JPS5837785B2 - motor brush - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a motor brush fixedly connected to a printed circuit board.

In the conventional motor brush, as shown in FIG. 1 or 2, a commutator contact piece 1 is provided with a printed board connecting piece 2 in the opposite direction, and the printed board connecting piece 2 is fitted into a recess 4 provided in a printed board 3. They were then firmly connected by soldering.

In this case, the brush effective length l, which is one of the factors that determines the brush repelling constant, is shortened because a certain length is necessary for fixing it to the printed board 3. 3
When assembled into a motor as shown in the figure, the deflection of the brush varies due to variations in dimensions of related parts, and the brush pressure deviates from the optimum value accordingly.

In order to reduce the deviation of the brush pressure from the optimum value, the smaller the brush splash constant, the better.

However, the ones shown in FIG. 1 and C and FIG. 2 have a short effective length, so they have the disadvantage of a large spring constant.

In addition, in order to increase the effective length, there is a type in which the printed board connection piece 2 is provided in the same direction as the commutator contact piece 1 as shown in Fig. 4, but the commutator contact piece is placed directly above the printed board connection piece 1. 1, it had the disadvantage that soldering work was extremely difficult.

In addition, in FIG. 1, 5 is an electric element such as a rectifier, a noise prevention capacitor, and a 66-pin input terminal. In FIG. support.

10 is a flat commutator, and 11 is a stator formed of a permanent magnet.

The present invention has been made in view of the above points, and the object of the present invention is (6) to maximize the effective length of the brush, reduce the spring constant of the brush pressure, and bring the brush pressure close to the optimum value. In addition, the cross-sectional area of the brush base can be reduced to further reduce the repelling constant, and furthermore, light beam soldering can be easily performed.

This will be explained in detail below using examples.

In FIG. 5, reference numeral 1 denotes a commutator contact piece, which extends integrally from the base end of the commutator contact piece 1 so as to fold back the U-shaped part. The parallel opposing pieces are designated as printed board connection pieces 2.

Base end and tip end (free end) of this printed board connection piece 2
As shown in FIG. 6 or 7, insertion pieces 12 and 13 are formed by bending.

In FIG. 6, the tip of the insertion piece 12 is slightly bulged, and the insertion piece 13 is bent at an angle smaller than a right angle so that it does not easily come out when inserted into the printed board 3.

The recess 4 of the printed board 3 is made almost the same as the brush width,
A separate hole 14 is provided so that the insert piece 12, 13 can be inserted and fixed onto the printed board 3.

The insertion piece 12 is inserted into the hole 15 provided in the printed board 3 in FIG. 71i.

Reference numeral 16 denotes a hole provided in the printed board connection piece 2, and a hole 17 is provided in the commutator contact piece 1 approximately concentrically with this hole 16.

As described above, the printed circuit board 3 is temporarily fixed with the insertion pieces 12 and 13, and soldering is performed by irradiating a light beam.Solder is supplied by cutting pellet-shaped solder or thread solder into short pieces. An appropriate amount of solder or cream solder may be supplied to the holes 16 before heating, or the surface of the conductor portion of the printed board 3 may be coated with solder in advance.

The hole 16 provided in the printed board connection piece 2 allows the solder to melt and become molten solder, and infiltrate the gap between the printed board connection piece 2 and the conductor surface of the printed board 3 through the hole 16 by capillary action. Alternatively, when using a solder-coated printed board 3, the remaining molten solder escapes from the hole 16 to the surface, reducing the gap between the printed board connecting piece 2 and the conductor surface of the printed board 3 and increasing the degree of adhesion. As shown in FIG. 6 or 7, solder 18 is formed in the shape of a rivet head, and is provided to increase the bonding strength.

In other words, when the remaining part of the molten solder comes out to the surface and the solder 18 hardens in the shape of a rivet head, the upper surface of the printed board connection piece 2' can be held down by the periphery of the solder 18 shaped like a rivet head, and the anchor effect of the solder It is possible to increase the bonding strength by increasing the degree of adhesion between the printed board connecting pieces 2.

When soldering by irradiating a light beam, with a light beam using an elliptical reflector, it is customary to bring the heated part to the second focal point where the energy is concentrated the most, but the energy is concentrated at a perfect point. Instead, it is common to limit the size to a range of several millimeters in diameter.

On the other hand, when soldering the brush, the smaller the heating range, the better, in order to reduce thermal distortion to the periphery, such as variation in brush height due to deformation of the printed board 3.

As a method of minimizing the heating range, the heating range can be reduced to about % by providing a cover with a suitable dog-shaped circular hole above the second focal point and irradiating the light beam through this circular hole.

Therefore, by placing the solder in the hole 16 and irradiating the light beam L in the direction of the arrow through the hole 17 provided in the commutator contact piece 1 as shown in FIG. Furthermore, the heating range can be minimized.

In other words, the light beam is narrowed down by the hole 17 so that the area that hits the printed board connection piece 2 is within the hole 16, and the light beam hits a wide area other than the hole 16, widening the heating area and dissipating heat to the surrounding area. In addition to reducing the impact,
The solder placed in the hole 16 can be reliably heated and melted.

If soldering strength is a priority, such as with a large brush, the second focal point F should be located near the hole 17, and the hole 16 should be positioned below the second focal point F, as shown in FIG. Allows heating and soldering over a wider area.

As described above, in the present invention, the U-shaped portion is folded back from the base end of the commutator contact piece, and the piece facing parallel to the commutator contact piece of the U-shaped portion is connected to the printed board connecting piece. At the same time, a pair of insertion pieces are placed vertically at a certain distance from the printed board connection piece, and the insertion pieces are inserted around the periphery of the printed board on which electrical elements such as rectifiers and noise prevention capacitors and input terminals are attached. Since the plate contact piece and the printed board are soldered, the effective length of the brush can be maximized and the spring constant of the brush pressure can be reduced, making it possible to maintain the brush pressure near the optimum value. In addition, since the holes are provided in the commutator contact piece almost concentrically with the holes drilled in the printed board connection piece, the irradiation range can be limited without the need for a separate slit device during light beam soldering, and thermal distortion can be reduced. In addition to having the effect of being able to do this, the holes also have the advantage that the cross-sectional modulus of the brush base can be made smaller, thereby making it possible to further reduce the repulsion constant.

Note that soldering may be performed by inserting a soldering iron through a hole provided in the commutator contact piece.

[Brief Description of the Drawings] Figure 1 is a perspective view of a brush block equipped with an example of a conventional motor brush, Figure 2 is a perspective view of a brush block equipped with another example of the same as above, and Figure 3 is a perspective view of a brush block equipped with an example of a conventional motor brush. FIG. 4 is a partially cutaway perspective view of a brush block equipped with another example of a conventional moke brush; FIG. 5 is an embodiment of the present invention. FIG. 6 is an enlarged vertical cross-sectional view of the main part of the same as above, FIG. 7 is an enlarged vertical cross-sectional view of the main part of another embodiment of the present invention, and FIG. 8 is a soldering process using a light beam. FIG. 9 is an explanatory diagram of an example of attachment, and FIG. 9 is an explanatory diagram of another example of the same. 1... Commutator contact piece, 2... Printed board connection piece, 3... Printed board, 12...
・Insertion piece, 13... Insertion piece, 16...
Hole, 17... Hole.

Claims (1)

[Claims] 1. The U-shaped part is folded back from the base end of the commutator contact piece, and the piece facing parallel to the commutator contact piece of the U-shaped part is used as a printed board connection piece, and from the printed board connection piece. A pair of insertion pieces are placed vertically at a certain distance apart, and the insertion pieces are inserted around the periphery of the printed board on which electrical elements such as rectifiers and noise prevention capacitors and input terminals are attached, and holes are drilled in the printed board connection piece. A motor brush characterized in that a hole is provided in the commutator contact piece concentrically with the hole, and the printed board connecting piece and the printed board are soldered.