JPH04120418A - Assembly of magnetic rotary encoder - Google Patents

Abstract

PURPOSE:To easily adjust a gap by adjusting the gap between a magnetic drum and a magnetic sensor before assembling into a rotating machine. CONSTITUTION:As a preparatory process, a reference shaft is inserted into a through hole provided so that the center aligns with the center of rotation of a magnetic drum 21 and temporarily fixed. Then a holder 24 is mounted on the drum 21, a protrusion 21b is inserted into an opening 51, and spring force is applied to the protrusion 21b via an elastic tab 53 by a spring 54 so that the protrusion 21b is made to abut on a abutment part 52. Then a sensor unit 23 is inserted into an opening 61 of a cover 25, and the unit 23 is held by a holding means 62. The cover 25 with the unit 23 held is mounted on the holder 24, the cover 25 is laterally moved with respect to the reference shaft and after a gap between the drum 21 and the sensor 22 is adjusted by a gap adjusting hole 63, the cover 25 and the holder 24 are fastened by a screw 55. Then the holder 24 is separated from the drum 21, and the obtained blocks of the cover 25, the holder 24 and a unit 23 are carried to be assembled in a main process, thereby adjusting the gap easily.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for assembling a magnetic rotary encoder.
In particular, the present invention relates to a method of assembling a magnetic rotary encoder that is easy to incorporate into a rotating machine such as a motor.

[Prior Art] FIG. 4 shows a conventional example of this type of magnetic rotary encoder, which is described in Japanese Utility Model Application Publication No. 62-3012. In the figure, 1 is a magnetic drum, 2 is a rotating machine,
3 is a rotating shaft, 4 is a base material, 5 is a holding member, 6 is a magnetic sensor, 7 is a printed circuit board, 8 is a lead wire, 9 is a support cylinder,
10 is a cover 11 is a circuit component, and 12 is a screw.

The magnetic drum 1 is made of a magnetic material, and its surface has a magnetic pattern of N, S, S, N, N, S%S.

N... Adjacent magnetic pole pairs are continuously formed at equal pitch intervals so that they have opposite polarities. A rotating shaft 3 protrudes from a rotating machine 2 such as a motor, and the rotating shaft 3 is fixed to the center of the magnetic drum 1. This rotating machine 2
A stepped portion 2a serving as a mounting reference surface is formed at one end of the base member 4, and the base member 4 is screwed to the stepped portion 2a. This base material 4 is disk-shaped, and its upper surface is a reference plane part 4a perpendicular to the axis of the rotating shaft 2, and the holding member 5 is screwed onto this reference plane part 4a.

A magnetic sensor 6 made of a magnetoresistive element is adhered to the holding member 5, and the magnetic sensor 6 faces the curved surface of the magnetic drum 1 at a predetermined distance. A circuit component 11 for processing the electrical signal output from the magnetic sensor 6 is mounted on the printed circuit board 7, and the printed circuit board 7 is screwed into the base material 4 by inserting a screw 12 through the support tube 9. The magnetic drum 1 is disposed above the magnetic drum 1.

One end of the lead wire 8 is connected to the magnetic sensor 6, and the other end is connected to the printed circuit board 7. Further, a cover 10 is attached to the end face of the rotary machine 2, and the cover 10 protects the magnetic drum 1, the magnetic sensor 6, etc. described above from dust.

The magnetoresistive elements constituting the magnetic sensor 6 are arranged in two sets so that the phase is shifted by np+l/4p (where n is an integer) with respect to each magnetic pole pitch p of the magnetic pattern magnetized and arranged on the magnetic drum 1. Further, these magnetoresistive elements are arranged so as to face the magnetic pattern so that their respective magnetic directions are perpendicular to the rotation axis 3. Therefore, when the magnetic drum 1 rotates, each magnetoresistive element of the magnetic sensor 6 outputs a signal having a phase difference of 90 degrees.

In the magnetic rotary encoder configured as described above, when the magnetic drum 1 is rotated in a predetermined direction by the rotary machine 2, a continuous signal with a phase difference of 90 degrees is output from each magnetoresistive element of the magnetic sensor 6. A signal is output,
Incremental pulses are obtained by guiding these to the printed circuit board 7 via the lead wire 8 and performing processing such as amplification, detection, and matching in the signal processing circuit, and the displacement and rotation direction of the magnetic drum I are detected. Ru.

When adjusting the required gap between the magnetic drum 1 and the magnetic sensor 6, with the base material 4, the holding member 5, and the magnetic sensor 6 installed in the rotating machine 2, the holding member 5 is moved relative to the to obtain the appropriate gap,
The holding member 5 is fixed to the base material 4.

[Problem to be solved by the invention]

By the way, in the prior art described above, the magnetic drum 1
When adjusting the gap between the base material 4 and the magnetic sensor 6,
Since it is necessary to carry out the adjustment while the holding member 5 and the magnetic sensor 6 are assembled in the rotating machine 2, there is a problem in that the gap adjustment in this state is quite difficult and requires a special gap adjustment machine. Further, since the rotating machine 2 is required for adjusting the gear M, it is necessary to prepare the rotating machine 2 in advance.

The present invention has been made in view of the actual situation in the prior art, and its purpose is to provide a method for assembling a magnetic rotary encoder that can adjust the gap between the magnetic drum and the magnetic sensor before incorporating it into a rotating machine. Our goal is to provide the following.

[Means for Solving the Problem] In order to achieve this object, the present invention provides a magnetic drum having a magnetic pattern in the circumferential direction, a sensor unit including a magnetic sensor, a holder placed on the drum, and a magnetic drum having a magnetic pattern in the circumferential direction. and a cover that covers the holder and drum and holds the sensor unit.First, as a preliminary step, the drum is press-fitted onto the reference shaft, the holder is placed on the drum, and the spring attached to the holder is integrating the holder and the drum by means, then placing the cover holding the sensor unit on the holder;
Adjust the required gap between the drum and the sensor through gap adjustment holes provided in the cover, and then move the cover against the spring means to remove the holder from the drum. After that, in the main step, the drum is inserted and fixed on the rotating shaft of the rotating machine, the cover is attached and the holder is fixed on the drum, and the sensor unit is attached to the mounting surface of the rotating machine. After screwing on,
The cover and holder are configured to be removed from the drum.

[Effect]

Since the present invention is configured as described above, in a preliminary step, the holder and the magnetic drum are integrated by the spring means, and while the sensor unit is held by the cover, the drum and the sensor are connected to each other through the gap adjustment hole provided in the cover. adjust the required gap between At this time, the drum and the sensor are in a predetermined relative positional relationship via the holder and the cover. Next, the holder is separated from the drum by moving the cover against the spring means to obtain the cover, the holder and the sensor unit block, and the drum itself. Then, in the subsequent main process, after the drum is pushed into the rotating shaft of the rotary machine and fixed, a cover is attached and the holder is fixed to the drum, so that the drum and sensor are placed relative to each other again through the holder and the cover. After placing the sensor unit in the desired position, screw the sensor unit onto the mounting surface of the rotating machine. This makes it possible to adjust the gap between the magnetic drum and the magnetic sensor before incorporating it into the rotating machine.

After that, the cover and holder are removed from the drum, so that the rotational operation of the rotating machine is not hindered in any way.

[Example] Hereinafter, an example of the method for assembling a magnetic rotary encoder of the present invention will be described based on the drawings.

1 to 3 are diagrams illustrating an embodiment of the method for assembling a magnetic rotary encoder according to the present invention. FIG. 1 is a perspective view showing the overall structure of the magnetic rotary encoder, and FIG. 2 (a) -(d) is a process diagram for explaining the preliminary process of the assembly method, and FIGS. 3(a) to 3(d) are process diagrams for explaining the main process of the assembly method.

The magnetic rotary encoder used in this example is
As shown in FIG. 1, a magnetic drum 21 having a magnetic pattern in the circumferential direction, a sensor unit 23 including a magnetic sensor 22, a holder 24 placed on the drum 21, and a combination of these holders 24 and the drum 21 are shown. It also includes a cover 25 for holding the sensor unit 23 and the like.

The above-mentioned magnetic drum 21 is made of a magnetic material like the conventional one shown in FIG.
N..., adjacent magnetic pole pairs are formed continuously at equal pitches so that they have opposite polarities, and a protrusion 21b is provided at the top of this large diameter portion 21a. A rotating shaft 27 protruding from a rotating machine 26 such as a motor is fixed to the center of the magnetic drum 21.

The sensor unit 23 described above includes a sensor circuit board 31 on which a signal processing circuit is mounted together with the magnetic sensor 22;
A printed circuit board 32 connected to this sensor circuit board 31 and wired to the outside, a U-shaped base 33 on which this printed circuit board 32 and the like are mounted, and a U-shaped base 33 that is integrally formed on this base 33 and that Holding parts 34 and 35 that hold the respective ends, a protrusion 36 provided from the holding part 34 toward one end, and a protrusion 37 provided from the holding part 35 toward the other end; 2 (
It is composed of elongated holes 38 and 39 formed parallel to the left-right direction of c).

A pair of screws 40 inserted into each elongated hole 38, 39
The sensor unit 23 is attached to the rotating machine 26 by screwing them into screw holes 41 on the mounting surface of the rotating machine 26, respectively. Note that this sensor unit 23
Similar to the conventional one shown in FIG.
It faces the circumferential surface of a with a predetermined distance therebetween.

The holder 24 described above is provided with an opening 51 into which the protrusion 21b of the drum 21 is inserted.
A contact portion 52 that contacts the outer peripheral surface of the protrusion 21b and the opening 5
1, and an elastic tongue piece 53 that protrudes from the edge of the elastic tongue piece 53 and faces the contact part 52 via the protrusion 21b;
A spring 54 is provided that applies a spring force in the direction toward b. A pair of screws 5 are attached to the top of this holder 24.
A screw hole 56 into which the screw 5 is screwed is provided. The elastic tongue piece 53 and the spring 54 constitute a spring means for integrating the holder 24 and the drum 21.

The cover 25 described above has an opening 61 into which the sensor unit 23 is inserted, a holding means 62 provided in the opening 61 to hold the sensor unit 23, a gap adjustment hole 63 located above the opening 61, and a gap adjustment hole 63 located above the opening 61. A pair of elongated holes 6 formed parallel to the left-right direction in (C) and into which the screws 55 are inserted.
4.65 and a through hole 66 into which the upper part of the protrusion 21b is inserted.
and another opening 67 shown in FIG. 2(C).

The holding means 62 includes a pair of left and right elastic claws 68 that can lock the front end of the sensor unit 23, and a pair of left and right elastic claws 69 that can lock the rear end of the sensor unit 23.

In this example, first, as a preliminary step, the process shown in Fig. 2 (
As shown in a), in order to facilitate the insertion work and ensure positioning accuracy, a cylindrical shaft is provided on the reference shaft 7I with a slightly narrower tip shaft diameter so that the center of rotation of the magnetic drum 21 is the axis. Insert the through hole and temporarily secure it. Then,
As shown in FIG. 2(b), the holder 24 is placed on the drum 21, the protrusion 21b is inserted into the opening 51, and the spring 54 applies spring force to the protrusion 21b via the elastic tongue 53. Then, the protrusion 21b is brought into contact with the abutment part 52, that is, the holder 24 and the drum 21 are integrated by the spring means attached to the holder 24. Then, as shown in FIG. 2(C), the sensor unit 23 is inserted into the opening 61 of the cover 25, and the sensor unit 23 is held by the holding means 62. Next, as shown in FIG. 2(d), the cover 25 holding the sensor unit 23 is placed on the holder 24, and the cover 25 is moved relative to the reference axis 71 in the left-right direction in FIG. 2(d). After adjusting the required gap between the drum 21 and the sensor 22 through the gap adjustment hole 63 provided in the cover 25, the cover 25 and the holder 24 are tightened with the screws 55. . Next, the cover 25 is moved against the spring means to separate the holder 24 from the drum 21, and the cover 25,
The holder 24 and the block of the sensor unit 23 are obtained, and the drum 21 is removed from the reference shaft 71.

The blocks of the cover 25, holder 24, and sensor unit 23 obtained in this way, as well as the drum 21 itself, are transported to the trial court for the rotary encoder, and the assembly process at the customer is shown in FIG. 3(a) as the main process. As shown in FIG. As shown in Figure 3(b), this drum 2
1 through the opening 67 to cover the cover 25, and as shown in FIG. After placing the sensor unit 23 at a predetermined relative position again through the cover 25 and screwing the sensor unit 23 onto the mounting surface of the rotating machine 26 through the screws 40,
As shown in FIG. 3(d), the cover 25 and the holder 2
4 from the drum 21.

In the embodiment configured in this way, after adjusting the gap between the magnetic drum 21 and the magnetic sensor 22 in a preliminary step, the cover 25, holder 24, sensor unit 23 block, and drum 21 are disassembled. Then, in this process, these blocks and the drum 21 are assembled into the rotating machine 26, and at that time, the drum 21 and the sensor 22 are again placed at predetermined relative positions via the holder 24 and the cover 25. Before incorporating it into the cage 1 rotation machine 26,
The gap between the magnetic drum 21 and the magnetic sensor 22 can be adjusted.

Further, since the gap between the magnetic drum 21 and the magnetic sensor 22 is adjusted in advance as described above, it can be easily assembled into the rotating machine 26 without requiring gap adjustment in this step. And cover 25 as above
, a block of the holder 24 and the sensor unit 23,
Since the drum 21 is separated into a single unit, this drum 21
Engineering work on the rotating shaft 27 is easy.

[Effects of the Invention] Since the present invention is configured as described above, the gap between the magnetic drum and the magnetic sensor can be adjusted before being incorporated into a rotating machine. Therefore, the gap can be adjusted after being incorporated into a rotating machine. Compared to the conventional case, it is easier to adjust the gap between the magnetic drum and the magnetic sensor, and there is no need for a special gap adjustment machine. Further, since a rotating machine is not required for gap adjustment, it is possible to save time and effort to prepare the rotating machine in advance.

[Brief explanation of drawings]

1 to 3 are diagrams illustrating an embodiment of the method for assembling a magnetic rotary encoder according to the present invention. FIG. 1 is a perspective view showing the overall structure of the magnetic rotary encoder, and FIG. 2 (a) - (d) is a process diagram explaining the preliminary process of the assembly method, Figures 3 (a) to (d) are process diagrams explaining the main process of the assembly method, and Figure 4 is a conventional example of a magnetic rotary encoder. FIG. 21...Magnetic drum, 22...Magnetic sensor, 23...Sensor unit, 24...
・Holder, 25... Cover, 26... Rotating machine, 27... Rotating shaft, 40... Screw, 5
1... Opening, 52... Contact portion, 53...
... Elastic tongue piece, 54 ... Spring, 55 ...
...Screw, 56...Screw hole, 62...
Holding means, 63... Gap adjustment hole, 64.6
5...Elongated hole, 68.69...Elastic claw,
71...Reference axis. Fig. 112 (Q) (b) Fig. 2 (C) <Ch Lid 3 Fig.

Claims (1)

[Claims] A magnetic drum having a magnetic pattern in the circumferential direction, a sensor unit including a magnetic sensor, a holder placed on the drum, and covering these holders and the drum,
First, as a preliminary step, the drum is press-fitted onto the reference shaft, the holder is placed on the drum, and the holder and the drum are assembled together by a spring means attached to the holder. Then, the cover holding the sensor unit is placed on the holder, and the required gap between the drum and the sensor is adjusted through the gap adjustment hole provided in the cover. , the cover is moved against the spring means to separate the holder from the drum, and then, as a main step, the drum is inserted and fixed on the rotating shaft of a rotating machine and the cover is attached. A method for assembling a magnetic rotary encoder, characterized in that the holder is fixed to the drum, the sensor unit is screwed to a mounting surface of the rotary machine, and then the cover and holder are removed from the drum.