JPH03277164A - Linear motor - Google Patents

Abstract

PURPOSE:To suppress spark to be produced between a brush and a power supply board by providing a capacitor for discharging energy produced in a coil upon interruption of power supply to the coil. CONSTITUTION:Capacitors 13 are connected between brushes 4a-4c or between the terminals of coils 3a-3c to be connected with the brush 4. Consequently, energy produced in the coils 3a-3c can be discharged to the capacitors 13 and consumed therein upon interruption of power supply to the coils 3a-3c. Since such voltage as causing dielectric breakdown of air is not applied between the brush 4 and a power supply board 5, spark can be suppressed. Spark can also be suppressed by connecting the capacitors 13, respectively, across the coils 3a-3c.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a linear motor used for conveyance.

[Prior art] Recently, research has been conducted into using linear motors for conveyance.
This type of linear motor consists of flat permanent magnets that are magnetized with different polarities in the thickness direction and alternately magnetized with different polarities at constant intervals in the longitudinal direction, and are arranged along the longitudinal direction. A stator block and a plurality of electromagnets each having a reversely wound coil wound around each side of a substantially U-shaped iron core with a permanent magnet interposed between both sides are arranged in a row in the longitudinal direction of the permanent magnet. There is a so-called moving coil type, which consists of a formed mover block and in which current is selectively passed through the coils of the respective electromagnets to propel the mover block. Here, the mover block includes a brush to which a coil for each electromagnet is connected, and the stator block includes the permanent magnet, a base body in which the permanent magnet is disposed over the entire length of the center of the lower surface of the top plate, and the brush. and a power supply board on which a conductor part is formed, which slides into contact with the movable element block and applies positive and negative voltages alternately to the coil via the brush as the movable element block moves.

[Problem to be Solved by the Invention J] By the way, in the above-mentioned linear motor, the energization of the coil via the brush is intermittent, so when the current in the coil is interrupted, the coil will There was a problem in that when the current tried to continue flowing, the air insulation was destroyed and sparks were generated between the brush and the power supply board, and the electromagnetic energy released at this time caused radio interference to external equipment. .

The present invention has been made in view of the above points, and its purpose is to provide a linear motor that can suppress the generation of sparks between the brush and the power supply board. .

[Means for Solving the Problems 1] In order to achieve the above object, the present invention includes a capacitor that releases energy generated in the coil when power to the coil is cut off.

Incidentally, a housing plate may be formed in a brush holder made of an insulating material that attaches the brush to the movable element block, and the capacitor may be housed in the housing plate.

[Function] By having the configuration as described above, the present invention prevents the voltage that would destroy the air insulation between the brush and the power supply board from being applied, thereby suppressing the generation of sparks.

[Example 1 An embodiment of the present invention is shown in FIGS. 1 to 8.

The linear motor of this embodiment is of a moving coil type, and has a structure in which a movable block B slides along a stator block A.

As shown in FIG. 3 or 4, the stator block A includes an elongated base body 7 with a cross-section shaped like an arrow, and a horizontal piece 7 of this base body 7.
A long permanent magnet 1 arranged over the entire length of the center of a
and a power supply board 5 that is attached to the inner wall surface of the vertical piece 7b of the base body 7 and supplies power to the coil 3 of the movable block B.

As shown in Fig. 6, the permanent magnet 1 has a flat plate shape and is magnetized alternately to N and S poles at a constant pitch in the longitudinal direction, and also in the thickness direction as shown in Fig. 7(b) or (
As shown in c), it is magnetized to N and S poles. The permanent magnet 1 is attached to the horizontal piece 7a of the base body 7 by gluing or caulking. The length of a pair of magnet pieces consisting of an N pole and an S pole in the longitudinal direction of the permanent magnet 1 is L as shown in FIG.

As shown in FIG. 7(a), the power supply board 5 has an insulation section 5e that meanders vertically at regular intervals in the center, and the upper and lower sections separated by the insulation section 5c are connected to conductor sections 5m and 5b.
It's Toshide. A positive voltage is applied from the upper conductor W65a to the coil 3 of the mover block B, which will be described later, and a negative voltage is applied to the coil 3 from the lower conductor 5b.

Here, each conductor portion is 5 m long.

The width of the part protruding toward the center side of 5b is formed to be L/3, and the insulating part 5c located at both conductor parts 5a and Sb is open.
The width is L/6.

The mover block B includes an iron core 2 formed by laminating substantially U-shaped yokes, and a winding i! c coil 3,
It has three phases in which three electromagnets 8 each consisting of a brush 4 connected to one end of the coil 3 and in sliding contact with the power supply board 5 are arranged in a row. Note that the other ends of the coils 3 are connected to each other by IIl. The length of each electromagnet 8 along the longitudinal direction of the base body 7 is set not to exceed L/3. In other words, when the length of the iron core 2 along the longitudinal direction of the stator block A is 1+, /I<L/3, and when the coil 3 is wound, the length of the electromagnet 8 also exceeds the above L/3. I try not to. A brush holder 20 made of insulating material is provided for each electromagnet 8.
The distance between the brushes 4 attached to the mover block B is set to L/3, and these brushes 4 are attached to the movable block B.
It comes into contact with the center position of the power supply board 4 indicated by the dashed line in the figure (,).

As shown in FIG. 5, the stator block A' and movable block B are rectangular cylindrical blocks made of a conductive material such as aluminum, and are disposed inside the guide rail case 6. Seven guide grooves 9 are provided along the longitudinal direction at the center of the lower surface. A connecting body 10 for connecting objects to be conveyed, such as ornaments, is integrally fixed to the mover block B, and a connecting piece 10a protruding from this connecting body 10 is inserted through the id m9 of the boot rail 6. Mover block B
is housed in the boot rail case 6.

In addition, a flow 11 is provided in m1ll of the connecting body 10 to smooth the movement of the mover block B, and a slip with a small coefficient of friction is provided at the portion where the iron core 1 of the mover block B slides on the base 7. Attach the plate 12. Also,
The holes 16 formed in the connecting piece 10a are for connecting objects to be transported.

In this linear motor, with the above-described structure, a lightning current is passed from the power supply board 5 to any two of the three-phase coils 38 to 3C, and the magnetomotive force generated at this time generates a propulsive force in a certain direction. As a result, the movable block B moves forward. In addition, when moving the movable block B in the opposite direction, the conductor portion 5a of the power supply board 5.

The polarity of the voltage of 5b may be reversed.

By the way, in this embodiment, as shown in FIG.
A capacitor 13 is connected between each of the coils 3a to 4c (or between the terminals of the coils 3a to 3C to which the brush 4 is connected). In this way, the energy generated in the coils 3a to 3c when the current supply to the coils 38 to 3c is interrupted can be released to the capacitor 13 and consumed. This eliminates the voltage that would destroy the insulation of the air between the two, making it possible to suppress (or reduce) the generation of sparks. In addition, capacitor 13
are connected to both ends of each of the coils 38 to 3c as shown in FIG. 8, and the generation of sparks can be suppressed in the same manner as in the above case. As shown in FIG. 2, one end of each of the electromagnets 88 to 8C of the brush holder 20 to which the brush 4 is attached is bulged out, and a storage recess 20 is formed in the bulge to accommodate the capacitor 13. and the brush 4 etc. can be easily connected. In addition, this storage recess 20
When a pair of protrusions 21 are formed on the wall of the capacitor 13
can be prevented from falling off.

[Effects of the Invention] As described above, the present invention includes a capacitor that releases the energy generated in the coil when the current to the coil is cut off, so air insulation is provided between the brush and the power supply board. No destructive voltage is applied, so the generation of sparks can be suppressed.

Note that if a housing recess for housing the capacitor is formed in a brush holder made of an insulating material that attaches the brush to the movable element block, the capacitor can be easily connected to the brush or the coil.

[Brief explanation of drawings]

FIG. 1 is a circuit diagram showing a connection state of a capacitor according to an embodiment of the present invention, and FIGS. 2(a) and (b) are a perspective view of a brush holder in which a capacitor storage recess is formed and a sectional view of its essential parts. , Fig. 3 is a front view of the linear motor, Fig. 4 is a perspective view of the same as above, Fig. 5 is a perspective view when a boot rail is provided, and Fig. 6 is a perspective view of the linear motor.
The figure is a perspective view showing the structure of the main parts same as above, FIG. 7(,) is a front view of the power supply board, FIGS. FIG. 8 is a circuit diagram showing another method of connecting capacitors. A is a stator block, B is a mover block, 1 is a permanent magnet, 2 is an iron core, 3a to 3c are coils, 4a to 4c are brushes, 5 is a power supply board, 13 is a capacitor, 2 () is a brush holder, 21 is a storage recess.

Claims (2)

[Claims] (1) A stator block in which flat permanent magnets, which are magnetized with different polarities in the thickness direction and alternately magnetized with different polarities at regular intervals in the longitudinal direction, are arranged along the longitudinal direction, and the permanent magnets are arranged on both sides. a mover block formed by arranging a plurality of electromagnets in the longitudinal direction of the permanent magnets each having a reversely wound coil wound around each side piece of a substantially U-shaped iron core interposed therebetween; A brush to which the coil of each electromagnet is connected is provided on the movable block, and a conductor part is formed in which the brush comes into sliding contact and alternately applies positive and negative voltages to the coil through this brush as the movable block moves. What is claimed is: 1. A linear motor having a stator block provided with a power supply board provided with the above-mentioned power supply board, characterized in that the linear motor is equipped with a capacitor that releases energy generated in the coil when power to the coil is cut off. (2) The linear motor according to claim 1, characterized in that a brush holder made of an insulating material, which attaches the brush to the movable element block, has a storage recess for accommodating the capacitor.