JP2006194720A - Separate type encoder and method for attaching the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To easily carry out an alignment adjustment at an attaching operation, and to optimize the attached state. <P>SOLUTION: A separate type encoder having a plurality of tracks in the width direction perpendicular to a length measuring direction is provided, which comprises; a means for detecting phases of at least two tracks; means for detecting signal intensities of at least two tracks; and a means for judging the alignment to be abnormal in the yaw or roll direction, when a phase difference or a signal intensity ratio between above tracks exceeds a tolerance level. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a separate encoder having a plurality of tracks in the width direction orthogonal to the length measuring direction, and a mounting method thereof, and in particular, it is possible to easily perform alignment adjustment during mounting and optimize the mounting state. The present invention relates to a possible separate type encoder and a method of attaching the same.

  As shown in FIG. 2, a separate type encoder for position detection as exemplified by a linear encoder in FIG. 1 attaches a scale 10 to an apparatus main body (not shown) in step 100, and then in step 110, a detection head 20 Is mounted on a moving member (not shown) mechanically using a means such as butting against the scale 10, and then in step 120, the detection head mounting position is determined based on the signal strength. It is necessary to adjust the alignment and generate a predetermined signal.

  As an alignment adjustment method, a method is used in which a signal is output on a trial basis to confirm that the intensity value falls within a certain range and the attachment adjustment is performed. However, in this case, the position of the detection head 20 after mounting is not necessarily the optimal position, and is not limited to this, and it has not been possible to simply check the encoder mounting position at the time of mounting so far and perform optimization. It was.

  In Patent Document 1, additional tracks for tilt error detection are added on both sides (upper and lower sides in FIG. 1) in the width direction orthogonal to the length measurement direction of the displacement detection track to correct the measurement value. It is described.

JP 7-324948 A

  However, since it is necessary to add dedicated tracks on both sides of the displacement detection track, not only the scale 10 is widened and the encoder is enlarged, but also an optical system for reading the dedicated track is required, and the number of parts is large. There was a problem of high cost.

  The present invention has been made to solve the above-described conventional problems, and it is an object of the present invention to easily perform alignment adjustment at the time of mounting and to optimize the mounting state without complicating the configuration. .

  In the separate encoder having a plurality of tracks in the width direction orthogonal to the length measuring direction, the means for detecting the phase of at least two tracks, and when the phase difference between the tracks exceeds an allowable range, The above-mentioned problem is solved by providing a means for determining an alignment abnormality in the yaw direction.

  The present invention also relates to a separate type encoder having a plurality of tracks in the width direction orthogonal to the length measuring direction, and means for detecting the signal strength of at least two tracks, and the signal strength ratio between the tracks is within an allowable range. The above-mentioned problem is solved by providing a means for determining that the alignment abnormality in the roll direction is exceeded when the value exceeds.

  The present invention further provides means for detecting the phase of at least two tracks and the signal strength of at least two tracks in a separate encoder that also has a plurality of tracks in the width direction orthogonal to the length measuring direction. The above-mentioned problem is similarly solved by providing means and means for determining an alignment abnormality in the yaw direction or roll direction when the phase difference or signal intensity ratio between the tracks exceeds an allowable range.

  Further, according to the present invention, in the mounting method of the separate type encoder having a plurality of tracks in the width direction orthogonal to the length measuring direction, the alignment in the lateral direction is adjusted so that the signal intensity of at least one track is maximized. Then, adjust the alignment in the roll direction so that the signal strength of at least two tracks is the same, and then adjust the alignment in the gap direction so that the signal strength of at least one track is within an acceptable range Finally, the above problem is solved by adjusting the alignment in the yaw direction so that the phase difference between at least two tracks is within the allowable range.

  According to the present invention, it is possible to easily perform alignment adjustment at the time of mounting and to optimize the mounting state without complicating the configuration.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  In this embodiment, as shown in FIG. 3, a plurality of (two in the figure) tracks (tracks on the scale 10 side) in the width (lateral) direction (vertical direction in the figure) orthogonal to the length measuring direction (left and right direction in the figure). In the absolute position detection type separate linear encoder having the tracks 23, 24) on the sensor substrate 22 side mounted on the detection head 20, the phase difference between the tracks and the signal intensity ratio are detected, By comparing with the optimum state, the alignment state between the detection head 20 and the scale 10 in the yaw direction and the roll direction shown in FIG. 4 is determined. It has a function to send.

That is, as shown in FIG. 5, when the sensor substrate 22 rotates in the yaw direction with respect to the scale 10 and the alignment changes, the pattern of each track 23, 24 depends on the distance from the rotation center. In order to move in different directions and amounts in the length measurement direction, the phase data θ ₁ and θ ₂ of the tracks 23 and 24 output from the detection head 20 change according to the amount of movement. Therefore, since the difference (θ ₁ −θ ₂ ) in the phase data of each track changes depending on the alignment in the yaw direction, it is possible to determine the alignment attachment state by the following method.

  First, at the initial inspection before mounting, after mounting in an ideal alignment state, the data of the phase difference between tracks is recorded in the memory in the encoder.

  Next, when the device is mounted, the phase difference between the tracks is automatically measured in the detection head 20, and the initial data is referred to. If the value difference exceeds the allowable range, it is determined that the yaw direction alignment is abnormal and an alarm is generated. To send.

  On the other hand, as shown in FIG. 6, when the alignment in the roll direction changes, the gap (gap) G between the scale 10 and the detection head 20 changes by a different amount for each track depending on the direction and distance from the rotation center. To do. Since the signal intensity of each track also changes in accordance with this change in the gap amount, the signal intensity ratio between tracks is compared with the initial value of the inspection data, and if it exceeds the allowable range, it is determined that the roll direction alignment is abnormal. Send an alarm.

  In addition, the detection of the alignment abnormality in the lateral direction shown in FIG. 3 and the gap direction shown in FIG. 4 can be performed using only the signal intensity value as in the conventional case.

  Next, the actual mounting optimization procedure will be described in detail with reference to FIG.

  First, at step 200, the detection head 20 is attached and mechanically positioned as in the conventional case.

  Next, at step 210, data (phase / signal intensity) for each of the tracks 23 and 24 is output from the detection head 20.

  Next, at step 220, the position of the detection head 20 in the width direction (lateral direction) with respect to the scale 10 is adjusted so that the signal intensity becomes maximum.

  Next, at step 230, the ratio of the signal intensity of each track 23, 24 is compared with the optimum state. If it is outside the allowable range, it is determined that the roll direction alignment is abnormal, an abnormality signal is transmitted, an abnormality is displayed in step 232, and the roll direction alignment is adjusted in step 232 so that it is within the allowable range.

  If the determination result in step 230 is positive, or after the end of step 234, the process proceeds to step 240, and the signal intensity value of any one track is compared with the optimum state. If it is outside the allowable range, it is determined that the alignment is abnormal in the gap direction, an abnormality signal is transmitted, an abnormality is displayed in step 242, and in step 244, the alignment in the gap direction is adjusted to be within the allowable range.

  If the determination result in step 240 is positive, or after the end of step 244, the process proceeds to step 250, where the phase data difference between the tracks 23, 24 is compared with the optimum state. If it is outside the allowable range, it is determined that the alignment is abnormal in the yaw direction, an abnormal signal is transmitted, an abnormality is displayed in step 252, and in step 254, the alignment in the yaw direction is adjusted to be within the allowable range.

  Thus, by attaching to the detection head 20 while confirming the presence / absence of an abnormal signal / display, even an unfamiliar operator can easily optimize the attachment position.

  As a display method when an abnormal signal is transmitted, for example, as shown in FIG. 8 (A), a plurality of (five in the figure) LEDs of different colors are arranged side by side in the form of bar graphs 30, 32, and 34, and the initial value (optimum) The mounting state can be confirmed by moving the lighting position according to the difference between the state) and the measured value.

  Alternatively, as shown in FIG. 8B, for the yaw / roll / gap / lateral direction display on the encoder, depending on the blinking speed of the LED 36 respectively installed, for example, the LED is turned on outside the allowable range, flashed within the allowable range, It can be turned off.

  Alternatively, as shown in FIG. 8 (C), the LED 38 installed on the encoder for displaying the yaw, roll, gap, or lateral direction is displayed in a different color (for example, red within the allowable range, within the allowable range). Can be lit green and the optimum value is off).

  Alternatively, an alarm sound can be sounded instead of the LED, and the mounting state can be confirmed by the pitch, tone color, or intermittent state of the sound.

  Furthermore, the alignment state can also be grasped by directly reading the phase difference and the signal intensity ratio from a personal computer connected at the time of inspection.

  In the above embodiment, the present invention is applied to an absolute position detection type linear encoder having two tracks. However, the application target of the present invention is not limited to this, and an incremental type linear encoder, a rotary encoder, or the like Obviously, the same applies to the encoder. In particular, when there are three or more tracks, the configuration can be simplified using only signals from the tracks at both ends, or precise adjustment can be performed using signals from all tracks.

The perspective view which shows the basic composition of the separate type linear encoder which is one of the application objects of this invention Flow chart showing the same installation procedure The top view which shows the structure of the separate linear encoder which has two tracks in the width direction which is an application object of this invention The perspective view explaining an alignment direction similarly The top view which shows the detection principle of the yaw direction change by this invention Sectional view showing detection principle of roll direction change The flowchart which shows the attachment procedure of embodiment of this invention Similarly, a front view showing a display example of an abnormal signal

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Scale 11, 12, 23, 24 ... Track 20 ... Detection head 22 ... Sensor substrate 30, 32, 34 ... Bar graph 36, 38 ... LED

Claims (4)

In a separate type encoder having a plurality of tracks in the width direction orthogonal to the measurement direction,
Means for detecting the phase of at least two tracks;
Means for determining an alignment error in the yaw direction when the phase difference between the tracks exceeds an allowable range;
A separate type encoder comprising: In a separate type encoder having a plurality of tracks in the width direction orthogonal to the measurement direction,
Means for detecting the signal strength of at least two tracks;
Means for determining an alignment abnormality in the roll direction when the signal intensity ratio between the tracks exceeds an allowable range;
A separate type encoder comprising: In a separate type encoder having a plurality of tracks in the width direction orthogonal to the measurement direction,
Means for detecting the phase of at least two tracks;
Means for detecting the signal strength of at least two tracks;
Means for determining an alignment error in the yaw direction or roll direction when the phase difference between the tracks or the signal intensity ratio exceeds an allowable range;
A separate type encoder comprising: In the mounting method of the separate encoder having a plurality of tracks in the width direction orthogonal to the length measuring direction,
Adjust the lateral alignment so that the signal strength of at least one track is maximized,
Then adjust the alignment in the roll direction so that the signal strength of at least two tracks is the same,
Next, adjust the alignment in the gap direction so that the signal strength of at least one track is within the allowable range,
Finally, a method for mounting a separate encoder, wherein the alignment in the yaw direction is adjusted so that the phase difference between at least two tracks is within an allowable range.

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