JPH0611378Y2 - Friction brake with reduced braking noise - Google Patents

Description

TECHNICAL FIELD The present invention relates to a friction brake with reduced braking noise.

2. Description of the Related Art A conventional friction brake is disclosed in Japanese Utility Model Publication No. Sho 63-19635. In this friction brake, a braking plate whose rotation is restricted and a friction plate which rotates in conjunction with the motor are in pressure contact with each other to apply a braking force to the motor.

However, in such a brake, since the friction plate and the braking plate are in full contact with each other, the collision sound when they contact each other and the sliding friction between the plates when braking the rotating body are caused. There is a problem that the sound (for example, the brake sound of the "key") is loud.

Means for Solving the Problems The present invention relates to a friction brake for applying a braking force to the rotating body by pressure contact between a braking plate and a friction plate, one of which is restricted in rotation and the other of which interlocks with the rotating body. The problem is solved by a configuration in which a plurality of convex portions are formed on the contact surface with the friction plate at intervals in the circumferential direction.

The braking plate comes into contact with the friction plate at the convex portions formed at intervals in the circumferential direction.

Therefore, the cushioning function of the convex portion softens the collision between the braking plate and the friction plate.

Also, when the braking force is being applied to the rotating body, the braking plate does not come into full contact with the friction plate, so there are fewer contacting parts than before,
The occurrence of small surface vibrations (vibrations) due to resonance is reduced, thus reducing the production of braking noise.

Embodiment An embodiment of the present invention will be described below with reference to the drawings.

A friction type (disc) brake 10 (FIG. 4) is an example of a friction type brake that applies a braking force to the rotating body by pressure contact between a braking plate and a friction plate, one of which is restricted in rotation and the other of which interlocks with the rotating body. The ring-shaped coil 12 provided in the yoke 11, the three springs 13, and the yoke 11
An armature 15 movably provided on three guide shafts 14 installed upright, three braking plates 16, a spline hub 17 penetrating the three braking plates 16, and three braking plates. The spline hub 1 is interposed between the plates 16
The two friction plates (including a lining made of friction material) 18 included in FIG. The spline hub 17 and the friction plate 18 are in a spline engagement relationship and are integrated with each other in the rotational direction.
Further, the spline hub 17 is fitted and inserted in the output shaft 30 of the motor in the relationship of the key groove and the key.

As shown in FIGS. 1 and 2, the braking plate 16 is a metal plate having a substantially triangular shape, and a guide hole 19 through which the guide shaft 14 penetrates is formed near each vertex of the triangle. Has been done. The friction surfaces 20, 20 on both sides of the braking plate 16 are relatively short ridges (projections) 21 having an arcuate cross section formed radially by a press machine, so that the friction surfaces 20 are wavy. . It should be noted that, in order to make the braking plate 16 compatible with each other, as shown in FIGS. 1 and 2, all three ridges 21 are alternately formed on both sides in FIG.
The ridges may be formed on both surfaces in this way only on the central braking plate, and the ridges on both ends of the braking plates may be formed only on the surfaces facing the friction plates.

The ridges 21 formed on both sides of the braking plate shown in FIG.
May be narrowed so that the (circumferential direction) cross-sectional shape of the braking plate is literally “wavy”, and the tip of the protrusion 21 may be flat.

Next, the operation will be described.

In order to change the output shaft 30 of the motor from the braking state shown in FIG. 4 to the non-braking state, the coil 12 is excited and the armature 15 is attracted and moved to the coil 12 side against the spring 13.
The friction plate 18 and the braking plate 16, which have been pressed against each other by the spring 13 until now, are released from the pressed condition. As a result, the friction plate 18 and the spline hub 17 are in a rotatable state, and the output shaft 30 of the motor can freely rotate.

Further, in order to bring the output shaft 30 of the motor in the non-braking state into the braking state of FIG. 4, the current to the coil 12 is cut off, the attraction of the armature 15 is released, and the elasticity of the spring 13 causes the armature 15 to brake The plate 16 is brought into pressure contact with the rotating friction plate 18. As a result, the friction plate 18 and the spline hub 17 are restricted in rotation, and the output shaft 30 of the motor is stopped.

In the above-described operation, when the friction plate 18 is in contact with the rotating friction plate 18, the friction surface 20 has an elastic wavy shape, so that the collision is softened and the collision noise is reduced. Further, even if the braking plate 16 comes into contact with the rotating friction plate 18, the entire surface does not come into contact, so that a small surface vibration (chatter) due to resonance, that is, a braking sound of "key" is reduced.

By the way, the braking plate 36 shown in FIG. 5 is a conventional braking plate, and the friction surface 40 is flat, and since the entire surface is in contact with the friction plate, the braking sound is loudest. The braking plate 56 shown in FIG. 6 shows the braking plate 56 in which the contact surface 61 of the friction surface 60 becomes longer in the circumferential direction during use. According to the experimental results, the contact surface 61 becomes longer in the circumferential direction. If so, the brake sound will still be generated, so the depth of the ridges 21, etc.
It is necessary to determine that the contact surfaces will not be connected during use. As a reference, when the diameter is about 118 mm, the protrusion height A of the ridge (Fig. 2) is
The range of 0.05 mm to 0.5 mm is preferable.

Note that similar characteristics can be obtained by forming a plurality of circular protrusions (not shown) instead of providing the protrusions on the braking plate as described above.

Effect of the Invention The braking plate of the present invention serves as a cushioning function when the convex portions formed at intervals in the circumferential direction on the surface of the braking plate come into contact with the friction plate, so that the collision between the plates is softened and the braking plate is reduced. The impact sound of can be reduced.

Further, when the braking force is applied to the rotating body, the braking plate comes into contact with the friction plate only at the convex portion, so that the portion contacting the friction plate is reduced, and small surface vibration (chatter) due to resonance occurs. The braking noise can be reduced and the braking noise can be reduced.

[Brief description of drawings]

FIG. 1 is a front view of the brake plate of the present invention, and FIG. 2 is a front view of FIG.
2 is a sectional view taken in the direction of the arrow, FIG. 3 is a front view of a friction brake having a braking plate according to the present invention, FIG. 4 is a sectional view taken in the direction of arrow 4-4 in FIG. 3, FIG. 5 and FIG. It is a front view of a brake plate for explaining an experimental result. 10 ... Friction type brake, 16 ... Braking plate 18 ... Friction plate, 20 ... Friction surface 21 ... Ridge (projection)

Claims (1)

[Scope of utility model registration request] 1. A friction brake for applying a braking force to a rotating body by pressure contact between a braking plate and a friction plate, one of which is restricted in rotation and the other of which interlocks with the rotating body, wherein a contact surface of the braking plate with the friction plate. A friction brake characterized in that a plurality of convex portions are formed at intervals in the circumferential direction.