JPH0919110A - Brush unit for electric rotating machine - Google Patents

Abstract

PURPOSE: To provide an inexpensive brush unit for electric rotating machine in which the electric rotating machine can be protected reliably by preventing the temperature of brush from increasing unduly owing to abnormal spark occurring between the commutator and the brush. CONSTITUTION: The brush unit 41 for electric rotating machine comprises a brush 44 held in a tubular brush holder 43 secured to a holder insulator 42 while being urged by a spring 46 to press the commutator 29 of armature resiliently. A steel spring board 47 deformable freely in the direction approaching the wall part 43c of holder 43 is fixed to the holder insulator 42 while facing the outer surface of the wall part 43c. The spring board 47 is integrally provided with a brush engaging piece 47b projecting toward the wall part 43c. A through hole 43g for passing the engaging piece 47b is made through the wall part 43c while facing the engaging piece 47b and the brush 44. A spacer 48 taking solid state at a specified temperature and holding the spring board 47 while bending in the direction separating from the wall part 43c but being blown out at a specified temperature is interposed between the wall part 43c and the spring board 47.

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

[0002]

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

However, for example, even one armature coil is broken, the commutator is eccentric to prevent the brush from properly contacting the commutator piece, or the brush causes chattering due to brush loss or abnormal wear. Due to the above, when a current suddenly stops flowing during rotation, an abnormal spark is generated between the commutator and the brush. If this abnormal spark goes around the commutator, the brush may be burned.

Therefore, in order to prevent an abnormal decrease in the brush life due to the heat of abnormal sparks, 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 becomes high is disclosed in Japanese Patent Laid-Open No. 5-1.
It is known from Japanese Patent No. 93147.

In addition to the above, in order to prevent abrasion and burnout of the electric motor due to excessive temperature rise of the brush, the temperature of the brush or brush holder is detected using a temperature sensor, and the temperature of the electric motor is detected based on the detected temperature. A technique similar to the above-mentioned publication for stopping rotation is disclosed in JP-A-6-14501 and JP-A-2.
-26253, Japanese Patent Publication No. 61-48359,
And known from JP-A-51-129601.

Further, in order to prevent the abrasion of the brush during the cooling operation, or to prevent the abrasion of the brush due to the excessive temperature rise, a shape memory alloy or a bimetal is used, and the above situation is reached by these operations. At this time, a technique for stopping the operation by placing the brush and the commutator in a non-contact state is disclosed in Japanese Patent Application Laid-Open No. Hei 5
It is known in Japanese Patent Application Laid-Open No. 300705, Japanese Patent Application Laid-Open No. 2-177282, Japanese Patent Publication No. 56-23379, and the like.

[0007]

These various techniques are effective as protection measures for electric motors.

However, the above-mentioned 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 of the entire protection device is large and the cost is high. Moreover, there is a problem that it is difficult to provide a high quality product because the operation reliability of the signal processing circuit is reduced depending on the number of the circuit components and the temperature sensor itself is varied.
Further, since the temperature sensor has an insulating layer such as glass or ceramics and has a considerable heat capacity, it is disadvantageous in quickly following the rapid brush temperature rise caused by the abnormal spark and protecting the electric motor. There is also a problem.

Further, in the technique of using a shape memory alloy instead of the temperature sensor, there is a problem that the shape memory alloy itself is a considerably expensive material, and thus the cost is high. In addition, in the technique of using a bimetal instead of the temperature sensor,
It has a considerable heat capacity and is slow in operation against temperature changes, which is disadvantageous in quickly following the rapid brush temperature rise due to abnormal sparks to protect the motor, and in terms of the reliability of the protection operation. There is also the problem of being inferior.

An object of the present invention is to prevent the temperature of the brush from rising too much due to an abnormal spark generated between the commutator and the brush, and to protect the rotating electric machine with high reliability. To get the equipment.

[0011]

DISCLOSURE OF THE INVENTION The present invention is directed to a rotary electric machine in which a cylindrical brush holder fixed to holder insulation is provided with a brush which is biased by a spring and elastically pressed against a commutator of an armature. Assuming a brush device.

In order to achieve the above object, the invention of claim 1 is characterized in that a spring plate made of a steel plate that faces the outer surface of one side wall of the brush holder and is freely deformed in a direction approaching the one side wall is insulated from the holder. A brush engaging piece that projects toward the one side wall is integrally provided on the spring plate, and an engaging piece through hole that faces the brush engaging piece and the brush and that allows the brush engaging piece to pass therethrough. Is provided on the one side wall,
A thermosensitive fusing spacer, which is solid at a temperature equal to or lower than a predetermined temperature and is bent and held in a direction away from the one side wall, and which melts at a predetermined temperature or more, is provided between the one side wall and the spring plate. Is.

In order to achieve the same object, the invention according to claim 2 is configured to close the current path flowing through the armature at a predetermined temperature or lower, and to melt at a predetermined temperature or higher to cut off the current path. A heat-sensitive melting body is provided, and this melting body is arranged in the vicinity of the commutator and on the spark generation side generated between the brush and the commutator, and the brush and the brush holder are formed of an electric conductor, The brush holder and the brush are electrically connected to each other, and the brush holder and the heat-sensitive melting member are electrically connected to each other.

[0014]

In the invention of claim 1, the heat-sensitive fusing spacer provided between the one side wall of the brush holder and the spring plate is solid at a predetermined temperature or less, and the spring plate is moved away from the one side wall. Since the spring is bent and held, the brush engaging piece of the spring plate is arranged in non-contact with the brush without passing through the engaging piece through hole of the one side wall. As a result, the brush urged by the spring is pressed against the commutator and a current path flowing through the armature is secured, so that the rotary electric machine can be operated in this state.

Further, when an abnormal spark occurs between the brush and the commutator and the heat-sensitive fusing spacer reaches a predetermined temperature or higher, the spacer melts and loses its spacer function. Therefore, the flexed spring plate is freely deformed and rapidly approached to the one side wall side, and at the same time, the brush engaging piece is inserted into the brush holder through the engaging piece through hole of the one side wall. The brush is brought into contact with the brush in a state of pressure contact or bite into the brush, and the brush is stopped. As a result, the brush is separated from the commutator, the current path is cut off, and the operation of the rotating electric machine is stopped.

As described above, based on the free deformation of the spring plate which is evoked at the same time as the heat-sensitive fusion spacer is melted, the current path can be quickly cut to protect the rotating electric machine. And
This protective action utilizes the free deformation that the bent spring plate restores, so the action is agile and reliable. Moreover, since the spring plate is made of spring steel and the heat-sensitive fusing spacer can be formed by solder or the like, it is cheaper than the one using a shape memory alloy or bimetal.

In the second aspect of the present invention, the conductive heat-sensitive melting material that does not melt below a predetermined temperature keeps the current path flowing through the armature closed below a predetermined temperature to operate the rotary electric machine. It is possible.

Further, since the heat-melting / dissipating body is arranged in the vicinity of the commutator and on the spark generation side, it is greatly affected by the heat of the abnormal spark as compared with the case where it is arranged at another position. Therefore, when the heat-melting fuse melts and cuts the current path when the heat-melting fuse has a predetermined temperature or higher due to the occurrence of the abnormal spark, the operation of the rotating electric machine equipped with this brush device is stopped.

As described above, since the heat-sensitive fusing body inserted in the current path flowing through the armature melts and cuts the current path, the rotating electric machine can be protected accordingly, and the operation is reliable and the conductive heat-sensitive Since the fusing body can be formed by a thermal fuse, solder or the like, it is less expensive than one using a shape memory alloy, bimetal or the like.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a side view showing a partial cross-section of the structure of an electric vacuum cleaner. In FIG. 1, reference numeral 1 denotes a cleaner body formed by connecting a lower case 1a and an upper case 1b, and the front of the lower case 1a. A lid 4 is mounted on the upper side of the portion to open and close a top opening of a dust collection chamber 3 formed in the front portion of the cleaner body 1 by rotating around a pivot portion 2.

The cleaner main body 1 is provided with a front wheel 5 and a large-diameter rear wheel 6 which can be swung, and the cleaner main body 1 can be moved by rolling them. The cleaner body 1 is
It is routed through a dust suction hose (not shown) inserted and connected to a suction port (not shown) provided at the front end thereof.

Reference numeral 7 in FIG. 1 designates a suction grid for partitioning the rear end of the dust collecting chamber 3, and a filter 8 is supported on the front surface thereof. The grid 7 supports a dust bag 9 connected to the suction port from the rear side through a filter 8. In addition, 10 in FIG.
Is an exhaust hole.

An electric blower 11 is housed in the cleaner body 1 between the suction grid 7 and the exhaust 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) that is rotated by the commutator motor 13, a fan cover that covers the fan, and a commutation 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 on the blower support walls 14 and 15 of the cleaner body 1 through the first rubber packing 16 in a vibration-proof manner, and the other members of the cleaner body 1 are also provided. The second rubber packing 1 is attached to the blower support wall 17.
It is built in the cleaner body 1 with its axis lined horizontally by being supported in a vibration-proof manner via 8. The arrangement of the electric blower 11 is not limited to the horizontal arrangement. For example, in the case of a pot type electric cleaner, the electric blower 11 is built in the cleaner main body with its axis line vertical. The ring-shaped first rubber packing 16 is fitted and arranged in the peripheral part of the fan cover, and the cap-shaped second rubber packing 18 is fitted and arranged in the rear end of the commutator motor 13. ing. The electric blower 11 sucks the air in the dust collection chamber 3 and discharges it from the commutator motor 13 to the outside.

The vacuum cleaner body 1 accommodates a cylindrical silencer 19 which surrounds the commutator motor 13 once. The muffler 19 is made of a breathable synthetic resin such as urethane foam and is flammable. The air flowing out from the electric blower 11 flows through the muffler 19 in the rear portion of the cleaner body 1, and is discharged from the exhaust hole 10 to the outside of the cleaner body 1.

The structure of the commutator motor 13 will be described with reference to FIG. Reference numeral 21 in FIG. 2 is 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 shape of a strip plate that traverses the opening of the frame 21 in the radial direction, and suction openings are formed 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 rotary shaft 26 of the armature 25 is supported over the bearings 22 and 24, and the centrifugal fan (not shown) is attached to the end of the shaft 26 that penetrates the bearing 24. The armature 25 includes a rotating shaft 26, an armature core 27 fitted and fixed to the rotating shaft 26, an armature coil 28 wound around the core 27, and a fixed commutator 29 fitted to the rotating shaft 26. The terminal portion of the armature coil 28 is connected to a plurality of commutator pieces 29a that are arranged in parallel with each other on the peripheral portion of the commutator 29 in an insulated state.

A plurality of (only one is shown in FIG. 2) outlets 38 are provided in the peripheral portion of the frame 21 on the bottom side. Located between the discharge port 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,
It is provided by press-fitting the four corners into the inner peripheral surface of the frame 21,
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.

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

A pair of brush devices 41 are attached to the peripheral wall of the frame 21 so as to penetrate therethrough in the radial direction. As shown in FIG. 3, these brush devices 41 include holder insulation 42, brush holder 43, brush 44, and
Pigtail 45, coiled spring 46, spring plate 4
7 and a heat-sensitive fusing spacer 48.

More specifically, the holder insulation 42 is made of a synthetic resin such as nylon with glass having an electric insulation property. The holder insulation 42 has a holder insulation main body 42a penetrating the peripheral wall of the frame 21 and a mounting flange 42b. The mounting flange 42b overlaps with the outer 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 49 that penetrates the peripheral wall of the frame 21 and is screwed into the peripheral wall. As shown in FIGS. 3 and 4, holder insulating body 4
2a is provided with a spring mounting hole 50.

The brush holder 43 has a cylindrical shape with one end opened and the other end closed by a bottom wall 43e by an electric conductor such as a brass or galvanized steel plate or a copper plate. As shown in FIG. 5, the brush holder 43
Is a rectangular tube having a pair of flat wall portions 43a, 43b facing each other and a pair of other wall portions 43c, 43d facing each other by connecting the both wall portions 43a, 43b. And a side wall, for example, the wall portion 43c
An engaging piece through hole 43g is formed at the end of the commutator 29 side. The brush 44 housed in the brush holder 43 faces the through hole 43g.

This brush holder 43 has a holder insulation 42.
On the other hand, the commutator 29 is inserted from the side and is attached to the holder insulating member 42 so as to penetrate the holder insulating member 42 so as not to move in the axial direction. The bottom wall 43e side is arranged outside the frame 21. Reference numeral 43f in FIG. 5 is a stopper that is cut and raised from the brush holder 43 and engaged with the holder insulating main body 42a. Further, the brush holder 43 is electrically connected to the connection terminal 34 via a connecting means (not shown).

As the brush 44 made of an electric conductor, a carbon brush in which carbon powder is bound with a binder made of a binder made of synthetic resin and solidified into a prismatic shape is used. Brush 44
Is provided in the brush holder 43 so as to be movable in the axial direction 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.
Thereby, the brush holder 43 and the brush 44 are electrically connected via the pick tail 45.

The spring 46 is housed in the brush holder 43 with its both ends in contact with the brush 44 and the bottom wall 43e. The spring force of this spring 46 causes the brush 44 to project from the open end of the brush holder 43. Is urged by. Therefore, in the free state of the brush device 41, the brush 4 is
4 is projected from the brush holder 43, and when the brush device 41 is fixed to the frame 21, the brush 44 hits the outer peripheral surface of the commutator 29 and is pushed into the brush holder 43 as shown in FIGS. 2 and 3. And is pressed against and held on the outer peripheral surface.

The spring plate 47 is made of spring steel, as shown in FIGS.
As shown in FIG. 5, the connecting portion 4 is bent in a substantially V-shape.
7a, and this connecting portion 47a is attached to the spring mounting hole 5
By being elastically brought into close contact with the inner surfaces of the brush holder 0 facing each other, the side wall of the brush holder 43, for example, the wall portion 43c.
Mounted opposite the outer surface of the. Spring mounting hole 50
The connection terminal 34 inserted in the contact portion is pressed against the connection portion 47a, whereby the spring plate 47 and the connection terminal 34 are electrically connected. The spring plate 47 extends in the longitudinal direction of the wall portion 43c, and is freely deformed in a direction approaching the wall portion 43c side as shown in FIG. 4 in a free state.

At the end of the spring plate 47 on the commutator 29 side, a brush engaging piece 47b protruding toward the wall 43c is cut and raised. The engaging piece 47b is formed in the engaging piece through hole 4
It is provided corresponding to 3 g and can pass through this through hole 43 g as the spring plate 47 is freely deformed. Moreover, the cut-and-raised angle θ of the brush engaging piece 47b is not particularly limited, but in order to give the brush 44 a force for separating the brush 44 from the commutator 29 in accordance with the free deformation. 90 ° or less, particularly preferably 90 °, as shown in FIG. 3 and FIG.

The heat-fusing spacer 48 is sandwiched between the wall portion 43c and the spring plate 47 which face each other, and more preferably between the commutator 29 side tip portions 43c1 and 47c, whereby the spring plate 47 is provided. Against the elastic force of the wall 43
It is bent in a direction away from c (see FIG. 3). The spacer 48 is made of a low melting point metal such as solder (in the present embodiment), or a conductive heat-melting synthetic resin or synthetic rubber, and is solid at a predetermined temperature (melting point) or lower. , The wall portion 43c is blown off at a predetermined temperature or more.
And between the spring plate 47 and the spring plate 47. The melting point of the heat-melting spacer 48 made of solder or the like is lower than the melting point of the holder insulation 42.

Further, the heat-melting spacer 48 is formed by molding a certain amount of heat-melting material in advance into a predetermined shape, such as a short columnar shape. One end surface of the heat-melting spacer 48 is formed by pressure welding such as resistance welding or ultrasonic welding. Part 43c or spring plate 4
7 is melted and adhered to either one of them, and the other end face is a spring plate 4
By the elastic force of 7, the wall portion 43c or the spring plate 47 is pressed against the other.

FIG. 6 is a diagram showing an electric circuit of the commutator motor 13, in which one brush device 41 pressed against the commutator 29 is provided with one stator coil 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 that corresponds to the direction of current passed through the stator coil 31a every half cycle of alternating current.
The magnetic flux direction and the current direction of the armature 25 are switched in correspondence with each other, thereby continuing the rotation of the armature 25 in one direction. The arrow A in FIGS. 3 and 4 indicates the rotation direction of the armature 25.

In the first embodiment having the above structure, the stator coil 31a of the stator 31 of the commutator motor 13 and the brush 44 elastically pressed against the commutator 29 are electrically connected via the pigtail 45 and the like. Connected to each other. Therefore, when the commutator motor 13 is energized, the current supplied from the power supply is passed from the commutator 29 with which the brush 44 is in sliding contact to the armature coil 28 via the brush device 41 on the positive electrode side. Since a current is returned from the commutator 29 to the negative brush device 41, the commutator motor 13 is operated.

Since the centrifugal fan is rotated along with the operation of the commutator motor 13, the blowing operation by the electric blower 11 is carried out. As a result, dust can be sucked into the vacuum cleaner body 1 of the electric vacuum cleaner, and the wind discharged from the centrifugal fan is
Frame 2 through a straightening plate and a suction opening (not shown)
1, the stator 31 in this frame 21 after being introduced into
While passing through the ventilation gap 32 while air-cooling, and further after air-cooling the brush device 41, flows out through the discharge port 30 to the outside of the commutator motor 13. This wind noise is attenuated by passing through the silencer 19 surrounding the commutator motor 13. The air exhausted as described above is exhausted through the exhaust hole 10 of the cleaner body 1. Therefore, it is possible to perform cleaning with the electric vacuum cleaner under the above operating conditions.

During this operation, the short-circuit current flowing through the brush 44 between the adjacent commutator pieces 29a of the commutator 29 is cut off every time the commutator 29 is rectified.
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. In addition, the temperature of the brush 44 rises due to resistance heat generated by energizing the brush 44.
Is transmitted to the brush holder 43.

In such an operation, since the brush 44 sways, the heat transfer to the brush holder 43 is not stable. Further, the wall portion 43c of the brush holder 43 and the tip end side of the spring plate 47, in other words, the area around the heat-sensitive fusion spacer 48 is not properly exposed to the steady spark. Therefore, the temperature rise of the heat-sensitive fusing spacer 48 is not so large, and the temperature of the heat-fusing spacer 48 does not rise to a predetermined temperature (melting point of the heat-fusing spacer 48). Under these conditions, the wall 43c
And heat sensitive fusing spacer 48 provided between the spring plate 47 and the spring plate 47.
Holds a preformed fixed state, the spring plate 47 is maintained in a state of being bent in a direction away from the side wall 43c.

In this state, as shown in FIG. 3, the brush engaging piece 47b of the spring plate 47 does not pass through the engaging piece through hole 43g of the wall portion 43c and is arranged in non-contact with the brush 44. It As a result, the brush 44 biased by the spring 45 can move in the brush holder 43 toward the commutator 29 and is pressed against the commutator 29 to secure the current path flowing through the armature 25. Therefore, the operation of the commutator motor 13 described above is continued.

By the way, for example, the armature coil 28
If even one is broken due to some reason, commutator 2
Since the value of the current cut by the rotation of 9 increases and the current ripple increases remarkably, the generated spark also becomes abnormally large, and naturally, the thermal influence on the peripheral parts such as the brush 44 becomes great.

When an abnormal spark occurs, the temperature of the brush 44 and the heat-sensitive fusing spacer 48 rapidly rises due to the thermal effect thereof. Therefore, when the temperature of the heat-fusing spacer 48 exceeds a predetermined temperature, the heat As the fusing spacer 48 melts, the wall 43c and the spring plate 47
It is immediately leaked from between. As a result, the spacer function of the heat-sensitive fusion spacer 48 is lost.

Then, the bent spring plate 47 is deformed by the elastic force so as to be immediately restored to the free state and rapidly comes close to the wall portion 43c of the brush holder 43. At the same time, the brush engaging piece 47b is also moved. The brush 44 is inserted into the brush holder 43 through the engaging piece through hole 43g, and the tip of the brush 44 is brought into pressure contact with or digs into the brush 44 facing the engaging hole through hole 43g to make the brush 44 stand still.

As a result, the brush engaging piece 4 of the spring plate 47 is
7b serves as a stopper, and the brush 4 is pushed by the spring 45.
4 is prevented from moving toward the commutator 29 side, the commutator 2
Due to the abrasion of the brush 44 caused by the sliding contact with the brush 9, the brush 44 and the commutator 29 are separated at a relatively early stage as shown in FIG. 4, and the current path is disconnected.

In addition, in the present embodiment in which the cut-and-raised angle θ of the brush engaging piece 47d is 90 ° or less, when the brush engaging piece 47b is engaged with the brush 44, as described above,
Since the brush 44 can be forcibly separated from the commutator 29 by applying a force to the spring 4 in the direction of the spring 45, it is more excellent in that the responsiveness of cutting the current path can be made extremely high.

According to the commutator motor 13 having the brush device 41 having the above-described structure, when the brush 44 reaches a predetermined temperature or higher due to the occurrence of abnormal spark, the brush device 41 is operated to move the brush 44 to the commutator. By separating from 29, the current path flowing through the armature 25 can be quickly cut off, and the continuous operation of the commutator motor 13 can be stopped further. Therefore, the abnormal spark between the commutator 29 and the brush 44 causes The temperature of the brush 44 does not rise abnormally.

As a result, there is no risk that the synthetic resin component forming the binder of the brush 44 will burn and cause smoke or ignition. Therefore, the flame of the brush 44 does not spread to the flammable silencer 19 through the discharge port 38. In other words, the commutator motor 13 and the cleaner main body 1 incorporating the commutator motor 13 are prevented from being burnt out by the protective operation that quickly copes with the occurrence of the condition that abnormally raises the temperature of the brush 44 such as the occurrence of abnormal spark. You can

Further, since the above-described protective operation is obtained by the brush device 41 having the above-mentioned configuration, the temperature sensor for obtaining the similar protective operation and the accompanying signal processing circuit having a large number of parts are not required. Therefore, the number of parts is small, the structure is simple, and the device can be operated with high reliability. Moreover, since the heat-sensitive fusion spacer 48 melts at a predetermined temperature and the spring plate 47 is deformed at the same time, that is, the free deformation that the bent spring plate 47 restores is used, the current path is cut off. Agile and certain. Further, the spring plate 4
7 is made of spring steel, and the heat-sensitive fusing spacer 48 can also be formed by solder or the like. Therefore, the brush device 41 can be provided at a lower cost as compared with the one in which the same protection operation is performed using a shape memory alloy, bimetal, or the like. it can.

Further, in this embodiment, the heat-sensitive fusing spacer 4 is used.
Since a block preformed in a predetermined shape is adopted in FIG. 8, the amount of the heat-sensitive fusion spacer 48 can be controlled as compared with the case where solder is placed between the wall portion 43c of the brush holder 43 and the spring plate 47. It can be done easily and surely and mass productivity can be improved. Further, since the amount of solder or the like forming the heat-sensitive fusion spacer 48 can be made constant in this way, the variation in the temperature at which the spacer 48 is fused can be reduced,
Accordingly, the protection operation can be performed with high reliability.

7 to 9 show a second embodiment of the present invention. The second embodiment differs from the first embodiment in the arrangement and mounting structure of the heat-sensitive fusing spacers. Other configurations are the same as or similar to those of the brush device for a rotary electric machine of the first embodiment shown in FIGS. 1 to 6 including parts not shown in FIGS. 7 to 9. 1 to 6 are substituted, 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 explanation of the action and effect based thereon are omitted. However, these same or similar parts also form part of the apparatus of this embodiment.

In the second embodiment, it is located on the front side of the rotation direction of the commutator 29 (indicated by the arrow A in FIG. 7), in other words, on the spark generation side between the commutator 29 and the brush 44. The tip of the commutator side of the wall portion 43a is a spacer arranging portion 51 that is raised over the entire width of the wall portion 43a.
Has made. By providing this arrangement portion 51,
A gap 52 is provided between the back surface and the commutator side end of the brush 44 in order to increase the thermal resistance from the brush 44 to the spacer arranging portion 51. A heat-sensitive fusing spacer 48 is attached to the outer surface of the spacer arrangement portion 51. As shown in FIG. 9, the spacer 48 has a caulking protrusion 48 a, and the protrusion 48 a is fixed to the disposing portion 51 by passing through the hole provided in the spacer disposing portion 51 and caulking. There is.

A heat sensitive piece 51a extending to the commutator 29 side is integrally provided in the spacer arrangement portion 51. This heat sensitive piece 51a is provided on the other wall portions 43b to 43c of the brush holder 43.
Is closer to the commutator 29 than the commutator-side end of the. Further, the wall portion 43a is provided with a slit 53 so as to partition the spacer arrangement portion 51 and the engagement piece through hole 43g. The slit 53 is provided to increase the thermal resistance from the spacer arrangement portion 51 to the engaging piece through hole 43g side, and is formed by a notch provided over the width of the wall portion 43a. With this, engaging piece through hole 43
It is in communication with g. The configuration other than the above points is
This is the same as the first embodiment.

Also in this second embodiment, the engaging piece through hole 4
3 g, the spring plate 47, the brush engaging piece 47 b thereof, and the heat-sensitive fusing spacer 48 are provided in the brush device 41, so that the brush device 41 has the same function as that of the first embodiment, and the desired effect of the present invention can be obtained. Can achieve the purpose.

Moreover, according to the second embodiment, the reliability of the protective operation against the abnormal spark can be further enhanced.

That is, transmission of the temperature of the tip of the brush 44 heated by the steady spark to the spacer disposition portion 51 is prevented by the thermal resistance of the air gap 52, and at the same time from the holder insulation 42 side of the wall 43a. The heat resistance of the slit 53 prevents the heat from being transferred to the spacer arrangement portion 51. Thereby, the temperature of the spacer arranging portion 51 during the normal operation in which the steady spark is generated,
In other words, the temperature of the thermal fusing spacer 48 can be suppressed low. On the other hand, when an abnormal spark occurs, the heat-sensitive piece 51a is directly exposed to this spark (note that the steady-state spark is small compared to this, the heat-sensitive piece 51a is directly exposed to this steady-state spark. The slit 53 can prevent heat from escaping from the spacer 51 to the holder insulation 42 side of the wall 43a when the temperature of the spacer 51 is raised. , The spacer arranging portion 51 more quickly
The temperature of the heat-blown spacer 48 can be raised via the.

Therefore, in the second embodiment, when the abnormal spark is generated, the heat-sensitive fusion spacer 48 is melted more quickly to perform the protection operation, and the reliability of the protection operation can be further enhanced.

FIG. 10 shows a third embodiment of the present invention. The third embodiment differs from the first embodiment in the arrangement and mounting structure of the heat-sensitive fusion spacers. Other configurations are the same as or similar to those of the brush device for a rotary electric machine of the first embodiment shown in FIGS. 1 to 6 including parts not shown in FIG. 10. 6 is used as a substitute, and the same or similar components shown in the drawings are denoted by the same reference numerals as those in the first embodiment, and a description of those components and an explanation of the action and effect based thereon will be omitted. These same or similar parts also form part of the apparatus of this embodiment.

In the third embodiment, it is located on the front side of the rotation direction of the commutator 29 (indicated by the arrow A in FIG. 10), in other words, on the spark generation side between the commutator 29 and the brush 44. The tip of the commutator side of the wall portion 43a is bulged over the width of the wall portion 43a.
It is 1. By providing the disposing portion 51, a gap 52 is provided between the rear surface of the disposing portion 51 and the commutator side end portion of the brush 44 in order to increase the thermal resistance from the brush 44 to the spacer disposing portion 51. A heat-sensitive fusing spacer 48 is attached to the outer surface of the spacer arrangement portion 51. The spacer 48 has a caulking protrusion 48 a.
It is fixed to the disposing portion 51 by passing a through a hole provided in the spacer disposing portion 51 and then caulking it.

A spacer arranging portion 51 is provided on the wall portion 43a.
The slit 53 is provided so as to partition the engaging piece through hole 43g. The slit 53 is formed by the spacer arrangement portion 5
It is provided in order to increase the thermal resistance from 1 to the engaging piece through hole 43g side, and is formed by a notch provided over the full width of the wall portion 43a, and the engaging piece through hole It communicates with 43g.

A heat sensitive piece 47d extending toward the commutator 29 is integrally provided at the tip of the spring plate 47. The heat-sensitive piece 47d is formed on each of the wall portions 43a to 43 of the brush holder 43.
It is closer to the commutator 29 than the commutator-side tip of d.
The structure other than the above points is the same as that of the first embodiment.

Also in this third embodiment, the engaging piece through hole 4
3 g, the spring plate 47, the brush engaging piece 47 b thereof, and the heat-sensitive fusing spacer 48 are provided in the brush device 41, so that the brush device 41 has the same function as that of the first embodiment, and the desired effect of the present invention can be obtained. Can achieve the purpose.

Moreover, according to the third embodiment, the reliability of the protective operation against the abnormal spark can be further enhanced.

That is, the transfer of the temperature of the tip portion of the brush 44 heated by the steady spark to the spacer arranging portion 51 is prevented by the thermal resistance of the void 52, and the holder 43 of the wall portion 43a side is prevented. The heat resistance of the slit 53 prevents the heat from being transferred to the spacer arrangement portion 51. Moreover, the heat-sensitive piece 47d of the spring plate 47
Is farther than the tip of the spacer arranging portion 51 with respect to the spark generation point, the heat-sensitive piece 47d is not exposed to a steady spark, and the spacer arranging portion 51 corresponds to the heat-sensitive piece. Since it has no configuration,
The influence of the steady spark on the arrangement portion 51 is not so great. As a result, the temperature of the spacer arranging portion 51, in other words, the temperature of the heat-sensitive fusing spacer 48 during the normal operation in which the steady spark is generated can be suppressed low. On the other hand, when an abnormal spark occurs, the heat-sensitive piece 47d of the spring plate 47 is directly exposed to this spark to raise the temperature of the spacer arranging portion 51 and the wall portion from the arranging portion 51. Since it is possible to prevent heat from escaping to the holder insulation 42 side of 43a by the slit 53, it is possible to more quickly raise the temperature of the heat-sensitive fusion spacer 48 via the spacer disposition portion 51 when an abnormal spark occurs.

Therefore, in the third embodiment, when the abnormal spark is generated, the heat-sensitive fusion spacer 48 is melted more quickly to perform the protection operation, and the reliability of the protection operation can be further enhanced.

11 and 12 show a fourth embodiment of the present invention. In the fourth embodiment, the structure of the holder insulation, the brush holder, and the abnormal spark protection means is the same as that of the first embodiment.
Different from the configuration of the embodiment, the rest of the configuration is the same as or similar to the brush device for a rotating electric machine of the first embodiment shown in FIGS. 1 to 6 including a portion not shown in FIGS. 11 and 12. 1 to 6 are used for the constitutions not shown, and the same or similar constitutional portions as shown are designated by the same reference numerals as those in the first embodiment to explain the constitutions and The description of the action and effect based thereon is omitted, but these same or similar parts also form a part of the apparatus of this embodiment.

The holder insulation 42 is formed without the structure corresponding to the spring mounting hole of the first embodiment, and the brush holder 43 has the structure corresponding to the engaging piece through hole of the first embodiment. Is formed without. Therefore, in the fourth embodiment, the spring plate having the brush engaging piece and the heat-sensitive fusing spacer used in the first embodiment are not used.

In this fourth embodiment, the holder insulation 4
A conductive heat-sensitive melting body, for example, a thermal fuse 61 is attached to the cylindrical brush holder 43 fixed to 2. The fuse 61 is used in place of the protection means for abnormal sparks, which is provided with the spring plate, the heat-sensitive fusing spacer, and the engaging piece through hole of the first embodiment. The thermal fuse 61 is located in the vicinity of the commutator 29 and includes the brush 44 and the commutator 2.
It is arranged on the side where the sparks generated between 9 and 9 occur. Therefore, in the fourth embodiment, the brush holder 43
A thermal fuse 61 as a conductive heat-sensitive melting member is fixed to the outer surface of the commutator-side tip portion of the wall portion 43a.

The thermal fuse 61 has a stator coil 31a of the stator 31 via an appropriate electrical connecting means (not shown).
The brush holder 43 is electrically connected to the brush holder 43 through an appropriate electrical connecting means (not shown). With this connection, the thermal fuse 6
1 is inserted in the current path flowing through the armature 25. Therefore, the temperature fuse 61 closes the current path at a predetermined temperature or lower, and melts and cuts the current path at a predetermined temperature or higher. The configuration other than the above points is the same as or similar to that of the first embodiment.

In this fourth embodiment, the commutator motor 1
When 3 is operated, a steady spark is generated between the brush 44 and the commutator 29, but since this spark is small, the temperature fuse 61 is not directly affected by the temperature, and the temperature fuse 61 is The temperature is maintained below a predetermined temperature, in other words, below the fusing temperature. As a result, the thermal fuse 61 maintains the closed state of the current path flowing to the armature 23 via the brush holder 43 and the brush 44 electrically connected to the holder 43 via the pigtail 45, so that the rectification is performed. The operation of the child electric motor 13 is continued.

However, if an abnormal spark is generated between the brush 44 and the commutator 29 due to the disconnection of the armature coil 28 or the like, the thermal influence of the abnormal spark is greatly exerted on the thermal fuse 61. In this case, the wall portion 43 of the brush holder 43 located near the commutator 29 and on the spark generation side.
Since the thermal fuse 61 is arranged on the outer surface of the tip portion of a, it is possible to effectively receive the thermal influence of the abnormal spark.

In this way, when the temperature of the thermal fuse 61 rises rapidly and reaches a predetermined temperature, the fuse 61 is melted and the current path flowing through the armature 25 is cut off. As a result, the operation of the commutator motor 13 can be stopped, so that it is possible to prevent the occurrence of abnormal sparks and the burning of the brush 44.

Then, the brush device 41 of the fourth embodiment.
Since the temperature sensor and the signal processing circuit associated therewith are not required, the structure is simple and the reliability of the protection operation described above is high. Since the cost is lower than that of the bimetal, the brush device 41 can be provided at a low cost.

13 and 14 show a fifth embodiment of the present invention. In the fifth embodiment, the structure of the holder insulation, the brush holder, and the abnormal spark protection means is the same as that of the first embodiment.
Different from the configuration of the embodiment, the rest of the configuration is the same as or similar to that of the brush device for a rotary electric machine of the first embodiment shown in FIGS. 1 to 6 including parts not shown in FIGS. 13 and 14. 1 to 6 are used for the constitutions not shown, and the same or similar constitutional portions as shown are designated by the same reference numerals as those in the first embodiment to explain the constitutions and The description of the action and effect based thereon is omitted, but these same or similar parts also form a part of the apparatus of this embodiment.

The holder insulation 42 is formed without the structure corresponding to the spring mounting hole of the first embodiment, and has the heat sensitive body mounting convex portion 42c. The mounting convex portion 42c is parallel to and faces the spark generating side wall portion 43a of the cylindrical brush holder 43 and faces the commutator 29.
It is projected to the side. Further, the brush holder 43 is formed without the structure corresponding to the engaging piece through hole of the first embodiment. Therefore, in the fifth embodiment, the spring plate having the brush engaging piece and the heat-sensitive fusing spacer used in the first embodiment are not used.

In the fifth embodiment, the thermal fuse 61 as a conductive heat-sensitive melting member is attached to the surface of the tip of the heat-sensitive-member mounting convex portion 42c facing the wall portion 43a. The fuse 61 is used in place of the protection means for abnormal sparks, which is provided with the spring plate, the heat-sensitive fusing spacer, and the engaging piece through hole of the first embodiment. Therefore, the thermal fuse 61 is connected to the commutator 29.
Is disposed in the vicinity of and on the spark generation side between the brush 44 and the commutator 29.

The thermal fuse 61 is a stator coil 31a of the stator 31 via an appropriate electrical connecting means (not shown).
The brush holder 43 is electrically connected to the brush holder 43 through an appropriate electrical connecting means (not shown). With this connection, the thermal fuse 6
1 is inserted in the current path flowing through the armature 25. Therefore, the temperature fuse 61 closes the current path at a predetermined temperature or lower, and melts and cuts the current path at a predetermined temperature or higher. The configuration other than the above points is the same as or similar to that of the first embodiment.

Also in the fifth embodiment, in the normal operating state of the commutator motor, the temperature fuse 61 is not directly affected by the steady spark which is smaller than the abnormal spark, and the temperature of the temperature fuse 61 is Since the temperature is maintained below the predetermined temperature, the temperature fuse 61 keeps the current path flowing through the armature 23 closed and the operation of the commutator motor is continued.

However, when an abnormal spark is generated between the brush 44 and the commutator 29, the thermal effect of the abnormal spark occurs on the commutator 2.
The temperature fuse 61 located near the spark generating side in the vicinity of 9 and greatly rises to reach a predetermined temperature.
Is melted and the current path flowing through the armature 25 is cut. Therefore, since the operation of the commutator motor is stopped, it is possible to prevent the occurrence of abnormal sparks and the burning of the brush 44.

Moreover, since the thermal fuse 61 is not in contact with the brush holder 43, it is not affected by the heat of the brush 44, and the temperature difference of the thermal fuse 61 between the steady spark and the abnormal spark can be increased. Thereby,
The reliability that the thermal fuse 61 blows at a predetermined temperature can be improved.

Then, the brush device 41 of the fifth embodiment.
Since the temperature sensor and the signal processing circuit associated therewith are not required, the structure is simple and the reliability of the protection operation described above is high. Since the cost is lower than that of the bimetal, the brush device 41 can be provided at a low cost.

15 to 17 show a sixth embodiment of the present invention. The sixth embodiment is different from the first embodiment in the structure of the holder insulation, the brush holder, the abnormal spark protection means, etc., and the following structure is shown in FIGS.
7 is the same as or similar to that of the brush device for a rotating electric machine of the first embodiment shown in FIGS. 1 to 6 including a portion not shown in FIG.
6 is used as a substitute, and the same or similar constituent parts shown in the figure are designated by the same reference numerals as those in the first embodiment, and a description of those structures and a description of the function and effect based thereon will be omitted. The same or similar parts of the above are also a part of the apparatus of this embodiment.

An electrically insulating winding holder 33 made of synthetic resin is attached to the end of the stator 31 located on the bottom side of the frame 21, and the stator coil 31a supported by this holder 33 is attached to the stator coil 31a. The terminal fitting 71 is connected. The tip of the terminal fitting 71 is near the commutator 29 and the commutator 2
9 and the brush 44 are arranged on the side where sparks are generated.

Next, the brush device 41 will be described.
A pair of brush devices 41 are attached to the peripheral wall of the frame 21 so as to penetrate therethrough in the radial direction. As shown in FIGS. 16 and 17, these brush devices 41 include a holder insulation 42, a brush holder 43, a brush 44, and
It is provided with a pigtail 45, a coil-shaped spring 46, a terminal fitting 72, and a temperature sensor 61 as a conductive heat-sensitive melting member.

More specifically, the holder insulation 42 made of synthetic resin such as glass-filled nylon having electrical insulation has a holder insulation body 42a penetrating the peripheral wall of the frame 21 and a mounting flange 42b. The mounting flange 42b overlaps with the outer 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 49 that penetrates the peripheral wall of the frame 21 and is screwed into the peripheral wall. As shown in FIG. 16, the holder insulating body 42a has a holder mounting hole 7 extending axially therethrough.
3 and a terminal mounting hole 74 are provided.

The brush holder 43 is made of brass, galvanized steel plate, copper plate or the like, and has a pair of flat wall portions 43a and 43b facing each other.
It has a pair of other wall portions 43c and 43d facing each other by connecting between 3a and 43b, respectively, and is formed into a rectangular tube shape with both ends open.

This brush holder 43 has a holder insulation 42.
It is inserted into the holder mounting hole 49 from the commutator 29 side and is mounted on the holder insulation 42 so as not to move in the axial direction. It should be noted that 43f in FIGS. 15 and 17 is cut and raised from the brush holder 43 to remove the holder insulating body 42a.
It is a stopper that is engaged with.

As the brush 44 made of an electric conductor, a carbon brush in which carbon powder is bound with a binder made of a synthetic resin binder to be solidified into a prismatic shape is adopted. Brush 44
Is provided in the brush holder 43 so as to be movable in the axial direction using the holder 43 as a guide. One end of a pigtail 45 is embedded in the brush 44, and these are electrically connected.

As shown in FIG. 16, the terminal fitting 72 is
The commutator 2 is inserted into the terminal mounting hole 74 of the holder insulating main body 42a.
It is attached by inserting it through an opening on the side opposite to 9. The terminal fitting 72 has a receiving portion 75 arranged to close an opening of the holder mounting hole 73 located outside the frame 21, and the terminal fitting 72 is bent from the receiving portion 75.
4 and the terminal main part 76 which penetrates. In FIG. 16, reference numerals 76a and 76b denote the first pressure contact portion and the second pressure contact portion that are in pressure contact with the inner surface of the terminal mounting hole 74 due to the spring property of the terminal main portion 76, and 76c is the commutator side of the holder insulating main body 42a. It is a cut and raised stopper tongue that is hooked on the end face,
As a result, the state in which the terminal fitting 72 is inserted into the holder insulation 42 is maintained.

The other end of the pigtail 45 is fixed to the receiving portion 75 by spot welding or the like, and the brush holder 43 and the brush 44 are electrically connected via the picktail 45.

Both ends of the spring 46 are in contact with the brush 44 and the receiving portion 75 and are housed in the brush holder 43.
The spring force of the spring 46 causes the brush 44 to move the brush 44 to the brush holder 43.
Is biased to project from the open end of the. Therefore, in the free state of the brush device 41, most of the brushes 44 are projected from the brush holder 43, and the brush device 4
When 1 is fixed to the frame 21, the brush 44 hits the outer peripheral surface of the commutator 29 and is pushed into the brush holder 43 as shown in FIG. 16, and is elastically pressed and held on the outer peripheral surface.

As described above, the terminal fitting 72 electrically connected to the brush 44 has a tip portion of the terminal main portion 76 opposite to the receiving portion 75 in the vicinity of the commutator 29 and the commutator 29. It is arranged and provided on the side where the spark generated between the brush 44 and the brush 44 occurs. A thermal fuse 61 is attached to this tip. This thermal fuse 61
Is electrically connected to the terminal metal fitting 72, and also comes into contact with the tip of the terminal metal fitting 71.
1 electrically.

Due to these electrical connections, the thermal fuse 61 is inserted in the current path flowing through the armature 25. Therefore, the temperature fuse 61 closes the current path at a predetermined temperature or lower, and melts and cuts the current path at a predetermined temperature or higher. The configuration other than the above points is the same as or similar to that of the first embodiment.

In the sixth embodiment having the above-described structure, the stator coil 31a of the stator 31 of the commutator motor 13 and the brush 44 elastically pressed against the commutator 29 are connected to the pigtail 45, the terminal fitting 72, The temperature fuse 61 is electrically connected via the temperature fuse 61 and the terminal metal fitting 71, and the temperature fuse 61 is located in the vicinity of the commutator 29, and the sparks generated between the brush 44 and the commutator 29. It is located on the generation side.

Therefore, below the predetermined temperature (melting point of the thermal fuse 61), the thermal fuse 61 closes the current path flowing through the armature 13. Thereby, the commutator motor 1
When the current is supplied to the armature 3, the current supplied from the power supply is passed through the brush device 41 on the positive electrode side from the commutator 29 with which the brush 44 is in sliding contact to the armature coil 28, so that the commutator 29 Since the current is returned from the negative side brush device 41 to the negative side brush device 41, the commutator motor 13 is operated.

During this operation, the short-circuit current flowing through the brush 44 between the adjacent commutator pieces 29a of the commutator 29 is cut off each time the commutation is performed, so that the brush 44 is removed each time.
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. The temperature of the brush 44 also rises due to resistance heat generated by energizing it.

Due to such temperature rise, the temperature of the brush 44 is transmitted to the brush holder 43 with which the brush 44 is in contact. However, the terminal fitting 34 electrically connected to the brush 44 is
The heat of the brush 44 and the brush holder 43 is transferred to the terminal fitting 72 because it is thermally insulated by a (the partition portion 42d that partitions the holder mounting hole 73 and the terminal mounting hole 74 of the main body 42a is thermally insulated). It is prevented from being transmitted. Moreover, since the thermal fuse 61 is not in contact with the brush holder 43, the thermal fuse 61 is not affected by the heat of the brush 44, and the steady-state spark is properly applied to the point where the steady-state spark occurs (the point where the short-circuit current is cut off). Because they are placed so that they are not exposed to
The temperature rise of the fuse 61 does not become so large. Therefore, the temperature difference of the thermal fuse 61 between the steady spark and the abnormal spark can be increased, and
The reliability that the thermal fuse 61 blows at a predetermined temperature can be improved.

By the way, for example, the armature coil 28
If even one is broken due to some reason, commutator 2
Since the value of the current cut by the rotation of 9 increases and the current ripple increases remarkably, the spark that occurs is also greatly abnormally generated, and of course, the thermal influence on the peripheral parts such as the brush 44 becomes great.

Due to such a situation, the thermal fuse 61 located closest to the commutator 29 on the spark generation side, which is the place where the temperature rises the fastest in the brush device 41, extends along the outer peripheral surface of the commutator 29. Effectively exposed to an abnormal spark that greatly extends to the temperature, the temperature rises rapidly.

As a result, when the temperature of the thermal fuse 61 exceeds the predetermined temperature, it melts, so that the electrical connection between the terminal fittings 71 and 72 is cut off. In other words, the current path flowing through the armature 25 is cut in the thermal fuse 61, so to speak, the switch is opened.

As described above, with the occurrence of abnormal sparks,
Due to this spark, the current path flowing through the armature 25 can be quickly cut by the temperature fuse 61, and the continuous operation of the commutator motor 13 can be stopped further. Therefore, the abnormal spark between the commutator 29 and the brush 44 is caused. As a brush 44
The temperature will not rise abnormally and will not burn.

Further, in the brush device 41 of the sixth embodiment, since the temperature sensor and the signal processing circuit associated therewith are unnecessary, the structure is simple and the protection operation described above is highly reliable, and Since the thermal fuse 61 as the heat-sensitive melting body is lower in cost than the shape memory alloy or the bimetal, the brush device 41 can be provided at low cost.

FIG. 18 shows a seventh embodiment of the present invention. In the seventh embodiment, the structure of the tip portion of the brush holder is different from the structure of the sixth embodiment, and the structure thereafter is shown in FIGS. 15 to 17 including the part not shown in FIG. Since the brush device for a rotary electric machine according to the sixth embodiment has the same or similar configuration, the configuration not shown is substituted by FIGS. 1 to 6 and FIGS. 15 to 17, and the same or similar components shown in FIG. Is the sixth
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 seventh embodiment, it is located on the front side of the rotation direction of the commutator 29 (indicated by the arrow A in FIG. 10), in other words, on the spark generation side between the commutator 29 and the brush 44. The tip of the wall 43a on the commutator side is provided with a heat-sensitive body arranging portion 55 which is raised over the entire width of the wall 43a.
Has made. By providing this arrangement portion 55,
A gap 56 is provided between the back surface of the brush 44 and the commutator side end of the brush 44 to increase the thermal resistance from the brush 44 to the heat-sensitive material arranging portion 55. On the outer surface of the heat sensitive body arranging portion 55, a thermal fuse 61 as a heat sensitive blower is attached.
The fuse 61 is electrically connected to the terminal fittings 71 and 72, respectively, and is inserted in the current path flowing through the armature.

The wall portion 43a is provided with a slit 57 for separating the heat-sensitive material mounting portion 55 from the wall portion 43a. The slit 57 is provided in order to increase the thermal resistance from the heat-sensitive material arranging portion 55 to the holder insulation 42 side of the wall portion 43a, and is formed by a notch provided over the width of the wall portion 43a. ing.

Further, a heat-sensitive piece 55a extending toward the commutator 29 side is integrally provided at the tip of the heat-sensitive member arranging portion 55. The heat-sensitive piece 55a is formed on each wall 43 of the brush holder 43.
It is closer to the commutator 29 than the commutator-side tips of b to 43d. The configuration other than the above points is the same as that of the sixth embodiment.

Also in the seventh embodiment, the temperature fuse 61 inserted in the current path flowing through the armature is connected to the commutator 29.
Since it is provided in the vicinity of and on the spark generation side, the same operation as that of the sixth embodiment can be obtained, and the intended object of the present invention can be achieved.

Moreover, according to the seventh embodiment, the reliability of the protective operation against the abnormal spark can be further enhanced.

That is, the transfer of the temperature of the tip of the brush 44 heated by the steady spark to the heat-sensitive body arranging portion 55 is prevented by the thermal resistance of the void 56, and the holder insulation 42 side of the wall portion 43a is prevented. From heat sensitive body arrangement part 5
The heat resistance of the slit 57 prevents the heat from being transferred to 5. As a result, the temperature of the heat-sensitive material arranging section 55 and the temperature fuse 61 supported by the heat-sensitive element arranging section 55 can be suppressed to a low level during normal operation in which a steady spark is generated. On the other hand, if an abnormal spark occurs, the heat-sensitive piece 55a of the heat-sensitive material arranging portion 55 is directly exposed to this spark to raise the temperature of the heat-sensitive material arranging portion 55, Since the slit 57 can prevent heat from escaping from the wall portion 55 to the holder insulation 42 side of the wall portion 43a, the temperature of the thermal fuse 61 can be raised more quickly through the heat sensitive body mounting portion 55 when an abnormal spark occurs. it can.

Therefore, in the seventh embodiment, when the abnormal spark occurs, the temperature fuse 61 is blown more quickly to perform the protection operation, and the reliability of the protection operation can be further enhanced.

FIG. 19 shows an eighth embodiment of the present invention. In the eighth embodiment, the structure around the tip of the brush holder is different from the structure of the sixth embodiment, and the structure thereafter is shown in FIGS. 15 to 17 including parts not shown in FIG. Since the brush device for a rotary electric machine according to the sixth embodiment has the same or similar configuration, the configuration not shown is substituted with FIGS. 1 to 6 and FIGS. 15 to 17, and the same or similar components shown in the diagram are used. Are denoted by the same reference numerals as in the sixth embodiment, and a description of their configuration and a description of the action and effect based thereon will be omitted. However, for these same or similar parts, a part of the device of the present embodiment will be omitted. It is an eggplant.

In the eighth embodiment, it is located on the front side of the rotation direction of the commutator 29 (indicated by the arrow A in FIG. 10), in other words, on the spark generation side between the commutator 29 and the brush 44. The tip of the wall 43a on the commutator side is provided with a heat-sensitive body arranging portion 55 which is raised over the entire width of the wall 43a.
Has made. By providing this arrangement portion 55,
A gap 56 is provided between the back surface of the brush 44 and the commutator side end of the brush 44 to increase the thermal resistance from the brush 44 to the heat-sensitive material arranging portion 55.

Terminal fittings 72 are provided on the outer surface of the heat-sensitive material mounting portion 55.
The commutator side end portions of the two are superposed in surface contact with each other, and a thermal fuse 61 as a heat-sensitive fusing body is attached to this front end portion. The fuse 61 is electrically connected to the terminal fittings 71 and 72, respectively, and is inserted in the current path flowing through the armature.

The wall portion 43a is provided with a slit 57 for separating the heat sensitive body mounting portion 55 from the wall portion 43a. The slit 57 is provided in order to increase the thermal resistance from the heat-sensitive material arranging portion 55 to the holder insulation 42 side of the wall portion 43a, and is formed by a notch provided over the width of the wall portion 43a. ing.

Further, a heat-sensitive piece 72a extending toward the commutator 29 is integrally provided at the commutator-side end of the terminal fitting 72. The heat-sensitive piece 72a is closer to the commutator 29 than the commutator-side tips of the wall portions 43b to 43d of the brush holder 43. The configuration other than the above points is the same as that of the sixth embodiment.

Also in the eighth embodiment, the temperature fuse 61 inserted in the current path flowing through the armature is connected to the commutator 29.
Since it is provided in the vicinity of and on the spark generation side, the same operation as that of the sixth embodiment can be obtained, and the intended object of the present invention can be achieved.

Moreover, according to the eighth embodiment, the reliability of the protective operation against the abnormal spark can be further enhanced.

That is, the transfer of the temperature of the tip end portion of the brush 44 heated by the steady spark to the heat-sensitive material arranging portion 55 is prevented by the thermal resistance of the void 56, and the holder insulation 42 side of the wall portion 43a is prevented. From heat sensitive body arrangement part 5
The heat resistance of the slit 57 prevents the heat from being transferred to 5. As a result, the temperature of the thermal fuse 61 can be suppressed low during normal operation in which steady sparks are generated. On the other hand, if an abnormal spark occurs,
The heat-sensitive material arranging portion 55 and the heat-sensitive piece 72a are directly exposed to this spark to raise the temperature of the heat-sensitive material arranging portion 55, and the holder insulation 42 of the wall portion 43a is provided from the heat radiating portion 55.
Since the slit 57 can prevent heat from escaping to the side,
When an abnormal spark occurs, the heat-sensing body arranging portion 55 can be more quickly provided.
The temperature of the thermal fuse 61 can be raised via the.

Therefore, in the eighth embodiment, when the abnormal spark occurs, the temperature fuse 61 is blown more quickly to perform the protection operation, and the reliability of the protection operation can be further enhanced.

FIG. 20 shows a ninth embodiment of the present invention. In the ninth embodiment, the structure around the tip of the brush holder is different from the structure of the sixth embodiment, and the structure thereafter is shown in FIGS. 15 to 17 including a part not shown in FIG. Since the brush device for a rotary electric machine according to the sixth embodiment has the same or similar configuration, the configuration not shown is substituted with FIGS. 1 to 6 and FIGS. 15 to 17, and the same or similar components shown in the diagram are used. Are denoted by the same reference numerals as in the sixth embodiment, and a description of their configuration and a description of the action and effect based thereon will be omitted. However, for these same or similar parts, a part of the device of the present embodiment will be omitted. It is an eggplant.

In the ninth embodiment, the front side of the commutator 29 in the direction of rotation (indicated by arrow A), in other words, the commutator 29.
The tip of the commutator side of the wall portion 43a positioned on the spark generation side between the brush 44 and the brush 44 is
The heat sensitive body arranging portion 55 is largely bulged over the entire width of the heat sensitive body arranging portion. By providing the disposing portion 55, the brush 4 is provided between the rear surface of the disposing portion 55 and the commutator side end portion of the brush 44.
A void 56 is provided in order to increase the thermal resistance from No. 4 to the heat sensitive body disposition portion 55.

Terminal fittings 71 are provided on the inner surface of the heat-sensitive material mounting portion 55.
The commutator-side tips of the are stacked in surface contact. Further, inside the heat sensitive body arranging portion 55, a thermal fuse 61 as a heat sensitive melting body attached to the tip of the terminal fitting 72.
Is arranged in contact with the commutator-side tip portion of the terminal fitting 72. The fuse 61 is electrically connected to the terminal fittings 71 and 72, respectively, and is inserted in the current path flowing through the armature.

The wall portion 43a is provided with a slit 57 for separating the heat-sensitive material mounting portion 55 from the wall portion 43a. The slit 57 is provided in order to increase the thermal resistance from the heat-sensitive material arranging portion 55 to the holder insulation 42 side of the wall portion 43a, and is formed by a notch provided over the width of the wall portion 43a. ing. The configuration other than the above points is the same as that of the sixth embodiment.

Also in the ninth embodiment, the temperature fuse 61 inserted in the current path flowing through the armature is connected to the commutator 29.
Since it is provided in the vicinity of and on the spark generation side, the same operation as that of the sixth embodiment can be obtained, and the intended object of the present invention can be achieved.

The present invention is not limited to the above embodiments. For example, in each of the first to third embodiments, the stator coil 31a and a metal component such as a terminal fitting electrically connected to the brush holder 43 or the pick tail 45 are connected via an electrical connection component such as a lead wire. In the case of electrical connection by means of a heat-sensitive melting material, a material having no electrical conductivity can be used as the heat-sensitive melting material. Further, in the heat-sensitive melting member used in each of the fourth to ninth embodiments, conductive solder may be used instead of the thermal fuse.

[0130]

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

According to the rotating electrical machine brush device of the first aspect, the brush is stopped based on the free deformation of the spring plate that is evoked at the same time as the heat-sensitive fusing spacer melts due to an abnormal temperature, and the current path is quickly cut off. Thus, the rotating electric machine can be protected against excessive temperature rise of the brush, and the free deformation that the bent spring plate restores is used to make the brush stand still, so the operation is agile and reliable. Moreover, since the temperature sensor and the signal processing circuit used in connection with it and having a large number of parts are not required, the number of parts is small and the structure is simple, and the spring plate is made of spring steel, and the heat-sensitive fusion spacer is also used. Since it can be formed of solder or the like, it is less expensive than one using a temperature sensor, shape memory alloy, bimetal, or the like.

According to the brush device for a rotating electric machine of the second aspect, since the conductive heat-sensitive fusing body inserted in the current path flowing through the armature melts due to an abnormal temperature and cuts the current path,
The rotating electric machine can be protected against excessive temperature of the brush. Moreover, since the temperature sensor and the signal processing circuit used in connection with it and having a large number of parts are not required, the number of parts is small and the structure is simple, and the spring plate is made of spring steel, and the heat-sensitive fusion spacer is also used. Since it can be formed of solder or the like, it is less expensive than one using a temperature sensor, shape memory alloy, bimetal, or the like.

[Brief description of the drawings]

FIG. 1 is a side view showing a partial cross-section of a configuration of an electric vacuum cleaner including 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 an electric blower included in the electric vacuum cleaner shown in FIG.

FIG. 3 is a cross-sectional view showing a configuration around a brush device included in the commutator motor shown in FIG. 2 in a state before the heat-sensitive fusing spacer is melted.

FIG. 4 is a cross-sectional view showing a configuration around a brush device included in the commutator motor shown in FIG. 2 in a state after the heat-sensitive fusing spacer has melted.

5 is an exploded perspective view showing a configuration of a main part of the brush device shown in FIG.

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

FIG. 7 is a sectional view showing a structure around a brush device according to a second embodiment of the present invention.

FIG. 8 is a front view showing the configuration of the brush device according to the second embodiment as viewed from the commutator side.

FIG. 9 is a perspective view showing an exploded configuration of a main part of a brush device according to a second embodiment.

FIG. 10 is a sectional view showing a structure around a brush device according to a third embodiment of the present invention.

FIG. 11 is a side view showing the configuration of a commutator motor provided with a brush device according to a fourth embodiment of the present invention in a partial cross section.

FIG. 12 is a cross-sectional view around the brush device, which is taken along line ZZ in FIG.

FIG. 13 is a cross-sectional view corresponding to FIG. 12, showing a configuration around a brush device according to a fifth embodiment of the present invention.

FIG. 14 is a front view showing the brush device shown in FIG. 13 as viewed from the commutator side.

FIG. 15 is a side view showing the configuration of a commutator motor including a brush device according to a sixth embodiment of the present invention in a partial cross section.

16 is a cross-sectional view around the brush device, which is taken along line YY in FIG.

FIG. 17 is a front view showing the brush device shown in FIG. 16 as viewed from the commutator side.

FIG. 18 is a cross-sectional view corresponding to FIG. 12, showing a configuration around a brush device according to a seventh embodiment of the present invention.

FIG. 19 is a cross-sectional view corresponding to FIG. 12, showing a configuration around a brush device according to an eighth embodiment of the present invention.

FIG. 20 is a cross-sectional view corresponding to FIG. 12, showing a configuration around a brush device according to a ninth embodiment of the present invention.

[Explanation of reference numerals] 13 ... commutator motor, 25 ... armature, 29 ... commutator, 31 ... stator, 31a ... stator coil, 41 ... brush device, 42 ... holder insulation, 43 ... brush holder, 43a ... spark Wall part (one side wall) of the brush holder located on the generation side, 43c ... Wall part (one side wall) of the brush holder, 43g ... Engaging piece through hole, 44 ... Brush, 45 ... Pigtail, 46 ... Spring, 47 ... Spring plate, 47b ... Brush engaging piece, 48 ... Thermal fusing spacer, 61 ... Thermal fuse (thermal fusing body), 71 ... Terminal fitting, 72 ... Terminal fitting.

Claims (2)

[Claims] 1. A brush device for a rotary electric machine, comprising a cylindrical brush holder fixed to holder insulation, and a brush urged by a spring to elastically press against a commutator of an armature. A spring plate made of a steel plate, which is free to deform in a direction approaching the one side wall, is attached to the holder insulation, facing the outer surface of the one side wall, and a brush engaging piece protruding toward the one side wall is integrally provided on the spring plate. An engaging piece through hole that faces the brush engaging piece and the brush and through which the brush engaging piece can pass is provided on the one side wall, and is solid at a predetermined temperature or less and keeps the spring plate away from the one side wall. A brush device for a rotating electric machine, characterized in that a heat-sensitive fusing spacer that bends and holds in a direction and is fused at a predetermined temperature or more is provided between the one side wall and the spring plate. 2. A brush device for a rotating electric machine, comprising a cylindrical brush holder fixed to a holder insulation and provided with a brush biased by a spring and elastically pressed against a commutator of an armature. A conductive heat-sensitive fusing element that closes the current path flowing through the armature and blows off at a predetermined temperature or more to cut off the current path is provided in the vicinity of the commutator and between the brush and the commutator. The brush and the brush holder are formed of an electric conductor, and the brush holder and the brush are electrically connected to each other, and the brush holder and the heat-sensitive melting body are electrically connected to each other. A brush device for a rotating electric machine, characterized in that the brush device is connected to.