JP2643161B2 - Brake device for linear DC motor - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an emergency brake device mainly used for a FA linear DC motor such as an industrial robot.

2. Description of the Related Art As shown in FIGS. 4 and 5, a conventional brake device for a linear DC motor of this type is a non-excited operation type brake device 2 in a width direction orthogonal to a running direction of a linear DC motor 1.
Was arranged. Although not shown in detail in the figure, the brake device is provided with a dedicated permanent magnet and a movable element, and the movable element is in close contact with the friction plate 3 to perform a braking action during non-excitation such as a power failure, while exciting during normal operation. sometimes it was supposed to be released separated by a gap g ₁ as shown in the figure.

4, 5 , 6, and 7 are a motor plate, a stator, a permanent magnet, and a back core of the linear DC motor, respectively. 8 is a back plate, and 9 is a linear bearing.

[Problems to be Solved by the Invention] Since the conventional one uses a dedicated non-excitation actuated brake device, this configuration is required extra, and the linear DC motor must be installed to install this brake device. There is a drawback in that a space for providing the friction plate of the brake device over the entire stroke in the width direction orthogonal to the running direction is required.

[Means for Solving the Problems] A brake device for a linear DC motor according to the present invention aims to solve the above-mentioned problems of the conventional device.
In order to achieve this object, a linear DC motor having permanent magnets for a field arranged linearly includes a brake core having an exciting coil juxtaposed in the traveling direction of the stator core. The permanent magnet and the back core are also used for braking, and the magnetic flux of the permanent magnet attracts the brake core to the back core to operate the emergency brake, while the power supply of the brake coil is excited during normal operation with a power supply. With this configuration, the magnetic flux of the permanent magnet is canceled and the brake is released.

Embodiment An embodiment of the present invention shown in FIGS. 1 to 3 will be described below. In the figure, components corresponding to those of the prior art are denoted by the same reference numerals as in FIGS.
In the brake device 10 of the present invention, a brake core 10a having a U-shaped cross section is connected to a stator of a linear DC motor as shown in the figure.
If the traveling direction of the length of 5 the core 5a and the L _m, with collocated stator core as L _b becomes the length of the same width as this (L _m> L _b), the central portion S of the brake core 10a stator core 5a and are opposed to each other across the permanent magnet 6 and the gap g ₂ Similarly, while its opposite ends T is constituted so as to face each other with the back core 7 and the gap g _1. In this case, they are arranged so that g ₂ > g ₁ . The permanent magnets 6 have N poles and S poles alternately arranged at a predetermined pitch. 10c is a coil for excitation. In FIG. 1 and FIG. 2, for convenience of explanation, the portion of the brake core 10a is shown by hatching.

FIG. 3 is a perspective view showing only the structure of the brake device 10 for illustrating the operation of the present invention.

Although the basic configuration and operation of the linear motor provided with the above-described brake device of the present invention are well known, the driving principle thereof will be briefly described below.

The linear motor has a shape as if a general rotary servomotor is developed. As shown in FIGS. 1 and 2 or FIGS. 4 and 5 described above, the back plate 8 and the motor It is composed of a plate 4, a stator 5, a permanent magnet 6, a back core 7, and the like.

The driving principle is the same as that of the servo motor.

In other words, a thrust is generated by passing a current through the winding of the stator facing the permanent magnet 6 as a field through a gap.

As described above, the permanent magnet has a predetermined pitch N
The poles and S poles are alternately arranged. The current is caused to flow in a predetermined direction while detecting the relative position between the field pole and the winding so that the direction of the thrust is the same in all windings. Such a linear motor is capable of moving by a command pulse at a speed proportional to the frequency of the command pulse, for example, by a command signal from a controller, and performs a positioning operation.

[Operation] Next, the operation of the present invention will be described mainly with reference to FIG. During normal operation, the direction of the current flowing through the coil 10C is switched by the means for detecting the magnetic pole of the permanent magnet 6 in accordance with the polarity of the magnet, and the coil 10c is excited by turning on a power supply (not shown). Magnetic flux Φ by this coil
Because ₂ is generated to cancel out the magnetic fluxes from [Phi ₁ by the permanent magnet 5, the brake can gap g ₁ between the back core 7 is in a released state, the linear direct current motor 1 is in a predetermined operating. Note that various types of means for detecting the magnetic pole of the permanent magnet have been known. This embodiment also employs these conventionally known detection means.

Thus when the unexpected situation occurs that power failure during a normal operation, since the magnetic flux of only the permanent magnets 6 the excitation is interrupted coil 10C, the brake core 10a and the gap g ₁ zero
Is attracted to the back core 7 and the emergency braking is applied to the motor 1 .

In the event of an unexpected event other than a power failure, a sensor for detecting this emergency is provided, and the power is turned off in conjunction with the operation of this sensor to apply an emergency brake in the same manner as described above.

[Effects of the Invention] As described above, the present invention is not a conventional linear DC motor, but instead of the non-excitation operation type brake device provided in the width direction orthogonal to the traveling direction, the progress of the stator core of the motor described above. A brake core provided with an exciting coil is provided in parallel with the direction, and the permanent magnet and the back core of the linear DC motor are also used for the brake device.

Therefore, it has the following excellent effects as compared with the conventional one.

The number of parts can be reduced because the permanent magnet and the brake friction plate, which were required in the conventional one, can be omitted.

Conventionally, a brake friction plate provided at a position in the width direction orthogonal to the traveling direction over the entire length of the stroke can be omitted, so that the space in the width direction of the device can be reduced accordingly.

As a result, the entire apparatus can be manufactured small and inexpensively.

BRIEF DESCRIPTION OF THE DRAWINGS FIGS. 1 to 3 show one embodiment of the present invention, wherein FIG. 1 is a plan view, FIG. 2 is a sectional view taken along line AA 'of FIG.
The figure is a perspective view. 4 and 5 show conventional examples, respectively.
FIG. 4 is a plan view, and FIG. 5 is a sectional view taken along line AA 'of FIG. 1 Linear DC motor 10 Brake device 10c Coil 6 Permanent magnet 7 Back core

Claims (1)

(57) [Claims] 1. A linear DC motor having permanent magnets for a field arranged linearly, comprising: a brake core having an exciting coil juxtaposed in a direction in which the stator core travels; And the back core also serve as a brake. The magnetic flux of the permanent magnet adsorbs the brake core to the back core to operate the emergency brake. A brake device for a linear DC motor, wherein a magnetic flux of a permanent magnet is canceled and a brake is released.