JP2579652Y2 - Electromagnetic brake - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in an electromagnetic brake used alone or as an electromagnetic brake portion of an electromagnetic clutch / brake unit.

[0002]

2. Description of the Related Art A conventional electromagnetic brake of this type is configured as shown in FIG. In the figure, reference numeral 1 denotes a magnetic pole body having an inverted U-shaped cross section, and the magnetic pole body is fixed to a fixing portion 2 such as a frame of a machine or a casing of a clutch / brake unit with screws 3 or the like. An excitation coil 4 is housed in the recess 1a of the magnetic pole body 1. Reference numeral 5 denotes a brake plate having a substantially U-shaped cross section, which is fixed to the magnetic pole body 1 by screws 6. 5a is a notch groove, and 5b is a friction plate. Reference numeral 7 denotes an armature, the base of which is spline-coupled to an armature hub 9 and a return spring 8 is mounted on the drive shaft 10.
Are fixed in the radial direction and are movable in the axial direction. It is assumed that the drive shaft 10 is connected to a drive member (not shown) to be controlled.

In the above configuration, the armature 7 rotates together with the drive shaft connected to the drive member when the coil 4 is not energized and is not excited. In this state, when the coil 4 is excited, the magnetic flux passes as shown by the broken line in FIG. 2 and the armature 7 is attracted to the left by the magnetic attraction of the magnetic pole body 1 and adheres to the friction plate 5b side of the brake plate body 5. Thus, a braking force is applied to the armature 7, and thus the drive shaft 10, that is, the drive member.

[0004]

By the way, in the case of a conventional electromagnetic brake of this type, as shown in FIG. 2, the connecting portion between the magnetic pole body 1 and the brake plate body 5 constituting a magnetic circuit, particularly, ,
Mutual contact between the inner peripheral tip 1N of the magnetic pole body 1 and the inner peripheral step 5D of the brake plate 5 is a surface contact, and the magnetic resistance of this portion is small, so that the coil 4 Even if the current is cut off, the magnetic flux (magnetic attraction force) is not attenuated well and the armature 7
However, there was a problem that the release time of the brakes was prolonged without being released quickly. An object of the present invention is to provide an electromagnetic brake which solves the above-mentioned problems (problems) of the conventional one.

[0005]

In order to solve the above-mentioned problems, the electromagnetic brake of the present invention has a recess for accommodating the exciting coil 4, and has a reverse U-shaped cross section in which the base is fixed to the fixed portion. Magnetic pole body 1, a brake plate body 5 having a substantially U-shaped cross section, which is disposed to face the magnetic pole body 1 and is fixed so as to be fitted to an outer periphery of a tip end of the magnetic pole body 1, and a back surface of the brake plate body 5. The armature 7 is supported by a spline or the like so as to be movable in the axial direction of the drive shaft and fixed in the radial direction at a predetermined interval with respect to the friction surface provided on the armature 7 and a return spring 8 of the armature 7. In the electromagnetic brake, the armature 7 is brought into close contact with the friction surface of the brake plate 5 by the attraction force generated by the excitation of the excitation coil 4 to apply a control force to the drive shaft 10. Step 1M in part A step 5E is formed in the brake plate 5 at a position facing the step 1M of the magnetic pole body 1, and a nonmagnetic collar 11 is formed in a recess formed between the steps 1M and 5E. Was configured to be mounted.

[0006]

According to the present invention, the connecting portion between the magnetic pole body and the brake plate constituting the magnetic circuit is the conventional one, especially the tip of the inner circumference of the magnetic pole body 1 having a low magnetic resistance. A non-magnetic collar is attached to a contact portion between the step portion 1M and the inner peripheral step portion 5E of the brake plate body 5 as described later so that the magnetic resistance of the magnetic circuit is increased to be appropriate. As a result, when the energization of the coil is cut off, the attenuation of the magnetic flux (magnetic attraction force) is accelerated, and the release time of the armature is shortened.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be specifically described below with reference to an embodiment shown in FIG. In this figure, the same parts as those in the prior art are denoted by the same reference numerals as in FIG. Reference numeral 11 denotes a non-magnetic collar such as aluminum or stainless steel. The non-magnetic collar 11 is fitted to a step 1M formed at the tip of the inner circumference of the magnetic pole body 1 and a step 1M of the magnetic pole body 1 of the brake plate 5. A step 5E is formed at the opposing position where the step
It is press-fitted into a recess formed between M and 5E. The electromagnetic brake of the present invention is configured as described above.

In the present invention, the application of the braking force to the drive shaft 10 connected to the drive member (not shown) by the energization of the coil 4 is performed in exactly the same manner as in the prior art. By the way, in the present invention, since the non-magnetic collar 11 is present in the magnetic circuit, the magnetic flux (magnetic attraction force) after the energization of the exciting coil 4 is cut off rapidly, and the armature 7
Release time is reduced.

[0009]

The electromagnetic brake of the present invention has a step 1M formed at the inner peripheral tip of the magnetic pole body 1 forming the magnetic circuit as described above, and a step of the magnetic pole body 1 of the brake plate body 5. 1
The stepped portion 5E is formed at a position facing the M and the nonmagnetic collar is mounted in the recess formed between the stepped portions 1M and 5E. Have. Since the magnetic flux (magnetic attraction force) is attenuated immediately after the energization of the coil is cut off, the release time of the armature, that is, the brake, is greatly reduced as compared with the conventional one. Therefore, when the present invention is applied to the electromagnetic clutch and the brake of the brake unit, the inching operation of the clutch and the brake is performed smoothly, and the abnormal friction of the clutch caused by the long release time of the brake in the conventional one is caused. That situation was prevented. Moreover, in the present invention, the configuration for this is a simple operation of mounting a non-magnetic collar separately manufactured as a part between the steps 1M and 5E, so that the practicality in manufacturing and management is great. . Since the non-magnetic collar 11 is configured to be mounted between the steps 1M and 5E, when the friction plate 5b or the brake plate 5 is rubbed, the screws 6 are loosened to remove the assembly from the friction plate. And the brake plate can be easily removed and replaced with a good one.

[Brief description of the drawings]

FIG. 1 is a half vertical sectional front view showing an embodiment of the present invention.

FIG. 2 is a half vertical sectional front view showing a configuration of a conventional example.

[Explanation of symbols]

 1: magnetic pole body 1M: stepped portion 4: excitation coil 5: brake plate 5E: stepped portion 7: armature 8: return spring 11: non-magnetic color

Claims (1)

(57) [Scope of request for utility model registration] 1. A magnetic pole body (1) having a concave portion for accommodating an exciting coil (4) and having a base fixed to a fixing portion and having a reverse U-shaped cross section, and disposed opposite to the magnetic pole body (1). Beyond this pole body (1)
A brake plate (5) having a substantially U-shaped cross-section, which is fixed so as to be fitted to the outer periphery of the end, and is driven at a predetermined distance from a friction surface provided on the back surface of the brake plate (5). An armature (7) supported by a spline or the like so as to be movable in the axial direction and fixed in the radial direction, and a return spring (8) of the armature (7); In the electromagnetic brake, the armature (7) is brought into close contact with the friction surface of the brake plate (5) by an attraction force generated by the excitation to apply a control force to the drive shaft (10). stepped portion on the inner peripheral tip portion (1) and (1M), also stepped portions of the pole pieces of the brake plate member (5) (1) (1
A step (5E) is formed at the position where the step ( M) is fitted, and a non-magnetic collar (11) is mounted in a recess formed between the steps (1M) and (5E). An electromagnetic brake characterized by the following.