KR930000483B1 - Rotary coding apparatus - Google Patents

Abstract

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Description

Rotary encoder

1 and 2 show one embodiment of the invention, in which FIG. 1 is a longitudinal front view.

2 shows the coupling means, with the figure (a) being a partial cross-sectional side view and the figure (b) a bottom view.

Figure 3 shows another example of the coupling means, the same figure (a) is a side view, and (b) is a bottom view.

4 and 5 are each a longitudinal front view of the conventional example.

* Explanation of symbols for main parts of the drawings

1: Hollow rotating shaft 1a: Inner peripheral surface of hollow rotating shaft

2: axis under measurement 2a: outer peripheral surface of the axis under measurement

3: support flange 4: code board

6: bowl bearing 7: support member

8 detector 10a, 10b measuring surface

11: fixing means 12a, 12b: wedge shaped sleeve

13: fastening bolt 14, 15: mountain-shaped sleeve

17: coupling means 18: fixed part

19: hook pin 20: hang bracket

21: Push pin 24: Piano wire

25: fixed bracket

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a rotary encoder, and more particularly to a rotary encoder that facilitates mounting on an axis to be measured.

Conventionally, in the high-resolution rotary encoder, as shown in FIG. 4, the hollow shaft 42 which fixed the code board 41 is fitted in the state which provided the clearance to the to-be-measured shaft 43, and it is axial direction. Circumference of the fixing ring 44 which is positioned by abutting the one end of the hollow shaft 42 against the abutting surface 43a formed on the measuring axis 43 and screwed to the end of the measuring axis 43. The other end of the hollow shaft 42 is fixed by pressing the bolt 45 provided in a plurality of directions via the pressing plate 46, and in the radial direction, radially in a plurality of circumferential directions of the hollow shaft 42. The tip of the screw 47 installed through the abutment is brought into contact with the outer circumferential surface of the shaft under measurement 43 so that the shaft 47 of the nose plate 41 and the shaft under measurement 43 can be adjusted so that the screw 47 can be adjusted. It is. Moreover, the detector 48 which the code | board plate 41 detects a rotation position is attached so that a position adjustment is possible through the bracket 49 to the fixed side.

On the other hand, in the relatively low rotary encoder, as shown in FIG. 5, the hollow rotating shaft 52 on which the nose plate 51 is fixed is supported so as to be freely rotated by the support member 54 via the bearing 53. At the same time, the support member 54 is fitted with a detector 55 for detecting the rotational position of the nose plate 51. At the time of installation, the hollow rotating shaft 52 is attached to the measuring shaft 56. The fastening is fixed between the surface 55a which is fitted and abuts by the fixing nut 57 screwed to the end of the axis 56 to be measured. Moreover, in order to prevent rotation of the support member 54, the outer peripheral part of the annular leaf spring 58 perpendicular | vertical with respect to a rotating shaft center is fixed to the fixed side by the bolt 59a, and the inner peripheral part is supported by the support member 54 ) Is fastened by bolts 59b.

By the way, in the structure of attachment as shown in FIG. 4, since the code plate 41 is directly attached to the to-be-measured shaft 43, the code plate 41 is mounted with respect to the to-be-measured shaft 43. FIG. It can be mounted with low eccentricity, so the cumulative pitch error is small and it can cope with the high resolution rotary encoder. However, the assembly of the rotary encoder itself and its mounting must be performed at the same time at the installation site of the rotary encoder. Since the assembly adjustment of the rotary encoder, such as the output waveform adjustment, is necessary during the mounting operation, there is a problem that it takes a very long time.

On the other hand, in the configuration of the mounting as shown in FIG. 5, since the rotary encoder is unitized, the mounting work is simple, but the board is formed by the coupling gap between the measuring shaft 56 and the hollow rotating shaft 52. The eccentricity between the 51 and the to-be-measured shaft 56 cannot be avoided, and the cumulative pitch error becomes large, and there is a problem that it cannot cope with a high resolution rotary encoder.

Moreover, since the support member 54 is fixed to the inner peripheral part of the annular leaf spring 58 which fixed the outer peripheral part to the fixed side, the restraint force by the rigidity of this leaf spring 58 is large, and the support member 54 is supported. ) And the eccentricity of the measurement target shaft 56 also cause a large sign fluctuation in the bearing 53 at the time of rotation, thereby causing rotation unevenness.

In addition, in FIG. 5, when the internal diameter of the hollow rotating shaft 52 is enlarged, the bearing 5 3 of large diameter is needed, and the rotation precision of the code board 51 falls by that, and the code board ( Since there exists a possibility that a detection error may arise because the clearance gap between 51 and the detector 55 becomes large, it is not considered to interpose an axis center adjusting means between the to-be-measured shaft 56 and the hollow rotating shaft 52. FIG.

An object of the present invention is to provide a rotary encoder which is simple in mounting work, small in accumulated pitch error, and can cope with high resolution position detection.

The present invention, in order to achieve the above object, through the annular shape of the corrugated plate attached to the rotational direction of the scale indicating the rotational position, the hollow rotating shaft concentrically fixed to the support plate with the support flange, the hollow rotating shaft through the bearing And a supporting member fixed to the fixed portion by a coupling means and equipped with a detector for freely supporting rotation and detecting the rotational position of the code plate, and an inner circumferential surface of the hollow rotating shaft and an outer circumferential surface of the measurement target to be measured. And a fixing means for interposing the hollow rotating shaft to the outer circumferential surface of the measuring shaft so that the hollow rotating shaft can be axially adjusted with respect to the measuring axis. It is characterized by including a measuring surface for measuring.

Preferably, a laser detector which irradiates a laser beam from a laser light source to a light plate, and irradiates the light detecting element through the slit with light and dark stripes on the Fraunhofer diffraction formed by slits regularly formed in the wood plate. do. It is also preferable that the measuring surface is formed at both ends of the hollow rotating shaft, and the fixing means is composed of a pair of wedge-shaped sleeves and a mountain-shaped clamp that are attracted to each other by a screw mechanism.

In addition, a coupling means is used for fixing the support member only in the rotational direction centered on the axis of the hollow rotating shaft and engaging the fixed side in a floating direction in other directions. The engaging means includes a engaging pin protruding radially from the base member and a locking member on a fixed side engaged with the engaging pin in a circumferential direction, or on a circumference centering on an axis of the hollow rotating shaft. It is suitable to have a flexible wire member which is disposed in the tangential direction with respect to the support member and whose intermediate portion is fixed to the support member, and a fixing bracket for fixing both ends thereof to the fixing side.

According to the rotary encoder of the present invention, since the plate, the detector, the hollow rotating shaft, the bearing, and the supporting member are unitized, they can be simply attached to the shaft under measurement, and the hollow rotating shaft can be attached. Since the fixing means fixed to the axis to be measured can be adjusted, the eccentricity can be reduced and the cumulative pitch error can be reduced by adjusting the axial center while measuring the axial center position from the measurement surface, so that it can cope with high resolution. .

In addition, if the detector is used as a laser to detect light and dark streaks in a narrow beam state due to Fraunhofer diffraction, there is no fear of detecting an error even if a large gap between the wood plate and the detector is provided. As a result, the diameter of the hollow rotating shaft and the bearing increases, so that the bearing accuracy decreases, and even if the surface vibration of the plate increases, the detection error does not occur.

In addition, when the measurement surface is disposed at both ends of the hollow rotating shaft, the detection accuracy of the shaft center is increased.

In addition, since the supporting member is fixed only in the rotational direction and floatable in the other direction, no load fluctuations occur in the bearings due to rotation, and the rotational system is not adversely affected.

Hereinafter, an embodiment of the present invention will be described with reference to FIGS. 1 and 2.

In Fig. 1, reference numeral 1 denotes a hollow rotating shaft that is fitted to the measurement target shaft 2, and a support flange 3 of the code plate 4 is formed on the outer circumference thereof. The inner circumferential portion of the wood plate 4 abuts on and is fixed to the supporting surface, which is one surface of the support flange 3. The hollow rotating shaft 1 is supported to rotate freely by a supporting member 7 made of an annular plate via a pair of bowl bearings 5. The support member 7 is provided with a detector 8 for detecting the rotational position of the nose plate 4. The detector 8 irradiates the laser plate from the laser light source to the light plate 4, and transmits the light to the photodetecting device via the slit through the light and dark pattern of the Fraunhofer diffraction formed by the slit regularly formed on the wood plate 4. It is configured to investigate.

9 is a cover which covers the code board 4 and the detector 8, The outer peripheral part is being fixed to the outer periphery of the support member 7. As shown in FIG. 6a is a fixing nut of the bearing 6, and is screwed to the outer circumference of the hollow rotating shaft 1. The outer circumferential surfaces of both ends of the hollow rotating shaft 1 in the axial direction outward from the cover 9 and the fixing nut 6a are measured surfaces 10a and 10b which are formed in the same coaxial center state exactly as the wood plate 4. )

(11) is interposed between the outer circumferential surface of the shaft to be measured 2 and the inner circumferential surface of the hollow rotating shaft 1, and is a fastening means for fixing the hollow rotating shaft to the shaft under measurement so that the center of gravity can be adjusted. A pair of wedge-shaped sleeves 12a and 12b pulled together by each other and these wedge-shaped sleeves 12a and 12b are engaged with the inner circumference and pressed against the outer peripheral surface of the axis to be measured 2. And a mountain-shaped sleeve 14 in contact with each other and a mountain-shaped sleeve 15 engaged with the outer circumference and pressed against the inner circumferential surface of the hollow rotating shaft 1. The mountain-shaped sleeve 15 of the outer periphery is divided into two at the central position in the axial direction, and the adjustment distance 16 is interposed therebetween.

In addition, as shown in Figs. 2A and 2B, the support member 7 is fixed to the outer circumference of the support member 7 in a state in which the support member 7 is fixed only in the rotational direction and floatable in another direction. Coupling means 17 for engaging with 18 are disposed. The engaging means 17 is different from the engaging pin 19 protruding radially from the supporting member 7, and the engaging bracket 20 engaged with the engaging pin 19 from one circumferential direction. It consists of a pressing pin 21 which is engaged from the side, the locking bracket 20 is mounted to the fixing portion 18, the pressing pin 21 is mounted to the locking bracket 20 to be accessible. At the same time, it is projected by the spring 22.

Next, the procedure of attaching the rotary encoder of the above structure to the to-be-measured shaft 2 is demonstrated. An inner peripheral surface of the hollow rotating shaft 1 and the measuring shaft 2 are fitted with the fixing means 11 with the hollow rotating shaft 1 externally fitted to the measurement shaft 2 and the fastening bolt 13 loosened. Interposed between the outer circumferential surfaces of the rollers and press the engaging pins 19 protruding from the support member 7 between the locking brackets 20 and the pressing pins 21.

Next, the fastening bolt 13 is fastened to fix the measurement axis 2 and the hollow rotating shaft 1, and then the dial gauge is placed on the measurement surfaces 10a and 10b while rotating the measurement axis 2. Measure the eccentricity of the hollow rotating shaft (1). When the eccentric amount and the eccentric direction are found, loosen the fastening bolt 13 slightly to adjust the axial center of the hollow rotating shaft 1, and repeat the adjustment work of tightening and fastening the fastening bolt 13 again, and then the measuring shaft 2 is measured. And the sounding of the hollow rotating shaft (1). The installation work is completed.

In addition, if the shaft center adjustment of the said hollow rotating shaft 1 is forcibly displaced by means, such as lightly tapping on the hollow rotating shaft 1, the wedge-shaped sleeves 12a and 12b of the fixing means 11 will be accordingly followed. And the relative positions of the mountain sleeves 14 and 15 are changed.

Next, operation as a rotary encoder will be described. When the axis under measurement 2 rotates, the code plate 4 rotates together with the hollow axis of rotation 1, the rotation state is detected by the detector 8, and the axis under measurement is processed by processing the detection signal. The rotation position and rotation speed of (2) are detected.

At this time, since the measuring shaft 2 and the hollow rotating shaft 1 are fixed by being oriented by the fixing means 11, the nose is rotated according to the rotation of the measuring shaft 2 due to the eccentricity of the nose plate 4. The wood plate 4 is not eccentrically rotated (vibrationally rotated) to generate a cumulative pitch error in the detection result.

Moreover, since the detector 8 is a laser system and detects the light and dark stripes of the narrow beam state by the Fraunhofer diffraction of a laser beam, even if a comparatively large gap is formed in both surfaces of the code board 4, an error will reliably occur. Position detection is possible. Therefore, in order to interpose the fixing means 11, the diameters of the hollow rotating shaft 1 and the bowl bearing 6 become large, so that the bearing precision decreases, and a detection error occurs even if the rotating surface vibration occurs in the code plate 4. There is no concern.

In addition, since the support member 7 is fixed only in the rotational direction by the engaging means 17 and is floatable in the other direction, even when there is a slight eccentricity such that there is no influence on the rotation detection, at the time of rotation Since the support member 7 can be displaced in accordance with the eccentricity, a large load acts on the bearing 6, which is not a cause of rotation unevenness.

In the above embodiment, although the engaging pin 19 is used as the coupling means 17 of the support member 7 and the fixing portion 18, an example shown in FIGS. 3A and 3B is shown. As described above, the center portion of the piano wire 24 may be fixed by the mounting holes 23 mounted on the outer circumference of the support member 7, and both ends of the piano wire 24 may be fixed by the fixing bracket 25. . Also in this case, the piano wire 24 acts as a rigid body in the rotational direction along the axial center direction, and acts as a weak elastic body in other directions, and thus the same effect can be obtained.

According to the rotary encoder of the present invention, as is apparent from the above description, since the code plate, the detector, the hollow rotating shaft, the bearing, and the supporting member are unitized, the rotary encoder can be simply mounted on the shaft under measurement. In addition, since the fixing means for fixing the hollow rotating shaft to the side to be measured is axially adjusted, the eccentricity can be reduced and the cumulative pitch error can be reduced by performing the axial center adjustment while measuring the axial center position on the measurement surface. It can also respond to.

In addition, if the detector is used as a laser system to detect light and dark streaks in a narrow beam state by Fraunhofer diffraction, there is no risk of detection error even if a large gap between the wood plate and the detector is provided. As a result, the diameter of the hollow rotating shaft and the bearing increases, so that the bearing accuracy decreases, and even if the surface vibration of the plate increases, the detection error does not occur.

In addition, when the measurement surface is disposed at both ends of the hollow rotating shaft, the detection accuracy of the shaft center is increased.

In addition, since the supporting member is fixed only in the rotational direction and floatable in another direction, the bearing member does not adversely affect the rotating system without causing load fluctuations in the bearing, thereby exerting a great effect. .

Claims (7)

An annular shaped nose plate 4 having a scale indicating a rotational position in the rotational direction, a hollow rotating shaft 1 in which the nose plate 4 is fixed concentrically with a support flange 3, and a hollow rotating shaft 1 Support member fixed to the fixing portion 18 by a coupling means 17, equipped with a detector 8 for freely supporting rotation through the bearing 6 and detecting a rotational position of the code plate 4. (7) interposed between the inner circumferential surface 1a of the hollow rotating shaft 1 and the outer circumferential surface 2a of the measurement shaft 2 to be measured as the rotation position, thereby measuring the hollow rotating shaft 1 to be measured. The fixing means 11 fixed to the outer circumferential surface 2a of the measurement target shaft 2 so that the axial center can be adjusted with respect to the shaft 2, and on the outer circumferential surface of the hollow rotating shaft 1 in the same axial center state as the wood plate 4; And a measuring surface (10a), (10b) for forming an eccentricity of the hollow rotating shaft (1). The rotary encoder according to claim 1, wherein the measuring surfaces (10a) and (10b) are formed at both end projections of the hollow rotating shaft (1). The pair of wedge-shaped sleeves 12a, 12b and the mountain sleeves 14, 15 according to claim 1 or 2, wherein the fixing means 11 are attracted to each other by a screw mechanism. Rotary encoder comprising a clamp means having a. 5. The clamp means according to claim 4, wherein the clamping means engages with the inner circumferences of the wedge-shaped sleeves 12a and 12b and is in contact with the mountain-shaped sleeve 14 pressed against the outer circumferential surface of the axis to be measured 2, with a wedge shape. It consists of a mountain sleeve (15) which is engaged with the outer circumference of the sleeve (12a), (12b) and pressed against the inner circumferential surface of the hollow rotating shaft, the outer sleeve (15) of the outer circumference of the sleeve The rotary encoder which is divided | segmented and it arrange | positions through the distance distance 16 for adjustment between them. The method according to claim 1, wherein the supporting member (7) is provided with a coupling means (17) for fixing only in the rotational direction centered on the axis of the hollow rotating shaft (1) and floatingly coupled to the fixed side in the other direction. Rotary encoder characterized in that. The engaging means (17) according to claim 5, characterized in that the engaging means (17) is provided with an engaging pin (19) protruding radially from the support member and a locking member on a fixed side engaged with the engaging pin (19) in a circumferential direction. Rotary encoder characterized in that. 6. The flexible wire 24 according to claim 5, wherein the coupling means 17 is disposed in a tangential direction with respect to the circumference centered on the axis of the hollow rotating shaft 1, and the intermediate portion is fixed to the support member 7, and And a fixing bracket (25) for fixing both ends to the fixing side.

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