JP4083365B2 - Brushless motor - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a brushless motor.
[0002]
[Prior art]
FIG. 9 is a cross-sectional view showing an example of a conventional product. This brushless motor a is described in JP-A-9-191625, and a drive circuit d for rotating a motor shaft c is accommodated in a circuit protection case b.
[0003]
The drive circuit d is formed on a circuit board e having a predetermined wiring pattern. Generally, the drive circuit d is a filter circuit d1 that removes a surge from supplied power, and the current that has passed through the filter circuit d1 is supplied to the stator f. And a control circuit d2 that controls the magnetic field of the stator f by switching the current path at a predetermined time. The control circuit d2 includes a switching element g that switches a current path from the filter circuit d1 of the current flowing through the coil f1 of the stator f, and the switching element g serves as a heat sink h that radiates the heat generated outside the circuit protection case b. It is attached.
[0004]
The control circuit d2 and the coil f1 of the stator f electrically connect the terminal pin i electrically connected to the coil f1, the joint bar j mounted on the circuit board e, and the joint bar j and the terminal pin i. Are electrically connected to each other via a connection bus bar k.
[0005]
[Problems to be solved by the invention]
In this brushless motor a, three components of a terminal pin i, a joint bar j, and a connection bus bar k are required for electrical connection between the control circuit d2 and the coil f1, and electrical connection between the control circuit d2 and the coil f1 is required. There are a lot of parts. For this reason, the number of work steps for electrical connection between the control circuit d2 and the coil f1 increases, resulting in a decrease in yield and an increase in manufacturing cost.
[0006]
Moreover, when connecting the connecting bus bar k to the joint bar j and the terminal pin i by welding or the like, a holding jig for holding the connecting bus bar k in a predetermined position is required. For this reason, the work efficiency of the connection work of the connection bus bar k is lowered, and the manufacturing cost is also increased in this respect.
[0007]
Therefore, in the present invention, the number of work steps for electrical connection between the stator coil and the control circuit can be reduced as compared with the conventional product, and the holding bus bar is held in a predetermined position when the connecting bus bar is connected. It is an object of the present invention to provide a brushless motor that can eliminate the need for a jig and, as a result, can improve yield and reduce manufacturing costs.
[0008]
[Means for Solving the Problems]
According to the first aspect of the present invention, circuit protection includes a filter circuit that removes a surge from supplied power, and a control circuit that controls a magnetic field of the stator by switching a current path to the stator of current that has passed through the filter circuit at a predetermined time. In a brushless motor in which a terminal pin housed in a case and electrically connected to a stator coil and the control circuit are electrically connected via a connecting bus bar, the filter circuit is assembled with a wiring bus bar. The circuit board is formed in a synthetic resin inner case fixed to the circuit protection case and disposed at a predetermined position in the internal space of the circuit protection case, and the control circuit has a predetermined wiring pattern and is fixed to the inner case. The connecting bus bar is assembled to the inner case and disposed at a predetermined position in the circuit protection case. Together they have, one end of which is soldered to the circuit board and the other end is characterized by being electrically connected to the terminal pins.
[0009]
The invention according to claim 2 is the brushless motor according to claim 1, wherein the wiring bus bar includes at least two connector terminals electrically connected by a connector, and the connector terminal is a bus bar of the wiring bus bar. It is formed separately from the main body and is fixed to the bus bar main body.
[0010]
The invention described in claim 3 is the brushless motor according to claim 2, wherein the wiring bus bar is assembled to the inner case by insert molding, and the fixing portion between the connector terminal and the bus bar body is in the synthetic resin of the inner case. It is characterized by being embedded.
[0011]
【The invention's effect】
According to the first aspect of the present invention, the connecting bus bar has one end soldered to the circuit board and the other end electrically connected to the terminal pin. Can be made unnecessary. Therefore, compared with the conventional product shown in FIG. 9, the number of working steps for electrical connection between the stator coil and the control circuit can be reduced, and the yield can be improved and the manufacturing cost can be reduced.
[0012]
In addition, since the connecting bus bar is assembled to the inner case fixed to the circuit protection case and disposed at a predetermined position in the circuit protection case, the connection bus bar and the terminal pin are fixed after the inner case is fixed to the circuit protection case. By performing the connection, the connection bus bar can be held at a predetermined position by the inner case at the time of this connection. Accordingly, it is possible to eliminate the need for a holding jig for holding the connecting bus bar at a predetermined position when the connecting bus bar is connected. Compared to the conventional product shown in FIG. The work efficiency of the work can be improved, and the manufacturing cost can be reduced also in this respect.
[0013]
According to the second aspect of the present invention, at least two connector terminals of the wiring bus bar are formed separately from the bus bar main body of the wiring bus bar and are fixed to the bus bar main body. Even when the shape or arrangement of the mating terminal is changed, it can be dealt with by changing the shape of the connector terminal, changing the position where the connector terminal is fixed to the bus bar body, or the like. Therefore, it is easy to cope with the type of connector, and a change used for the correspondence can be realized at low cost.
[0014]
In addition, when the connector terminal is subjected to an oxidation-preventing plating process, only the connector terminal can be easily plated. On the other hand, when the bus bar main body of the wiring bus bar and the connector terminal are integrally molded, the entire plating of the wiring bus bar or the partial plating of the connector terminal is required. Therefore, the cost of the plating process for preventing oxidation can be reduced as compared with the case where the bus bar body of the wiring bus bar and the connector terminal are integrally formed.
[0015]
According to the third aspect of the present invention, in the wiring bus bar, the fixing portion between the connector terminal and the bus bar main body is embedded in the synthetic resin of the inner case. It is possible to enhance the reliability of the fixed portion by preventing the fixed portion from being oxidized.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a cross-sectional view showing an example of an embodiment of the present invention. The brushless motor 1 is used as a blower fan motor for an air conditioner for automobiles, and a sirocco fan for blowing air is attached to an upper end portion of a motor shaft 2. The motor shaft 2 is rotatably supported by the housing 4 via a pair of upper and lower bearing portions 3 and 3.
[0017]
The housing 4 is provided with a bearing portion 3 positioned on the lower end side of the motor shaft 2 and a stator 5 is assembled to the outer peripheral surface. The stator 5 includes a core 5a in which thin metal plates are laminated, a pair of upper and lower electric insulators 5b and 5b assembled to the core 5a, and a coil wound around the core 5a with the electric insulator 5b interposed therebetween. 5c. The electrical insulator 5b assembled to the upper part of the core 5a is provided with a bearing portion 3 located on the upper end side of the motor shaft 2.
[0018]
On the outside of the stator 5, four permanent magnets 6 are arranged at substantially equal intervals in the vicinity of the stator 5. A yoke 7 that holds these permanent magnets 6 covers the stator 5 and is fixed to the upper part of the motor shaft 2. A circuit protection case 10 made of synthetic resin is fixed to a flange portion 4 a provided at the lower end portion of the housing 4 with a vibration-proof rubber 8 interposed therebetween. The circuit protection case 10 includes an upper case 11 located on the upper end side of the motor shaft 2 and a lower case 12 located on the lower end side of the motor shaft 2.
[0019]
In the circuit protection case 10, a sensor magnet 13 fixed to the lower end of the motor shaft 2 and a drive circuit 14 for rotating the motor shaft 2 are accommodated. In the sensor magnet 13, a portion corresponding to the position where each permanent magnet 6 is disposed is magnetized to the same polarity as the corresponding permanent magnet 6. The drive circuit 14 includes a filter circuit 20 that removes a surge from the supplied power, and a control circuit 30 that controls the magnetic field of the stator 5 by switching the current path to the stator 5 of the current that has passed through the filter circuit 20 at a predetermined time. I have.
[0020]
FIG. 2 is a plan view showing a drive circuit of what is shown in FIG. As shown in FIGS. 1 and 2, the control circuit 30 is formed on a circuit board 31 having a predetermined wiring pattern. The circuit board 31 includes a switching element 32 for switching a current path from the filter circuit 20 for a current flowing through the coil 5c of the stator 5 through the filter circuit 20 and a control IC 33 for controlling a current path switching timing of the switching element 32. Electric components such as a Hall element (not shown) for detecting the rotational position of the permanent magnet 6 in cooperation with the sensor magnet 13 and an electrolytic capacitor 34 are mounted.
[0021]
The switching element 32 is press-contacted by a spring member 36 to an aluminum heat sink 35 provided with heat radiating fins 35 a for radiating the generated heat to the outside of the circuit protection case 10. The heat sink 35 has a gate shape and is fixed to the circuit board 31. The spring member 36 is disposed below the switching element 32 and is fixed to the circuit board 31.
[0022]
FIG. 3 is a bottom view showing a state in which the lower case is removed from that shown in FIG. FIG. 4 is a plan view showing the filter circuit shown in FIG. As shown in FIGS. 3 and 4, the filter circuit 20 includes an electrolytic capacitor 22, a common mode choke coil 23, a varistor 24, a fuse member, and a synthetic resin inner case 21 in which a wiring bus bar 40 is assembled by insert molding. Electrical components such as 25 are mounted and formed.
[0023]
As shown in FIGS. 1 to 4, the inner case 21 is screwed to a mounting boss portion that is suspended from the top wall of the upper case 11 and is disposed at a predetermined position in the circuit protection case 10. The circuit board 31 is attached to the inner case 21, is fixed to the upper case 11 via the inner case 21, and is positioned above the inner case 21.
[0024]
Three connecting bus bars 15 are also assembled to the inner case 21 by insert molding. Each connection bus bar 15 is electrically connected to the terminal pin 16 that is welded and electrically connected to the coil 5c of the stator 5 and passes through the upper case 11, and the control circuit 30. Is provided with a U-shaped anti-vibration structure (see FIG. 1) that prevents the signal from being transmitted to the circuit board 31 of the control circuit 30.
[0025]
Each connection bus bar 15 is assembled to the inner case 21 and disposed at a predetermined position in the circuit protection case 10, and one end thereof is bent upward, and the through hole 37 of the circuit board 31 (see FIG. 2). The other end is bent downward and welded to the lower end portion of the terminal pin 16. This welding is performed by resistance welding. The connection bus bar 15 and the terminal pin 16 are welded after the inner case 21 and the circuit board 31 are fixed to the upper case 11.
[0026]
A predetermined portion of the wiring bus bar 40 is bent upward and soldered to the circuit board 31 at a predetermined position. By this soldering, the filter circuit 20 and the control circuit 30 are electrically connected.
[0027]
FIG. 5 is a bottom view showing the wiring bus bar and the connection bus bar before assembly to the inner case. 6 is a bottom view showing the connector terminal of the device shown in FIG. 5, wherein (a) shows a ground terminal and a positive terminal, and (b) shows a signal terminal.
[0028]
As shown in FIG. 5, the wiring bus bar 40 and the connection bus bar 15 are connected to each other at a plurality of hatched cross-linked portions, and are insert-molded in this connected state. Is removed, and a predetermined part is bent in a predetermined direction.
[0029]
As shown in FIGS. 5 and 6, the wiring bus bar 40 includes a plus terminal 41 that receives power from the in-vehicle power source and a ground terminal that is electrically connected to the vehicle body as connector terminals electrically connected by the connector. 42 and a signal terminal 43 for receiving an external control signal. These terminals 41, 42 and 43 are fixed to the bus bar body 44 of the wiring bus bar 40 by welding. And the welding location of these terminals 41, 42, 43 and the bus-bar main body 44 is embedded in the synthetic resin which forms the inner case 21 at the time of insert molding of the inner case 21.
[0030]
The bus bar main body 44 to which the plus terminal 41 is welded is divided by the bus bar main body 44 for the signal terminal 43 to which the signal terminal 43 is welded. However, the divided portion is bridged by the fuse member 25 (see FIG. 4). The signal terminal 43 is electrically connected to the circuit board 31 of the control circuit 30 via the bus bar main body 44 for the signal terminal 43. Further, since a weak current flows in the signal terminal 43 as compared with the plus terminal 41 and the ground terminal 42, an anti-oxidation plating process for preventing a conduction failure due to an oxide film with the mating terminal connected to the connector is performed. Has been.
[0031]
FIG. 7 is a bottom view showing an example different from that shown in FIG. 8 is a bottom view showing the connector terminal shown in FIG. 7, wherein (a) shows a ground terminal, (b) shows a signal terminal, and (c) shows a plus terminal. As shown in FIGS. 7 and 8, the one shown in FIG. 7 is different from that shown in FIG. 5 in the plus terminal 41 ', the ground terminal 42', and the signal terminal 43 'of the wiring bus bar 40'.
[0032]
That is, these terminals 41 ′, 42 ′, and 43 ′ are different from the positive terminal 41, the ground terminal 42, and the signal terminal 43 shown in FIG. 5 in the shape and attachment position to the bus bar main body 44. Therefore, in the one shown in FIG. 7, the bus bar main body 44 and the connecting bus bar 15 can be shared with those shown in FIG.
[0033]
Also in the wiring bus bar 40 ′, the plus terminal 41 ′, the ground terminal 42 ′, and the signal terminal 43 ′ are fixed to the bus bar main body 44 by welding in the same way as the wiring bus bar 40, and the bus bar 40 ′ A welded portion with the main body 44 is embedded in the synthetic resin.
[0034]
In the brushless motor 1 described above, the connecting bus bar 15 is assembled to the inner case 21, one end is soldered to the circuit board 31, and the other end is welded to the terminal pin 16. Therefore, the conventional product shown in FIG. Then, the necessary joint bar j can be made unnecessary. Therefore, compared with the conventional product shown in FIG. 9, the number of work steps for electrical connection between the coil 5c of the stator 5 and the control circuit 30 can be reduced, and the yield can be improved and the manufacturing cost can be reduced. it can.
[0035]
In addition, the connecting bus bar 15 is assembled to the inner case 21, and the welding between the connecting bus bar 15 and the terminal pin 16 is performed after the inner case 21 is fixed to the upper case 11, so that the connecting bus bar 15 and the terminal are connected. When connected to the pin 16 by welding, the connecting bus bar 15 can be held at a predetermined position by the inner case 21 fixed to the upper case 11. Therefore, a holding jig for holding the connection bus bar 15 at a predetermined position when the connection bus bar 15 is connected can be eliminated. Therefore, compared with the conventional product shown in FIG. 9 which requires this holding jig, the work efficiency of the connection work of the connection bus bar 15 can be improved, and the manufacturing cost can be reduced also in this respect.
[0036]
In the conventional product shown in FIG. 9, the connection between the coil f1 of the stator f and the terminal pin i, the connection between the terminal pin i and the connection bus bar k, and the connection between the connection bus bar k and the joint bar j are resistance welding. It is common to do by. However, since the resistance value of the coil f1 of the stator f is small, the yield of resistance welding between the coil f1 and the terminal pin i is deteriorated unless the resistance value of the terminal pin i is increased to some extent. Therefore, in the conventional product shown in FIG. 9, the resistance value of the terminal pin i must be increased to some extent, the resistance value of the connecting bus bar k must be decreased, and the resistance value of the joint bar j must be increased to some extent. A part of the electric power is wasted in heat by the joint bar j.
[0037]
On the other hand, in the brushless motor 1, since the joint bar j required in the conventional product shown in FIG. 9 can be eliminated, waste of electric power can be suppressed compared to the conventional product shown in FIG. As a result, motor efficiency can be improved.
[0038]
In the brushless motor 1, the plus terminal 41, the ground terminal 42, and the signal terminal 43 of the wiring bus bar 40, and the plus terminal 41 ', the ground terminal 42', and the signal terminal 43 'of the wiring bus bar 40' are for wiring. The bus bars 40, 40 ′ are formed separately from the bus bar main body 44 and welded to the bus bar main body 44. For this reason, even if the shape and arrangement of the mating terminal connected to these terminals 41, 41 ', 42, 42', 43, 43 'are changed by changing the mating connector, the positive terminal 41, 41 ', ground terminals 42, 42', signal terminals 43, 43 'can be dealt with by changing the shape, changing the welding position with respect to the bus bar main body 44, or the like. Therefore, it is easy to cope with the type of the mating connector, and a change used for the correspondence can be realized at low cost.
[0039]
When these terminals 41, 41 ', 42, 42', 43, 43 'are plated for oxidation prevention, only these terminals 41, 41', 42, 42 ', 43, 43' are used. It is also possible to easily apply a plating process. On the other hand, when the bus bar main body 44 of the wiring bus bar 40, 40 'and these terminals 41, 41', 42, 42 ', 43, 43' are integrally formed, the wiring bus bar 40, 40 is formed. ', Or partial plating of these terminals 41, 41', 42, 42 ', 43, 43' is required. Therefore, the cost of the oxidation plating treatment is lower than that in which the bus bar main body 44 of the wiring bus bars 40, 40 'and these terminals 41, 41', 42, 42 ', 43, 43' are integrally formed. Reduction can also be achieved.
[0040]
Further, in the brushless motor 1, the wiring bus bars 40, 40 ′ have a welded portion between the plus terminals 41, 41 ′ ground terminals 42, 42 ′ signal terminals 43, 43 ′ and the bus bar body 44 in the synthetic resin of the inner case 21. Embedded in. Therefore, the welded portion between these terminals 41, 41 ', 42, 42', 43, 43 'and the bus bar main body 44 can be reinforced by the synthetic resin of the inner case 21, and the welded portion is prevented from being oxidized. Thus, the reliability of the welded part can be improved.
[0041]
In the brushless motor 1, the connection bus bar 15 and the terminal pin 16 are connected by welding. However, the connection between the connection bus bar 15 and the terminal pin 16 is not limited to welding, and may be, for example, a connection by screws or a connection by a connector.
[0042]
In the brushless motor 1, the wiring bus bars 40 and 40 ′ have the positive terminals 41 and 41 ′ ground terminals 42 and 42 ′ signal terminals 43 and 43 ′ fixed to the bus bar main body 44 by welding. However, the fixing of the terminals 41, 41 ', 42, 42', 43, 43 'to the bus bar main body 44 is not limited to welding, and may be, for example, bonding with silver solder or fixing with screws. good.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing an example of an embodiment of the present invention.
FIG. 2 is a plan view showing a drive circuit of what is shown in FIG. 1;
3 is a bottom view showing a state where a lower case is removed from the one shown in FIG. 1. FIG.
4 is a bottom view showing the filter circuit shown in FIG. 1. FIG.
FIG. 5 is a bottom view showing a wiring bus bar and a connection bus bar before assembling to the inner case.
6 is a bottom view showing the connector terminal of the device shown in FIG. 5, wherein (a) shows a ground terminal and a positive terminal, and (b) shows a signal terminal.
7 is a bottom view showing an example different from that shown in FIG. 5. FIG.
8 is a bottom view showing the connector terminal shown in FIG. 7, wherein (a) shows a ground terminal, (b) shows a signal terminal, and (c) shows a plus terminal.
FIG. 9 is a cross-sectional view showing an example of a conventional product.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Brushless motor 5 Stator 5c Coil 10 Circuit protection case 15 Connection bus bar 16 Terminal pin 20 Filter circuit 21 Inner case 30 Control circuit 31 Circuit board 40, 40 'Wiring bus bar 41, 41' Positive terminal (connector terminal)
42, 42 'Ground terminal (connector terminal)
43, 43 'Signal terminal (connector terminal)
44 Bus bar body of wiring bus bar

Claims (3)

A filter circuit (20) for removing a surge from the supplied power, and a control circuit for controlling the magnetic field of the stator (5) by switching the current path to the stator (5) of the current passing through the filter circuit (20) at a predetermined time (30) is housed in the circuit protection case (10), and the terminal pin (16) electrically connected to the coil (5c) of the stator (5) and the control circuit (30) are connected bus bars. In the brushless motor electrically connected via (15),
The filter circuit (20) is made of a synthetic resin, which is fixed to the circuit protection case (10) with the wiring bus bars (40, 40 ') assembled thereto and arranged at a predetermined position in the internal space of the circuit protection case (10) . The control circuit (30) formed on the inner case (21) is formed on a circuit board (31) having a predetermined wiring pattern and fixed to the inner case (21) , and the connecting bus bar (15) is connected to the inner case. (21) is mounted at a predetermined position in the circuit protection case (10), one end is soldered to the circuit board (31), and the other end is electrically connected to the terminal pin (16). A brushless motor characterized by The brushless motor according to claim 1,
The wiring bus bar (40, 40 ') includes at least two connector terminals (41, 41', 42, 42 ', 43, 43') electrically connected by connectors, and the connector terminals (41, 41). ′, 42, 42 ′, 43, 43 ′) are formed separately from the bus bar main body (44) of the wiring bus bar (40, 40 ′) and are fixed to the bus bar main body (44). Features a brushless motor. The brushless motor according to claim 2,
The wiring bus bars (40, 40 ') are assembled to the inner case (21) by insert molding, and the connector terminals (41, 41', 42, 42 ', 43, 43') are fixed to the bus bar body (44). A brushless motor characterized in that the portion is embedded in the synthetic resin of the inner case (21).

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