JP3485126B2 - Method of manufacturing disk with slit for angular acceleration sensor - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention comprises two discs with slits, and based on the relative movement of the slits of these discs, the angular acceleration of a rotating body such as a motor shaft is detected. It relates to a sensor. More particularly, the invention relates to a method for forming slits on a slitted disc in this type of angular acceleration sensor.

[0002]

2. Description of the Related Art As an angular acceleration sensor for detecting an angular acceleration of a rotating body such as a motor shaft over an infinite rotation angle range, Japanese Patent Application No. 4-108 previously filed by the present application.
No. 77 proposes a structure using two slitted disks. In this angular acceleration sensor, two discs with slits are attached so as to rotate integrally with the rotating body, and the angular acceleration of the rotating body is detected based on the relative movement of the slits formed in these discs. ing.

In such a sensor, if the slits are not formed on each disk at an accurate pitch, the detection accuracy will decrease. For example, if the slit has a pitch error, even if the rotation speed is constant, a sensor output similar to that in the case where the rotation unevenness occurs due to the pitch error of the formed slit is obtained.

[0004]

In order to accurately form the slits on the disk without a pitch error, it is necessary to accurately form the slits on the disk master for manufacturing the disk with slits. However, in order to manufacture a disk master having accurately formed slits, the manufacturing equipment is large and the cost is high.

In view of this point, an object of the present invention is to provide an angular acceleration sensor with a slit that can prevent the output from being affected even if a pitch error occurs in the formed slit. It is to propose a method of manufacturing a disc.

[0006]

DISCLOSURE OF THE INVENTION The present invention comprises first and second discs with slits which are fixed so as to rotate integrally with a rotating body, and the relative movement of the slits formed in these discs. A method for manufacturing the above-mentioned first and second disks with slits in an angular acceleration sensor adapted to detect the angular acceleration of a rotating body based on the above, wherein two disk master materials are prepared, and these disks are prepared. The master material is mounted parallel to the same rotation axis, the photomask for slit formation is arranged facing the photoresist surface of each disc master material, and each disk master material is pitched 1 pitch by the rotation axis. First, by forming slits on the photoresist surface of each disc master material through the photomask while rotating each first,
And the second disk master, and the first and second disks with slits are manufactured using these disk masters.

Here, in the state of being mounted on the same rotary shaft, a circumferential alignment mark is formed on the two disc master materials, and these alignment marks are also formed on the first and second slit discs. It is preferable to form marks. In this case, when assembling the angular acceleration sensor, the two discs with slits are attached so that these alignment marks are aligned.

[0008]

When the two discs with slits manufactured by the method of the present invention are arranged so that their alignment marks are in alignment, the pitch error of the slits of both discs will be the same. Therefore, these pitch errors do not affect the sensor output. Therefore, accurate angular acceleration can be detected.

[0009]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows an angular acceleration sensor having a disk with slits manufactured by applying the method of the present invention. As shown in the figure, the angular acceleration sensor 10 has a thin cylindrical housing 11, and the center of the housing 11 is provided with a bearing 12 and a rotary shaft 1 to be measured.
3 rotatably penetrates. On the outer periphery of the rotary shaft 13 located in the housing 11, two slitted disks 14 and 15 manufactured by the method of the present invention are fixed so as to face each other. Slit groups 16 and 17 are formed on the outer peripheral portions of these disks 14 and 15 at the same pitch in the circumferential direction. The detection unit 19 of the semiconductor position detection device is arranged so as to sandwich the slit groups 16 and 17. This detection unit 19
It is composed of a light emitting diode 20 and a semiconductor position detector 21.

2 and 3, the disk 15 described above is shown.
The shape of is shown. As shown in these figures, the disk 15 of this example has a thin annular portion 1 on the outermost peripheral side.
5a, and the slit group 17 is formed here. Inside the annular portion 15a, a thick annular weight portion 15b is formed. This weight portion 15b is
It is supported by ribs 15c extending toward the center at 90 degree intervals from the inner peripheral surface side. These ribs 15
The center side of c is the flange 1 fixed to the outer circumference of the rotating body 13.
It is supported on the outer periphery of 5d. Here, the rib 15c is a spring portion that is elastically deformable in the circumferential direction of the disk. The other disk 14 is a rigid disk having the same thickness as a whole.

In the thus configured angular acceleration sensor 10 of this example, when the rotary shaft 13 starts to rotate or the rotational speed changes, the slit group 17 on the side of the disk 15 of the other disk 14 is changed. It is displaced in the circumferential direction with respect to the side slit group 16. That is, since the spring portion 15b is elastically deformed in the circumferential direction by the inertial force of the annular weight portion 15b formed on the disk 15, the slit group 17 is also displaced in the circumferential direction accordingly. As a result, the intersecting portion formed between the slit group 16 and the slit group 17 is displaced in the radial direction. By detecting this deviation by the semiconductor position detector 21, the angular acceleration generated on the rotary shaft 13 can be measured.

The disk master for forming the slit group on the disks 14 and 15 of this example is manufactured as follows.

That is, as shown in FIG. 4, the two disk masters 34 and 35 are mounted in parallel while facing each other on the same rotary shaft 41. At this time, the photoresist surfaces 34a and 35a of the master disk are made to face outward. The photomasks 44, 4 are made to face the slit forming portions of the disk masters 34, 35, respectively.
Place 5. Then, the drive source 51 and the drive driver 52
The rotation shaft 41 is rotated by one pitch by using the rotation control mechanism of the rotation shaft 41 including the angle sensor 53. In synchronization with this, each photomask 44,
The light sources 61 and 62 facing the light source 45 are connected to the light emitting driver 63.
Driven by. The drive of these rotating shafts 41 and the light emission of the light sources 61 and 62 are controlled by the host controller 71. By this operation, slit portions are formed at a constant pitch on the photoresist surfaces of the two disc masters 34 and 35.

Here, apart from the slit baking operation,
For the two disc masters 34, 35, the rotary shaft 41
Alignment mark (not shown) when attached to
Is formed.

In this way, the two disc masters 34, 3
By processing 5 simultaneously, the pitch error of the slit groups formed therein becomes the same. A slit group 1 is used for two discs 14 and 15 shown in FIG. 1 by using a disc master having slits having the same pitch error.
6 and 17 are formed. As a result, each disk 14, 15
The slit groups 16 and 17 are also slit groups having the same pitch error. In addition, in each disk 14 and 15,
Alignment marks attached to the disk masters 34 and 35 are also formed.

These discs 14 and 15 are arranged such that the alignment marks formed on them coincide with each other.
Mounted to.

As a result, in the slit groups 16 and 17 of the disks 14 and 15, the slits formed at the same position in the circumferential direction have the same pitch error. Therefore,
Even if there are pitch errors, these pitch errors do not affect the sensor output.

[0019]

As described above, in the present invention, two disk master materials are attached in parallel to the same rotary shaft, and each disk master material is rotated by one pitch by the rotary shaft. Meanwhile, the first and second disc masters are manufactured by forming slits on the photoresist surface of each disc master material through a photomask, and using these disc masters, two sheets of an angular acceleration sensor are manufactured. We manufacture slitted discs. Therefore, since the two discs have the slits having the same pitch error, it is possible to prevent the detection accuracy of the sensor from being lowered by these pitch errors.

[Brief description of drawings]

FIG. 1 is a schematic vertical cross-sectional view showing the structure of an angular acceleration sensor including a disk manufactured by the method of the present invention.

2 is a cross-sectional view showing the shape of a disk of the device of FIG.

FIG. 3 is a plan view showing the shape of a disk of the apparatus shown in FIG.

FIG. 4 is a schematic configuration diagram showing an apparatus for manufacturing a disk master for manufacturing the disk of FIG.

[Explanation of symbols]

10 ... Angular acceleration sensor 14, 15 ... Slit disc 16, 17 ... Slit group 34, 35 ... Disk master 34a, 35a ... Photoresist surface 41 ... Rotary axis 44, 45 ... Photomask 61, 62 ... Light source

─────────────────────────────────────────────────── ─── Continuation of front page (56) Reference JP-A-61-172067 (JP, A) JP-A-62-57140 (JP, A) JP-A-59-224514 (JP, A) JP-A-2- 181608 (JP, A) JP-A-1-43722 (JP, A) JP-A-6-337212 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) G01D 5/26-5 / 38 G01P 15/00

Claims (2)

(57) [Claims] 1. A disk having first and second slits fixed so as to rotate integrally with a rotating body,
A method for manufacturing the first and second slitted discs in an angular acceleration sensor for detecting the angular acceleration of a rotating body based on the relative movement of slits formed in these discs. Prepare the disc master materials of the above, mount these disc master materials in parallel to the same rotation axis, and place the photomask for slit formation facing the photoresist surface of each disc master material. , The first and second disc masters are manufactured by forming slits on the photoresist surface of each disc master material through a photomask while integrally rotating each disc master material by one pitch by the rotation axis. An angular acceleration sensor characterized by manufacturing the first and second slitted disks using these disk masters. Manufacturing method of the difference between the slit with a disk. 2. The alignment mark in the circumferential direction is formed on two disc master materials in a state where they are mounted on the same rotary shaft according to claim 1, and the first and second
A method for manufacturing a disk with slits for an angular acceleration sensor, characterized in that these alignment marks are also formed on the disk with slits.