JP4321033B2 - Linear motor device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a linear motor field part and a linear motor device using the same.
[0002]
[Prior art]
[First prior art]
FIG. 6 is a perspective view of a linear motor showing the first prior art.
In the figure, 1 'is a conventional field yoke (stator) in which a large number of permanent magnets 2 are arranged and fixed to form a linear motor field part, and a linear motor electric machine as a mover is interposed therethrough via a gap. The child parts 4 are arranged to face each other and move in the longitudinal direction on the stator 1 ′ by the field generated by the field yoke 1 ′ and the current flowing through the armature 4.
7 is a plan view of the field yoke 1 ′ of FIG. 6. FIG. 7A shows a magnetic flat plate as one unit constituting the field yoke 1 ′, and FIG. 7B shows two magnetic flat plates 1 ′. The state arranged in series is shown. As shown in FIG. 7, a conventional magnetic flat plate (field yoke) 1 ′ is a parallelogram flat plate having the same acute angle as the oblique angle of the permanent magnet 2 to be arranged, and 2n (n is a positive integer). The permanent magnets are arranged and fixed at an equal pitch.
[0003]
[Second prior art]
FIG. 8 is a diagram for explaining a linear scale of a linear motor showing the second prior art, in which (a) is a front sectional view and (b) is a plan view thereof.
In the figure, reference numeral 60 denotes a mover, which mainly comprises the following parts 61 to 66. That is, 61 is a drive table, 62 is a linear motor armature, 63 is a linear guide (two on the left and right), 64 is a scale head, 65 is a scale holder, and 66 is a scale lead.
On the other hand, 70 is a stator, which mainly comprises the following parts 71-73. That is, 71 is a slider base, 72 is a magnetic plate, 73 is a permanent magnet, and 74 is a linear scale.
As shown in FIG. 8, the conventional linear motor has a pair of a magnetic plate 72 having a permanent magnet 73 at the center of a stator 70 and a mover 60 having one armature 62 opposed to the magnetic plate. Linear guides 63 are arranged and fixed in parallel on both sides of the linear motor, and linear scale portions 64 and 65 are formed on one outer side thereof.
[0004]
[Problems to be solved by the invention]
However, in the first prior art magnetic flat plate, the parallelogram processing of the magnetic flat plate not only reduces the material yield but also increases the number of processing steps, which increases the manufacturing cost by about 20%.
Further, when only one magnetic flat plate is removed after assembling a plurality of magnetic flat plates, there is a problem that the removal work becomes inconvenient if it is a parallelogram.
The present invention solves the above-mentioned problems, and the first object of the present invention is to eliminate the need for parallelogram processing of a magnetic flat plate, improve the material yield, reduce the number of processing steps, and reduce the manufacturing cost. Another object of the present invention is to provide a linear motor field part that can be easily removed when a single magnetic flat plate is removed after a plurality of magnetic flat plates have been assembled.
[0005]
In the second prior art, since the linear scale portions 64 and 65 are arranged and fixed at the position L farthest from the drive center axis O of the linear motor, the gap is affected by the running accuracy of the linear motor. Events such as differing depending on the position occurred, causing problems such as a decrease in detection accuracy of the linear scale.
In addition, since it is the longest distance L from the central axis O, it is very easily affected by the vibration of the linear motor, causing problems such as difficulty in increasing the gain when adjusting the servo gain, resulting in deterioration of speed control accuracy and positioning accuracy. There was a problem, such as raising it.
[0006]
On the other hand, in order to improve the drive device for the linear motor used as a position measuring device, a pair of drive devices are provided symmetrically with respect to the linear motor arranged at the center of the main body, and the dovetail groove provided in the yoke of the drive device A permanent magnet is fixed, and a number of winding coils each configured so that the longitudinal direction portion is located on the same plane are incorporated in a mover that linearly drives between opposing permanent magnets. There is one in which a linear scale is provided at the center between coils (see, for example, Patent Document 1).
[0007]
[Patent Document 1]
Japanese Patent Laid-Open No. 10-52022
In the drive device for the linear motor described in Patent Document 1, a force from the side acts on a linear scale used as a position measuring device, and accurate control becomes impossible or damage to the machine itself may occur. However, since the linear scale described therein is installed separately from the slide unit mover, it requires a large space and the mover. Both the part and the scale head part have the disadvantage of weakening in strength, and the structure in which the scale head is inserted in the long groove processing takes a lot of man-hours for manufacturing, thus increasing the cost.
The present invention solves the above problems, and a second object of the present invention is to provide a linear motor detector that improves the detection accuracy of the linear scale and does not degrade the accuracy of speed control and the positioning accuracy. At the same time, it is an object of the present invention to provide a linear motor that can sufficiently withstand both the mover part and the linear scale part and that does not require a large space, has a small number of manufacturing steps, and thus reduces costs.
[0009]
[Means for Solving the Problems]
In order to solve the above-described problem, the linear motor device according to the first aspect of the present invention is configured such that a plurality of magnetic plates as a unit constituting the field yoke are arranged in series, and each of the magnetic plates has a traveling direction. a linear motor field portion having a plurality of permanent magnets formed by arranging fixed and equal pitch each other with a predetermined oblique angle, the linear motor field magnet part with two opposite arrangement, said two linear motor field and a linear motor armature disposed with a gap between the magnet portion, the to a linear motor field portion of the stator is fixed to the slider base, suction force constitutes the linear motor armature as the mover In the offset type linear motor device, the linear motor field portion has a rectangular magnetic plate, and the permanent magnet has a total number of 2n + 1 (n is a positive integer) on the magnetic plate. The permanent magnets arranged at both ends of the magnetic flat plate have the same shape as that of the other permanent magnets with the same left and right area in the state having the constant oblique angle. A linear scale scale portion on the drive center axis of the linear motor so as to face the linear motor armature portion on the slider base. A scale head portion that is arranged and fixed in parallel with a linear guide that supports and guides the movable element of the movable member is arranged on the armature that moves in the thrust direction between the two linear motor field portions via a heat insulating material. It is fixed.
According to a second aspect of the present invention, in the linear motor device according to the first aspect, the thermal insulating material is a material having physical properties of 0.3 [W / K · m] or less. To do.
With the above configuration, parallel plate processing is not performed on the magnetic flat plate, which improves the material yield and lowers the manufacturing cost. In addition, after assembling multiple magnetic flat plates, only one intermediate magnetic flat plate is removed. The removal work becomes easy.
In addition, the detection accuracy of the linear scale is improved, the accuracy of speed control and positioning accuracy are not degraded, and both the mover and linear scale parts can withstand sufficient strength and require a large space. In addition, the number of manufacturing steps is reduced, and thus the cost is reduced.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail with reference to the drawings.
[First Embodiment]
A first embodiment of the present invention will be described with reference to FIG. 1 and FIG.
In the figure, 1 is a field yoke according to the present invention, 2 is a first permanent magnet, and 3 and 3 'are second permanent magnets according to the present invention. In addition, 4 is the linear motor armature part as a mover like FIG. For simplicity of explanation, a linear guide and the like for supporting and guiding the mover is not shown. Due to the field generated by the field yoke 1 and the current flowing through the armature 4, it moves in the longitudinal direction on the stator 1.
2 is a plan view of the field yoke shown in FIG. 1. FIG. 2A shows a magnetic plate (field yoke) 1 as a unit constituting the field yoke, and FIG. 2B shows two magnetic plates. The state arranged in series is shown.
In the figure, the magnetic flat plate 1 is not a conventional parallelogram but a rectangle.
A total number of 2n + 1 (n is a positive integer) permanent magnets (of which 2n-1 are the first permanent magnets 2 and two are the second permanent magnets 3, 3 ') are arranged and fixed on the magnetic plate. When doing so, it is arranged with a certain oblique angle with respect to the traveling direction.
Further, as the two magnets disposed at both ends of the magnetic plate 1, the second permanent magnets 3 and 3 ′ are used. The shape of the second permanent magnet is one (3) and the other (3 ′) of the shape of the first permanent magnet 2 which is vertically cut so that the left and right areas are the same in the state having the oblique angle. It has become.
When two magnetic flat plates 1 of FIG. 1 are arranged in series, the result is as shown in FIG.
That is, when the plurality of field yokes 1 are connected, the field length of the linear motor can be increased by simply aligning the right angle portions.
As described above, according to the first embodiment, it is not necessary to process the magnetic flat plate with a parallelogram, so that the material yield can be improved.
In addition, the manufacturing cost can be reduced by reducing the number of processing steps.
In addition, when only one magnetic flat plate is removed after assembling a plurality of magnetic flat plates, the removal work is simplified because they are attached at right angles.
[0011]
If the surfaces of the permanent magnets 2, 3, 3 ′ are covered with a cover (not shown) formed of a non-magnetic thin plate material, the permanent magnets are resistant to secular change.
Furthermore, if the volume in which all the permanent magnets 2, 3, 3 ′ are included is molded with resin (not shown), it becomes stronger.
[0012]
FIG. 3 shows an application example of the first embodiment, which is an example applied to a magnetic attractive force canceling linear motor. FIG. 3A is a perspective view of a field yoke (stator) according to the present invention, and FIG. It is front sectional drawing of a magnetic attraction force cancellation type | mold linear motor.
In the figure, 5 is a mover (armature), 51 is a linear motor armature portion, 6 is a stator (field yoke), and 61 is a field yoke. The field yoke 61 that faces the linear motor armature 51 via the air gap is according to the first embodiment. That is, the magnetic flat plate 1 is rectangular, and the first permanent magnet 2 and the second permanent magnets 3 and 3 ′ are fixedly disposed on the magnetic flat plate 1 in the same way as in FIG.
Thus, even in the magnetic attraction force canceling linear motor, according to the first embodiment, since it is not necessary to process the parallelogram on the magnetic material flat plate, the material yield can be improved, and the Manufacturing costs can be reduced by reducing the number of processing steps.
In addition, when only one magnetic flat plate is removed after assembling a plurality of magnetic flat plates, the removal work is simplified because they are attached at right angles.
[0013]
[Second Embodiment]
Next, a second embodiment of the present invention will be described with reference to FIG.
FIG. 4 is a front view (a) and a plan view (b) of a linear motor according to the second embodiment of the present invention. In the figure, 11 is a drive table, 12 is a magnetic attraction force canceling type movable element, 13 is a linear guide, 14 is a heat insulating material, 16 is a scale lead, 21 is a slider base, 22 is a magnet stator, 41 is a linear scale, Reference numeral 42 denotes a scale head.
The magnetic attraction force canceling linear motor shown in the figure is a linear motor in which two magnet stators 22 are arranged parallel to and perpendicular to the upper surface of the slider base 21.
A scale 41 of a linear scale is disposed and fixed on the upper surface of the slider base 21 in parallel with the linear guide 13, and a scale head 42 that opposes the scale 41 moves between two magnet stators 22 in a thrust direction. This is a structure that is fixed to the child 12 via a heat insulating material 14.
The thermal insulating material 14 is provided so as not to raise the temperature of the scale head 42, and a thermal insulation material having a thermal conductivity of 0.3 [W / K · m] or less is used.
[0014]
As described above, according to the second embodiment of the present invention, since the linear scale 41 and the scale head 42 are on the drive center axis of the linear motor, it is less affected by the running accuracy of the linear motor. The phenomenon that the gap differs depending on the position does not occur, and the detection accuracy of the linear scale is improved.
Further, since it is on the central axis, it is not easily affected by the vibration of the linear motor, and therefore, the problem that the gain is difficult to increase during the servo gain adjustment does not occur. The speed control accuracy and positioning accuracy will not deteriorate.
[0015]
FIG. 5 shows an application example of the second embodiment of the present invention.
FIG. 5 is a front view (a) and a plan view (b) of a linear motor according to the second embodiment of the present invention. In the figure, the same reference numerals as those in FIG. Reference numeral 17 denotes a limit switch (target), and 18 denotes a limit switch (sensor unit). As can be seen from FIG. 5, the limit switch (target) 17 is stopped when it comes into contact with the limit switch (sensor unit) 18 or the like, thereby preventing overrun of the linear motor.
[0016]
【The invention's effect】
As described above, according to the first embodiment, not only the material yield is increased by making the flat plate yoke rectangular, but also the number of processing steps is reduced, and as a result, the manufacturing cost can be reduced by about 20%. In addition, when only one intermediate field yoke is removed after assembling a plurality of field yokes, the parallelogram yoke has a problem in that it is inconvenient to remove. This work becomes easy.
In addition, according to the second embodiment, by arranging and fixing the linear scale on the drive center axis of the slider, it becomes less affected by the running accuracy of the slider. Problems such as reduced detection accuracy are eliminated. Moreover, since it is on the central axis, it is not easily affected by the vibration of the linear motor, and when the servo gain is adjusted, the gain can be increased. Therefore, the speed control accuracy and the positioning accuracy can be greatly improved.
Furthermore, unlike the invention of Patent Document 1, it is possible to obtain a linear motor that can sufficiently withstand both the mover part and the linear scale part, does not require a large space, has a small number of manufacturing steps, and thus reduces the cost. Become.
[Brief description of the drawings]
FIG. 1 is a perspective view of a linear motor placed on a field yoke according to a first embodiment of the present invention.
2A is a plan view of the field yoke of FIG. 1. FIG. 2A shows a magnetic plate as a unit constituting the field yoke, and FIG. 2B shows a state in which two magnetic plates are arranged in series. Show.
FIG. 3 is a conceptual diagram showing an example in which the magnetic flat plate according to the first embodiment of the present invention is applied to a magnetic attractive force canceling linear motor, (a) is a perspective view showing left and right field yokes; (B) is a front view of a magnetic attraction force canceling linear motor.
FIG. 4 is a front view and a plan view of a linear motor according to a second embodiment of the present invention.
FIGS. 5A and 5B are a front view and a plan view of a linear motor showing an application example according to the second embodiment of the present invention. FIGS.
FIG. 6 is a perspective view of a linear motor mounted on a field yoke of a conventional linear motor.
7A is a plan view of the field yoke of FIG. 6. FIG. 7A shows a magnetic flat plate as one unit constituting the field yoke, and FIG. 7B shows a state in which two magnetic flat plates are arranged in series. Show.
FIG. 8 is a front view and a plan view of a conventional slider.
[Explanation of symbols]
1: Field yoke 2: Field permanent magnet A
3: Field permanent magnet B
4: Armature 5: Magnetic attractive force canceling type armature 6: Magnetic attractive force canceling type field yoke 11 Driving table 12 Magnetic attractive force canceling type movable element 13 Linear guide 14 Thermal insulation 16 Scale lead 17 Limit switch (target)
18 Limit switch (sensor part)
21 Slider base 22 Magnet stator 41 Linear scale 42 Scale head

Claims (2)

A plurality of permanent magnetic plates as a unit constituting a field yoke are arranged in series, and a plurality of permanent plates are arranged and fixed on each of the magnetic plates at a constant oblique angle with respect to the traveling direction and at an equal pitch. a linear motor field portion having a magnet,
The addition to the linear motor field magnet part two oppositely disposed, and a linear motor armature disposed with a gap between the two linear motors field portion,
In wherein the as a linear motor field portion of the stator is fixed to the slider base, a linear motor device of the suction force cancellation type which constitutes the linear motor armature as the mover,
The linear motor field portion has a rectangular magnetic plate, and when the permanent magnets whose total number is 2n + 1 (n is a positive integer) are arranged and fixed on the magnetic flat plate, Each permanent magnet arranged at both ends is composed of the same shape as the shape of the other permanent magnets, but vertically cut so that the left and right areas are the same with the above-mentioned constant oblique angle. Has been
A scale part of a linear scale is arranged and fixed in parallel with a linear guide that supports and guides the mover of the linear motor on the drive center axis of the linear motor so as to face the linear motor armature part on the slider base. ,
A linear motor device characterized in that a scale head portion facing the scale portion is fixed to an armature that moves in a thrust direction between the two linear motor field portions via a heat insulating material. The linear motor device according to claim 1, wherein the thermal insulating material is a material having physical properties of 0.3 [W / K · m] or less.

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