KR20120064115A - Linear scale - Google Patents

Abstract

An object of the present invention is to provide a linear scale capable of reducing the physical space required for wiring of the combined scale, facilitating the installation work of the combined scale in the field, and the like. Therefore, the combined scale 43 has a plurality of stage scales 51 and 52 and a common line 61 arranged in a line, and connects the coils of all stage scales by connecting the coils of the scale scale to the common line, respectively. The configuration is made in parallel. In addition, a resistor 56 is connected to each of the short scale coils as an impedance matching component to match the short scale impedance. The resistance is a resistance value of a magnitude (100 times or more of the difference in impedance) which can ignore the difference in impedance of a short scale. Further, the common line is formed by connecting a plurality of divided common lines 61A by coupling the connectors 62 of both ends, and a single-scale coil is connected to each divided common line, respectively.

Description

Linear scale {LINEAR SCALE}

The present invention relates to a linear scale of the inductosyn method.

Inductor linear scales have a slider and a scale. The slider and the scale are disposed to face each other so that the coil provided on the slider and the coil provided on the scale face each other with a small gap therebetween, and an alternating voltage of the SIN wave / COS wave is applied to one coil. By passing the excitation current, the change of the voltage induced in the other coil by the electromagnetic induction action is taken out and position detection is performed.

And the linear scale is used to detect the linear movement amount of the moving object (table of machine tool, etc.), but when the moving distance of the moving object is long, it is necessary to use the scale of the long stroke according to the moving distance.

10 shows a configuration of a conventional long stroke scale. As shown in FIG. 10, when the scale of a long stroke is conventionally needed, a plurality of lines of short (for example, 1 m) scale 1 (also called the scale of such a single member) are arranged in a row. The coils 2 provided in each stage scale 1 were connected in series (series). Thereby, the group of several single scale 1 can be regarded as the scale 10 of one long stroke (this scale is also called a combined scale). The output of the combined scale 10 is input to the preamplifier 4 via the connector 3.

However, when a combined stroke of a long stroke is formed by series connection, the C (capacitor: floating capacity) component and L (inductance) component distributed on the scale increases. And when the combination scale of the long stroke exceeding 4m stroke is comprised by series connection on the specification, the C component and L component of the said scale will increase too much, and the waveform of an applied voltage will be induced by this, Since the phase shift (phase difference) of the waveform of the voltage which becomes becomes large and phase reversal generate | occur | produces, a count miss occurs by the A / D converter which processes an induced voltage, and it becomes impossible to detect a movement amount correctly. This is especially noticeable when the frequency of the excitation current is high.

Therefore, when constituting the combined scale of the long stroke exceeding 4 m, for example, it responded by performing grouping wiring.

For example, in the case of constituting a combined scale of 11 m long strokes, as shown in Fig. 11, two groups of four single scales 1 are connected in series to form a combined scale 5 of 4 m long strokes. And one group of three single scales 1 connected in series to form a combination scale 6 of 3 m long strokes in a row, and the coils of these combined scales 5 and 6 ( By connecting 2) in parallel (parallel), it can be regarded as the combined scale 20 of one long stroke of 11 m in length. The output of the combined scale 20 is input to the preamplifier 4 via the connector 3.

In addition, since the single scale 1 is insufficient in the combined scale 6 as compared to the combined scale 5, the resistor 7 having a resistance value corresponding to the resistance value of one single scale 1 of the single scale 1. Was connected to the output terminal of the combined scale 6 at the installation site of the linear scale so that the resistance values of the combined scale 5 and the combined scale 6 were equal.

Japanese Patent Application Laid-open No. Hei 9-325002

However, in the case where the combined scales 5 and 6 are simply connected in parallel as shown in Fig. 11, large bundles of wiring 21 are generated, so it is sometimes difficult to secure a physical space in which the combination scales 5 and 6 can be arranged.

In FIG. 11, although the number of scale differences between groups is one, the number of scale differences between groups is two or three due to the difference in strokes, and therefore, the resistance according to the number of scale differences at the installation site of the linear scale at each time. The resistance of the value was selected, and the resistor had to be installed in a group lacking the scale 1, which was cumbersome.

In addition, in the conventional installation site of the linear scale, it was necessary to perform work such as the type of the pin (terminal) to the short scale 1, the crimping of the lead wire to the pin of this type, the wiring of the crimped lead wire, and the like. Therefore, the installation work of the scale was troublesome, and wiring error was easy to produce.

Accordingly, the present invention has been made in view of the above-described circumstances, and a problem is to provide a linear scale capable of reducing the physical space required for wiring of the combined scale, facilitating the installation work of the combined scale in the field, and the like. do.

The linear scale of 1st invention which solves the said subject is a linear scale which has a slider and a combined scale,

The combined scale has a plurality of single scales arranged in a line and a common line, and the coils of all the single scales are connected in parallel by connecting the coils of the single scale to the common line, respectively. .

In addition, the linear scale of 2nd invention is a linear scale of 1st invention,

The common line is formed by connecting a plurality of the divided common lines by using a divided common line having connectors provided at both ends, and combining the connectors.

The said short scale coil is connected to each division common line, It is characterized by the above-mentioned.

In addition, the linear scale of 3rd invention is a linear scale of 1st or 2nd invention,

As the plurality of stage scales, stage scales of plural kinds of different lengths are used,

In addition, an impedance matching component may be connected to each of the plurality of types of short-scale coils of different lengths to match the impedances of the plurality of different lengths of short scales.

In addition, the linear scale of 4th invention is a linear scale of 3rd invention,

All of the impedance matching components connected to the plurality of different types of short-scale coils, respectively, are resistors having the same resistance value,

Moreover, the said resistance is characterized by having the resistance value of the magnitude | size which can ignore the difference of the impedance between the short scales of the said several kind of different length.

In addition, the linear scale of 5th invention is a linear scale of 3rd invention,

Each of the impedance matching components connected to the plurality of different types of short-scale coils, respectively, is a combination of a plurality of resistors, inductors, and capacitors, and has the same composite impedance value.

The combination of any of the above resistors, inductors, and capacitors is characterized by having a combined impedance value of a magnitude that can ignore the difference in impedance between short scales of different types of lengths.

In addition, the linear scale of 6th invention is a linear scale of 3rd invention,

All of the impedance matching components connected to the plurality of different types of short-scale coils, respectively, are resistors having the same resistance value,

Moreover, the said resistance is characterized by having the resistance value 100 times or more of the difference of the impedance of the single scale of the said several types of different length.

In addition, the linear scale of 7th invention is a linear scale of 3rd invention,

Each of the impedance matching components connected to the plurality of different types of short-scale coils, respectively, is a combination of a plurality of resistors, inductors, and capacitors, and has the same composite impedance value.

The combination of any of the above resistors, inductors, and capacitors is characterized by having a combined impedance value of 100 times or more of the difference in impedances between the single scales of different lengths of the plural kinds.

According to the linear scale of 1st invention, it is a linear scale which has a slider and a combined scale, The said combined scale has several single scales arrange | positioned in a line, and has a common line, The said single scale coil is a said common scale. Each of the single-scale coils in parallel is connected by connecting the two to each other. Therefore, even if the combined scale is increased to some extent, the phase shift between the waveform of the applied voltage and the waveform of the induced voltage does not increase. In addition, the pin group wiring as in the prior art becomes unnecessary, and no large bundles of wiring occurring in a simple parallel connection are generated. For this reason, the physical space required for the wiring of the combined scale can be reduced, the wiring work is easy, and wiring errors are less likely to occur.

According to the linear scale of 2nd invention, in the linear scale of 1st invention, the said common line uses a split common line which provided the connector in both ends, and couples the said split common line by combining said connectors, Since the short-scale coil is connected to each divided common line, the wiring work may simply be performed by connecting the connectors of the divided common lines, and the coil and the common line connecting work in the field. Since this becomes unnecessary, wiring work becomes easier, and wiring error also becomes less likely to occur.

According to the linear scale of the third invention, in the linear scale of the first or second invention, a plurality of types of different lengths of short scales are used for the plurality of single scales, and the plurality of different types of different lengths Impedance matching components are respectively connected to short-scale coils to match the short-scale impedances of the plural kinds of different lengths, so that the effects of the first and second inventions can be obtained. Irrespective of the difference, arbitrary scales of different lengths can be arbitrarily combined to form a combined scale of a desired length, thereby facilitating installation work of the combined scale in the field.

According to the linear scale of 4th invention, in the linear scale of 3rd invention, all the said impedance matching components respectively connected to the said coil of a short scale of several kinds of different length are all the resistance which has the same resistance value, and The resistance is characterized by having a resistance value of a size that can ignore the difference in impedance between the scales of the plurality of different lengths, the same effect as the third invention is obtained, and further, When manufacturing a short scale provided with an impedance matching component (resistance), it is not necessary to provide an impedance matching component (resistance) having a different resistance value for each short scale having a different length, so that the short scale production is very easy.

According to the linear scale of the fifth aspect of the invention, in the linear scale of the third aspect of the invention, any of the impedance matching components respectively connected to the coils of the short scales of the plural kinds of different lengths is either a resistor, an inductor, or a capacitor. And a combination of a plurality of the resistors, the inductors, and the capacitors, each having a size that can ignore the difference in impedance between single scales of different lengths of the plural kinds. Since it has a synthetic impedance value, the same effect as the said 3rd invention is acquired, Furthermore, the short scale provided with the impedance matching component (combination of a plurality of resistor, inductor, and capacitor | condenser) is provided. When manufactured, impedance-matching components with different synthetic impedance values for different scales of different lengths (resistance It is not necessary to provide a combination of a plurality of either an inductor or a capacitor), and manufacturing of scale is very easy.

According to the linear scale of the sixth aspect of the invention, in the linear scale of the third aspect of the invention, all of the impedance matching components connected to the coils of the plurality of different lengths of the short scale are all resistors having the same resistance value. Moreover, since the said resistance has the resistance value 100 times or more of the difference of the impedance of the single scale of the said several types of different length, the effect similar to the said 3rd invention is acquired, Furthermore, When manufacturing a short scale provided with an impedance matching component (resistance), it is not necessary to provide an impedance matching component (resistance) having a different resistance value for each short scale having a different length, so that the short scale production is very easy.

According to the linear scale of the seventh aspect of the invention, in the linear scale of the third aspect of the invention, any of the impedance matching components connected to the plurality of different types of short-scale coils, respectively, is either a resistor, an inductor, or a capacitor. And a combination of a plurality of the resistors, the inductor, and the capacitor are combined impedances of at least 100 times the difference in impedances between the single scales of different lengths of the plural kinds. Since it has a value, the same effect as that of the third invention can be obtained, and a short scale provided with an impedance matching component (which combines a plurality of resistors, an inductor and a capacitor) can be manufactured. Impedance matching components (resistors and inductors) It is not necessary to provide for a combination of a plurality of capacitors which will), it is very easy to manufacture of a single scale.

BRIEF DESCRIPTION OF THE DRAWINGS It is a block diagram of the feedback control apparatus of the full closed loop using the linear scale which concerns on the example of 1st Embodiment of this invention.
It is a block diagram of the combined scale in the linear scale which concerns on the example of 1st Embodiment of this invention.
Fig.3 (a) is a block diagram of the short scale which is a component of the said combined scale, and FIG.3 (b) is a block diagram of the other short scale which is a component of the said combined scale.
It is a block diagram of the combined scale in the linear scale which concerns on the example of 2nd Embodiment of this invention.
FIG. 5A is a configuration diagram of a short scale that is a component of the combined scale, and FIG. 5B is a configuration diagram of another short scale that is a component of the combined scale.
It is a block diagram of the combined scale in the linear scale which concerns on the example of 3rd Embodiment of this invention.
FIG. 7A is a configuration diagram of a short scale that is a component of the combined scale, and FIG. 7B is a configuration diagram of another short scale that is a component of the combined scale.
It is a block diagram of the combined scale in the linear scale which concerns on the example of 4th Embodiment of this invention.
FIG. 9A is a configuration diagram of a short scale that is a component of the combined scale, and FIG. 9B is a configuration diagram of another short scale that is a component of the combined scale.
It is a block diagram of the combined scale which connected the conventional series.
11 is a configuration diagram of a combined scale in which a conventional grouping wiring is performed.

EMBODIMENT OF THE INVENTION Hereinafter, embodiment of this invention is described in detail based on drawing.

<First Embodiment Example>

Based on FIGS. 1-3, the 1st Embodiment Example of this invention is described.

First, based on FIG. 1, the case where the linear scale of this 1st Embodiment example is applied to the feedback control apparatus of the full closed loop in a machine tool is demonstrated.

As shown in Fig. 1, the ball screw 31 has a screw shaft 31a and a nut 31b for screwing together, and the screw shaft 31a is connected to a rotation shaft of the drive motor 32, and the nut ( 31b) is mounted to the mobile chain table 33. Therefore, when the screw shaft 31a rotates as arrow A by the drive motor 32, the table 33 will move linearly like the arrow B with the nut 31b.

In order to detect the position (movement amount) of this table 33, the linear scale 41 of the example of the first embodiment is used. The linear scale 41 of the inductor system has a slider 42 and a combination scale 43. The slider 42 is mounted on the table 33 to move linearly with the table 33. 43 is attached to the fixed part (not shown) of a machine tool. By arranging the slider 42 and the combination scale 43 to face each other, the coil 44 provided on the slider 42 and the coils 54 and 58 provided on the combination scale 43 form a small gap. Are facing away.

And the combined scale 43 has the long stroke matched with the movement distance of the table 33. As shown in FIG. The detail of the structure of this combination scale 43 is mentioned later.

When the excitation current flows by applying an alternating voltage of the SIN wave / COS wave from the A / D converter 46 to the coil 44 of the slider 42, the coil 54 of the combined scale 43 is caused by an electromagnetic induction action. At 58, the voltage is induced. The induced voltage changes in accordance with the change of the relative position of the slider 42 (coil 44) and the combined scale 43 (coils 54 and 58). The induced voltage is taken out from the combined scale 43 through the connector 47, amplified by the preamplifier 48, and then input to the A / D converter 46.

The A / D converter 46 processes the induced voltage to detect the position (movement amount) of the table 33, and feeds back the signal of the detected position to the NC servo amplifier 49 which is a control device. In the NC servo amplifier 49, in order to make the position of the table 33 become a command position, the rotation of the drive motor 32 is controlled in accordance with the deviation between the detection position and the command position.

Next, based on FIG. 1 thru | or FIG. 3, the structure of the combined scale 43 of an example of this 1st Embodiment is demonstrated.

As shown in FIG. 1 and FIG. 2, the combined scale 43 includes a plurality of short scales 51 (for example, 1 m) and a plurality of short scales (for example, 1 m), and a plurality (two in the example). The short scale 52 of a short stroke (for example, 250 mm) of () is arrange | positioned in a line, and can be regarded as the scale of one long stroke (for example, 8.5 m).

The short scale 51 has a structure in which a zigzag coil 54 is provided on a base 53 that is a rectangular iron plate. The resistors 56 are connected to both sides of the coil 54 of the short scale 51, respectively. Similarly, the short scale 52 has the structure in which the zigzag coil 58 was provided in the base 57 which is a rectangular iron plate. The resistors 56 are also connected to both sides of the coil 58 of the short scale 52, respectively. These short scales 51 and 52 are the products with the impedance matching component (resistance 56) shown to Fig.3 (a) and FIG.3 (b), and are the manufacturing plants of the linear scale 41. Is manufactured in.

As shown in FIG. 1 and FIG. 2, since the coils 54 and 58 are all connected in parallel (parallel), the scales 51 and 52 can be treated as individual scales on the connection. However, when a simple parallel connection as shown in Fig. 11 is performed, the wiring is increased by the number of the short scales 51 and 52, and a large wiring bundle is generated.

Therefore, the form of the multi-drop wiring used by the serial bus connection is employ | adopted for the coil connection of the short scales 51 and 52. As shown in FIG. That is, by arranging the common line (bus line) 61 and connecting the coils 54 and 58 of each stage scale 51 and 52 to this common line 61, all the stage scales 51 and 52, respectively. Coils 54 and 58 are arranged in parallel. A connector 47 is provided at the end of the common line 61, and the connector 47 is coupled to the connector 47 of the preamplifier 48.

On the other hand, since the short scale 51 and the short scale 52 have different lengths (strokes), the R (resistance) component, the C (capacitor: floating capacity) component, and L of each of the short scales 51 and 52 are different. The value of the (inductance) component is different, and the impedance with respect to the frequency of the excitation current is different. Therefore, if the coils 54 and 58 of the short scales 51 and 52 of different lengths are simply connected to the common line 61, the position detection accuracy in the joint part of the short scales 51 and 52 will deteriorate.

For this reason, the above-mentioned resistance is a component (impedance matching component) for matching the impedance of the short scale 51 and the short scale 52 to all of the coils 54 and 58 of the short scales 51 and 52, too. 56 is connected. The resistor 56 is provided on either of the stage scales 51 and 52 and has the same resistance value, and the impedances of the stage scale 51 and the stage scale 52 of different lengths (that is, the resistor 56 is not provided). It has a resistance value of the magnitude which can ignore the difference of the impedance of the short scales 51 and 52 which are not in a state. In other words, the resistor 56 has a sufficiently large resistance value compared with the difference in impedance.

In this case, it is preferable that the resistance value of the resistor 56 is 100 times or more of the difference of the impedance of the short scales 51 and 52 mentioned above, and the said difference of impedance may be 1% or less with respect to the said resistance value. Do. For example, when the difference in impedance is 10 kHz, the resistance value of the resistor 56 is 1 ㏀ or more.

However, if the resistance value of the resistor 56 is made too large, the output (gain) of the combined scale 43 becomes too small, and the position detection with high precision cannot be performed. Therefore, the resistance value of the resistor 56 needs to be such that the output (gain) of the combined scale 43 does not become extremely small. In addition, it is good to determine how much more the magnitude | size of the said output is needed according to the processing capability of the said output, etc. That is, what is necessary is just to determine suitably the upper limit of the resistance value of the resistor 56 according to the magnitude | size of the required output.

In the short scale 51 of the illustrated example, since the resistors 56 are provided on both sides of the coil 54, the combined resistance values of the resistors 56 on both sides may be the same values as described above. Similarly, since the resistors 56 are provided on both sides of the coil 58 in the scale 52 of the illustrated example, the combined resistance values of the resistors 56 on both sides may be the same values as described above. The resistors 56 are provided on both sides of the coils 54 and 58 to improve the stability of the alternating voltage induced in the coils 54 and 58.

However, the present invention is not limited thereto, and from the viewpoint of matching the impedances of the short scales 51 and 52, it is not necessary to provide the resistors 56 on both sides of the coils 54 and 58 as described above. The resistors 56 may be provided only on one side of 54 and 58. In this case, the resistance value of the resistor 56 provided on one side of the coil 54 is set as above, and the resistance value of the resistor 56 provided on one side of the coil 58 is also the same as described above. The value is good.

As described above, according to the linear scale 41 of the first embodiment, the linear scale 41 includes the slider 42 and the combined scale 43, and the combined scale 43 is arranged in a line. It has a plurality of stage scales 51 and 52 and a common line 61, and connects the coils 54 and 58 of the stage scales 51 and 52 to the common line 61, respectively. Since the coils 54 and 58 of 52 are arranged in parallel, even if the combination scale 43 is lengthened to some extent, the phase shift of the waveform of the applied voltage and the waveform of the induced voltage does not become large. In addition, the pin group wiring as in the prior art becomes unnecessary, and no large bundles of wiring occurring in a simple parallel connection are generated. For this reason, the physical space required for the wiring of the combined scale 43 can be reduced, wiring work becomes easy, and wiring error hardly arises.

Further, according to the linear scale 41 of the first embodiment, the resistors 56 are connected as the impedance matching components to the coils 54 and 58 of the short scales 51 and 52 of different lengths, respectively. Since the impedances of the single scales 51 and 52 are matched, the combined scales of desired length can be constructed by arbitrarily combining the single scales 51 and 52 of different lengths, regardless of the impedance difference. Therefore, the installation work of the combined scale 41 in the field becomes easy.

In addition, according to the linear scale 41 of the first embodiment, all of the impedance matching components connected to the coils 54 and 58 of the short scales 51 and 52 of different lengths each have the same resistance value. (56), and the resistor 56 has a resistance value of a magnitude (100 times or more of the difference in impedance) that can ignore the difference in impedance of the short scales 51 and 52 of different lengths. Therefore, when manufacturing the short scales 51 and 52 provided with the impedance matching component (resistance 56), the impedance matching component (resistance) having a different resistance value for each of the short scales 51 and 52 having different lengths is produced. There is no need to provide the structure, and manufacture of the scales 51 and 52 is very easy.

In addition, in the above, although two types of short scales 51 and 52 of different lengths (strokes) are used, it is not limited to this, but is not limited to this, and the scales of three or more different lengths (strokes) (for example, 1 m and 500 mm) And a short scale of 250 mm) may be used. Also in this case, the resistance of the short scale may be matched by connecting a resistor to the coil of each short scale as described above, and the resistance value of the resistance may be a magnitude that can ignore the difference of impedance between the short scales (the 100 times or more). In the case where the difference between the impedances of one stage scale and the difference between the impedances of the other stage scales is different, the resistance value having a magnitude (100 times or more of the difference of the above-described impedance difference) can be ignored.

<Example 2 Embodiment>

Based on FIG. 4 and FIG. 5, the 2nd Embodiment Example of this invention is described. In addition, since the arrangement relationship of the slider and combination scale in a linear scale, the application example of a linear scale, etc. are the same as that of the said 1st Embodiment example (refer FIG. 1), description here is abbreviate | omitted.

In addition, the same code | symbol is attached | subjected about the part similar to the combined scale (refer FIG. 2, FIG. 3) of the said 1st Embodiment, and the overlapping detailed description is abbreviate | omitted.

As shown in FIG. 4, in the combined scale 71 in the linear scale of the 2nd Embodiment example, the common line 61 is divided into several part 61A (this part is also called division common line). The connectors 62 are provided at both ends of each divided common line 61A. By connecting the plurality of divided common lines 61A by joining the connectors 62 of the adjacent divided common lines 61A, it can be regarded as one common line 61 (also referred to as a combined common line). have.

And the coils 54, 58 of each stage scale 51 and 52 are connected to 61 A of each division common lines, respectively. The short scales 51 and 52 are divided common lines 61A provided with an impedance matching component (resistance 56) and a connector 62 as shown in Figs. 5A and 5B. ) Is manufactured in a linear scale manufacturing plant. Therefore, at the installation site of the linear scale, the wiring work is simply completed by only coupling the connectors 62 of the adjacent divided common lines 61A. In addition, in the end scale 52 of the end, the connector 62 of the split common line 61A is coupled with the connector 47 of the preamplifier 48.

Other configurations of the combined scale 71 of the second embodiment are similar to those of the combined scale 43 of the first embodiment.

As described above, according to the linear scale of the example of the second embodiment, the common line 61 is divided by using a divided common line 61A in which connectors 62 are provided at both ends, and joining the connectors 62 to each other. The plurality of common lines 61A are connected, and the coils 54 and 58 of the scales 51 and 52 are connected to the divided common lines 61A, respectively. It is only necessary to couple the connectors 62 of the divided common lines 61A, and since the connection work between the coil and the common line in the field becomes unnecessary, the wiring work becomes easier and the wiring error also becomes less likely to occur.

<Example 3 Embodiment>

6 and 7, a description will be given of a third embodiment of the present invention. In addition, since the arrangement relationship of the slider of a linear scale and a combination scale, the application example of a linear scale, etc. are the same as that of the said 1st Embodiment example (refer FIG. 1), description here is abbreviate | omitted.

As shown in FIG. 6, the combined scale 81 in the linear scale of the example of the third embodiment includes a plurality of short strokes (e.g., 1 m) of short scales 82 (e.g., 1 m). The short scales 83 of a plurality of (e.g. two) short strokes (e.g. 250 mm) can be arranged in a line, and can be regarded as a scale of one long stroke (e.g. 8.5 m). It would be.

The short scale 82 has a configuration in which a zigzag coil 85 is provided on a base 84 that is a rectangular iron plate. A resistor 88, an inductor 89, and a capacitor 90 are connected to both sides of the coil 85 of the short scale 82, respectively. Similarly, the short scale 83 has the structure in which the zigzag coil 87 was provided in the base 86 which is a rectangular iron plate. A resistor 88, an inductor 89, and a capacitor 90 are also connected to both sides of the coil 87 of the short scale 83, respectively.

The short scales 82 and 83 are products provided with impedance matching components (resistance 88, inductor 89, and capacitor 90) as shown in Figs. 7A and 7B. It is manufactured in the manufacturing plant of a linear scale.

As shown in FIG. 6, since the coils 85 and 87 are all connected in parallel (parallel), the scales 82 and 83 can be treated as individual scales on the connection. However, when the simple parallel connection as shown in Fig. 11 is performed, the wiring is increased by the number of the short scales 82 and 83, and a large wiring bundle is generated.

Therefore, the form of the multi-drop wiring used by the serial bus connection is employ | adopted for the coil connection of the short scales 82 and 83. As shown in FIG. That is, by arranging the common line (bus line) 91 and connecting the coils 85 and 87 of the respective stage scales 82 and 83 to the common line 91, all the stage scales 82 and 83, respectively. Coils 85 and 87 are arranged in parallel. A connector 94 is provided at the end of the common line 91, and the connector 94 is coupled to the connector 95 of the preamplifier 96.

On the other hand, since the short scale 82 and the short scale 83 have different lengths (strokes), the R (resistance) component, C (capacitor: floating capacity) component, and L of each of the short scales 82 and 83 are different. The value of the (inductance) component is different, and the impedance with respect to the frequency of the excitation current is different. Therefore, if the coils 85 and 87 of the short scales 82 and 83 are simply connected to the common line 91, the position detection accuracy at the joint portion of the short scales 82 and 83 is deteriorated.

For this reason, the above-described resistance is a component (impedance matching component) for matching the impedance of the short scale 82 and the short scale 83 to any of the coils 85 and 87 of the short scales 82 and 83. An 88, an inductor 89, and a capacitor 90 are connected.

The common line 91 includes a common core line 92 and a common shield line 93 covering the common core line 92. In addition, for convenience of explanation, the shield line 93 is shown in perspective view (broken line) in FIG. 6 (it is the same also in FIG. 8, FIG. 9 mentioned later).

In the short scale 82, the resistor 88 and the inductor 89 are connected in series, and the coil 85 of the short scale 82 is connected to the common core wire (via the resistor 88 and the inductor 89). 92). One end of the capacitor 90 is connected to the coil 85, and the other end thereof is connected to the common shield line 93. Similarly, in the short scale 83, the resistor 88 and the inductor 89 are connected in series, and the coil 87 of the short scale 83 is common through the resistor 88 and the inductor 89. It is connected to the core wire 92. One end of the capacitor 90 is connected to the coil 87, and the other end thereof is connected to the common shield line 93.

The common shield line 93 is grounded to the circuit ground 97 via the preamplifier 96.

In any of the scales 85 and 87, the resistor 88, the inductor 89, and the capacitor 90 have the same resistance value, the same inductance value, and the same capacitance value, that is, have the same composite impedance value. . The resistor 88, the inductor 89, and the capacitor 90 have impedances of the short scale 82 and the short scale 83 of different lengths (that is, the resistor 88, the inductor 89, and the capacitor 90). Has a synthesized impedance value of a magnitude that can ignore the difference in the impedance of the short scales 51 and 52 in the state where? Is not provided. That is, the resistor 88, the inductor 89, and the capacitor 90 have a sufficiently large synthesized impedance value as compared with the difference in the impedance.

In this case, the value of the synthesized impedance of the resistor 88, the inductor 89, and the capacitor 90 is set to 100 times or more of the difference between the impedances of the short scales 51 and 52 described above, and with respect to the synthesized impedance value. It is preferable that the difference in impedance is 1% or less. For example, if the difference in impedance is 10 kHz, the combined impedance value of the resistor 88, the inductor 89, and the capacitor 90 is 1 Ω or more.

However, if the combined impedance value of the resistor 88, the inductor 89, and the capacitor 90 is made too large, the output (gain) of the combined scale 81 will be too small, so that accurate position detection cannot be performed. do. Therefore, the combined impedance value of the resistor 88, the inductor 89, and the capacitor 90 needs to be such that the output (gain) of the combined scale 81 does not become extremely small. In addition, it is good to determine how much more the magnitude | size of the said output is needed according to the processing capability of the said output, etc. That is, the upper limit of the combined impedance value of the resistor 88, the inductor 89, and the capacitor 90 may be appropriately determined according to the required output size.

In the short scale 82 of the illustrated example, since the resistors 88, the inductors 89, and the capacitors 90 are provided on both sides of the coil 85, the resistors 88, the inductors 89, What is necessary is just to make the synthesized impedance value of the capacitor | condenser 90 into the above values. Similarly, in the short scale 83, since the resistor 88, the inductor 89, and the capacitor 90 are provided on both sides of the coil 87, the resistors 88, the inductor 89, and the capacitor ( What is necessary is just to make the synthesized impedance value of 90) into the above values. The resistance 88, the inductor 89, and the capacitor 90 are provided on both sides of the coils 85 and 87 in order to improve the stability of the AC voltage induced in the coils 85 and 87.

However, the present invention is not limited thereto, and from the viewpoint of matching the impedances of the short scales 82 and 83, the resistor 88, the inductor 89, and the capacitor () are provided on both sides of the coils 85 and 87 as described above. It is not necessary to provide 90, and the resistor 88, the inductor 89, and the capacitor 90 may be provided only on one side of the coils 85 and 87. In this case, the combined impedance values of the resistor 88, the inductor 89, and the capacitor 90 provided on one side of the coil 85 are set to the same values as described above, and provided on one side of the coil 87. The combined impedance values of the resistor 88, the inductor 89, and the capacitor 90 may be the same values as described above.

As described above, according to the linear scale of the third embodiment, the linear scale includes a slider and a combined scale 81, and the combined scale 81 is a plurality of single scale scales 82 and 83 arranged in a line. And the coils 85 and 87 of all the short scales 82 and 83 by having the common line 91 and connecting the coils 85 and 87 of the short scales 82 and 83 to the common line 91, respectively. In this configuration, the phase shift between the waveform of the applied voltage and the waveform of the induced voltage does not increase. In addition, the pin group wiring as in the prior art becomes unnecessary, and no large bundles of wiring occurring in a simple parallel connection are generated. For this reason, the physical space required for the wiring of the combined scale 81 can be reduced, wiring work becomes easy, and wiring error hardly arises.

In addition, according to the linear scale of the third embodiment, the resistor 88, the inductor 89, and the capacitor 90 are impedance matching components to the coils 85 and 87 of the short scales 82 and 83 of different lengths, respectively. And the impedances of the short scales 51 and 52 of different lengths are matched. Therefore, arbitrary lengths of the short scales 82 and 83 of different lengths are arbitrarily combined without regard to the difference in impedance. Since the combination scale of can be configured, the installation work of the combination scale in the field becomes easy.

Further, according to the linear scale of the third embodiment, all of the impedance matching components connected to the coils 85 and 87 of the short scales 82 and 83 of different lengths, respectively, have a resistance 88 having the same synthetic impedance value. ), An inductor 89, and a capacitor 90, and the resistor 88, the inductor 89, and the capacitor 90 can ignore the difference in impedance between the short scales 82 and 83 of different lengths. Since it has a composite impedance value of magnitude (100 times or more of the difference in impedance), the short scale 82 provided with an impedance matching component (resistance 88, inductor 89, and capacitor 90) is provided. , 83), there is no need to provide impedance matching components (resistors, inductors, and capacitors) of different synthetic impedance values for each of the short scales 82 and 83 having different lengths. Very easy.

In addition, in the above description, although two types of short scales 82 and 83 of different lengths (strokes) are used, the present invention is not limited to this, but is not limited to three or more types of short scales (for example, 1 m and 500 mm). And a short scale of 250 mm) may be used. Also in this case, a resistor, an inductor, and a capacitor may be connected to the coils of each short scale as described above, and the impedances of these short scales may be matched. Also in this case, the combined impedance value of the resistor, the inductor, and the capacitor may be a value that can ignore the difference in impedance between scales (a value 100 times or more of the difference in impedance). In addition, when the difference between the impedances of one stage scale and the difference between the impedances of other stage scales is different, it is good to set it as the composite impedance value which can ignore the largest difference of impedance (100 times or more of the difference of the said impedance).

In addition, although the impedance matching component installed in the short scale is a combination of a resistor, an inductor, and a capacitor | condenser in the above, it is not limited to this, The combination of the impedance matching component provided in a short scale combines a resistor and an inductor, And a capacitor may be combined, or an inductor and a capacitor may be combined.

Fourth Embodiment Example

Based on FIG.8 and FIG.9, the 3rd Embodiment Example of this invention is described. In addition, since the arrangement relationship of the slider and combination scale in a linear scale, the application example of a linear scale, etc. are the same as that of the said 1st Embodiment example (refer FIG. 1), description here is abbreviate | omitted.

In addition, the same code | symbol is attached | subjected about the part similar to the combined scale (refer FIG. 6, FIG. 7) of the said 3rd Embodiment, and the overlapping detailed description is abbreviate | omitted.

As shown in FIG. 8, in the combined scale 101 in the linear scale of the fourth embodiment, the common line 91 is divided into a plurality of portions 91A (this portion is also called a divided common line). It is. Each divided common line 91A is formed by dividing the common core wire 92 into a plurality of portions 92A (this portion is also referred to as a divided common core wire), and the common shield line 93 by the plurality of portions 93A. It is made by dividing into (this part is also called a division common shield line). Connectors 102 are provided at both ends of each divided common line 91A. The plurality of divided common lines 91A are connected by joining the connectors 102 of the adjacent divided common lines 91A, so that they can be regarded as one common line 91 (also referred to as a combined common line). have. At this time, when the plurality of divided common core wires 92A are connected, it can be regarded as one common core wire 92 (also called a combination common core wire), and when the plurality of divided common shield wires 93A are connected, 1 It can be regarded as the common shield line 93 of the sieve (this is also called a combination common shield line).

The coils 85 and 87 of the respective stage scales 82 and 83 are respectively connected to the divided common lines 91A. Specifically, the coils 85 and 87 of the short scales 82 and 83 are connected to the divided common core wire 93A through the resistor 88 and the inductor 89. One end of the capacitor 90 is connected to the coils 85 and 87, and the other end thereof is connected to the divided common shield wire 93A.

The short scales 82 and 83 include impedance matching components (resistor 88, inductor 89, condenser 90) as shown in FIGS. 9A and 9B, and a connector ( It is a product of the state in which the division common line 91A with 102 was attached, and is manufactured in the manufacturing plant of a linear scale. Therefore, at the installation site of the linear scale, the wiring work is simply completed by only coupling the connectors 102 of the adjacent divided common lines 91A. In the shortest scale 83, the connector 102 of the split common line 91A is coupled with the connector 95 of the preamplifier 96.

Other configurations of the combined scale 101 of the fourth embodiment are the same as those of the combined scale 81 of the third embodiment.

As described above, according to the linear scale of the fourth embodiment, the common line 91 is divided by using the divided common line 91A provided with the connector 102 at both ends, and joining the connectors 102 to each other. The plurality of common lines 91A are connected, and the coils 85 and 87 of the scales 82 and 83 are connected to the respective divided common lines 91A. It is only necessary to couple the connectors 102 of the divided common lines 91A, and the connection work between the coil and the common line in the field becomes unnecessary, so that the wiring work becomes easier and the wiring error is less likely to occur.

The present invention relates to a linear scale of the inductance method, and is useful for applying to a combined scale of a linear scale used for detecting a position of a moving object having a long moving distance.

31: ball screw
31a: screw shaft
31b: Nut
32: drive motor
33: table
41: linear scale
42: slider
43: combination scale
44: coil
46: A / D Converter
47: connector
48: preamp
49: NC servo amplifier
51, 52: short scale
53: base
54: coil
56: resistance
57: base
58: coil
61: common line
61A: Split Common Line
62: connector
71, 81: Combination scale
82, 83: short scale
84: base
85: coil
86: base
87 coil
88: resistance
89: inductor
90: condenser
91: common line
91A: Split Common Line
92: common core wire
92A: Split Common Core
93: common shield wire
93A: Split Common Shield
94, 95: connectors
96: preamp
97: circuit ground
101: combination scale
102: connector

Claims (7)

It is a linear scale which has a slider and a combination scale,
The combined scale has a plurality of single scales arranged in a line and a common line, and the coils of all the single scales are connected in parallel by connecting coils of the single scale to the common line, respectively. , Linear scale. The method of claim 1,
The common line is formed by connecting a plurality of divided common lines by using a divided common line having connectors provided at both ends, and coupling the connectors.
The said short scale coil is connected to each division common line, respectively, The linear scale. The method according to claim 1 or 2,
As the plurality of stage scales, stage scales of plural kinds of different lengths are used,
The linear scale according to claim 1, wherein an impedance matching component is connected to each of the coils of different scales of different lengths, and the impedances of the short scales of different types of lengths are matched. The method of claim 3,
All of the impedance matching components connected to the plurality of different types of short-scale coils, respectively, are resistors having the same resistance value,
The resistance has a linear scale, wherein the resistance has a resistance value of a magnitude that can ignore a difference in impedance between single scales of different types of lengths. The method of claim 3,
Each of the impedance matching components connected to the plurality of different types of short-scale coils, respectively, is a combination of a plurality of resistors, inductors, and capacitors, and has the same composite impedance value.
The combination of any of the above resistors, inductors, and capacitors has a combined impedance value of a magnitude that can ignore a difference in impedance between short scales of different kinds of lengths. . The method of claim 3,
All of the impedance matching components connected to the plurality of different types of short-scale coils, respectively, are resistors having the same resistance value,
Moreover, the said resistance has the resistance value 100 times or more of the difference of the impedance of the single scale of different length of the said several kind, The linear scale characterized by the above-mentioned. The method of claim 3,
Each of the impedance matching components connected to the plurality of different types of short-scale coils, respectively, is a combination of a plurality of resistors, inductors, and capacitors, and has the same composite impedance value.
The combination of any of the above resistors, inductors, and capacitors has a combined impedance value of at least 100 times the difference in impedance between the short scales of the different types of lengths.

Images