, and the description of those configurations and the description of the operation and effect based on them are omitted. However, these same or similar parts also form part of the apparatus of this embodiment.

In the sixth embodiment, the fusing body arrangement part 52
As shown in FIG. 15, the brush holder 43 is formed of a first disposition portion 52 a and a second disposition portion 52 b which are continuous to two circumferential surfaces of the brush holder 43.

The first disposing portion 52a is provided at an end of the commutator side of the wall portion 43a which is located on the side where a spark is generated when rotated, and the second disposing portion 52b is provided on the first disposing portion 52a. Is provided at a commutator-side end of a wall 43d of the brush holder 43 located downstream of the electric blower in the blowing direction, for example. Therefore, the fusing body arrangement part 52
Has an L-shape.

In the sixth embodiment, since the axial direction of the commutator 29 is up and down, the wall 43d is a lower wall, and the brush 44 is in contact with its inner surface by its own weight. Although heat can be conducted from the brush 44 to the wall 43d, the brush 44 is provided on the inner surface of the upper wall 43c.
Is not contacted, so that heat transfer from the brush 44 to the wall 43c by heat conduction is impossible.

A gap 53 as a heat resistance means is formed between the inner surface of the fusing body arrangement portion 52 having such a configuration and the brush 44 inserted into the brush holder 43. The heat-sensitive fusing body 51 is provided on the outer surface of the first mounting portion 52a. The configuration other than the above is the same as in the first embodiment.

In the sixth embodiment, the provision of the protection switch means 47 provides the same operation as in the first embodiment, thereby achieving the intended object of the present invention.

Further, in the sixth embodiment, the fusing body arrangement portion 52 is provided with the first
Since the end portion of the brush 44 is formed by the arrangement portion 52a and the second arrangement portion 52b, there is little contact between the tip end portion of the brush 44 and the tip end portion of the brush holder 43, and the tip end portion of the brush 44 heated by the steady spark generation. The air gap 53 can reduce the temperature transmitted to the tip of the brush holder 43. Thereby, the temperature of the first disposing portion 52a of the fusing body disposing portion 52 in which the heat-sensitive fusing member 51 is disposed can be kept lower.

Further, due to design restrictions, the first disposing unit 5
When the heat-sensitive fusing body 51 cannot be provided in the second mounting portion 52b, the fusing body 51 can be provided in the second mounting portion 52b.

FIGS. 16 and 17 show a seventh embodiment of the present invention. The seventh embodiment differs from the first embodiment only in the configuration of the fusing body arrangement portion formed on the brush holder. Other configurations are the same or similar to those of the rotary electric machine brush device of the first embodiment shown in FIGS. 1 to 7, including portions not shown in FIGS. 16 and 17. 1 to 7 are substituted, the same or similar components shown in the drawings are denoted by the same reference numerals as in the first embodiment, and the description of those configurations and the description of the operation and effect based on them are omitted. However, these same or similar parts also form part of the apparatus of this embodiment.

In the seventh embodiment, the fusing body arrangement part 52
As shown in FIG. 17, the first disposing portion 52a, the second disposing portion 52b, and the third
An arrangement portion 52c is formed.

The first disposing portion 52a is provided at a commutator side end of the wall portion 43a which is located on the side where a spark is generated when rotated, and the second disposing portion 52b is provided on the first disposing portion 52a. Is provided at the commutator-side end of the wall 43d of the brush holder 43 positioned downstream of the electric blower in the blowing direction, for example, and the third mounting portion 52c is
Are provided at the commutator-side end of the wall 43b. Therefore, the fusing body arrangement portion 52 has a U shape.

In the seventh embodiment, since the axial direction of the commutator 29 is vertical, the wall 43d is a lower wall, and the brush 44 is in contact with its inner surface by its own weight. Although heat can be conducted from the brush 44 to the wall 43d, the brush 44 is provided on the inner surface of the upper wall 43c.
No heat transfer is possible due to heat conduction from the brush 44 to the wall 43c since the upper surface of the brush is not contacted. When the configuration of the brush holder 43 of the seventh embodiment is applied to a commutator motor capable of rotating forward and reverse, the wall portion 43b
Is also located on the spark generating side.

A gap 53 as a heat resistance means is formed between the inner surface of the fusing body disposition portion 52 having such a configuration and the brush 44 inserted into the brush holder 43. The heat-sensitive fusing body 51 is provided on the outer surface of the first mounting portion 52a. The configuration other than the above is the same as in the first embodiment.

In the seventh embodiment as well, the provision of the protection switch means 47 provides the same operation as in the first embodiment, thereby achieving the intended object of the present invention.

Further, in the seventh embodiment, the fusing body disposing portion 52 is provided on the first surface of the brush holder 43 which is continuous with the three surfaces in the circumferential direction.
To the third disposing portions 52a to 52c,
The contact between the tip of the brush holder 43 and the tip of the brush 44 is small, and the gap 53 prevents the temperature of the tip of the brush 44 heated by the generation of the steady spark from being transmitted to the tip of the brush holder 43. Thereby,
The temperature of the fusing body arrangement part 52 in which the heat-sensitive fusing body 51 is arranged can be kept lower.

Further, due to design restrictions, the first disposing unit 5
When the heat-sensitive fusing body 51 cannot be disposed on the second mounting part 52a, the heat-sensitive fusing body 51 can be disposed on the second mounting part 52b, and the heat-sensitive fusing body 51 can be disposed on the outer surface of the third mounting part 52c. It is also possible.

FIGS. 18 and 19 show an eighth embodiment of the present invention. The eighth embodiment differs from the first embodiment only in the configuration of the fusing body arrangement portion formed on the brush 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 7 including portions not shown in FIGS. 18 and 19. 1 to 7 are substituted, the same or similar components shown in the drawings are denoted by the same reference numerals as in the first embodiment, and the description of those configurations and the description of the operation and effect based on them are omitted. However, these same or similar parts also form part of the apparatus of this embodiment.

In the eighth embodiment, the fusing body arrangement part 52 is
The brush holder 43 is formed by first to fourth disposing portions 52 a to 53 d which are annularly continuous over the whole in the circumferential direction of the brush holder 43. The first disposition portion 52a is provided at a commutator side end of the wall portion 43a which is located on the side where a spark is generated when rotated, and the second disposition portion 52b is provided at one end of the first disposition portion 52a. The brush holder 43 is provided at a commutator-side end of a wall 43d of the brush holder 43 positioned downstream of the electric blower in the blowing direction, for example. The third disposing unit 52c is a second disposing unit 52b.
Are provided at the commutator-side end of the wall 43b, and the fourth arranging part 52d is connected to the third arranging part 52c and the first arranging part 52a at right angles to the wall 43c, respectively. It is provided at the end on the commutator side. Therefore, the fusing body arrangement portion 52 has a rectangular frame shape.

In the eighth embodiment, since the axial direction of the commutator 29 is vertical, the wall 43d is a lower wall, and the brush 44 is in contact with its inner surface by its own weight. Although heat can be conducted from the brush 44 to the wall 43d, the brush 44 is provided on the inner surface of the upper wall 43c.
Is not contacted, so that heat transfer from the brush 44 to the wall 43c by heat conduction is impossible. When the configuration of the brush holder 43 of the eighth embodiment is applied to a commutator motor capable of rotating forward and reverse, the wall portion 43b
Is also located on the spark generating side.

[0113] A gap 53 is formed between the inner surface of the fusing body arrangement portion 52 having such a configuration and the brush 44 inserted into the brush holder 43 as a heat resistance means. The heat-sensitive fusing body 51 is provided on the outer surface of the first mounting portion 52a. The configuration other than the above is the same as in the first embodiment.

In the eighth embodiment, the provision of the protection switch means 47 provides the same operation as that of the first embodiment, thereby achieving the intended object of the present invention.

Further, in the eighth embodiment, since the fusing body arrangement portion 52 is formed by the first to fourth arrangement portions 52a to 53d which are continuous over the entire circumferential direction of the brush holder 43, The contact between the tip of the brush 44 and the tip of the brush holder 43 is small, and the temperature of the tip of the brush 44 heated by the steady spark generation is less transmitted to the tip of the brush holder 43 by the annular gap 53. it can.
Thereby, the temperature of the first disposing portion 52a of the fusing body disposing portion 52 in which the heat-sensitive fusing member 51 is disposed can be kept lower.

Further, due to design restrictions, the first disposing unit 5
When the heat-sensitive fusing body 51 cannot be provided in the 2a, the fusing body 51 can be provided in any of the second to fourth mounting portions 52b to 52d.

FIG. 20 shows a ninth embodiment of the present invention. The ninth embodiment differs from the first embodiment only in the configuration of the fusing body arrangement portion formed on the brush holder and the tip of the terminal fitting. The remaining configuration is the same or similar to that of the rotary electric machine brush device of the first embodiment shown in FIGS. 1 to 7 including portions not shown in FIG. 20. 7 to FIG. 7, 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 on them will be omitted. These same or similar parts also form part of the apparatus of this embodiment.

In the ninth embodiment, the fusing body arrangement part 52
Wall portion 4 located on the spark generation side of brush holder 43
It is provided by inclining the commutator-side tip of 3a so as to protrude outward. Note that the inclination angle is set to be larger than the maximum inclination angle at which the brush 44 can be inclined in the brush holder 43.
Can be secured.

The fusing and disposing portion 52 is formed over the entire length of the wall portion 43a in the width direction or on a part thereof. Therefore, a gap 53 as a thermal resistance means is formed in a wedge shape between the inner surface of the fusing body arrangement portion 52 and the tip of the brush 44.

The distal end of the terminal fitting 50 is bent in parallel with the fusing body arrangement portion 52, and the heat-sensitive fusing body 51 is arranged between them. Thus, the terminal fitting 5
By bending the leading end of the zero, the spring force can be uniformly applied to each part of the heat-sensitive fusing body 51. In addition,
The configuration other than the above is the same as in the first embodiment.

In the ninth embodiment as well, the provision of the protection switch means 47 provides the same operation as in the first embodiment, thereby achieving the intended object of the present invention.

FIG. 21 shows a main part of a tenth embodiment of the present invention. The tenth embodiment differs from the first embodiment only in the configuration of the heat resistance means formed on the brush 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 7, including portions not shown in FIG. 21. 7 to FIG. 7, 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 on them will be omitted. These same or similar parts also form part of the apparatus of this embodiment.

The thermal resistance means of the tenth embodiment is formed by a thermal resistor which increases the thermal resistance between the brush 44 and the brush holder 43, instead of the gap. This thermal resistor may be provided so as to be adhered to the inner surface of the fusing body disposing portion 52 by using a plate material or the like of the same type or different type from the brush holder.
In order to obtain a larger thermal resistance, it is preferable that the thermal insulator 153 is formed of a thermal insulator 153 such as ceramics, which has a lower thermal conductivity than the brush holder 43 and has excellent heat resistance.

The thermal insulator 153 is provided at the tip of the brush holder 43 on the commutator side so as to be housed in the fusing body mounting portion 52 formed to protrude outward. Thermal insulator 15
The inner surface of 3 may or may not be continuous with the inner surface of the wall portion 43a located on the spark generation side except for the fusing body arrangement portion 52.

The heat insulator 153 prevents the commutator-side end of the brush 44 from coming into contact with the fusing body disposition portion 52 from the inside thereof, so that the brush 44 and the commutator-side end of the fusing member dispose the fusing member disposition portion 52. 52 is kept out of contact, and the brush 44 and the wall 43a of the brush holder 43 are kept out of contact, thereby preventing heat transfer between them by heat conduction. Furthermore, thermal insulator 1
53 is the commutator side end of the brush 44
2 and interrupts heat transfer from the brush 44 to the fusing body arrangement part 52 due to its heat insulation performance. Therefore, compared to the thermal resistance means by the air gap, the thermal insulator 15
3, the thermal resistance is more effective. The configuration other than the above is the same as in the first embodiment.

In the tenth embodiment, the provision of the protection switch means 47 provides the same operation as in the first embodiment, thereby achieving the intended object of the present invention.

The thermal resistor, for example, the thermal insulator 153 shown in the tenth embodiment is implemented in place of the one in which the thermal resistance is obtained by the air gap.
To the ninth embodiment and the like.

FIGS. 22 to 25 show an eleventh embodiment of the present invention. In the eleventh embodiment, instead of omitting the heat resistance means, a means for rapidly raising the temperature of the fusing body arrangement portion due to an abnormal spark is provided. Only the second embodiment differs from the first embodiment. Other configurations are the same or similar to those of the rotary electric machine brush device of the first embodiment shown in FIGS. 1 to 7 including portions not shown in FIGS. 22 to 25. 1 to 7 are substituted, the same or similar components shown in the drawings are denoted by the same reference numerals as in the first embodiment, and the description of those configurations and the description of the operation and effect based on them are omitted. However, these same or similar parts also form part of the apparatus of this embodiment.

As shown in FIGS. 24 and 25, the cylindrical portion of the brush holder 43 of the eleventh embodiment has a pair of first wall portions 43a and 43b which are parallel to each other and face each other. , 43b, and is formed in a square cylindrical shape from a pair of second wall portions 43c, 43d which are parallel to each other and face each other.

The protruding tips 43a1 and 43b1 protruding toward the commutator 29 are provided at the commutator-side ends of the walls 43a and 43b positioned on the front or rear side in the rotational direction of the commutator 29.
Is extended. The extension of the projecting tips 43a1 and 43b1 is possible because the outer peripheral surface of the commutator 29 is substantially circular, whereby the projecting tips 43a1 and 43b1 approach the outer peripheral surface of the commutator 29. The end edges of the second wall portions 43c and 43d located in the thrust direction of the commutator 29 are formed as concave arcs (see FIG. 23) connecting the protruding ends 43a1 and 43b1.

[0131] The commutator-side tip having the protruding tip 43a1 in the wall 43a located on the side where the spark is generated is used as a fusing body arrangement part 52, and a heat-sensitive fusing body 51 is arranged on the outer surface thereof. ing. The configuration other than the above is the same as in the first embodiment.

In the eleventh embodiment, the protruding tip 4
Since the distance from the commutator 29 is reduced by providing 3a1, when an abnormal spark is generated, its influence is reduced by the protruding tip 43a1.
Can be received promptly. Thereby, the temperature of the heat-sensitive fusing body 51 of the protection switch means 47 can be quickly raised, and the responsiveness of the switch means 47 can be improved.

In the eleventh embodiment, the provision of the protection switch means 47 provides the same operation as in the first embodiment, thereby achieving the intended object of the present invention.

That is, the protection switch means 47 using the brush holder 43 and the terminal fitting 50 as switch contact pieces,
Below a predetermined temperature (the melting point of the heat-sensitive fusing body 51), the heat-sensitive fusing body 51 does not melt, so that a state equivalent to closing the switch is maintained, so that the protection switch means 47 electrically connected to each other can be used. The commutator 29 is electrically connected to a current path flowing through the armature 25 via the brushes 44 and the brushes 44. When the temperature of the protection switch unit 47 becomes equal to or higher than a predetermined temperature, the electrical connection between the brush holder 43 as a switch contact piece and the terminal fitting 50 is cut off by melting of the heat-sensitive fusing body 51, so that the switch is opened. Become.

Thus, the current is cut off in the brush device 41, and the operation of the rotating electric machine (commutator motor 13) including the brush device 41 is stopped.

The spark generating side of the tip of the brush holder 43 is particularly easily affected by the spark generated between the brush 44 and the commutator 29.
It is a place where the temperature rises quickly in the brush device 41, and since the heat-sensitive fusing body 51 is provided in the fusing body mounting portion 52 provided at that position, it is possible to make this fusing body 51 react sharply to abnormal spark. it can.

In addition, the tip of the wall 42a located on the spark generating side of the brush holder 43 has a protruding end 43a1 protruding toward the commutator.
3a1 makes it more susceptible to abnormal sparks,
The temperature of the fusing body arrangement portion 52 in which the protection switch means 47 is arranged can be quickly raised by the abnormal spark. Thereby, the temperature difference of the fusing body arrangement portion 43 can be increased between the time of occurrence of the steady spark and the time of occurrence of the abnormal spark, so that the reliability of the protection operation against the occurrence of the abnormal spark can be improved.

In the eleventh embodiment, since the protruding tip 43b1 is also provided on the wall 43b of the brush holder 43, in addition to the commutator motor 13 rotating only in one direction, the brush holder 43 is rotated forward and backward. Also suitable for use in commutator motors.

FIGS. 26 and 27 show a twelfth embodiment of the present invention. In the twelfth embodiment, instead of omitting the heat resistance means, a means is provided for quickly raising the temperature of the fusing body arrangement portion due to abnormal spark.
Only the configuration of the brush holder and the arrangement of the heat-sensitive fusing body are the first type.
Different from the embodiment. Other configurations are shown in FIG. 26 and FIG.
7 is the same or similar to that of the first embodiment shown in FIGS. 1 to 7 including the parts not shown in FIGS.
7, the same or similar components shown in FIG. 7 are denoted by the same reference numerals as in the first embodiment, and the description of those components and the description of the operation and effect based on them will be omitted. The same or similar parts form part of the apparatus of this embodiment.

As shown in FIG. 27, the cylindrical portion of the brush holder 43 of the twelfth embodiment has a pair of first wall portions 43a and 43b which are parallel to each other and face each other.
a, a pair of second wall portions 43c, 43d which are provided parallel to each other and are opposed to each other, and are formed in a square tubular shape.

The wall 43a located on the front side in the rotation direction of the commutator 29, in other words, on the spark generation side.
A protruding tip 43a1 that protrudes toward the commutator 29 extends from the end of the commutator side. The extension of the protruding tip 43a1 is possible because the outer peripheral surface of the commutator 29 is substantially circular, whereby the protruding tip 43a1 approaches the outer peripheral surface of the commutator 29.

The commutator-side tip having the protruding tip 43a1 in the wall 43a located on the side where the spark is generated is used as a fusing body arrangement part 52, and a heat-sensitive fusing body 51 is arranged on the outer surface thereof. ing. The configuration other than the above is the same as in the first embodiment.

In the twelfth embodiment as well, the provision of the protection switch means 47 achieves the same operation as in the first embodiment, thereby achieving the intended object of the present invention.

Further, in the twelfth embodiment, since the protruding tip 43a1 is provided to reduce the distance from the commutator 29, when an abnormal spark is generated, the influence of the abnormal spark is provided via the protruding tip 43a1. The part 52 can be quickly received, thereby quickly raising the temperature of the heat-sensitive fusing body 51 of the protection switch means 47, and
7 can be made more responsive.

FIGS. 28 to 31 show a thirteenth embodiment of the present invention. The thirteenth embodiment is an example in which the first embodiment and the twelfth embodiment are combined, and is different from the first embodiment only in the configuration of the fusing body arrangement portion of the brush holder. Other configurations are the same or similar to those of the rotary electric machine brush device of the first embodiment shown in FIGS. 1 to 7, including portions not shown in FIGS. 28 to 31. Are replaced with FIGS. 1 to 7 and the same or similar components shown in FIG.
The same reference numerals as those in the embodiment are assigned to the same components, and the description of those components and the description of the operation and effect based on them will be omitted.
These same or similar parts also form part of the apparatus of this embodiment.

In the thirteenth embodiment, the fusing body mounting portion 52 formed on the commutator 29 side of the wall portion 43a located on the spark generating side of the brush holder 43 has a protruding tip protruding toward the commutator 29 side. 52a1 is extended. The extension of the protruding tip 52a1 is possible because the outer peripheral surface of the commutator 29 is substantially circular, whereby the protruding tip 52a1 approaches the outer peripheral surface of the commutator 29. The configuration other than the above is the same as in the first embodiment.

In the thirteenth embodiment, the provision of the protection switch means 47 provides the same operation as in the first embodiment, thereby achieving the intended object of the present invention.

Further, in the thirteenth embodiment, since the protruding tip 52a1 is provided to reduce the distance from the commutator 29, when an abnormal spark is generated, the influence of the spark is disposed via the protruding tip 53a1. The part 52 can be quickly received, thereby quickly raising the temperature of the heat-sensitive fusing body 51 of the protection switch means 47, and
7 can be made more responsive.

FIGS. 32 and 33 show a fourteenth embodiment of the present invention. The fourteenth embodiment is an example in which the first embodiment, the sixth embodiment, and the twelfth embodiment are combined.
Only the structure of the fusing body disposition portion formed at the end of the brush holder on the commutator side is different from that of the first embodiment. 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 7 including portions not shown in FIGS. 32 and 33. Is replaced with FIGS. 1 to 7,
The same or similar components shown in the drawings are denoted by the same reference numerals as in the first embodiment, and the description of those components and the description of the operation and effect based on them will be omitted. Also form a part of the apparatus of this embodiment.

Fused body disposing portion 52 in the fourteenth embodiment
Is formed of a first disposition portion 52a and a second disposition portion 52b which are continuous with two circumferential surfaces of the brush holder 43. The first disposition portion 52a is provided at a commutator side end of the wall portion 43a which is located on the side where a spark is generated when the first disposition portion 52a is rotated.
The arranging portion 52b is connected to one end of the first arranging portion 52a at a right angle, and is provided, for example, at a commutator-side end of a wall portion 43c of the brush holder 43 located on the upstream side in the blowing direction of the electric blower. Therefore, the fusing body arrangement portion 52 has an L-shape.

In the fourteenth embodiment, since the axial direction of the commutator 29 is vertical, the wall 43c is an upper wall, and the inner surface of the commutator 29 is in contact with the upper surface of the brush 44. Therefore, heat conduction from the brush 44 to the wall 43c is impossible.

A gap 53 as a heat resistance means is formed between the inner surface of the fusing body arrangement portion 52 having such a configuration and the brush 44 inserted into the brush holder 43. The heat-sensitive fusing body 5 is provided on the outer surface (upper surface) of the second disposition portion 52b.
1 is provided.

A projecting tip 52b1 projecting toward the commutator 29 is extended from the second disposing portion 52b, and its leading edge is formed in an arc shape as shown in FIG. I have. The extension of the protruding tip 52b1 is possible because the outer peripheral surface of the commutator 29 is substantially circular, whereby the protruding tip 52b1 approaches the outer peripheral surface of the commutator 29.
The configuration other than the above is the same as in the first embodiment.

In the fourteenth embodiment as well, the provision of the protection switch means 47 provides the same operation as in the first embodiment, thereby achieving the intended object of the present invention.

Further, in the fourteenth embodiment, since the fusing body mounting portion 52 is formed of the first mounting portion 52a and the second mounting portion 52b which are continuous in the circumferential direction of the brush holder 43, the brush is provided. The L-shaped gap 53 reduces the contact between the tip of the brush holder 43 and the tip of the brush holder 43, and the temperature of the tip of the brush 44 heated by the generation of the steady spark is transmitted to the tip of the brush holder 43. it can. As a result, the fusing body disposing portion 5 on which the thermal fusing body 51 is disposed
The temperature of the second first disposition portion 52b can be kept lower.

Further, the commutator 2 is provided with the protruding tip 52b1.
When the abnormal spark is generated, the influence of the abnormal spark can be quickly received by the fusing body arrangement portion 52 via the protruding tip 52b1. Thereby, the temperature of the heat-sensitive fusing body 51 of the protection switch means 47 can be quickly raised, and the responsiveness of the switch means 47 can be improved.

The present invention is not limited to the above embodiments. For example, the present invention can be applied to a commutator motor driven by direct current and capable of unidirectional rotation or forward / reverse rotation. Further, in implementing 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. It may be.

[0158]

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, the brush holder and the terminal fitting are connected to the switch connecting piece .
And the heat-sensitive solution provided between these commutator-side ends.
The protection switch means having a disconnection keeps the switch equivalent at a predetermined temperature or lower and the switch is opened at a predetermined temperature or higher, and stops the operation of the rotary electric machine including the brush device. The rotating electric machine can be protected against abnormal overheating of the brush caused by abnormal spark between the child and the brush. 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 reduction in the number of parts , the fusing body arrangement at the commutator side end of the brush holder
Since the temperature difference between the normal spark and the abnormal spark can be increased by the thermal resistance means provided between the installation portion and the brush, 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 second aspect, since the heat resistance means for increasing the temperature difference between the steady spark and the abnormal spark of the protection switch means is an air gap, a simple structure is provided. Thus, the intended object of the present invention can be achieved.

According to the brush device for a rotating electric machine according to the third aspect, the protection switch means can be made to react sharply on the spark generating side which is most susceptible to the influence of the abnormal spark. The intended purpose of the present invention can be achieved by performing a protective operation of the rotating electric machine that quickly copes with the problem.

According to the brush device for a rotating electric machine according to the fourth aspect, the present invention is applied to a rotating electric machine that can be rotated forward and backward. Regardless of the rotating direction, the protection switch means can directly determine the influence of the abnormal spark. To react sharply on the spark generating side, which is more susceptible to noise, to protect the rotating electrical machine, which quickly responds to the temperature rise of the brush, and to increase the temperature difference between the normal spark and the abnormal spark. Thus, the intended object of the present invention can be achieved.

According to the brush device for a rotating electric machine according to the fifth aspect, the protection switch means is most directly influenced by the abnormal spark by the protruding end of the end of the wall located on the spark generating side of the brush holder. To react more sharply on the spark generating side, which is more susceptible to noise
Thus, the intended object of the present invention can be achieved.

[Brief description of the drawings]

FIG. 1 is a side view partially showing a 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 a sectional view around the brush device shown along the line ZZ in FIG. 2;

4 is a front view showing the brush device shown in FIG. 3 as viewed from a commutator side.

FIG. 5 is a perspective view showing a configuration of a brush holder provided in the brush device shown in FIG. 3;

FIG. 6 is a sectional view corresponding to FIG. 3 showing a relationship between the brush device and the commutator when the commutator motor shown in FIG. 2 is operated.

FIG. 7 is a diagram showing a configuration of an electric circuit of the commutator motor shown in FIG. 2;

FIG. 8 is a perspective view showing a partial configuration of a brush holder provided in a brush device according to a second embodiment of the present invention.

FIG. 9 is a perspective view showing a configuration of a part of a brush holder provided in a brush device according to a third embodiment of the present invention.

FIG. 10 is a front view showing a configuration of a brush holder provided in a brush device according to a fourth embodiment of the present invention.

FIG. 11 is a cross-sectional view corresponding to FIG. 3 showing a configuration of a brush device according to a fifth embodiment of the present invention.

12 is a perspective view showing a configuration of a brush holder provided in the brush device shown in FIG.

FIG. 13 is a diagram showing a configuration of an electric circuit of a commutator motor including a brush device according to a fifth embodiment.

FIG. 14 is a cross-sectional view corresponding to FIG. 3 showing a configuration of a brush device according to a sixth embodiment of the present invention.

FIG. 15 is a perspective view showing a configuration of a brush holder provided in the brush device shown in FIG. 14;

FIG. 16 is a sectional view, corresponding to FIG. 3, showing a configuration of a brush device according to a seventh embodiment of the present invention.

FIG. 17 is a perspective view showing a configuration of a brush holder provided in the brush device shown in FIG. 16;

FIG. 18 is a sectional view, corresponding to FIG. 3, showing a configuration of a brush device according to an eighth embodiment of the present invention.

FIG. 19 is a perspective view showing a configuration of a brush holder provided in the brush device shown in FIG. 18;

FIG. 20 is a cross-sectional view corresponding to FIG. 3 showing a configuration of a brush device according to a ninth embodiment of the present invention.

FIG. 21 is a cross-sectional view corresponding to FIG. 3 showing a configuration of a brush device according to a tenth embodiment of the present invention.

FIG. 22 is a side view showing, in partial cross section, a configuration of a commutator motor including a brush device according to an eleventh embodiment of the present invention.

FIG. 23 is a sectional view around the brush device shown in FIG. 22 along the line YY.

24 is a front view showing the brush device shown in FIG. 23 as viewed from the commutator side.

FIG. 25 is a perspective view showing a configuration of a brush holder provided in the brush device shown in FIG. 23;

FIG. 26 is a cross-sectional view corresponding to FIG. 3 showing a configuration of a brush device according to a twelfth embodiment of the present invention.

FIG. 27 is a perspective view showing a configuration of a brush holder provided in the brush device shown in FIG. 26;

FIG. 28 is a side view showing, in partial cross section, a configuration of a commutator motor including a brush device according to a thirteenth embodiment of the present invention.

FIG. 29 is a cross-sectional view around the brush device shown in FIG. 28 along the line XX;

30 is a sectional view showing the configuration of the brush device shown in FIG. 29 in a free state.

FIG. 31A is a plan view showing a configuration of a brush holder provided in the brush device shown in FIG. 29; (B) is a front view which shows the structure of the brush holder with which the brush apparatus shown in FIG. 29 is provided.

FIG. 32 is a sectional view showing a configuration of a brush device according to a fourteenth embodiment of the present invention.

FIG. 33A is a plan view illustrating a configuration of a brush holder provided in the brush device illustrated in FIG. 32; 32B is a front view illustrating a configuration of a brush holder included in the brush device illustrated in FIG. 32.

[Explanation of symbols]

 13 commutator motor, 25 armature, 29 commutator, 31 stator, 41 brush device, 42 holder insulation, 43 brush holder, 43a wall (first wall), 43b wall Part (first wall part), 43c ... wall part (second wall part), 43d ... wall part (second wall part), 43a1, 43b1 ... protruding tip, 44 ... brush, 45 ... pigtail, 46 ... spring, 47 ... Protection switch means, 50 ... Terminal fitting, 51 ... Heat-sensitive fusing body, 52 ... Fusing body disposition part, 52a ... First disposition part, 52b ... Second disposition part, 52c ... Third disposition part, 52d ... 4th disposition part, 52a1 ... protruding tip, 53 ... air gap (heat resistance means), 153 ... heat insulator (heat resistance means).

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H02K 13/00 H02K 11/00

Claims (5)

(57) [Claims] 1. A brush device for a rotating electrical machine, wherein a brush urged by a spring and elastically pressed against a commutator is provided in a cylindrical brush holder fixed to holder insulation, wherein the brush and the brush holder are electrically driven. The brush holder and the brush are electrically connected to each other, and the brush holder and the brush are electrically connected to a current path flowing through an armature by being used together with the brush holder as a switch contact piece and provided near the brush holder. Terminal fitting, the brush holder, and the rectification of the brush holder and the terminal fitting .
And a protection switch means comprising a heat-sensitive fusing member which is provided between the daughter-side end portions and electrically connects them at a predetermined temperature or lower, and cuts and cuts off this connection at a predetermined temperature or higher; and A brush device for a rotating electric machine, wherein a thermal resistance means for making the non-contact portion of the brush and the fusing body disposed at a commutator-side end thereof non-contacting is provided. 2. The brush holder has a pair of first wall portions facing each other, and a pair of second wall portions provided between the wall portions and facing each other. 2. A heat-dissipating member disposed on at least one wall portion, comprising a protrusion protruding outwardly to form a gap between the brush and the brush, and the heat resistance means is formed by the gap. The brush device for a rotating electric machine according to the above. 3. The brush holder according to claim 1, wherein the fusing member is formed on a wall of the brush holder located on a side where a spark generated between the commutator and the brush is generated. A brush device for a rotating electric machine according to item 1. 4. A brush device for a rotary electric machine which is rotatable in forward and reverse directions, wherein a brush which is urged by a spring and elastically pressed against a commutator is provided in a cylindrical brush holder fixed to holder insulation. A holder having a pair of opposed first wall portions and a pair of opposed second wall portions provided between the wall portions, and forming the brush holder and the brush with an electric conductor; A terminal fitting that is electrically connected to the brush holder and the brush, is electrically connected to a current path flowing through an armature by being used as a switch contact piece together with the brush holder, and is provided near the brush holder; Rectification of the brush holder, the brush holder and the terminal fitting
And a protection switch means comprising a heat-sensitive fusing member which is provided between the daughter-side end portions and electrically connects them at a predetermined temperature or lower, and cuts and cuts off this connection at a predetermined temperature or higher; and Rectification of the pair of first wall portions in the brush holder located on the front side and the rear side in the rotation direction of the brush holder
A brush device for a rotating electric machine, characterized in that a fusing body disposition portion is provided at each of the child side end portions , and a thermal resistance means is provided between these disposition portions and the brush to make them non-contact. 5. A brush device for a rotating electrical machine, wherein a brush urged by a spring and elastically pressed against a commutator is provided in a cylindrical brush holder fixed to holder insulation, wherein the brush holders are opposed to each other. A pair of first wall portions and a pair of second wall portions provided between the wall portions and opposed to each other, and on a side where a spark generated between the commutator and the brush is generated. A protruding tip protruding toward the commutator side is extended at a tip of a wall portion of the brush holder to be positioned, and the brush and the brush holder are formed of an electric conductor, and the brush holder and the brush are electrically connected. A terminal fitting provided in the vicinity of the brush holder by being electrically connected to a current path flowing through an armature and used as a switch contact piece together with the brush holder; the brush holder; It has an end provided between the tip portion of the distal end portion and the terminal fitting of the wall of the brush holder that is positioned to the generation side of the spark as well as electrically connecting these at a predetermined temperature or less, the connection And a heat-sensitive fusing body for fusing at a predetermined temperature or higher.