JP3320394B2 - 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. The present invention relates to a rotating electrical machine brush device provided with a protection measure for preventing abnormal overheating.

[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 to operate the brush. A technique for bringing a brush and a commutator into a non-contact state when a situation occurs is disclosed in Japanese Patent Application Laid-Open No. 5-30070.
No. 5, JP-A-2-177282, and the like.

[0007]

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

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

Further, in the technique using a 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 machine for a rotating electrical machine, wherein a brush is urged by a spring into a cylindrical brush holder fixed to holder insulation. A brush device for a rotating electric machine provided with a brush elastically pressed against a commutator, wherein the brush holder and the brush are formed of an electric conductor, and the brush holder and the brush are electrically connected to each other; A terminal fitting which is used as a switch contact piece and is provided near the brush holder while being electrically connected to a current path flowing through the armature; and a predetermined portion between the brush holder, the brush holder and the terminal fitting. A protection switch means is provided which is electrically connected at a temperature lower than the predetermined temperature and is thermally cut at a predetermined temperature or higher. And, at the commutator side end of the brush holder, there is provided heat transfer suppressing means for preventing heat transfer from the commutator side toward the spring side, and the heat transfer suppressing means and the commutator side tip of the brush holder are provided. The heat-sensitive fusible member is disposed in a portion between the conductive members in a thermally conductive manner.

In the construction of the first aspect of the present invention, the protection switch means using the brush holder and the terminal fitting as switch contacts does not melt the heat-sensitive blown body at a predetermined temperature or lower, which is equivalent to closing the switch. Is maintained, the commutator is electrically connected to the current path flowing to the armature via the protection switch means and the brush electrically connected to each other. This protection switch means
When the temperature becomes equal to or higher than the predetermined temperature, the electrical connection between the brush holder as the 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.

The heat transfer suppressing means provided on the brush holder suppresses heat conduction from the commutator side of the brush holder to the spring side due to its thermal resistance. Accordingly, when an abnormal spark occurs, the temperature of the portion between the commutator-side tip of the brush holder heated by the spark and the heat transfer suppressing means can be rapidly increased, so that the heat sensitivity of the protection switch means is reduced. The temperature difference at the portion where the fusing body is disposed in a thermally conductive manner can be increased between the occurrence of a steady spark and the occurrence of an abnormal spark.

Further, in order to easily form the heat transfer suppressing means for achieving the above object, the brush device for a rotating electric machine according to the second aspect of the present invention is configured such that the heat transfer suppressing means is a slit. .

According to the second aspect of the present invention, since the heat transfer suppressing means comprises a slit, the slit can be easily provided by cutting the brush holder.

[0016]

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 vacuum cleaner main body formed by connecting a lower case 1a and an upper case 1b.
A lid 4 that pivots about a pivot portion 2 and opens and closes an upper surface opening of a dust collection chamber 3 formed in the front portion of the cleaner body 1 is attached to a front upper portion of the lower case 1a.

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

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

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

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

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

At the end of the stator 31 located on the bottom side of the frame 21, a winding holder 33 made of synthetic resin for electrical insulation is mounted, and a pair of unshown members 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 has, for example, a melting point.
It is formed of a synthetic resin such as nylon with glass having an electrical insulation of 210 ° C. The holder insulation 42 has a holder insulation main body 42a penetrating the peripheral wall of the frame 21 and a mounting flange 42b. Mounting flange 42
b overlaps the outer peripheral surface of the peripheral wall of the frame 21, and the holder insulation 42 is detachably fixed to the frame 21 by tightening a screw 48 passing therethrough and screwing to the peripheral wall. As shown in FIGS. 3 and 4, the holder insulating body 42a is provided with a terminal mounting hole 49.

The brush holder 43 has a cylindrical shape with one end opened and the other end closed by a bottom wall 43e made of an electric conductor such as a brass or galvanized steel plate or a copper plate. 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 FIG. 5, reference numeral 43f denotes a stopper cut and raised from the brush holder 43 and brought into contact with 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 solidifying it into a prismatic shape is employed. Brush 44
Is provided movably in the axial direction in the brush holder 43 using the holder 43 as a guide. One end of a pigtail 45 is embedded in the brush 44, and these are electrically connected. 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 of the spring 46 causes the brush 44 to protrude from the open end of the brush holder 43. Has been energized. Therefore, in the free state of the brush device 41, the brush 4
When the brush device 41 is fixed to the frame 21, the brush 44 hits the outer circumferential surface of the commutator 29 and is pushed into the brush holder 43 when the brush device 41 is fixed to the frame 21. And is pressed and held against the outer peripheral surface.

The protection switch means 47 includes a part of the brush holder 43, a terminal fitting 50 disposed near the part of the brush holder 43, and a conductive heat-sensitive fusing body 51. The terminal fitting 50 is formed of a spring plate having elasticity, and has a connection portion 50a bent in a substantially rectangular shape. By inserting the connecting portion 50 a into the terminal mounting hole 49, the terminal fitting 50 is attached to the wall 43 of the brush holder 43.
It is arranged near the outside of a.

The connecting portion 50a is elastically and closely contacted with the opposing inner surfaces of the terminal mounting holes 49, and holds the mounting 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 in parallel with 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 rotation direction of the commutator 29 (indicated by an arrow A in FIG. 3), in other words, on the side where the spark generated between the commutator 29 and the brush 44 is generated. The wall to be located. The end of the wall 43a of the brush holder 43 on the commutator side is provided with the wall 43a.
Are formed over the entire width of the slit 55. The slit 55 is formed in the brush holder 4 by the heat resistance of the portion.
3 is a heat transfer suppressing means for preventing heat transfer in the brush holder 43 from the commutator 29 side toward the spring 46 side. It is used as

The disposing portion 52 and the distal end of the terminal fitting 50 are electrically connected to each other via a heat-sensitive fusing body 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 synthetic rubber having conductivity. The melting point of the heat-sensitive fusing body 51 made of solder or the like is lower than the melting point (210 ° C.) of the holder insulation 42, for example, 180 ° C. The heat-sensitive fusing body 51 is solidified below its melting point, and
3 and the terminal fitting 50 are electrically connected, and are melted at a temperature equal to or higher than the melting point and the brush holder 43 and the terminal fitting 50 are melted.
It is provided in order to cut off the electrical connection with the device.

The heat-sensitive fusing body 51 is formed by molding a fixed amount of heat-sensitive fusing material into a predetermined shape in advance, for example, a short cylindrical shape as shown by a two-dot chain line in FIG. Is melted and adhered to the fusing body disposition portion 52 by the pressure contact, and is electrically connected to the disposition portion 52 and fixed thermally.

A terminal fitting 50 is attached to the heat-sensitive fusing body 51.
Are in close contact with each other by the spring force of the metal fitting 50, whereby the heat-sensitive melting body 51 and the terminal metal fitting 50 are electrically connected. Note that the terminal fitting 50 is provided in a free state when the heat-sensitive fusing body 51 is blown, or is 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. 6 is a diagram showing an electric circuit of the commutator motor 13. One of the brush devices 41 pressed against the commutator 29 is connected to one of the stator coils 31 a of the stator 31. 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 a switch contact piece, and a spark generated between the brush 44 and the commutator 29 is formed. It is located on the originating side.

Therefore, below 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 maintained in a pre-formed state, and both switches are connected. The wall 43 of the brush holder 43 forming a piece
b and the terminal fitting 50 are electrically connected. In other words, when the temperature is lower than the predetermined temperature, the protection switch 47
Is maintained in a state equivalent to closing the switch.

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

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

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

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

Due to such a situation, the thermal cutoff 51 of the protection switch means 47 is affected by the thermal influence.
When the temperature becomes equal to or higher than 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. Thus, the current path flowing through the armature 25 in the brush device 41 is cut off, and the operation of the commutator motor 13 can be stopped.

In this case, a slit 55 is provided in the wall 43a to which the heat-sensitive fusing body 51 is fixed.
Since the thermal resistance inside the slit 55 is maximized in the slit 55, when the abnormal spark occurs, the fusing body disposing portion 5
The heat path that is to be conducted from 2 to the spring 46 side is cut off, so that the escape of heat from the fusing body arrangement portion 52 is reduced, and the temperature of the arrangement portion 52 can be quickly increased.

As a result, the temperature difference of the fusing body disposition portion 52 between the occurrence of the steady spark and the occurrence of the abnormal spark, and consequently, the temperature difference of the heat-sensitive fusing member 51 disposed on this disposition portion 52 can be increased. Therefore, the malfunction of the protection switch means 47 performing the protection operation despite the occurrence of the steady spark is prevented, and the protection operation can be performed only when the abnormal spark occurs. Operation reliability can be improved.

Further, since the heat transfer suppressing means for realizing the above operation is formed by the slit 55, the slit 55 can be easily formed simply by performing a cutting process with a cutter such as a circular saw in providing the heat transfer suppressing means. Moreover, slits,
In other words, since the thermal resistance due to the void is large, the temperature of the fusing and disposing portion 52 can be quickly increased.

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

Further, since the heat-sensitive fusing body 51 provided in the protection switch means 47 is formed of a block formed in a predetermined shape by solder or the like, the amount of the solder or the like can be made constant. Accordingly, it is possible to reduce the variation in the temperature at which the heat-sensitive fusing body 51 melts, and to thereby make the protection switch means 47 perform the protection operation with high reliability.

Further, the quantified heat-sensitive fusing body 51 is
Since the outer surface of the wall portion 43a of the brush holder 43 is melt-bonded by pressure contact, the fusing body 51 is
The heat-sensitive fusing body 51 is not fixed in point contact with the wall 3a, and is bonded to the wall 43a on the entire bonding surface. Thereby, the variation of the thermal resistance between the heat-sensitive fusing body 51 and the wall 43a of the brush holder 43 can be reduced.

Therefore, the heat conduction from the brush holder 43 heated by the abnormal spark to the heat-sensitive fusing body 51 becomes smooth, and the variation in the temperature at which the heat-sensitive fusing body 51 blows can be reduced, so that this operation has high reliability. The protection switch means 47 can perform the protection operation.

Also, as described above, since the heat-sensitive fusing member 51 is bonded to the wall 43a of the brush holder 43 on the entire bonding surface instead of the point contact, the contact area between the heat-sensitive fusing member 51 and the brush holder 43 is reduced. It is large, and the contact resistance between them can be reduced. As a result, it is possible to prevent the current from being concentrated on one point when the commutator motor 13 is turned on and off, and thus to eliminate the possibility that the heat-sensitive fusing body 51 is inadvertently blown by the current flowing through the protection switch means 47. be able to.

In addition, the tip side of the brush holder 43 is easily affected by spark generated between the brush 44 and the commutator 29. In addition, the temperature of the spark generating side rises faster than the brush device 41. Location. Then, the heat-sensitive fusing body 5 of the protection switch means 47 is provided at that location.
Since the number 1 is provided, the fusing body 51 can react sharply to the abnormal spark. In addition, since the heat-sensitive fusing body 51 formed of solder or the like has a small heat capacity, it can quickly follow the temperature rise of the brush 44 while having a small number of components and a simple structure. Therefore, the protection switch means 47 can be opened in response to the abnormal temperature rise of the brush 44 quickly.

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 brush switch 41 is quickly turned on by the protection switch means 47. Since the current can be cut off and the further operation of the commutator motor 13 can be stopped, the temperature of the brush 44 does not rise abnormally due to the abnormal spark between the commutator 29 and the brush 44.

As a result, there is no danger that the synthetic resin component forming the binder of the brush 44 will burn and emit smoke or fire. Therefore, the flame of the brush 44 does not spread to the combustible silencer 19 through the outlet 38. In other words, the protection switch means 47 protects the commutator motor 13 and the main body 1 of the cleaner with the protection operation for quickly coping with an abnormal temperature rise of the brush 44, thereby eliminating the risk of burning.

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

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

FIGS. 7 to 9 show a second embodiment of the present invention. The second embodiment is different from the first embodiment only in the structure in which the fusing body is provided 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 6, including portions not shown in FIGS. 21 to 23. 6 are substituted for FIGS. 1 to 6, 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 functions and effects based on them are omitted. However, these same or similar parts also form part of the device of the present embodiment.

In the second embodiment, the brush holder 43
A slit 55 is formed at the end of the commutator side. As shown in FIG. 9, the slit 55 is provided with a first slit 55a provided over substantially the entire width of the wall 43a, and is connected to one end of the slit 55a on the side of the wall 43d. A second slit portion 55b provided over half the width, and a third slit portion 55c provided on the wall portion 43d over the slit portion 55b and the end of the wall portion 43d on the commutator side. I have.

The slit 55 serves as a heat transfer suppressing means for preventing heat transfer of the brush holder 43 from the commutator 29 side to the spring 46 side of the brush holder 43 due to the thermal resistance of the portion. The portion between the commutator-side tip and the commutator-side tip is used as a fusing body disposition portion 52. The disposition portion 52 is connected only to a commutator-side end of the wall portion 43 c of the brush holder 43. On the outer surface of the fusing body disposition portion 52, for example, located on the spark generation side, a heat-sensitive fusing body 51 composed of a block formed in advance using solder or the like is pressed by spot welding or ultrasonic welding or the like. Melt bonded. The configuration other than the above is the same as that of the first embodiment.

In the second embodiment as well, the provision of the protection switch means 47 and the slit 55 provides the same operation as in the first embodiment, thereby achieving the intended object of the present invention.

That is, by providing the slit 55 extending to the wall portions 43a, 43d,
The thermal resistance in d is largest at the slit 55. Therefore, at the time of occurrence of an abnormal spark, the heat path which is to be conducted from the fusing body arrangement part 52 to the spring 46 side is cut off at the wall parts 43a and 43d whose temperature rises under the influence of the spark, and the fusing body arrangement part It is possible to increase the temperature of the disposition portion 52 quickly by reducing the escape of heat from the dispensing portion 52. In this case, since heat conduction is hindered by the two wall portions 43a and 43d, the temperature of the fusing and disposing portion 52 can be increased more quickly.

As a result, the temperature difference of the fusing body disposition portion 52 at the time of occurrence of a steady spark and the occurrence of abnormal spark, and the temperature difference of the heat-sensitive fusing member 51 disposed at this disposition portion 52 can be increased. Therefore, the malfunction of the protection switch means 47 performing the protection operation despite the occurrence of the steady spark is prevented, and the protection operation can be performed only when the abnormal spark occurs. Operation reliability can be improved.

Since the heat transfer suppressing means for realizing the above operation is formed by the slit 55, the slit 55 can be easily formed only by performing a cutting process with a circular saw or the like in providing the heat transfer suppressing means. Moreover, since the thermal resistance due to the slits, in other words, the gaps, is large, the temperature of the fusing and disposing portion 52 can be quickly increased.

Further, since the fusing body arrangement portion 52 of the second embodiment is composed of a part of the wall 43a and a part of the wall 43d, either one of them is selected and the part is selected. The heat-sensitive fusing body 51 can be disposed at the bottom. As described above, the degree of freedom in designing the heat-sensitive fusing body 51 is high.

FIGS. 10 to 12 show a third embodiment of the present invention. The third embodiment is different from the first embodiment only in the structure in which the fusing body is provided 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 6 including portions not shown in FIGS. 6 are substituted for FIGS. 1 to 6, 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 functions and effects based on them are omitted. However, these same or similar parts also form part of the device of the present embodiment.

In the third embodiment, the brush holder 43
A slit 55 is formed at a commutator side end of the wall 43a. As shown in FIG. 12, the slit 55 has a first slit portion 55a provided over substantially the entire width of the wall portion 43d, and is connected to one end of the slit portion 55a on the wall portion 43a side. A second slit portion 55b provided over half the width, and a third slit portion 55c provided on the wall portion 43a over the slit portion 55b and the end of the wall portion 43a on the commutator side. I have.

The slit 55 serves as a heat transfer suppressing means for preventing heat transfer of the brush holder 43 from the commutator 29 side to the spring 46 side of the brush holder 43 due to the thermal resistance of the portion. The portion between the child side tip is used as a fusing body disposition portion 52. The disposition portion 52 is connected to only a commutator-side end of the wall portion 43 b of the brush holder 43. And, this fusing body arrangement part 5
A heat-sensitive fusing body 51 made of a block formed in advance by using solder or the like is melt-bonded to the outer surface of the second member, for example, on the spark generating side by pressure welding such as spot welding or ultrasonic welding. The configuration other than the above is the same as that of the first embodiment.

In the third embodiment, the provision of the protection switch means 47 and the slit 55 provides the same operation as in the first embodiment, thereby achieving the intended object of the present invention.

That is, by providing the slit 55 over the wall portions 43a and 43d,
The thermal resistance in 43d is largest at the slit 55. Therefore, at the time of occurrence of an abnormal spark, the heat path which is to be conducted from the fusing body arrangement part 52 to the spring 46 side is cut off at the wall parts 43a and 43d whose temperature rises under the influence of the spark, and the fusing body arrangement part It is possible to increase the temperature of the disposition portion 52 quickly by reducing the escape of heat from the dispensing portion 52. In this case, the two walls 43a, 43
Since the heat conduction is hindered at d, the temperature of the fusing arrangement portion 52 can be raised more quickly.

As a result, the temperature difference of the fusing body disposition portion 52 between the occurrence of a steady spark and the occurrence of an abnormal spark, and, consequently, the temperature difference of the heat-sensitive fusing member 51 disposed on this disposition portion 52 can be increased. Therefore, the malfunction of the protection switch means 47 performing the protection operation despite the occurrence of the steady spark is prevented, and the protection operation can be performed only when the abnormal spark occurs. Operation reliability can be improved.

Since the heat transfer suppressing means for realizing the above operation is formed by the slit 55, the slit 55 can be easily formed only by performing a cutting process with a cutter such as a circular saw for providing the heat transfer suppressing means. Moreover, slits,
In other words, since the thermal resistance due to the gap is large, the temperature of the fusing and disposing portion 52 can be quickly increased.

Further, since the fusing body arrangement portion 52 of the third embodiment is composed of a part of the wall 43a and a part of the wall 43d, either one of them is selected and the part is selected. The heat-sensitive fusing body 51 can be disposed at the bottom. As described above, the degree of freedom in designing the heat-sensitive fusing body 51 is high.

FIG. 13 and FIG. 14 show a fourth embodiment of the present invention. The fourth embodiment is different from the first embodiment only in the structure in which the heat transfer suppressing means is formed in the brush holder, and other structures are the same as those in FIGS. 6 is the same as or similar to that of the rotary electric machine brush device of the first embodiment shown in FIG.
And the same or similar components shown in the drawings are given the same reference numerals as in the first embodiment.
Although 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 device of the present embodiment.

In the fourth embodiment, the brush holder 43
Is formed of a holder base 61 occupying a large part thereof, and a holder tip 62 welded to the commutator side of the base 61. The holder tip 62 is made of the same or different conductive metal as the holder base 61.

The joint 63 between the holder base 61 and the holder tip 62 forms a heat transfer suppressing means. That is, the holder base 61 and the holder tip 6
2 are welded with their end faces abutting against each other, so that these joint surfaces do not completely contact with each other but are in point contact, so that the joint 63 has a minute gap, The thermal resistance is increased (compared to the case where the brush holder 43 is integrated).

The tip end portion 62 of the holder is used as a fusing body disposition portion. For example, the outer surface of the wall portion 52 located on the spark generating side is formed of a block formed in advance using solder or the like. Is melted and bonded by pressure welding such as spot welding or ultrasonic welding. The configuration other than the above is the same as that of the first embodiment.

Also in the fourth embodiment, by providing the protection switch means 47 and the joint 63, the same effect as in the first embodiment can be obtained, and the intended object of the present invention can be achieved.

FIGS. 15 to 17 show a main part of a fifth embodiment of the present invention. The fifth embodiment is different from the first embodiment only in the structure in which a fusing body arrangement portion is formed on a 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 6, including portions not shown in FIGS. 15 to 17. 6 are substituted for FIGS. 1 to 6, 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 functions and effects based on them are omitted. However, these same or similar parts also form part of the device of the present embodiment.

In the fifth embodiment, the brush holder 43
On the commutator side end of the wall 43a, a concave groove 65 is formed over the entire width of the wall 43a. This concave groove 65
The commutator 2 of the brush holder 43 is
Heat transfer suppressing means for preventing heat transfer of the brush holder 43 from the 9 side to the spring 46 side is formed, and a portion between the brush holder 43 and the commutator-side tip is used as a fusing body disposition portion 52. . A heat-sensitive fusing body 51 made of a block formed in advance using solder or the like is melt-bonded to the outer surface of the disposing portion 52 by pressure welding such as spot welding or ultrasonic welding. The concave groove 65 may be provided continuously or discontinuously along the circumferential direction of the brush holder 43, and may be provided over two or more surfaces of the brush holder 43. The configuration other than the above is the same as that of the first embodiment.

In the fifth embodiment as well, the provision of the protection switch means 47 and the concave groove 65 achieves the same operation as in the first embodiment, thereby achieving the intended object of the present invention.

That is, since the concave groove 65 is provided in the wall 43a, the thermal resistance in the wall 43a is the largest in the concave groove 65. Therefore, when abnormal spark occurs,
In the wall portion 43a whose temperature rises under the influence of the spark, a heat path which is to be conducted from the fusible member disposition portion 52 to the spring 46 side is hindered, and the escape of heat from the fusible member disposition portion 52 is reduced. Thus, the temperature of the disposition portion 52 can be quickly raised.

As a result, the temperature difference of the fusing body disposition portion 52 between the occurrence of a steady spark and the occurrence of an abnormal spark, and consequently, the temperature difference of the heat-sensitive fusing member 51 disposed on this disposition portion 52 can be increased. Therefore, the malfunction of the protection switch means 47 performing the protection operation despite the occurrence of the steady spark is prevented, and the protection operation can be performed only when the abnormal spark occurs. Operation reliability can be improved.

Further, since the heat transfer suppressing means for realizing the above-mentioned action is formed by the groove 65, the groove 65 can be easily formed only by forming a groove with a cutter such as a circular saw when providing the groove.

FIGS. 18 and 19 show a sixth embodiment of the present invention. The sixth embodiment is different from the first embodiment only in the structure in which the fusing body is provided 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 6, including portions not shown in FIGS. 18 and 19. 6 are substituted for FIGS. 1 to 6, 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 functions and effects based on them are omitted. However, these same or similar parts also form part of the device of the present embodiment.

In the sixth embodiment, the brush holder 43
A plurality of small holes 75 are formed at predetermined intervals over the entire width of the wall 43a at the end of the wall 43a on the commutator side. The small hole 75 serves as a heat transfer suppressing means for preventing heat transfer of the brush holder 43 from the commutator 29 side of the brush holder 43 toward the spring 46 due to the thermal resistance of the portion. A portion between the side tip and the end is used as a fusing body disposition portion 52. A heat-sensitive fusing body 51 made of a block formed in advance using solder or the like is melt-bonded to the outer surface of the disposing portion 52 by pressure welding such as spot welding or ultrasonic welding. Multiple small holes 75
May be provided continuously or discontinuously along the circumferential direction of the brush holder 43, and may be provided over two or more surfaces of the brush holder 43. The configuration other than the above is the same as that of the first embodiment.

In the sixth embodiment as well, by providing the protection switch means 47 and the plurality of small holes 75, the same operation as in the first embodiment can be obtained, and the intended object of the present invention can be achieved.

That is, since the plurality of small holes 75 are provided in the wall 43a, the thermal resistance in the wall 43a is greatest at the position where the small holes 75 are provided in a row. Therefore, at the time of occurrence of abnormal spark, the heat path which tends to conduct from the fusing body disposition portion 52 to the spring 46 side is hindered in the wall portion 43a whose temperature rises due to the influence of this spark, and the fusing member disposition portion 52 And the temperature of the disposing portion 52 can be quickly raised.

As a result, the temperature difference between the fusing body disposition portion 52 and the temperature-sensitive fusing member 51 disposed on the disposing portion 52 can be increased between the occurrence of a steady spark and the occurrence of an abnormal spark. Therefore, the malfunction of the protection switch means 47 performing the protection operation despite the occurrence of the steady spark is prevented, and the protection operation can be performed only when the abnormal spark occurs. Operation reliability can be improved.

Further, since the heat transfer suppressing means for realizing the above-mentioned operation is formed by the plurality of small holes 75, the small holes 75 can be easily formed only by performing a drilling process using a drill cutter or the like in providing the small holes 75.

FIGS. 20 to 24 show a seventh embodiment of the present invention. The seventh embodiment is different from the first embodiment in the configuration of a fusing body disposition portion formed in a brush holder, the fixing structure of a heat-sensitive fusing body there, and the like. 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 6, including portions not shown in FIGS. 20 to 24. 6 are substituted for FIGS. 1 to 6, 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 functions and effects based on them are omitted. But
These same or similar parts also form part of the apparatus of the present embodiment.

In the seventh embodiment, the wall 43a of the brush holder 43 located on the front side in the rotation direction of the commutator 29,
In other words, the fusing body disposition portion 52 provided at the commutator-side tip of the wall portion 43a located on the side where the spark generated between the commutator 29 and the brush 44 is generated has the configuration shown in FIGS.
As shown in FIG. 4, the protruding portion forms a step that protrudes outside the brush holder 43 over the entire width of the wall portion 43a. By providing the fusing body arrangement portion 52, a gap 53 as a heat resistance means is formed between the inner surface thereof and the tip of the brush holder 43.

As shown in FIGS. 21 and 24, a protruding tip 52c protruding toward the commutator 29 is extended from the fusing body disposition portion 52. The extension of the protruding tip 52c is possible because the outer peripheral surface of the commutator 29 is substantially circular, whereby the protruding tip 52c approaches the outer peripheral surface of the commutator 29.

As shown by a two-dot chain line in FIG. 24, the heat-sensitive fusing body 51 has a projection 51a integrally at the center of one surface thereof. The heat-sensitive fusing body 51 is fixed by bringing the one surface into close contact with the outer surface of the fusing body disposing portion 52 by passing the protruding portion 51a through a fixing hole provided in the fusing body disposing portion 52 and caulking the protruding portion 51a. Have been. The protrusion 51 a is accommodated in the gap 53 so as not to contact the brush 44 in the brush holder 43. Further, the one surface may be fixed to the outer surface of the fusing body disposition portion 52 by pressing the convex portion 51 a into the fixing hole.

A slit 55 is formed in the wall 43a on the spark generation side of the brush holder 43 over the entire width of the wall 43a. The slit 55 is formed on the wall 43a.
Is provided at a boundary position between the fusing body disposing portion 52 and other portions. This slit 55
Constitutes a heat transfer suppressing means for preventing heat transfer in the brush holder 43 from the commutator 29 side to the spring 46 side of the brush holder 43 due to the thermal resistance of the portion. The configuration other than the above is the same as that of the first embodiment.

Also in the seventh embodiment, the provision of the protection switch means 47 and the slit 55 allows the same operation as in the first embodiment to be obtained, thereby achieving the intended object of the present invention. In the form, the protruding tip 52
c and the gap 53 are superior to the first embodiment in the following points.

That is, the commutator 29 is provided with the protruding tip 52c extending from the fusing body arrangement part 52 and the fusing body arrangement part 52.
When the abnormal spark is generated, the influence can be promptly received through the protruding tip 52c, thereby quickly raising the temperature of the heat-sensitive fusing body 51 of the protection switch means 47. The responsiveness of the switch means 47 can be improved.

Since the fusing body mounting portion 52 is formed so as to protrude outward, so that the mounting portion 52 is not in contact with the brush 44, the commutator 29 is rotated (the direction of the commutator 29 is not shown). 21 is indicated by an arrow A), the brush 44 is slightly inclined with respect to the brush holder 43 based on a clearance between the brush 44 and the brush holder 43. There is no contact, and a gap 53 is secured between the fusing body arrangement portion 52 and the tip of the brush 44.

Due to the thermal resistance, 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 directly conducting heat to the fusing body arrangement portion 52. For this reason, the temperature of the fusing body
4 can be lower. In this way, the fusing body arrangement part 5
Since the gap 53 increases the thermal resistance between the brush 2 and the tip of the brush 44, 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.

Therefore, erroneous operation in which the protection switch means 47 performs the protection operation despite the occurrence of a steady spark is prevented due to a slight variation in the melting characteristics of the heat-sensitive fusing body 51, and an abnormal spark is generated. The protection operation can be performed only when
Can improve the reliability of the protection operation.

Furthermore, since the slit 55 is provided in the wall 43a, the thermal resistance in the wall 43a is the highest in the slit 55. Therefore, when an abnormal spark occurs, the wall portion 4 whose temperature rises under the influence of this spark
In 3a, the heat path that is to be conducted from the fusing body disposition portion 52 to the spring 46 side is cut off, the escape of heat from the fusing body disposition portion 52 is reduced, and the temperature of the disposition portion 52 is quickly increased. Can be raised.

As a result, the temperature difference between the fusing body disposition portion 52 and the temperature-sensitive fusing member 51 disposed on the disposing portion 52 can be increased between the occurrence of a steady spark and the occurrence of an abnormal spark. Therefore, the malfunction of the protection switch means 47 performing the protection operation despite the occurrence of the steady spark is prevented, and the protection operation can be performed only when the abnormal spark occurs. Operation reliability can be improved.

Further, since the heat transfer suppressing means for realizing the above-described operation is formed by the slit 55, the slit 55 can be easily formed only by performing a cutting process with a cutter such as a circular saw when providing the heat transfer suppressing means. And a slit,
In other words, since the thermal resistance due to the gap is large, the temperature of the fusing and disposing portion 52 can be quickly increased.

FIGS. 25 and 26 show an eighth embodiment of the present invention. The eighth embodiment is different from the first embodiment only in the configuration around the fusing body arrangement portion of 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 6, including portions not shown in FIGS. 25 and 26. 6 are substituted for FIGS. 1 to 6, 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 functions and effects based on them are omitted. However, these same or similar parts also form part of the device of the present embodiment.

Fused body disposing portion 52 in the eighth embodiment
Is formed of a first arranging portion 52d and a second arranging portion 52e which are formed on the outer surface of the brush holder 43 and are continuous with two circumferential surfaces of the brush holder 43. The first disposing portion 52d is provided at a commutator-side end of the wall portion 43a located on the side where a spark is generated when the commutator 29 is rotated, and the second disposing portion 52e is provided on the first disposing portion. The brush holder 43 is provided at a commutator-side end of the wall 43c of the brush holder 43 located at an upstream side in the air blowing direction of the electric blower, for example. Therefore, FIG.
As shown in the figure, the fusing body arrangement portion 52 has an L-shape.

In the eighth embodiment, since the axial direction of the commutator 29 is up and down, the wall 43c is the upper wall, and the inner surface of the commutator 29 is in contact with the upper surface of the brush 44. Therefore, heat transfer by heat conduction from the brush 44 to the wall 43c is impossible.

[0110] 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 5 is provided on the outer surface (upper surface) of the second disposition portion 52e.
1 is provided.

Further, as shown in FIGS. 26A and 26B, the brush holder 43 is provided with a slit 55. The slit 55 is formed in the wall 43a on the spark generation side.
A first slit portion 55a extending over the entire width of the wall portion 43a
And a second slit portion 55b connected to the second slit portion 55b over the entire width of the wall portion 43c. First slit portion 55a
Is provided at the boundary position between the first disposing portion 52d and other portions of the wall portion 43a, and similarly, the second
The slit portion 55b is connected to the second mounting portion 5 in the wall portion 43c.
2e and other parts are provided at these boundary positions. The slit 55 serves as a heat transfer suppressing unit for preventing heat transfer in the brush holder 43 from the commutator 29 side to the spring 46 side of the brush holder 43 due to the thermal resistance of the portion. The configuration other than the above is the same as that of the first embodiment.

In the eighth embodiment, the provision of the protection switch means 47 and the slit 55 provides the same operation as that of the first embodiment, thereby achieving the intended object of the present invention. According to the embodiment, the provision of the fusing body arrangement portion 52 having the above-described configuration and the gap 53 is superior to the first embodiment in the following points.

That is, the fusing body mounting portion 52 is connected to the first mounting portion 52 d continuous with the two circumferential surfaces of the brush holder 43 and the second mounting portion 52 d.
Since it is formed from the arrangement portion 52e, the possibility that the temperature of the tip of the brush 44 heated by the occurrence of the steady spark is transmitted to the tip of the brush holder 43 can be reduced. Thereby, the temperature of the second disposing portion 52e of the fusing member disposing portion 52 in which the heat-sensitive fusing member 51 is disposed can be kept low.
However, when an abnormal spark occurs, the fusing body arrangement part 52
As described above, the temperature is increased under the influence of the abnormal spark.

Therefore, it is possible to increase the difference between the temperature when the steady spark is generated and the temperature when the abnormal spark is generated in the second fusing and disposing portion 52e and the heat-sensitive fusing member 51 disposed therein. As a result, malfunction of the protection switch means 47 is prevented, and only when an abnormal spark occurs, the heat-sensitive blower 5
Thus, the protection operation of the protection switch means 47 can be improved.

Since the fusing body mounting portion 52 is formed so as to protrude outward so that the mounting portion 52 is not in contact with the brush 44, the commutator 29 is rotated (the direction thereof is not shown). 25 (indicated by an arrow A in FIG. 25), the brush 44 is slightly inclined with respect to the brush holder 43 based on the clearance between the brush 44 and the brush holder 43. A gap 53 is secured between the first disposition portion 52d and the tip of the brush 44 without contacting the first disposition portion 52d.

Due to the thermal resistance, 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 directly conducting heat to the first disposing portion 52d. For this reason, the temperature of the fusing body
4 can be lower. In this way, the fusing body arrangement part 5
The thermal resistance between the second mounting portion 52e and the outer surface of the second mounting portion 52e, which is thermally conductively connected to the first mounting portion 52d, is increased by increasing the thermal resistance between the second mounting portion 52 and the tip of the brush 44 by the gap 53. The temperature of the fusing body 51 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 fusing body arrangement part 5
2 and the temperature difference between the temperature of the heat-sensitive fusing body 51 and the temperature of the heat-sensitive fusing body 51 when the abnormal spark is generated can be increased.

Therefore, due to a slight variation in the melting characteristics of the heat-sensitive fusing body 51, a malfunction in which the protection switch means 47 performs the protection operation is prevented even when a steady spark is generated, and the occurrence of abnormal spark is prevented. The protection operation can be performed only when
Can improve the reliability of the protection operation.

Further, since the slit 55 is provided over the wall portions 43a and 43c,
The thermal resistance in 3c is largest at the slit 55.
Therefore, at the time of occurrence of abnormal spark, the heat path which is to be conducted from the fusing body arrangement part 52 to the spring 46 side is cut off at the wall parts 43a and 43c whose temperature rises due to the influence of the spark, and the fusing body arrangement part It is possible to increase the temperature of the disposition portion 52 quickly by reducing the escape of heat from the dispensing portion 52.

As a result, the temperature difference of the fusing body arrangement portion 52 between the occurrence of the steady spark and the occurrence of the abnormal spark, and, consequently, the heat-sensitive fusing body 5 arranged in the second installation portion 52
1 can be increased. Therefore, the malfunction of the protection switch means 47 performing the protection operation despite the occurrence of the steady spark is prevented, and the protection operation can be performed only when the abnormal spark occurs. Operation reliability can be improved.

FIGS. 27 to 32 show a ninth embodiment of the present invention. This ninth embodiment is different from the first embodiment in the arrangement of the protection switch means and the structure of the heat-sensitive fusing body, the structure for forming the fusing body arrangement portion, the holder insulation, and the brush. 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 6, including portions not shown in FIGS. 27 to 32. 6 are substituted for FIGS. 1 to 6, 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 functions and effects based on them are omitted. However, these same or similar parts also form part of the device of the present embodiment.

In the ninth embodiment, the brush 44 has, for example, an electric conductor 44a at the center thereof over the entire length in the axial direction. The conductor 44a is made of a material having a lower electric resistance than the carbon powder (such as a material obtained by solidifying a copper powder or a metal powder mainly composed of copper). 13 is provided to realize high input.

The steel plate brush holder 43 containing the brush 44 is attached to the holder mounting hole 42 c of the holder insulation 42.
28 (see FIGS. 30 and 31), which is mounted by press-fitting from the commutator 29 side.
g indicates a retaining piece for retaining. These locking pieces 43a are cut and raised diagonally, and air for cooling the brush 44 can flow into the brush holder 43 through the cut and raised traces. As shown in FIG. 30 and FIG. 31, a plurality of ribs 42d extending in the axial direction are provided on the inner surface of the holder mounting hole 42c in parallel with each other. The brush holder 43 is supported so as to float from the surface. The brush holder 43 is formed by the plurality of ribs 42d.
The resistance at the time of insertion into the holder mounting hole 42c is reduced to facilitate the work.

A slit 55 is provided at the end of the brush holder 43 on the commutator 29 side. As shown in FIG. 44, the slit 55 has a first slit portion 55a provided in a wall (not shown) on the spark generating side over approximately half of the width direction thereof, and a continuous width of the first slit portion 55a. And the second slit 55b provided over the second slit 55b. The first slit 55a is a wall 43a on the spark generation side.
The second slit 55b separates the second arrangement part 52b and other parts of the wall 53c from the first arrangement part 52a and other parts, and is provided at these boundary positions. Is provided. These slit portions 55a and 55b are formed by the thermal resistance of the portions.
Heat transfer suppressing means for preventing heat transfer in the brush holder 43 from the commutator 29 side to the spring 46 side of the brush holder 43 is provided.

The fusing body mounting portion 52 provided at the end of the brush holder 43 on the commutator 29 side is a protruding portion protruding from the outer surface of the brush holder 43 as shown in FIG. A first disposition portion 52d provided at a commutator-side end of a wall portion to be provided and a commutator-side end of a wall portion 43c of a brush holder 43 located on an upstream side in a blowing direction of the electric blower. The second mounting portion 52e is formed. An air gap 53 is provided between the inner surfaces of these arrangement portions 52d and 52e and the brush 44, and a heat-sensitive fusing body 51 is fixed to the outer surface (upper surface) of the second arrangement portion 52e. ing. This fixing is performed by crimping in the present embodiment, but may be fixed by press fitting, spot welding, ultrasonic welding, or the like.

[0125] The heat-sensitive fusing body 51 is formed of solder containing flux. That is, this solder is, for example, an alloy of tin, lead and flux, and the mixing ratio of tin and lead is 60% tin and 40% lead so that the melting temperature is 187 ° C.
In addition, ammonium chloride, zinc chloride and the like are employed as the flux. The flux is mixed in to increase the flowability of the molten solder.

As shown in FIGS. 28 to 31, the main body 42a of the holder insulator 42 is integrally provided with a terminal fitting supporting portion 42c having a fitting mounting surface 42c1 which is flush with the lower surface of the terminal mounting hole 49. Have been. The support portion 42c is provided to extend from the inlet side of the terminal mounting hole 49 to the commutator 29 side, and the locking groove 42c2 is provided on both sides in the width direction.
Is formed, and the lower surface thereof and the metal fitting installation surface 42c1 are on the same plane.

As shown in FIG. 32, the terminal fitting 50 is
Saw-shaped locking projections 50c1 are respectively provided on both side edges in the width direction of the main body 50c having a flat plate shape. The terminal fitting 50 is pressed into the locking groove 42c2 from the commutator 29 side so that the main body 50c is in close contact with the metal fitting surface 42c1 and the terminal end of the main body 50c is inserted in the insertion direction. The connecting portion 50a integrally raised from the portion is inserted into the terminal mounting hole 49 and mounted on the holder insulation 42. From the end of the main body 50c on the commutator 29 side, a fusing body contact portion 50e is integrally provided to protrude. This contact portion 50e
Has a spring property capable of being elastically deformed around its base, and is abutted against the heat-sensitive fusing body 51 in a slightly upwardly elastically deformed state as shown in FIG. Thereby, the fusing body contact portion 50e is elastically in surface contact with the fusing body 51, and closes the current path flowing through the armature 25. The configuration other than the above is the same as that of the first embodiment.

In the ninth embodiment as well, the provision of the protection switch means 47 and the slit 55 provides the same operation as in the first embodiment, thereby achieving the intended object of the present invention.

Moreover, in this case, since the heat-sensitive fusing body 51 made of solder is made of a material containing flux,
The reliability of the protection function by the protection switch means 47 can be further enhanced. That is, the flux mixed in the solder forming the heat-sensitive fusing body 51 has an effect of improving the fluidity when the solder is melted as its characteristic. Therefore, the solder 51 is melted by the protection switch function and the armature 2
5 when cutting (opening) the current path flowing through
1 can be quickly discharged to be discharged from between the fusing body arrangement part 52 of the brush holder 43 and the fusing body contact part 50e of the terminal fitting 51, and the melted solder 51 becomes an icicle-like shape and the fusing body arrangement is performed. It is possible to prevent the setting part 52 and the fusing body contact part 50e from being kept in an electrically connected state forever. Therefore, the current path can be reliably cut off when necessary in the protection switch means 47, and the reliability of the switching operation can be improved.

Further, according to the ninth embodiment, the provision of the fusing body arrangement portion 52, the gap 53, and the slit 55 having the above-described configuration provides the following advantages over the first embodiment. I have.

That is, the fusing body mounting portion 52 is connected to the first mounting portion 52 d continuous with the two circumferential surfaces of the brush holder 43 and the second mounting portion 52 d.
Since it is formed from the arrangement portion 52e, the possibility that the temperature of the tip of the brush 44 heated by the occurrence of the steady spark is transmitted to the tip of the brush holder 43 can be reduced. Thereby, the temperature of the second disposing portion 52e of the fusing member disposing portion 52 in which the heat-sensitive fusing member 51 is disposed can be kept low.
However, when an abnormal spark occurs, the temperature of the second arrangement part 52e of the fusing body arrangement part 52 is increased by the influence of the abnormal spark.

Therefore, it is possible to increase the difference between the temperature at the time of occurrence of the steady spark and the temperature at the time of occurrence of the abnormal spark of the second disposing portion 52e and the thermal fusible member 51 disposed thereon. Thus, malfunction of the protection switch means 47 is prevented, and the protection operation by fusing the heat-sensitive fusing body 51 can be performed only when an abnormal spark occurs, so that the reliability of the protection operation of the protection switch means 47 can be improved.

Since the fusing body mounting portion 52 is formed so as to protrude outward, so that the mounting portion 52 is not in contact with the brush 44, the commutator 29 is rotated (the direction of the commutator 29 is not shown). 28 (indicated by an arrow A in FIG. 28), the brush 44 is slightly inclined with respect to the brush holder 43 based on the clearance between the brush 44 and the brush 44, but the brush 44 is not A gap 53 is secured between the first disposition portion 52d and the tip of the brush 44 without contacting the first disposition portion 52d.

The gap 53 prevents the heat at the tip end of the brush 44, which becomes hot due to the resistance heat generation and the steady spark, from directly conducting heat to the first disposition portion 52d due to its thermal resistance. For this reason, the temperature of the fusing body
4 can be lower. In this way, the fusing body arrangement part 5
The thermal resistance between the second mounting portion 52e and the outer surface of the second mounting portion 52e, which is thermally conductively connected to the first mounting portion 52d, is increased by increasing the thermal resistance between the second mounting portion 52 and the tip of the brush 44 by the gap 53. The temperature of the fusing body 51 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 fusing body arrangement part 5
2 and the temperature difference between the temperature of the heat-sensitive fusing body 51 and the temperature of the heat-sensitive fusing body 51 when the abnormal spark is generated can be increased.

Therefore, due to a slight variation in the melting characteristics of the heat-sensitive fusing body 51, a malfunction in which the protection switch means 47 performs the protection operation even when a steady spark is generated is prevented, and an abnormal spark is generated. The protection operation can be performed only when
Can improve the reliability of the protection operation.

Further, since the slit 55 is provided over the wall portions 43a and 43c,
The thermal resistance in 3c is largest at the slit 55.
Therefore, at the time of occurrence of abnormal spark, the heat path which is to be conducted from the fusing body arrangement part 52 to the spring 46 side is cut off at the wall parts 43a and 43c whose temperature rises due to the influence of the spark, and the fusing body arrangement part It is possible to increase the temperature of the disposition portion 52 quickly by reducing the escape of heat from the dispensing portion 52.

As a result, the temperature difference of the fusing body arrangement portion 52 between the occurrence of a steady spark and the occurrence of an abnormal spark, and, consequently, the heat-sensitive fusing body 5 arranged in the second arrangement portion 52
1 can be increased. Therefore, the malfunction of the protection switch means 47 performing the protection operation despite the occurrence of the steady spark is prevented, and the protection operation can be performed only when the abnormal spark occurs. Operation reliability can be improved.

Note that the present invention is not limited to the above embodiments. For example, the present invention can be applied to a commutator motor driven by AC and capable of rotating forward and reverse, and also to a commutator motor driven by DC and capable of rotating in one direction or rotating forward and reverse. In carrying out the present invention,
The components of each of the above embodiments may be arbitrarily and selectively combined to form a brush device having a function equivalent to or different from that of each of the above embodiments, and this may be a new embodiment.

[0139]

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 protection switch means using the brush holder and the terminal fitting as switch contacts keeps the switch in a state equivalent to closing the switch at a predetermined temperature or lower, and the predetermined temperature. In the above, since the operation of the rotating electric machine including the brush device is stopped with the switch opened, the rotating electric machine is prevented from being overheated due to abnormal temperature rise of the brush due to abnormal spark between the commutator and the brush. Can be protected. In addition, since a temperature sensor and a signal processing circuit that is used in conjunction with the sensor and has a large number of components are not required, the number of components is small and the structure is simple.
In addition, since it does not use a shape memory alloy, it can be provided at low cost, and in combination with the reduction in the number of parts as described above, it is protected by heat transfer suppression means that hinders heat transfer from the commutator side to the spring side that disables the brush. Since the temperature difference in the portion of the switch means where the heat-sensitive fusing body is provided can be increased between the time of the normal spark and the time of the occurrence of the abnormal spark, 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 of the present invention, the heat transfer suppressing means comprising the slit is employed, so that the heat transfer with respect to the brush holder is achieved in order to achieve the intended object of the present invention. The suppression means can be easily provided.

[Brief description of the drawings]

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

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

FIG. 3 is a cross-sectional view around the brush device shown along line XX 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 diagram showing a configuration of an electric circuit of the commutator motor shown in FIG. 2;

FIG. 7 is a cross-sectional view corresponding to FIG. 3 showing a configuration of a brush device according to a second embodiment of the present invention.

FIG. 8 is a front view showing the brush device shown in FIG. 7 as viewed from the commutator side.

FIG. 9 is a perspective view showing a configuration of a brush holder provided in the brush device shown in FIG. 7;

FIG. 10 is a cross-sectional view corresponding to FIG. 3 showing a configuration of a brush device according to a third embodiment of the present invention.

11 is a front view showing the brush device shown in FIG. 10 as viewed from the commutator side.

FIG. 12 is a perspective view showing a configuration of a brush holder provided in the brush device shown in FIG. 10;

FIG. 13 is a cross-sectional view corresponding to FIG. 3 showing a configuration of a brush device according to a fourth embodiment of the present invention.

FIG. 14 is a perspective view showing a configuration of a brush holder provided in the brush device shown in FIG. 13;

FIG. 15 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.

FIG. 16 is an enlarged sectional view showing a W portion in FIG. 15;

FIG. 17 is a perspective view showing a configuration of a brush holder provided in the brush device shown in FIG. 15;

FIG. 18 is a sectional view, corresponding to FIG. 3, showing a configuration of a brush device according to a sixth 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 side view showing a cross section of a configuration of a commutator motor including a brush device according to a seventh embodiment of the present invention;

FIG. 21 is a cross-sectional view around the brush device shown along the line VV in FIG. 20;

FIG. 22 is a front view showing the brush device shown in FIG. 21 viewed from the commutator side.

FIG. 23 is a sectional view showing the configuration of the brush device shown in FIG. 21 in a free state.

FIG. 24 is a perspective view showing a configuration of a brush holder provided in the brush device shown in FIG. 21;

FIG. 25 is a sectional view showing a configuration of a brush device according to an eighth embodiment of the present invention.

26A is a plan view showing a configuration of a brush holder provided in the brush device shown in FIG. 25. FIG. (B) is a side view which shows the structure of the brush holder with which the brush apparatus shown in FIG. 25 is provided. (C) is a front view which shows the structure of the brush holder with which the brush apparatus shown in FIG. 25 is provided.

FIG. 27 is a side view showing, in partial cross section, a configuration of a commutator motor including a brush device according to a ninth embodiment of the present invention.

FIG. 28 is an enlarged cross-sectional view showing the periphery of a brush device according to a ninth embodiment;

FIG. 29 is a plan view showing the configuration of holder insulation provided in the brush device according to the ninth embodiment.

FIG. 30 is a sectional view showing the configuration of holder insulation provided in the brush device according to the ninth embodiment.

FIG. 31 is a front view showing the configuration of holder insulation provided in the brush device according to the ninth embodiment.

FIG. 32 is a plan view showing a configuration of a terminal fitting included in a brush device according to a ninth embodiment.

[Explanation of symbols]

 13 commutator motor, 25 armature, 29 commutator, 31 stator, 41 brush device, 42 holder insulation, 43 brush holder, 44 brush, 45 pigtail, 46 spring, 47 Protection switch means, 50: terminal fittings, 51: heat-sensitive fusing body, 52: fusing body arrangement part, 55: slit (heat transfer suppressing means), 63: joint (heat transfer suppressing means), 65: concave groove (heat) 75: Small holes (heat transfer suppressing means).

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Fumiyoshi Nakazawa 43, Horiyamashita, Hadano-shi, Kanagawa Prefecture Inside the Hadano Plant of Toshiba Tec Corporation (56) References JP-A-2-26253 (JP, A) JP-A Sho51 -129601 (JP, A) JP-A-8-237912 (JP, A) JP-A-8-168212 (JP, A) JP-A-2-136470 (JP, U) (58) Fields investigated (Int. Cl) . ^7, DB name) H02K 13/00 - 13/14 H02K 23/00 - 23/68 H01H 37/76 H01H 69/02 H01H 85/00 - 87/00 H01R 39/00 - 39/64

Claims (2)

(57) [Claims] 1. A brush device for a rotating electric machine, 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. The brush holder and the brush are electrically connected to each other, and the brush holder is used as a switch contact piece together with the brush holder to be electrically connected to a current path flowing through an armature and to be close to the brush holder; And a heat-sensitive fusing body that electrically connects the brush holder and the terminal fitting between the brush holder and the terminal fitting at a predetermined temperature or lower and cuts off the connection at a predetermined temperature or higher. Protection switch means, and prevents heat transfer from the commutator side to the spring side at the commutator side end of the brush holder. A brush for a rotating electrical machine, wherein a heat transfer suppressing means is provided, and the heat-sensitive fusing body is thermally conductively provided at a portion between the heat transfer suppressing means and the end of the brush holder on the commutator side. apparatus. 2. The brush device for a rotating electric machine according to claim 4, wherein said heat and heat transfer suppressing means is a slit.