JP4005472B2 - Position detection device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a position detection device that is attached to a main body device such as a machine tool or an industrial robot having a movable part and detects a movement amount or a movement position of the movable part.
[0002]
[Prior art]
Various machine tools, industrial robots, and other main body devices are provided with a position detection device for detecting the amount and position of movement of a movable part such as a table. The position detection device is equipped with a long scale part provided with a position signal indicating the amount of movement of the movable part and a movement position, and a sensor for detecting the position signal, and the sensor faces the position signal forming surface of the scale part. And a detection unit that is assembled as described above. In the position detection device, the sensor is positioned with respect to the scale portion with a predetermined facing interval with respect to the position signal forming surface of the scale portion, and combined.
[0003]
In the position detection device, the detection unit is coupled to the movable unit or the fixed unit of the main device by an appropriate coupling mechanism. In the position detection device, for example, when the detection unit is connected to the movable unit, the sensor slides along the position signal forming surface of the scale unit as the movable unit moves, and the sensor moves from the fixed point of the scale unit. A position signal at a predetermined position is detected. The position detection device outputs position information from the detection unit to the main device, and controls the moving operation of the movable unit. In the position detecting device, the facing interval of the sensor with respect to the scale unit is precisely set to a predetermined facing interval so that the sensor can accurately detect the position signal of the scale unit and appropriately control the movement of the main body device.
[0004]
[Problems to be solved by the invention]
In the conventional position detection device, the sensor is directly attached and fixed to the surface facing the scale portion of the detection unit, or is attached to the sensor support member that supports the sensor, and this sensor support member is opposed to the scale portion of the detection unit. It is directly attached to the surface to be fixed. For this reason, in the position detection device, when the sensor or the sensor support member is fixed to the detection unit, the sensor or the sensor support member is used with a jig or the like so that the facing interval between the scale unit and the sensor becomes a predetermined facing interval. After being temporarily fixed to the detection unit in the positioned state, it is permanently fixed to the detection unit.
[0005]
In the position detection apparatus, since the jig or the like is removed when the position is fixed, the position of the sensor or the sensor support member may be displaced, and the distance between the sensor and the scale portion may not be accurately set. In the position detection device, since the facing interval of the sensor with respect to the scale portion is not precisely set to a predetermined facing interval, it is difficult to accurately detect the position signal of the scale portion. Further, in the position detection device, the moving position of the movable part cannot be accurately detected, and thus there arises a problem that the position of the movable part is not properly controlled. Furthermore, in the position detection device, every time a position shift of the sensor or the sensor support member occurs, a troublesome operation for readjusting the position of the sensor or the sensor support member is required, and there is a problem that work efficiency is lowered. .
[0006]
SUMMARY OF THE INVENTION An object of the present invention is to provide a position detection device capable of precisely setting the position of a sensor with respect to a scale by a simple operation.
[0007]
[Means for Solving the Problems]
The position detection device according to the present invention that achieves the above-described object is a detection unit that detects the position signal by moving relative to the scale unit provided with the position signal in accordance with the moving operation of the movable unit of the main device. Is provided. The detection unit is attached to a substrate disposed opposite to the position signal formation surface of the scale unit, and a surface of the substrate opposite to the scale unit, and a sensor that detects the position signal is attached to face the position signal formation surface. The sensor holder and an adjustment member that adjusts the facing distance of the sensor to the scale portion by pressing the sensor holder from the substrate side. The sensor holder is formed with a pair of concave grooves in the width direction so as to sandwich the sensor mounting area where the sensor is mounted, and the outer area of the sensor mounting area formed by dividing by these concave grooves is the adjustment area. It is pressed by the member.
[0008]
According to the position detection device according to the present invention configured as described above, the detection unit moves relative to the scale unit by moving the movable unit of the main device relative to the fixed unit. In the position detection device, a sensor attached to the substrate of the detection unit detects a position signal of the scale unit, outputs position information to the main device, and performs position control of the movable unit.
[0009]
In the position detection device, by pressing the sensor holder with the adjusting member, an operation of precisely adjusting the facing distance between the position signal forming surface of the scale portion and the sensor is performed via the sensor holder. In the position detection device, the adjustment member is absorbed by the pair of concave grooves by pressing the outer region of the sensor attachment region formed by being divided by the pair of concave grooves provided in the sensor holder, The occurrence of bending in the sensor mounting area is suppressed. According to the position detecting device, the sensor mounting region moves in a state parallel to the position signal forming surface by the simple operation by the adjusting member and the pair of concave grooves of the sensor holder, thereby forming the position signal of the scale portion. The distance between the surface and the sensor is set precisely.
[0010]
Therefore, according to the position detection device, the detection unit is moved in accordance with the moving operation of the movable unit of the main device in a state where the facing distance between the sensor and the position signal forming surface of the scale unit is precisely maintained over the entire region. The sensor detects a position signal by moving relative to the scale portion. According to the position detection device, the position detection and the position control of the movable part are precisely performed by detecting the position signal by the precisely set sensor.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. As shown in FIGS. 1 and 2, the position detection device 1 shown in the drawings as an embodiment includes a scale unit 5 attached to a fixed unit 2 of a main body device 4 having a fixed unit 2 and a movable unit 3, and And a detection unit 6 attached to the movable unit 3 of the main device 4. The movable unit 3 of the main device 4 is a processing table or a tool table of various machine tools, industrial machines, or precision machines, and performs a precise movement operation.
[0012]
In the position detection device 1, a detection unit 6 is assembled to the scale unit 5, and a coupling mechanism 7 provided at one end of the detection unit 6 is connected to a carrier 8 connected to the movable unit 3. 3 is transmitted to the detection unit 6 via the coupling mechanism 7 and the carrier 8. In the position detection device 1, the detection unit 6 moves the scale unit 5 in accordance with the movement operation of the movable unit 3 transmitted to the detection unit 6. The position detection device 1 feeds back position information detected by the movement of the detection unit 6 to the movable unit 3 to control the movement operation of the movable unit 3.
[0013]
The scale unit 5 is formed in an elongated shape, and an optical, magnetic, or mechanical signal indicating position information such as a movement amount or a movement position of the movable unit 3 of the main device 4 is the first main surface. The first main surface is configured as a position signal forming surface 5a. The scale portion 5 is made of iron, stainless steel, or the like, has a length sufficient to cover the entire length direction, and is accommodated in a case member that is formed in a channel shape with an open bottom portion. Yes. Although the details of the case member are omitted on one side surface, an attachment portion for attaching and fixing to the fixing portion 2 of the main device 4 is formed.
[0014]
The detection unit 6 is provided with a substrate 9 that is disposed so as to be able to run facing the position signal forming surface 5a of the scale unit 5 and a sensor 10 that detects the position signal of the scale unit 5, and the scale unit 5 side of the substrate 9 is attached. The sensor holder 11 is fixed to the scale portion 5 and the adjustment member 12 is configured to adjust the facing distance Δx of the sensor 10 with respect to the scale portion 5 as will be described in detail later.
[0015]
As shown in FIGS. 2 and 3, the detection unit 6 is combined with the substrate 9 being precisely positioned and combined with the scale unit 5 as will be described in detail later, and a sensor holder 11 fixed to the substrate 9. Is precisely set by the adjusting member 12, the sensor 10 is precisely set with respect to the position signal forming surface 5 a of the scale unit 5 through the sensor holder 11. The detection unit 6 detects the position signal by causing the substrate 9 on which the sensor holder 11 is fixed to slide on the position signal forming surface 5a of the scale unit 5 in accordance with the movement operation of the movable unit 3 of the main device 4. 10, the movement amount and movement position of the movable part 3 are output to the main device 4.
[0016]
The substrate 9 is formed in a rectangular shape, and has a storage recess 13 in which the sensor holder 11 is fixed on a surface facing the scale portion 5. In the substrate 9, a through hole 14 a through which the screw 14 for fixing the sensor holder 11 passes is formed in the vicinity of both ends in the width direction of the storage recess 13. Further, the board 9 is formed with a screw hole 12a into which the adjusting member 12 is screwed, and a sensor holder 11 described later, and a hole 16 into which a convex portion 15 serving as a rotation fulcrum for angle adjustment in the rotation direction of the sensor 10 is fitted. Is formed.
[0017]
On the substrate 9, a plurality of guide rollers 18 a to 18 e that can freely slide in the longitudinal direction of the scale unit 5 are provided in the vicinity of both ends in the longitudinal direction of the scale unit 5 and at positions facing the lower edge of the scale unit 5. It has been. The substrate 9 is moved to the scale portion 5 by the guide rollers 18a to 18e rolling on the position signal forming surface 5a in accordance with the moving operation of the movable portion 3 of the main device 4 via the coupling mechanism 7 and the carrier 8. On the other hand, smooth slide movement is performed without causing vertical shake or horizontal shake.
[0018]
As shown in FIG. 4, the sensor holder 11 is formed in a substantially rectangular shape, and the central region is configured as a sensor attachment region 10 a that bonds and fixes the sensor 10 that detects the position signal of the scale unit 5. ing. One end of the sensor 10 is connected to the flexible cable 4a that is connected to the output unit of the main device 4. The sensor 10 outputs the detected position signal to the output unit as position information.
[0019]
In the sensor holder 11, a pair of concave grooves 17 </ b> A and 17 </ b> B are formed in the width direction on the surface facing the scale portion 5 so as to sandwich the sensor attachment region 10 a. When the sensor holder 11 adjusts the position of the sensor 10 with respect to the scale portion 5, the opposing outer regions 19 a and 19 b of the sensor attachment region 10 a divided by the concave grooves 17 </ b> A and 17 </ b> B are pressed by the adjusting member 12. In the sensor holder 11, the outer regions 19a and 19b are pressed against the adjustment member 12 from the substrate 9 side, so that distortions and deflections generated in the outer regions 19a and 19b are absorbed by the concave grooves 17A and 17B. 10a is prevented from being bent or distorted. Therefore, according to the sensor holder 11, the sensor 10 that is in proximity to the scale unit 5 while being in parallel is moved and adjusted parallel to the position signal forming surface 5 a of the scale unit 5. become. The shape of the concave grooves 17A and 17B only needs to have a function of absorbing the bending and distortion of the outer regions 19a and 19b, and is not limited to the concave shape as shown in FIG. Each may be constituted by a plurality of grooves.
[0020]
The sensor holder 11 has a screw hole 14b for screwing a screw 14 to be fixed to the substrate 9 in the vicinity of both ends in the width direction, and a convex portion 15 fitted to the hole portion 16 formed in the substrate 9. It is formed at a substantially central portion at one end of the region 10a. The convex portion 15 and the hole portion 16 serve as a rotation fulcrum of the sensor holder 11 with respect to the substrate 9 in the rotational direction indicated by the arrow A in FIG. To do. In the sensor holder 11, the angle of the rotation direction of the sensor 10 is adjusted with respect to the scale portion 5 in a state where the convex portion 15 is fitted in the hole portion 16. The swing mechanism is only required to be able to adjust the angle in the rotational direction with respect to the scale portion 5. For example, the convex portion 15 is provided on one side of the substrate 9 or the sensor holder 11, and the convex portion 15 is fitted on the other side. A hole 16 may be provided.
[0021]
The adjustment member 12 is screwed into the screw hole 12 a from the outside of the substrate 9, and the tip contacts the concave grooves 17 </ b> A and 17 </ b> B of the sensor holder 11 housed in the housing recess 13 of the substrate 9 at a position facing the sensor 10. Be equipped as such. The adjusting member 12 is, for example, a screw or the like having a groove formed in a spiral shape. The adjusting member 12 is screwed into the screw hole 12a and the tip presses the sensor holder 11 so that the adjusting member 12 can be freely adjusted in the direction close to the scale unit 5. It consists of members. The adjustment member 12 adjusts the facing distance Δx and the inclination of the sensor 10 with respect to the scale unit 5.
[0022]
As shown in FIG. 5, the sensor holder 11 is pressed toward the scale portion 5 side via the adjustment member 12, so that the sensor holder 11 is bent or distorted so as to be curved in an arc shape as a whole. , 17B is formed, the bending and distortion are absorbed, and the occurrence of bending and distortion in the sensor attachment region 10a is suppressed. Therefore, the sensor holder 11 brings the sensor 10 close to the scale portion 5 in a parallel state via the sensor attachment region 10a, and narrows the facing distance Δx between the scale portion 5 and the sensor 10.
[0023]
The adjustment member 12 is loosened in the external direction, so that the sensor holder 11 reversibly returns to its original state. Therefore, the adjustment member 12 is separated from the scale unit 5 of the sensor 10 in parallel. Is increased. Due to the elastic stress of the sensor holder 11 generated when the adjusting member 12 is pressed in the direction of the scale portion 5, a force in the direction of returning to the external direction is applied, and the effect of preventing loosening is obtained. As shown in FIG. 3, the adjustment member 12 is provided at three points in the outer regions 19a and 19b. However, if the opposing distance Δx and the inclination of the sensor 10 can be adjusted with respect to the scale portion 5, two or four points are provided. You may make it provide above.
[0024]
The position detection device 1 precisely adjusts the facing distance Δx and the inclination of the sensor 10 with respect to the scale unit 5 as follows. In the position detection device 1, the sensor holder 11 to which the sensor 10 is bonded is rotated using the convex portion 15 and the hole portion 16 as rotation fulcrums, thereby adjusting the angle of the sensor holder 11 in the rotation direction. The position detection apparatus 1 adjusts the facing interval Δx and the inclination of the sensor 10 with respect to the scale unit 5 to a predetermined interval and inclination, and in a set state, the plurality of screws 14 are tightened so that the sensor holder 11 holds the concave portion of the substrate 9. 13 is fixed.
[0025]
In the position detection device 1, in setting the rotation angle of the sensor holder 11 and the facing distance Δx and inclination of the sensor 10 with respect to the scale unit 5, the rotation angle and the output waveform indicating each movement amount are used to set the predetermined rotation angle and the facing angle. Adjust to spacing and tilt. In the position detection device 1, the position generated when the sensor holder 11 is fixed to the substrate 9 is adjusted with the adjustment member 12 while the output waveform indicating the pressing amount of the adjustment member 12 is observed, and the position of the sensor holder 11 is set to a predetermined position. Fine adjustment is made so that the interval Δx and the inclination are obtained. In the position detection device 1, by adjusting the sensor holder 11 with the adjusting member 12, the facing distance Δx and the inclination of the sensor 10 with respect to the scale unit 5 are easily and precisely set to a predetermined interval and inclination.
[0026]
According to the position detection device 1 described above, the displacement that occurs when the sensor holder 11 is permanently fixed to the substrate 9 can be easily operated using the adjustment member 12 and the pair of concave grooves 17A and 17B formed in the sensor holder 11. The facing interval Δx and the inclination are adjusted in a state where the sensor mounting region 10a is parallel to the position signal forming surface 5a of the scale portion 5, and the predetermined facing interval Δx and the tilt are precisely set. Therefore, according to the position detection device 1, the sensor 10 accurately holds the facing distance Δx and the inclination of the scale portion 5 with respect to the position signal forming surface 5 a at the predetermined facing distance and inclination as the movable portion 3 moves. In this state, it slides and detects the position signal. In the position detection device 1, the position detection and position control of the movable part 3 are precisely performed based on the position information detected by the precisely held sensor 10.
[0027]
In the position detection device 1, the scale unit 5 is attached to the fixed unit 2 of the main device 4, and the detection unit 6 is attached to the movable unit 3, but the detection unit 6 is attached to the fixed unit 2 and the movable unit 3 is attached to the movable unit 3. The scale unit 5 may be attached so that the scale unit slides relative to the detection unit 6. In the position detection device 1, the position information detected by the detection unit 6 is fed back to the movable unit 3 to control the moving operation of the movable unit 3. For example, the position information is sent to an appropriate display device. Then, the position of the movable part 3 may be displayed.
[0028]
【The invention's effect】
As described above in detail, the position detection device according to the present invention uses the adjustment member to adjust the deviation that occurs when the sensor holder is permanently fixed to the substrate. It becomes. In addition, since the position detection device suppresses the occurrence of bending of the sensor mounting area by the pair of concave grooves provided in the sensor holder, the sensor is parallel to the scale portion, and changes in the position signal due to the tilt of the sensor are prevented. Detection is highly accurate. Therefore, in the position detection device, the distance and inclination of the sensor with respect to the scale portion are precisely set, so that the detection of the position signal is highly accurate and stable, and the reliability of the position detection and position control of the movable portion is improved. .
[Brief description of the drawings]
FIG. 1 is a schematic view of a state in which a position detection device according to the present invention is provided in a main device.
FIG. 2 is a cross-sectional view of a detection unit of the position detection device.
FIG. 3 is a rear view of a detection unit of the position detection device.
FIG. 4 is a perspective view of a sensor holder of the position detection device.
FIG. 5 is a cross-sectional view of the main part for explaining the position adjustment operation of the sensor with respect to the scale unit in the position detection device.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Position detection apparatus, 5 Scale part, 6 Detection part, 7 Connection mechanism, 9 Substrate, 10 Sensor, 10a Sensor mounting area, 11 Sensor holder, 12 Adjustment member, 12a Screw hole, 13 Storage recessed part, 14 Screw, 14a Through-hole , 14b screw hole, 15 convex portion, 16 hole portion, 17a, 17b concave groove, 18a-18e guide roller, 19a, 19b outer region

Claims (2)

Along with the movement operation of the movable part of the main device, a relative movement with respect to the scale part provided with the position signal, provided with a detection part for detecting the position signal,
The detection unit is attached to a substrate disposed opposite to the position signal formation surface of the scale unit, and a surface of the substrate opposite to the scale unit, and the position signal is opposed to the position signal formation surface. A sensor holder to which a sensor to be detected is attached; and an adjustment member that adjusts the facing distance of the sensor to the scale portion by pressing the sensor holder from the substrate side;
A pair of concave grooves in the width direction are formed in the sensor holder so as to sandwich the sensor mounting area to which the sensor is mounted, and an outer area of the sensor mounting area formed by dividing by the concave grooves is the adjusting member. The position detecting device is characterized in that, by being pressed by the concave groove, occurrence of bending of the sensor mounting region is suppressed by the concave groove, and the facing distance between the sensor and the position signal forming surface of the scale portion is adjusted. . The substrate and the sensor holder are provided with a swing mechanism for swinging the sensor holder with respect to the substrate.
2. The position detection according to claim 1, wherein the angle of the sensor with respect to the position signal forming surface of the scale portion is adjusted by rotating the sensor holder with respect to the substrate by the swing mechanism. apparatus.

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