JPH03210419A - Rotation angle detection device - Google Patents

Abstract

PURPOSE:To detect displacement with a simple structure by detecting an amount of change of a displacement member caused by protrusions of different heights provided on the circumference of a rotating disk. CONSTITUTION:When a cam driving gear 13 is rotated, a rotating body 11 with a cam groove is rotated. When the rotating body 11 with the cam groove comes to a position of 0 deg., a protrusion 1a comes into contact with a contacting protrusion 2a of a plate spring 2 so that the plate spring 2 is displaced by an amount corresponding to a height h1 of the protrusion 1a. Then the rotating body 11 with the cam groove comes to positions of 90 deg. and 180 deg., protrusions 1b, 1c come into contact with the contacting protrusion 2a of the plate spring 2 so that the plate spring 2 is displaced by an amount of a height h2 of the protrusion 1b and h3 of the protrusion 1c, respectively. The displacement is detected by a displacement sensor 3 so that a rotation of the rotating body 11 with the cam groove by 0 deg., 90 deg. and 180 deg. can be detected.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention relates to a rotation angle detection device, and in particular, to a rotation angle detection device for detecting a rotation angle of a rotating body for controlling the rotation of a rotating body or controlling the operation of a movable part interlocked with the rotating body. The present invention relates to a rotation angle detection device that detects a rotation angle.

[Prior Art] Conventionally, a rotary switch is generally known as a rotation angle detection device for detecting the rotation angle of a loading cam or the like of a VTR. FIG. 6 is a schematic diagram for explaining a conventional VTR loading cam rotation angle detection device. Referring to FIG. 6, a rotary switch 12 is used as a rotation angle detection device. The rotary switch 12 is provided with a passive gear part 12a meshed with the teeth of the cam grooved rotating body 11, and inside the rotary switch.
A mechanical switch section 12 is provided with a large number of switches that are sequentially switched as the passive gear 12a rotates.
b.

Next, a conventional rotation angle detection operation will be explained. First, the cam drive gear 13 meshed with the teeth on the outer peripheral surface of the cam grooved rotating body 11 is rotated. As the cam drive gear 13 rotates, the cam grooved rotating body 11 is rotated. As the cam grooved rotating body 11 rotates, the cam grooved rotating body 11
The passive gear 12a meshed with the teeth of is rotated. Mechanical switch section 1 based on rotation of passive gear 12a
A predetermined number of mechanical switches installed at 2b are sequentially switched. In this way, in the conventional method, the passive gear 12a is rotated in conjunction with the rotation of the cam grooved rotary body 11, and a plurality of mechanical switches in the mechanical switch section 12b are switched one after another. Eleven rotation angles were detected.

[Problems to be Solved by the Invention] As described above, as a rotation angle detection device for a loading cam of a conventional VTR, a low-return switch 12 consisting of a passive gear 12a and a mechanical switch section 12b has been used. That is, the rotation angle of the cam grooved rotary body 11 is detected by rotating the passive gear 12a in conjunction with the rotation of the cam grooved rotary body 11, and sequentially switching a plurality of mechanical switches in the mechanical switch section 12b. It had been. However, since the structure of the mechanical switch section 12b constituting the rotary switch 12 is complicated, there has been an inconvenience that the device becomes large in size.

For this reason, it has been difficult to achieve miniaturization of the device, which is a conventional market need. Also, rotary switch 1
Since the mechanical switch section 12b of No. 2 is a mechanical contact switch, there are problems in that contact failure, malfunction, wear, etc. are likely to occur. As a result, there was a problem in that the reliability of rotation angle detection could not be improved.

The present invention was made in order to solve the above-mentioned problems, and provides a rotation angle detection device capable of reducing the size of the device and improving the reliability of rotation angle detection. The purpose is to

[Means for Solving the Problems] A rotation angle detection device according to the present invention includes a rotating disk in which protrusions of different heights are provided on the circumference, and a rotating disk provided in contact with the rotating disk. It includes a displacement member whose position is displaced by an amount of change corresponding to the amount of change in height based on a change in the height of the protruding portion of the plate, and a detection means for detecting the amount of displacement in the position of the displacement member.

[Function] In the rotation angle detection device according to the present invention, the protrusions having different heights are provided on the circumference of the rotating disk, and the position of the displacement member provided in contact with the rotating disk is Based on the change in the height of the protruding part of the plate, the plate is displaced by the amount of change corresponding to the amount of change, and the amount of displacement of the displaced member is detected by the detection means. The rotation angle can be easily detected without using.

[Embodiment of the Invention] FIG. 1 is a schematic diagram for explaining a rotation angle detecting device for a loading cam of a VTR showing an embodiment of the present invention, and FIG. It is a sectional view along A'. Referring to FIGS. 1 and 2, the rotation angle detection device is provided on a cam grooved rotating body 11, and includes a protrusion forming disk 1 on which protrusions la, lb, and lc having different heights are formed. is provided in contact with the protrusion-forming disc 1, and has an abutting protrusion 2a at its abutting portion, and as the protrusion-forming disc 1 rotates, the protrusions 1a, lb, and lc are brought into contact with each other. A leaf spring 2 that is displaced by an amount corresponding to the height of each of the projections la, lb, and lc when it comes into contact with the projection 2a, and a leaf spring 2 that is provided opposite to the leaf spring 2 to detect the amount of displacement of the leaf spring 2. displacement sensor 3.

The protrusions 1a, lb, and lc have different heights, l
h21 ha, and are formed at positions 0@, 90°, and 180'' on the outer periphery of the protrusion forming disk 1, respectively.The leaf spring is always biased in the direction of the arrow X in FIG. In addition, the ratio of the arms of the leaf spring 2 is b/a as shown in FIG.
>1, and is configured so that the displacement of the projections 1a, lb, and lc is magnified by the displacement detection section. This detection accuracy can be easily changed by changing the arm ratio (b/a). The displacement sensor 3 detects the displacement of the leaf spring 2 using magnetism or light.

*Figure 3A and Figure 3B are schematic diagrams for explaining the operation of the rotation angle detection device shown in Figure 1. The operation will be explained with reference to FIGS. 1 to 3B. First, as shown in FIG. 1, when the cam drive gear 13 is rotated, the gear part 13a of the cam drive gear 13 and the gear part 11a of the cam grooved rotating body 11 are meshed with each other, so that the cam groove 1
The cam grooved rotating body 11 having the cam groove 1b is rotated. When the cam grooved rotating body 11 reaches the 0° position, the protrusion 1a comes into contact with the abutting protrusion 2a of the leaf spring 2, and the leaf spring 2 is displaced by an amount corresponding to the height of the protrusion 1a.

The displacement amount d is detected by the displacement sensor 3, and it is determined that the position is 0°. After that, when the cam grooved rotating body 11 reaches the 90° position as shown in FIG. 3a, the protrusion 1b
comes into contact with the contact protrusion 2a of the leaf spring 2. Then, the displacement d2 of the leaf spring corresponding to the height h2 of the protrusion 1b is detected by the displacement sensor 3, and it is determined that the cam grooved rotating body 11 is at the 90° position. Further, when the rotation continues and the projection I reaches the 180° position as shown in Fig. 3b,
C comes into contact with the contact projection 2a of the leaf spring 2.

Then, the displacement jids of the leaf spring 2 corresponding to the height of the protrusion IC is detected by the displacement sensor 3, and it is determined that the cam grooved rotating body 11 has come to the 180° position.

FIG. 4 is a block diagram for explaining a rotation angle control device to which the rotation angle detection device shown in FIG. 1 is applied.

Referring to FIG. 4, a control circuit 4 is connected to the displacement sensor 3. This control circuit 4 determines that the displacement amount of the leaf spring 2 detected by the displacement sensor 3 is the displacement amount at the 90° position, and based on the determination result, the drive gear 13
It controls the motor 5 for driving the. For example, if you want to rotate the cam grooved rotating body 11 by 90 degrees and then stop it, the angle setting θ of the control circuit. 90°
Set to . Then, when the drive gear 13 is driven by the motor 5 and the cam grooved rotating body 11 comes to the 90'' position,
The protrusion 1b is brought into contact with the abutting protrusion 2a of the leaf spring 2, and the displacement sensor 3 detects the amount of displacement of the leaf spring 2 corresponding to the height of the protrusion 1b. The control circuit 4 determines that the amount of displacement is the amount of displacement at the 90° position, and the motor 5
A stop command signal is sent to As a result, the motor 5 is stopped and the drive gear 13 is stopped, so the cam grooved rotating body 11 is stopped at the 90° position.

As described above, in this embodiment, the protrusion forming disk 1 on which the protrusions 1a, lb, and IC of different heights are formed is installed on the cam grooved rotary body 11, and the rotation of the cam grooved rotary body 11 is controlled. Along with this, the protrusion forming disk also rotates. and,
When the leaf spring 2 reaches the protrusion forming position, the leaf spring 2 is displaced by an amount corresponding to the height of each protrusion, and the amount of displacement is detected by the displacement sensor 3. The rotation angle can be easily detected without requiring a mechanical switch that is difficult to improve.

As a result, the rotation angle device can be downsized and the reliability of rotation angle detection can be improved.

FIG. 5 is a schematic diagram for explaining a rotation angle detection device showing another embodiment of the present invention. Referring to FIG. 5, the difference from the rotation angle detection device shown in FIG. be. In other words! @1 In the rotation angle detection device shown in the figure, O''', 90", 180"
The rotation angle can only be detected at the fifth position.
In the illustrated embodiment, any rotation angle can be detected. Here, when detecting this arbitrary rotation angle, it is necessary to increase the ratio b/a of the arms of the leaf spring 2 to increase the detection accuracy of the displacement sensor 3.

[Effects of the Invention] As described above, according to the present invention, protrusions of different heights are provided on the circumference of the rotating disk, and the position of the displacement member provided in contact with the rotating disk is adjusted. Based on the change in the height of the protruding part of the rotating disk, the rotating disk is displaced by the amount of change corresponding to the amount of change, and the amount of displacement of the displaced member is detected by the detection means. Since the rotation angle can be easily detected without using a contact switch, the device can be made smaller and the reliability of rotation angle detection can be improved.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram for explaining a rotation angle detection device showing an embodiment of the present invention, and FIG.
3A and 3B are schematic diagrams for explaining the operation of the rotation angle detection device shown in FIG. Block diagram for explaining the applied rotation angle control device, 15
This figure is a schematic diagram for explaining a rotation angle detection device showing another embodiment of the present invention, and FIG. 6 is a schematic diagram for explaining a conventional rotation angle detection device for a loading cam of a VTR. In the figure, 1 is a projection-forming disk, la, lb. IC is a protrusion, 2 is a leaf spring, 2a is a contact protrusion, 3 is a displacement sensor, 4 is a control circuit, 6 is a rotating disk, and 6a is a build-up. In each figure, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Scope of Claims] A rotating disk in which protrusions of different heights are provided on the circumference; and a rotating disk provided in contact with the rotating disk, based on changes in the height of the protrusions of the rotating disk. A rotation angle detection device comprising: a displacement member whose position is displaced by an amount of change corresponding to the amount of change in height; and a detection means for detecting the amount of displacement in the position of the displacement member.