JP2001275328A - Brushless motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a brushless motor that enables to reduction in the number of steps in the process for the electrical connection of a stator coil to a control circuit compared with prior art and that dispenses with a support jig for supporting a connecting bus at a given position in connecting the bus. SOLUTION: A filter circuit 20 that removes a surge from a service voltage is formed in an inner casing 21 of a synthetic resin, in which a connecting bus is built fixed on a circuit protecting casing 10. A control circuit 30, that controls the magnetic field of a stator 5 by changing over the flow route of the current that has passed the filter circuit 20 for the stator 5 at a given time, is formed on a circuit board 31 provided with given wiring patterns. The connecting bus 15, that electrically connects the control circuit 30 to a terminal pin 16 connected to the coil 5c of the stator 5, is built in the inner casing 21 and arranged at a prescribed position inside the circuit protecting casing 10. One end of the bus is soldered to the circuit board 31, and the other end is electrically connected to the terminal pin 16.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a brushless motor.

[0002]

2. Description of the Related Art FIG. 9 is a sectional view showing an example of a conventional product. This brushless motor a is disclosed in Japanese Patent Application Laid-Open No. 9-19162.
The drive circuit d for rotating the motor shaft c is housed in a circuit protection case b.

The drive circuit d is formed on a circuit board e having a predetermined wiring pattern, and generally includes a filter circuit d1 for removing a surge from supplied power, and a stator for a current passing through the filter circuit d1. and a control circuit d2 for controlling the magnetic field of the stator f by switching the current path to f at a predetermined time. The control circuit d2 includes a switching element g that switches a current path of the current flowing through the coil f1 of the stator f from the filter circuit d1.
The switching element g is attached to a heat sink h that radiates heat generated outside the circuit protection case b.

The control circuit d2 and the coil f1 of the stator f include a terminal pin i electrically connected to the coil f1, a joint bar j mounted on a circuit board e,
The joint bar j is electrically connected to the terminal pin i via a connection bus bar k for electrically connecting the terminal bar i.

[0005]

In the 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 the control circuit The number of components for electrical connection between d2 and coil f1 is large. Therefore, the number of man-hours 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.

Further, when connecting the connection bus bar k to the joint bar j and the terminal pin i by welding or the like,
A holding jig for holding the connection bus bar k at a predetermined position is required. For this reason, the work efficiency of the connection work of the connection bus bar k decreases, and this also causes an increase in manufacturing cost.

Therefore, in the present invention, the number of work steps for electrical connection between the coil of the stator and the control circuit can be reduced as compared with the conventional product, and the connection bus bar is kept at a predetermined position when the connection bus bar is connected. An object of the present invention is to provide a brushless motor that can eliminate a holding jig for holding, and as a result, can improve the yield and reduce the manufacturing cost.

[0008]

According to the first aspect of the present invention,
A filter circuit for removing a surge from the supplied power and a control circuit for switching the current path of the current passing through the filter circuit to the stator at a predetermined time to control the magnetic field of the stator are housed in a circuit protection case, In a brushless motor in which a terminal pin electrically connected to a coil and the control circuit are electrically connected via a connection bus bar, the filter circuit has a wiring bus bar assembled and fixed to a circuit protection case. The control circuit is formed on a circuit board provided with a predetermined wiring pattern and fixed to the circuit protection case, and the connection bus bar is assembled to the inner case and is formed in the inner case made of synthetic resin. Position, with one end soldered to the circuit board and the other end electrically connected to the terminal pins. It is characterized in that it is connected.

According to a second aspect of the present invention, there is provided the brushless motor according to the first aspect, wherein the wiring bus bar has at least two connector terminals electrically connected by a connector, and the connector terminal is provided with a wiring terminal. The bus bar is formed separately from the bus bar main body, and is fixed to the bus bar main body.

According to a third aspect of the present invention, there is provided the brushless motor according to the second aspect, wherein the wiring busbar is assembled to the inner case by insert molding, and a fixing portion between the connector terminal and the busbar body is formed by combining the inner case. It is characterized by being embedded in a resin.

[0011]

According to the first aspect of the present invention, the connection bus bar has one end soldered to the circuit board and the other end electrically connected to the terminal pin. Then, the necessary joint bar can be eliminated. Therefore, as compared with the conventional product shown in FIG. 9, the number of work steps for electrical connection between the coil of the stator and the control circuit can be reduced, and the yield can be improved and the manufacturing cost can be reduced.

In addition, since the connection busbar is mounted on the inner case fixed to the circuit protection case and arranged at a predetermined position in the circuit protection case, the connection busbar is fixed after the inner case is fixed to the circuit protection case. By connecting the terminal bus and the terminal pin, in this connection, the connection bus bar can be held at a predetermined position by the inner case. Accordingly, a holding jig for holding the connection bus bar at a predetermined position when the connection bus bar is connected can be eliminated, and the connection of the connection bus bar can be reduced as compared with the conventional product shown in FIG. The work efficiency of the work can be improved, and also in this regard, the manufacturing cost can be reduced.

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 coupled to the 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 respond to the type of connector, and it is possible to realize a change used for the response at low cost.

When the connector terminal is subjected to plating treatment for preventing oxidation, it is possible to easily perform plating treatment only on the connector terminal. On the other hand, in the case where the bus bar body of the wiring bus bar and the connector terminal are integrally formed, plating of the entire wiring bus bar or partial plating of the connector terminal is required. Therefore, the cost of the plating treatment 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.

According to the third aspect of the present invention, in the wiring busbar, since the fixing portion between the connector terminal and the busbar body is embedded in the synthetic resin of the inner case, the fixing portion between the connector terminal and the busbar body. Can be reinforced by the synthetic resin of the inner case, and the oxidation of the fixed portion can be prevented, so that the reliability of the fixed portion can be improved.

[0016]

FIG. 1 is a sectional view showing an example of an embodiment of the present invention. The brushless motor 1 is used as a blower fan motor of an air conditioner for an automobile. A sirocco fan for blowing air is attached to an upper end of a motor shaft 2. The motor shaft 2 is rotatably supported by the housing 4 via a pair of upper and lower bearings 3 and 3.

The housing 4 includes a motor shaft 2
A bearing portion 3 is provided at the lower end side, and a stator 5 is mounted on the outer peripheral surface. The stator 5 includes a core 5a in which thin metal plates are stacked, and a core 5a
A pair of upper and lower electric insulators 5b, 5b
And a coil 5c wound around the core 5a with the electric insulator 5b interposed therebetween. A bearing 3 located on the upper end side of the motor shaft 2 is provided on the electric insulator 5b assembled on the upper part of the core 5a.

Outside the stator 5, four permanent magnets 6 are arranged at substantially equal intervals in the vicinity of the stator 5. The yoke 7 holding these permanent magnets 6 covers the stator 5 and is fixed to the upper part of the motor shaft 2. A flange 4a provided at a lower end of the housing 4 is provided with a circuit protection case 10 made of a synthetic resin with an anti-vibration rubber 8 interposed therebetween.
Are fixed with screws. This circuit protection case 10
Is composed of 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.

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 have 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 switches the current path of the current passing through the filter circuit 20 to the stator 5 at a predetermined time to control the magnetic field of the stator 5. Have.

FIG. 2 is a plan view showing a driving circuit of the one shown in FIG. As shown in FIG. 1 and FIG.
Are formed on a circuit board 31 provided with 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 the current path switching timing of the switching element 32. In addition, 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.

The switching element 32 is pressed by a spring member 36 to an aluminum heat sink 35 provided with a radiating fin 35 a for radiating the heat generated outside 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.

FIG. 3 is a bottom view showing a state where the lower case is removed from the one shown in FIG. FIG. 4 is a plan view showing a filter circuit of the one shown in FIG. Figures 3 and 4
As shown in FIG. 2, the filter circuit 20 includes a wiring bus bar 4.
Electric components such as an electrolytic capacitor 22, a common mode choke coil 23, a varistor 24, and a fuse member 25 are mounted on an inner case 21 made of a synthetic resin in which the reference numeral 0 is assembled by insert molding.

As shown in FIGS. 1 to 4, the inner case 21 is fixed at a predetermined position in the circuit protection case 10 by being screw-fixed to a mounting boss portion vertically provided on the top wall of the upper case 11. The circuit board 31 includes the inner case 21.
And is fixed to the upper case 11 via the inner case 21, and is located above the inner case 21.

The three connection bus bars 15 are also attached to the inner case 21 by insert molding. Each connection bus bar 15 is provided with a coil 5 c of the stator 5.
The control circuit 30 is electrically connected to the terminal pins 16 which are electrically connected to each other and penetrate the upper case 11, and the vibration from the stator 5 is controlled by the control circuit 30.
U-shaped anti-vibration structure (see FIG. 1) for preventing transmission to the circuit board 31 of FIG.

Each connection bus bar 15 is assembled to the inner case 21 and arranged at a predetermined position in the circuit protection case 10, and one end is bent upward to form a through hole 37 (see FIG. 2) and soldered to the circuit board 31, the other end is bent downward and welded to the lower end of the terminal pin 16.
This welding is performed by resistance welding. The welding between the connection bus bar 15 and the terminal pin 16 is performed after the inner case 21 and the circuit board 31 are fixed to the upper case 11.

A predetermined portion of the wiring bus bar 40 is bent upward and soldered to a predetermined position on the circuit board 31. This soldering allows the filter circuit 20
And the control circuit 30 are electrically connected.

FIG. 5 is a bottom view showing the wiring bus bar and the connection bus bar before assembly to the inner case. FIG. 6 is a bottom view showing a connector terminal of the one shown in FIG. 5, (a) shows a ground terminal and a plus terminal, and (b)
Indicates a signal terminal.

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-linking points, and are insert-molded in this connected state. The cross-linking portion is removed, and a predetermined portion is bent in a predetermined direction.

As shown in FIGS. 5 and 6, a wiring bus bar 40 has a plus terminal 4 for receiving power from a vehicle-mounted power supply as a connector terminal electrically connected by a connector.
1, an earth terminal 42 electrically connected to the vehicle body, and a signal terminal 43 for receiving an external control signal. These terminals 41, 42, 43 are fixed to the bus bar main body 44 of the wiring bus bar 40 by welding. The terminals 41, 42, 43 and the bus bar body 44
Are welded into the synthetic resin forming the inner case 21 at the time of insert molding of the inner case 21.

The bus bar body 44 to which the plus terminal 41 is welded is divided by the bus bar body 44 for the signal terminal 43 to which the signal terminal 43 is welded. However, the cut portion is bridged by the fuse member 25 (see FIG. 4). The signal terminal 43 is connected to the control circuit 30 via a bus bar body 44 for the signal terminal 43.
Is electrically connected to the circuit board 31. Since a weaker current flows through the signal terminal 43 as compared with the plus terminal 41 and the ground terminal 42, a plating process for preventing oxidation is performed to prevent conduction failure due to an oxide film with a mating terminal connected to the connector. Have been.

FIG. 7 is a bottom view showing an example different from that shown in FIG. FIG. 8 is a bottom view showing the connector terminal of the one shown in FIG.
(B) shows a signal terminal, and (c) shows a plus terminal. As shown in FIGS. 7 and 8, what is shown in FIG.
The positive terminal 41 ', the ground terminal 42', and the signal terminal 43 'of the wiring bus bar 40' are different from those shown in FIG.

That is, these terminals 41 ', 42',
43 'differs from the plus terminal 41, the ground terminal 42, and the signal terminal 43 in the shape shown in FIG. Therefore, in the configuration shown in FIG. 7, the bus bar body 44 and the connection bus bar 15 can be shared with those shown in FIG.

The wiring bus bar 40 'also has a positive terminal 41' and a ground terminal 4 like the wiring bus bar 40.
The 2 ′ and the signal terminals 43 ′ are fixed to the bus bar main body 44 by welding, and a welded portion with the bus bar main body 44 is embedded in the synthetic resin when the inner case 21 is insert-molded.

In the brushless motor 1 described above, the connection bus bar 15 is assembled to the inner case 21 and one end is soldered to the circuit board 31 and the other end is welded to the terminal pin 16, so that it is shown in FIG. In the conventional product of the above, the necessary joint bar j can be eliminated. Therefore, as compared with the conventional product shown in FIG. 9, the number of man-hours for electrical connection between the coil 5c of the stator 5 and the control circuit 30 can be reduced, thereby improving the yield and reducing the manufacturing cost. it can.

Moreover, the connection bus bar 15 is assembled to the inner case 21. Since the connection bus bar 15 and the terminal pins 16 are welded after the inner case 21 is fixed to the upper case 11, the connection bus bar 15 is welded. At the time of connection between the terminal 15 and the terminal pin 16 by welding, the connection 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, as compared with the conventional product shown in FIG.
The work efficiency of the connection work can be improved, and also in this regard, the manufacturing cost can be reduced.

By the way, 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. Generally, it is performed by resistance welding. 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, FIG.
In the illustrated conventional product, 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. In this case, part of the power is wasted by heat.

On the other hand, in the brushless motor 1, the joint bar j required in the conventional product shown in FIG. 9 can be omitted, so that the waste of electric power can be suppressed as compared with the conventional product shown in FIG. As a result, the motor efficiency can be improved.

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 'of the wiring bus bar 40', and the like.
The ground terminal 42 'and the signal terminal 43' are formed separately from the bus bar body 44 of the wiring bus bars 40, 40 ', and are welded to the bus bar body 44. Therefore, these terminals 41, 41 are changed by changing the mating connector.
Even if the shape and arrangement of the mating terminals coupled to 41 ', 42, 42', 43, 43 'are changed, the plus terminals 41, 41', the ground terminals 42, 42 ', and the signal terminals 43 are provided. , 43 ′, and the welding position with respect to the bus bar body 44. Therefore, it is easy to respond to the type of the mating connector, and it is possible to realize a change used for the response at low cost.

The terminals 41, 41 ', 42,
When plating for preventing oxidation is performed on the terminals 42 ', 43, 43', these terminals 41, 41 ', 42, 42',
It is also possible to easily apply plating to only 43 and 43 '. On the other hand, the bus bar body 44 of the wiring bus bars 40, 40 'and the terminals 41, 41', 42, 4
When 2 ′, 43 and 43 ′ are integrally formed,
Either the entire plating of the wiring bus bars 40, 40 'or the partial plating of these terminals 41, 41', 42, 42 ', 43, 43' is required. Therefore, the wiring bus bars 40, 4
0 'busbar body 44 and these terminals 41, 41',
The cost of the plating treatment for preventing oxidation can also be reduced as compared with the case where 42, 42 ', 43, 43' are integrally formed.

Further, in the brushless motor 1, the wiring busbars 40, 40 ′ are formed such that the welding portions between the plus terminals 41, 41 ′, the ground terminals 42, 42 ′ and the signal terminals 43, 43 ′ and the busbar body 44 are formed in the inner case 21. Embedded in synthetic resin. For this reason, these terminals 41, 4
1 ', 42, 42', 43, 43 'and busbar body 44
Can be reinforced by the synthetic resin of the inner case 21, and the oxidation of the welded portion can be prevented to improve the reliability of the welded portion.

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 using a screw or a connection using a connector.

In the brushless motor 1, the wiring busbars 40, 40 'have plus terminals 41, 41' ground terminals 42, 42 'and signal terminals 43, 43' fixed to the busbar body 44 by welding. However, the fixing of these terminals 41, 41 ', 42, 42', 43, 43 'to the bus bar body 44 is not limited to welding, and for example,
Bonding by silver brazing or fixing by screwing may be used.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating an example of an embodiment of the present invention.

FIG. 2 is a plan view showing a drive circuit of the one shown in FIG.

FIG. 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 a filter circuit of the one shown in FIG. 1;

FIG. 5 is a bottom view showing a wiring bus bar and a connection bus bar before assembly to an inner case.

FIG. 6 is a bottom view showing the connector terminal of FIG. 5, wherein (a) shows a ground terminal and a positive terminal,
(B) shows a signal terminal.

FIG. 7 is a bottom view showing an example different from the one shown in FIG. 5;

8 is a bottom view showing the connector terminal of FIG. 7, wherein (a) is a ground terminal, (b) is a signal terminal,
(C) shows a plus terminal, respectively.

FIG. 9 is a 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 Busbar body of wiring busbar

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Katsuhiro Machida, Inventor 5-24-15 Minamidai, Nakano-ku, Tokyo Calsonic Corporation F-term (reference) 5H019 AA10 BB01 BB04 BB15 BB19 CC04 DD01 FF01 5H605 AA08 BB05 BB09 BB10 BB19 CC06 CC10 EC05 GG02 GG18 5H611 AA00 BB01 BB07 BB08 TT01 UB02 5H621 GA01 GB14 HH02 JK14

Claims (3)

[Claims] 1. A filter circuit (20) for removing a surge from a supplied electric power, and a current path to a stator (5) of a current passing through the filter circuit (20) is switched at a predetermined time to change a magnetic field of the stator (5). A terminal pin (16) housed in a circuit protection case (10) and electrically connected to a coil (5c) of a stator (5); And the filter circuit (20) is electrically connected to the wiring bus bar (40, 4) through the connection bus bar (15).
0 ') is assembled and formed in a synthetic resin inner case (21) fixed to the circuit protection case (10),
The control circuit (30) is formed on a circuit board (31) having a predetermined wiring pattern and fixed to the circuit protection case (10), and the connection bus bar (15) is connected to the inner case (2).
1) is disposed at a predetermined position in the circuit protection case (10) and has one end mounted on the circuit board (31).
A brushless motor, the other end of which is electrically connected to a terminal pin (16). 2. A brushless motor according to claim 1, wherein the wiring busbars (40, 40 ') have connector terminals (41, 41', 4) electrically connected by connectors.
2, 42 ', 43, 43') and the connector terminals (41, 41 ', 42, 42', 43, 4).
3 ') is formed separately from the bus bar body (44) of the wiring bus bar (40, 40'), and the bus bar body (4
4) A brushless motor fixed to 4). 3. The brushless motor according to claim 2, wherein the wiring bus bar (40, 40 ') is assembled to the inner case (21) by insert molding, and the connector terminals (41, 41', 42, 42). ', 43, 4
A brushless motor characterized in that a fixing portion between 3 ') and the bus bar body (44) is embedded in a synthetic resin of the inner case (21).