JPS61216283A - Brush holder for small motor - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a brush holding device having a brush restraining structure for a small electric motor, and particularly relates to the assembly of a leaf spring for restraining a brush.

[Background of the invention]

Conventional brush holding devices for shed electric motors have been designed to prevent brush noise caused by the contact between the commutator and the brush when the armature is operated, and to prevent the brush vibration absorption structure shown in Japanese Utility Model Application No. 55-23774 or the brush vibration absorption structure shown in Japanese Utility Model Application No. 58-183072. Measures are being used to forcibly restrain people.

Particularly in small electric motors, the higher the brush vibration absorbing structure of Utility Model Publication No. 55-23774, the more the high-frequency brush noise generated by the frictional fluctuations between the brush and the container, which are directly rubbed against each other, becomes harsher. Utility Model Application No. 58-183072 is an effective means for the above-mentioned brush noise, but in order to obtain good rectification and performance in a shed electric motor, the pressure with which the brush is pressed against the commutator is usually as small as 500~aoog''/-1lI.
In addition, it is a sintered material made of carbon of around 40 inches of copper, and has a soft surface strength of less than 20° shore strength, so even if a slight lateral pressure is applied, the pressing force will decrease and cause poor rectification, while at the same time applying 1 lateral pressure. Depending on the method, the soft brush surface may be damaged,
If the brush does not move, it may cause sliding failure.

Therefore, when using a leaf spring as a means for applying side pressure, it is necessary to apply an appropriate pressure and to fix the spring itself to a holder so that it does not wobble.

[Purpose of the invention]

An object of the present invention is to provide an optimal locking structure for a leaf spring used as a restraining means in a brush holding device having a brush restraining structure that eliminates such drawbacks.

[Summary of the invention]

In the present invention, a leaf spring is used as a means for pressurizing the brush from the side, and the leaf spring is inserted into a notch at the rear end of the holder that stores the brush with the shape of the leaf spring being U-shaped. After simultaneously inserting a spring stopper having a convex part, the rear end of the holder is deformed by the convex part by tilting the end face of the holder toward the spring stopper, and the reaction force of the spring stopper deforms the rear end of the holder. Since it has a locking structure, even thin plate-like springs can be easily assembled into the holder.

[Embodiments of the invention] Embodiments of the invention will be described in detail below with reference to the drawings.

FIG. 1 shows the structure of a brush holding device having a restraining leaf spring according to the present invention, and FIG. 2 shows an exploded view of the restraining leaf spring and a spring stopper when assembled to a holder.

The structure of the brush holding device 1 is such that a holder 4 for storing a brush 3 is fastened to a brush base body 2 by rivets 5. After inserting a coil spring 6 that presses the brush 3 toward the commutator side into the holder 4, a notch 4-a is provided at the rear end of the holder with a U-shaped brush restraining plate spring 7 that applies lateral pressure to the brush. After inserting the spring stopper 8 into the notch 4-aK at the same time, one end 4-b of the holder on the side opposite to the tip of the brush is tilted toward the spring stopper 8 and fixed. Positive and negative horizontal lines 9-a from the brush,
9-b is connected to an external power supply connector 9-c to form a current collecting section 9.

Next, detailed shapes of the restraining leaf spring and holder 3 used in the present invention will be explained with reference to exploded views of each component when assembled. The holder 4 has a notch 4-a at the rear end, a restraining leaf spring tip width d, and a slightly larger width d at the side surface 4-c on the opposite side of the armature rotation.
An escape groove 4-d is provided, and the notch 4-a has a width d3 that is slightly larger than the rear end width d2 of the restraint spring, a depth d4 that is approximately the same as the restraint leaf spring plate thickness tl, and the spring stopper plate thickness t2.
．． This is a notch having a step formed by dd5.

The brush restraining plate spring 7 is a U-shaped plate spring, and the U-shaped bottom part 7-a is inserted into the groove 4-e having a depth d4 of the notch 4-a, and the spring stopper is also cut. Including part 4-a
At the same time, insert the rear end of the holder 4-
b is locked by tilting it towards the spring stopper 8 side. Here, the U-shaped bottom of the brush restraining leaf spring 7 is connected to the coil spring 6 that presses the brush against the commutator.
The inner wall width dI of the holder is attached to a part of the bottom.
A tongue piece 7-b having a width d6 slightly smaller than I is provided so as to position the holder in the width direction when assembling the holder.

In addition, since a partially raised convex portion 8-a is provided on the holder rear end 4-b side of the spring stopper 8, when the holder rear end 4-a tl- is tilted toward the spring stopper 8 side, The thin plate spring is partially deformed by the protrusion 8-a, and due to this reaction force, the thin leaf spring is fixed to the holder without wobbling. In this example, the shape of the convex part is a lip shape with a semicircular cross section, but the rear end of the holder can be easily pressed against it, and if the convex part is too large, the rear end of the holder can be easily pressed. Since the entire shaft is deformed due to springback, other shapes may be used as long as the optimal shape is such that only a portion of the rear end is deformed.

〔Effect of the invention〕

If the brush holding device of the present invention is used, a leaf spring is used as a means to press the brush from the side, and the shape of the leaf spring is U-shaped, and a part of the surface is convex in the notch at the rear end of the holder that stores the brush. The restraining leaf spring can be fixed by simultaneously inserting a spring stopper having a section. Also, since a convex portion is provided on a part of the spring stopper, the thin plate spring can be easily locked without wobbling.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a brush holding device using the present invention, and FIG. 2 is an exploded perspective view of the present invention. l...Brush holding device, 2...Brush base body, 3.
... Brush, 4... Holder, 7... Brush restraint plate, 8... Spring stopper 1)

Claims (1)

[Claims] 1. In a brush holding device for a small electric motor, which has means for suppressing the movement of the brush caused by frictional force when the commutator and brush come into contact with each other when the armature rotates, a notch at the rear end of the holder for storing the brush is provided. In the case where a leaf spring is assembled and the tip of the leaf spring presses the side surface of the brush, the holder and the leaf spring are connected through a spring stopper having a convex portion on a part of the surface, and the rear end face of the holder is pressed against the spring. A brush holding device for a small electric motor, characterized in that it is tilted and clipped onto the stopper side.