JPH0510833U - Non-excitation actuated electromagnetic brake - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a non-excitation actuated electromagnetic brake that increases the stable solution range of the brake and stabilizes the torque during brake braking (holding). . [Composition] A permanent magnet is arranged in parallel with a magnetic pole body and an exciting coil forming an electromagnet section, an armature is separated from the magnetic pole body of the electromagnet section by a gap, and a return for returning the armature in the axial direction. In the non-excitation actuated electromagnetic brake provided with a spring, the inner pole and the outer pole forming the magnetic circuit of the magnetic flux by the exciting coil face the outer pole with a magnetic gap therebetween. A predetermined notch is formed at the tip of the magnetic pole of the inner pole arranged in that part.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

  The present invention relates to improvement of a non-excitation actuated electromagnetic brake.

[0002]

[Prior art]

The conventional one is configured as shown in FIG. In the figure, 1 is a spline hub, 2 is a retaining ring for a shaft, 3 is a detent ring, 4 is a spring plate serving as a return spring, 5 is an armature ring, 6 is an armature, and 7 is a fader. Thing. Reference numeral 8 is a coil, 9 is a lead wire for feeding power to the coil 8, 10 is a flange, 11 is a mounting bolt, 12 is a magnet assembly consisting of an inner pole 12a and an outer pole 12b, and 13 is a permanent magnet. Is. In a normal state (when no current is applied), a magnetic flux is formed by the permanent magnet 13 in the armature 6, the inner pole 12a and the outer pole 12b as shown by the broken line in FIG. The magnet 7 is attracted to the facing 7 of the magnet assembly 12, and the rotating part is braked or held. When the coil 8 is energized in this state, the magnetic flux generated by energizing the coil 8 is generated as shown by the solid line, and the magnetic flux generated by the permanent magnet 13 is canceled. Since the magnetic attraction force in this case changes as shown in FIG. 6 and the offset point becomes the coil voltage V _A having the magnetic center axis, it is difficult to release the brake at this one point. The spring force F _B of the spring plate 4 is urged to release the brake. Specifically, when the voltage applied to the coil 8 reaches V _A or higher and the magnetic flux due to this voltage exceeds a predetermined value, the magnetic flux generated by the permanent magnet 13 is canceled by the reverse magnetic flux generated by the coil, and the armature 6 and the magnet assembly 12 are cancelled. The magnetic attraction force between them disappears, and the armature 6 is released by the spring force of the spring plate 4. In addition, FIG. 5 shows a magnetic flux passing state in the vicinity of the magnetic gap K between the inner pole 12a and the outer pole 12b constituting the magnet assembly 12 in this case, and the solid line indicates the effective magnetic flux φ, The broken line shows the leakage flux φ _L. FIG. 6 is a characteristic diagram showing this relationship, where the horizontal axis is the coil voltage (or current) and the vertical axis is the magnetic attraction force. In the figure, A is the magnetic center axis passing through the coil voltage V _{A at} which the magnetic flux from the coil 8 and the magnetic flux from the permanent magnet 13 are completely canceled, and B is the spring force F _B of the spring plate 4. The range of the coil voltages V _{1 to} V ₂ corresponding to the intersection of the characteristic of the level line B and the magnetic attraction force F is the stable release range of this non-excitation type brake.

[0003]

[Problems to be solved by the device]

  The conventional structure has the following problems due to the above structure.   That is, in the normal case, this break is voltage (current) controlled, and the voltage is kept at a substantially constant value. And release the brake by turning the power switch on and off. I was braking (holding).   In this case, as shown in Fig. 6, the stable release range is narrow, so the voltage must be within the release voltage range. Even if set to, coil resistance changes subtly due to changes in jule heat, atmosphere, temperature, etc. Therefore, if the setting voltage is not adjusted properly, the stable release range may be exceeded. Occurs, the brake may not be released normally, or the release operation may become unstable. There was a problem that   Therefore, it is necessary to increase the stable release range and stabilize the torque during brake braking (holding). Was requested.   The present invention is a non-excitation actuated type that solves the problems (problems) of the above-mentioned conventional ones. The purpose is to provide a break.

[0004]

[Means for Solving the Problems]

  The present invention arranges a magnetic pole body and an exciting coil forming an electromagnet part in parallel with a permanent magnet. , The armature is separated from the magnetic pole body of the electromagnet by a gap, and the armature is A non-excitation actuated electromagnetic brake equipped with a spring for returning in the direction The inner pole and the outer pole which form the magnetic circuit of the magnetic flux by the exciting coil. Of the inner pole, which is arranged in a portion facing the outer pole across the magnetic gap. -A non-excitation actuated electromagnetic brake with a predetermined notch formed at the magnetic pole tip Regarding rake.   In this case, the above-mentioned cutout portion is directed toward the inner pole in the radial direction. It is desirable to configure the portion to form a slope.

[0005]

[Action]

  In the present invention, the inner pole and the outer pole which form the magnetic circuit by the magnetic flux of the coil The magnets located in the part of the taper facing the outer pole across the magnetic gap. A predetermined notch is formed at the pole tip to increase the magnetic gap to an appropriate volume. Since the coil voltage is increased, the coil voltage increases and the magnetic flux of this coil is increased by a predetermined amount. When trying to rise above the above values, the magnetic poles were made to saturate magnetically at an early stage.   As a result, the characteristic of the magnetic attraction force of the brake is more rightward from the magnetic center axis than leftward. The slope becomes small, and the position of the intersection on the right side with the spring force of the return spring is moved to the right. It Therefore, the stable release range of the brake is increased.

[0006]

【Example】

Hereinafter, the present invention will be described with reference to an embodiment shown in FIGS. In FIG. 1, structures similar to those of the conventional example are designated by the same reference numerals as those in FIG. According to the present invention, as shown in the figure, a portion of the magnetic gap K existing in the portion of the inner assembly 12a constituting the magnet assembly 12 which forms a magnetic circuit by the magnetic flux of the coil and the outer assembly 12b is disposed. In order to increase the volume so as to be an appropriate volume, there is a structural feature in that a notch portion 14 having a predetermined shape is formed in the magnetic pole portion at the tip of the inner pole 12a. In the present embodiment, the notch portion 14 has a structure in which the tip end portion of the inner pole forms a slope toward the radial direction, which is said to be the simplest shape in machining, but other shapes, for example, Various deformations are conceivable, such as a conical shape with a flat tip. That is, in the present invention, the presence of the notch portion 14 reduces the cross-sectional area of the magnetic circuit through which the effective magnetic flux φ passes, thereby increasing the magnetic flux density of the effective magnetic flux and, as a reaction thereof, reducing the leakage magnetic flux. For this reason, the leakage flux φ _L generated in the conventional one as shown in FIG. 5 is reduced to φ _L 'as shown in FIG. 2, and when the magnetic flux due to the coil exceeds a predetermined amount, magnetic saturation occurs. I am trying to let you. As a result, the magnetic attraction force of the non-excitation actuated brake of the present invention has a characteristic with a small gradient on the right side (the side where the coil voltage is large) from the magnetic center axis A as shown in FIG. - stable release range of key is increased as compared with the conventional and V ₁ ~V _3.

[0007]

[Effect of device]

  According to the present invention, as described above, the inner portion of the magnetic circuit configuration section using the coil is used. For simple structural improvement by forming a predetermined notch in the magnetic pole at the tip of the pole Therefore, it has an excellent effect that the stable release voltage range of the brake can be increased. Have fruit.   In addition, in this case, the notch is directed in the radial direction of the inner pole. If the tip of the tool is constructed so as to form a slope, it is extremely easy to work and It is purposeful.

[Brief description of drawings]

FIG. 1 is a partially cutaway front view showing an embodiment of the present invention with a part omitted.

FIG. 2 is a cross-sectional view of an essential part of the present invention.

FIG. 3 is a characteristic diagram showing a comparison between the magnetic attraction force of the brake of the present invention and the magnetic attraction force of the conventional brake.

FIG. 4 is a front view of a half section showing a structure of a conventional example.

FIG. 5 is a sectional view of a main part of a conventional example.

FIG. 6 is a characteristic diagram of a magnetic attraction force of a brake of a conventional example.

[Explanation of symbols]

12: Magnet assembly 12a: Inner pole 12b: Outer pole 14: Notch

Claims (2)

[Scope of utility model registration request] 1. A magnetic pole body constituting an electromagnet section and an exciting coil are arranged in parallel with a permanent magnet, an armature is separated from the magnetic pole body of the electromagnet section by a gap, and the armature is returned in the axial direction. In a non-excitation actuated electromagnetic brake equipped with a return spring, the inner pole and the outer pole forming the magnetic circuit of the magnetic flux by the exciting coil are separated from the outer pole by a magnetic gap. A non-excitation actuated electromagnetic brake, characterized in that a predetermined notch is formed at the tip of the magnetic pole of the inner pole arranged at the facing portion. 2. The non-excitation actuated electromagnetic brake according to claim 1, wherein said notch portion is configured such that the tip end portion thereof forms a slope in the radial direction of the inner pole.