JPS61266916A - Adjusting method for magnetic rotary encoder - Google Patents

Abstract

PURPOSE:To easily adjust the relative position between a magnetic disk and a magnetic sensor by rotating a magnetic sensor around a center magnetic head and positioning it on magnetic tracks on both sides. CONSTITUTION:Three magnetic heads 15', 15'', and 15''' provided to the magnetic sensor 15 are arrayed on one straight line X-X prior to adjusting operation. The magnetic sensor 15 is adjusted by being moved in a radial direction of the 2nd magnetic disk 12 so that the 2nd center magnetic head 15'' is positioned on the 2nd magnetic track 12'', and the magnetic sensor 15 is rotated around the 2nd magnetic head 15'' to adjust the position relation between the 1st magnetic head 15' and the 3rd magnetic head 15''', and the 1st magnetic track 12' and the 3rd magnetic track 12'''.

Description

[Detailed Description of the Invention] 40 Objectives of the Invention E1. INDUSTRIAL APPLICATION FIELD This invention relates to a magnetic rotary encoder, and more particularly to a method for adjusting an absolute magnetic rotary encoder.

E2. Prior Art and Problems to be Solved by the Invention Absolute magnetic rotary encoders that detect the rotational position of a magnetic disk having a plurality of magnetic tracks are known, but the relative position between the magnetic disk and the magnetic sensor is is not easy to adjust.

An object of the present invention is to propose a simple method for adjusting the relative position between a magnetic disk having three concentric magnetic tracks and a magnetic sensor disposed close to the magnetic disk.

01 Structure of the Invention Row 101 Means for Solving Problems This invention consists of a magnetic disk having three concentrically arranged magnetic tracks, and three magnetic heads corresponding to these magnetic tracks arranged in a straight line. In adjusting the relative position with respect to the magnetic sensor B arranged at
Q), then rotate the magnetic sensor B around the central magnetic head (15") to adjust the positions of the magnetic heads (15') (15') on both sides to the first and second positions on both sides. The positions of the magnetic trunks (12') and (12') were made to correspond to each other.

Row 20 action First, by aligning the central magnetic head (15'') with the central magnetic track (12''),
“) patterns can be reliably detected.

Next, by adjusting the rotation of the magnetic sensor B, the phases of detecting the three magnetic tracks (12') (12") (12') can be adjusted simultaneously.

Row 3. Embodiment Before explaining the adjustment method of the present invention, first, the structure of an absolute type magnetic rotary encoder to which the present invention is applied will be described in detail.

In Figure 2, (1) is a shaft to which rotation is transmitted from the outside, (2) is a magnetic disk fixed to shaft (1), (3) is a first gear fixed to shaft (1), Shirt) (1), magnetic disc (2), and first gear (3) constitute a first magnetic disc wheel ('').

The first magnetic disc (2) includes a magnetic track made of a magnetic material,
Alternatively, magnetic tracks may be formed on the surface of a non-magnetic material by plating or vapor deposition. Then, the first magnetic disc wheel (″′
) is a shirt) (1) is supported by a bearing, etc.
It is rotatably supported by a body (5). (6
) is a magnetic sensor A placed close to the first magnetic disk (2) and fixed to the wall surface of the first body (5).

On the left surface of the first magnetic disc (2), as shown in Figure 3, two magnetic tracks (2') (2") are provided. The magnetic track (2') rotates one revolution. A pattern with a resolution of 8 parts is formed, and a magnetic track (2") is formed.
forms a magnetic pattern indicating the reference position of one rotation. The magnetic sensor A (6) detects the positions of these magnetic tracks (2') and (2'').
) corresponding to the magnetic head (6') ) (6"), and the magnetic sensor A (6) is arranged so that the gap between these magnetic tracks and the magnetic head is a predetermined distance as shown in FIG. The first magnetic disc (2) is arranged in close proximity to the first magnetic disc (2).

Again, in FIG. 2, (7) is a large gear A that meshes with the first gear (3), and is fixed to the shaft together with a small gear A (8) to form an intermediate gear A (9).

This intermediate gear A (9) is rotatably supported by the first body (5). The pinion A (8) is the first
It is fixed to a shaft portion that projects outside of the body (5).

Ql is a second large gear, which is fixed to the shaft together with a second small gear (11) and a second magnetic disc (work 2) to form a second magnetic disc wheel (13). (1″′) is a second body that rotatably supports this second magnetic disc wheel (13), and the left end peripheral edge of the second body is an engaging portion (1″′) that is connected and fitted with the first body (5). 14'). (15)
A magnetic sensor B is placed close to the second magnetic disc wheel (13) and is fixed to the wall surface of the second body (1''').

The second magnetic disk (12) has a
) three magnetic trunks (12') (1
2') (Has 12 forces, and each of these magnetic tracks is divided into 8 parts of one rotation, O to 7, as shown in the same figure (B).
It has a recognizable pattern of 0 or 1 corresponding to the number.

Note that the 1st to 3rd digits in FIG. 3B correspond to the magnetic tracks (12') to (12') in FIG. 1A, respectively. Magnetic track (12') is divided into 8 parts, (12'') is divided into 4 parts,
(12S> is divided into two parts and matched in phase as shown in the figure, and constitutes a magnetic track for absolute value detection.

Magnetic sensor B (15) has three magnetic heads (15')
(15') (15'), as shown in Figure 6, these magnetic heads (15') (15'') (1
5') respectively magnetic tracks (12') (12
2. A magnetic sensor B is fixed to the second body (1'') in FIG. 2 so as to face the body (12'') with a predetermined gap therebetween.

In Fig. 2, 0, (16) is a large gear B that meshes with the second small gear (11), and this large gear B and a small gear B (17) that is integrally fixed to the shaft constitute an intermediate gear B. This intermediate gear B (17) is connected to the second body (1'''
) is rotatably supported. Specifically, the shaft of this intermediate gear B (17) is the second body (1″′)
It is supported by bearings installed in the

The second body (1″′) is a cylinder with an outer diameter of Φ as a whole,
Disc-shaped walls (14a) and (14b) that rotatably support the second magnetic disc wheel (13) and intermediate gear B (18)
It has a barrel-shaped container. The second large gear (II) and small gear B (17) are protruding from the second body (1'') of the barrel-shaped container, and the second body (1'') is connected to the first body (15). The shape of the engaging portion (14') is determined so that the second large gear αω meshes with the small gear A(8) when they are stacked and connected and fitted as shown in FIG.

The second large gear aω to the intermediate gear B (18) constitute a first unit (19) as a whole. Then, the first gear (3), the canine tooth, *A (7)
, the small gear A(8), and the second large gear (II) have a fixed reduction ratio.

(19') is a second unit whose structure is the same as that of the first unit (19).
9) from the right side, the first unit (1
9) pinion B (17), the second UNISO) (19'
) is engaged with the large gear B (16').

Then, the second magnetic disk (12) of the first unit (19)
) so that the rotation of the second pinion (11) is reduced in speed and transmitted to the magnetic disc of the second unit (19').
The reduction ratio of the reduction gear train consisting of large gear B (16), small gear B (17), and large gear B (16') is determined. In addition, large gear B (16) and large gear B (16)
It has the same number of teeth and shape.

(19 勺 (19 orders) are respectively the second uni 7) <1
9'), the third and fourth units have the same structure as the first unit (19), and are marked with a dash to distinguish them from the first unit, but the structures are the same. By stacking them one after the other, the rotation of the first magnetic disk on the left is decelerated and transmitted to the magnetic disk of that unit.

Note that when each unit is stacked and connected, the rotational positions of the gears are adjusted so that the reference points of the magnetic discs of adjacent units are in phase, and the units are connected and fitted together.

(20) is a cover fitted on the right side of the fourth unit (20').

The three magnetic tracks (12') (12") (12") of the second magnetic disc (12) provided in the first unit (19) to the fourth unit (19') are shown in Figure 6. As shown, magnetic heads (15') (15'') are arranged concentrically and are placed opposite to this magnetic track.
(15”/) is, viewed from the rotational axis direction of the second magnetic disk,
As shown in FIG. 8, they are arranged linearly in the radial direction of the second magnetic disc (12), and their positional relationship is adjusted as follows (see FIG. 1).

Prior to adjustment, the three magnetic heads (15') (15'') (15) provided on the magnetic sensor (15) are arranged on one straight line XX.
The second magnetic head (15”) in the center is connected to the second magnetic track (
12”) to match the position of the second magnetic disk (12).
Adjust by moving the magnetic sensor (15) in the radial direction of
Next, the magnetic sensor (15) is rotated around the second magnetic head (15) so that the first magnetic head (15') and the third magnetic head (15')
Magnetic head (15//) and first magnetic trunk (12')
Adjust the positional relationship with the third magnetic track (12).

The operation of the thus adjusted magnetic encoder shown in the drawings will be described below.

The magnetic head (6') of the magnetic sensor A (6) cooperates with the magnetic torque (2') of the first magnetic disk (2) to generate an electrical signal of 10 pulses per revolution of the shaft (1). occurs. Also, the magnetic head (6') has a magnetic track (2'')
In cooperation with the motor, it generates one electrical pulse per revolution of the shaft (1), resulting in a reference point signal for the shaft (1). These signals are shown in FIG.

The rotation of the shaft (1) is decelerated to % and transmitted to the second magnetic disc (12) of the first unit, (19), on the three magnetic tracks (12') (1) of the magnetic disc (12).
By cooperation with three magnetic heads (15') (15'') (15'), two heads (12'') and a magnetic sensor (15), the rotational position of the magnetic disk (12) becomes 3 as an absolute value.
Detected with rotational resolution. Similarly, the second. Third. Fourth
unit (19') (19') (19'/)
Each of the magnetic disks is driven at a rotation speed reduced by the unit in the previous stage, and position detection is performed with a resolution of % rotation. Therefore, for one rotation of the shaft (1), the rotation from the first unit (19) to the fourth unit (19'
Since the rotation is lowered for each unit up to /), it is possible to detect the absolute value of 4096 rotations of the shaft (1). Also, a first magnetic disk (2) fixed to the shaft (1)
As a result, a signal of 10 pulses and a reference point signal can be generated per revolution of the shaft, so a high resolution of 40,960 pixels can be achieved.

C1 Effects of the Invention According to the present invention, since adjustment can be performed with two simple operations, an absolute type magnetic rotary encoder can be produced at low cost.

[Brief explanation of drawings]

FIG. 1 is a diagram for explaining the adjustment method of the present invention, in which magnetic tracks are developed in a straight line. 2 to 9 are diagrams for explaining an example of a magnetic rotary encoder to which the present invention is applied and its operation. FIG. 2 is a schematic diagram showing a longitudinal section, and FIG. Figure 4 is a side view showing the arrangement of the first magnetic disk and magnetic sensor A;
Figure 5 is a diagram explaining the signal of magnetic sensor A, Figure 6 (
A) and (B) are respectively diagrams illustrating the front of the second magnetic disk and its magnetic track pattern, FIG. 7 is a side view showing the arrangement of the second magnetic disk and magnetic sensor B, and FIG. 9 is a diagram illustrating the signals of the magnetic sensor B, and FIG. 9 is a front view illustrating the arrangement of the magnetic tracks of the second magnetic disk and the magnetic head.

Claims (1)

[Claims] In adjusting the relative positions of a magnetic disc with three concentrically arranged magnetic tracks and a magnetic sensor B with three magnetic heads arranged linearly corresponding to these magnetic tracks, first The magnetic head (15'') is moved in the radial direction of the magnetic disk to cover the second magnetic track (15'') in the center.
2"), and then rotate the magnetic sensor B around the central magnetic head (15") to align the positions of the magnetic heads (15') (15") on both sides with the first and second magnetic heads (15") on both sides. A method for adjusting a magnetic rotary encoder, the method comprising adjusting the position of a second magnetic track (12') to coincide with the position of a second magnetic track (12'').