JPS6258105A - Rotary encoder - Google Patents

Abstract

PURPOSE:To bring the relative vibration between a rotary disk and a detection head to zero, by providing the rotary bar for supporting a detector and supporting the same by the rotary shaft of the rotary disk through a bearing. CONSTITUTION:A rotary disk 3 is fixed to the rotary shaft 2 of a motor 1 being a rotary driving source and magnetic graduations are provided on the circumference of said rotary disk 3. The detection head opposed thereto generates a pulse signal every when the graduations rotate and move to detect the pulse row signal corresponding to angle of rotation and the number of rotations and said signal is counted to detect the angle of rotation. Further, a rotational speed is detected by the number of the detection pulses per unit time of the detection head. A detector 4 is supported by a fixing bar 6 and the shaft 2 of the disk 3 is supported by said fixing bar 6 through a bearing 5. Because the vibration of the disk 3 propagates through the bar 6 to act on the detection head and synchronously vibrates the detection head, the relative vibration between the disk 3 and the detector 4 comes to zero. Therefore, the generation of the detection error due to the vibration of the disk 3 can be prevented, and a position and a speed can be always simultaneously detected with high accuracy.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a rotary encoder used as a length measuring device for measuring moving distance of machine tools, positioning, numerical control, large layout machines, inspection equipment, etc. - [Prior Art] Conventionally, encoders include optical types, magnetic types, electromagnetic types, etc. depending on the scale reading method. In either case, a scale is attached to a rotating disk, which is read by an opposing detector, and the read value is digitally displayed on a display.

〔problem〕

1. Since the detector facing the disk rotating with the rotary drive body is fixed to a stationary part,
The disc and the detector vibrate relative to each other, and this vibration has the disadvantage of causing errors in detected values.

(Means for Solving Problems) The present invention was proposed in order to improve this point, and includes a fixed bar that fixedly supports the scale detector of a rotary encoder. It is supported on the rotating shaft of.

〔Example〕

The present invention will be explained below with reference to an embodiment of the drawings.

FIG. 1 is a side view, and FIG. 2 is a top view. Reference numeral 1 denotes a motor as a rotational drive source, which fixes a driven body of a mechanical device to a rotating shaft 2 and applies rotation to it, and performs drive control such as rotation and feeding. Reference numeral 3 denotes a rotating disk fixed to the motor rotating shaft 2. In a magnetic encoder, a rotating disk is used that is made of a magnetic material or whose surface is coated with a magnetic material or magnetic tape so that it can be magnetized.

A magnetic scale is provided on the circumference of the rotating disk 3. As shown in the figure, if the magnetization is perpendicular to the peripheral end surface of the disk plate 3, the magnetization will be 1.
1 density can be increased and resolution can be improved. A detector 4 is provided facing the circumferential edge of the rotating disk 3.

5 is a bearing that engages with the rotating shaft 2; 6 is a fixed bar that fixedly supports the detector 4, and is coupled to the rotating shaft 2 via the bearing 5. Further, the other end is fixed to the motor 1 itself and is prevented from rotating.

In the above, the magnetic scale of the rotating disk is detected by the opposing detection head, and the detection head generates a pulse signal every time the magnetic scale rotates and detects a pulse train signal corresponding to the rotation angle and rotation speed, The rotation angle can be detected by counting the signal pulses with a counter. Further, the rotation speed can be detected by the number of detection pulses per unit time of the magnetic detection head, and displacement and speed can be detected simultaneously.

The detector 4 is supported by a fixed bar 6, and the fixed bar 6 is supported on the rotating shaft 2 of the rotating disk 3 via a bearing 5. Therefore, the vibration of the rotating disk 3 propagates through the fixed bar 6 and acts on the detection head, and the detection head moves in synchronization, so the relative vibration between the rotating disk 3 and the detector 4 becomes 0. Therefore, detection errors caused by photographing the rotating disk 3 can be prevented from occurring.

In addition to the roller type bearing shown in the figure, the bearing interposed at the joint between the rotating shaft 2 and the fixed bar 6 may be a sliding bearing that rotatably supports the rotating shaft, a bearing that supports the tip of the rotating shaft in point contact, or the like. be able to.

Note that detection can be performed without detection errors not only with magnetic encoders but also with optical encoders, brush type encoders, and the like.

〔Effect of the invention〕

As described above, the present invention includes a fixed bar that fixedly supports the detector, and the fixed bar is supported on the rotating shaft of the rotating disk via a bearing, so that the rotating disk does not vibrate. Even if this happens, the vibrations propagate through the fixed bar, preventing detection errors due to photographing of the detector isk, and ensuring highly accurate detection at all times. Therefore, the encoder of the present invention is particularly effective when installed in mechanical devices that vibrate frequently.

[Brief explanation of drawings]

FIG. 1 is a side view of an apparatus according to an embodiment of the present invention, and FIG. 2 is a top view thereof. 1...Motor 2...Rotating shaft 3...Rotating disk 4...Detector 5...・・・・・・Bearing 6・・・・・・Fixed bar

Claims (1)

[Claims] In a rotary encoder that detects a pulse train signal corresponding to the rotation of the disk by placing a scale detector facing a rotating disk provided with a scale, a fixed bar is provided to fixedly support the scale detector, and the fixed bar is attached to a bearing. A rotary encoder, characterized in that the rotary encoder is supported on the rotating shaft of the rotary disk via the rotating shaft.