JPS60155920A - Apparatus for detecting rotary position - Google Patents

Abstract

PURPOSE:To obtain frequency dividing signals and rotary signals of a plurality of CHs as optical signals and to make it possible to arrange a control part to an arbitrary position, by connecting the control part for administering the emission and reception of plural optical signals having different wavelengths to a wave splitter and a mixer through an optical fiber. CONSTITUTION:Optical signals emitted from a control part 15 in a flashing state are converted to parallel light by a collimator lens 13 and the optical signal with a wavelength lambda1 is reflected toward a rotor 3 by a dichroic mirror 10 while the optical signal with a wavelength lambda2 is reflected to the rotor 3 by a dichroic mirror 11. Therefore, when reflection parts 5, 8a reach positions corresponding to both dichroic mirrors 10, 11, the optical signals with the wavelengths lambda1, lambda2 are reflected by the reflection parts 5, 8a and further reflected by the mirrors 10, 11 to be condensed by the collimator lens 13. This optical signal containing the wavelengths lambda1, lambda2 is transmitted to the control part 15 through an optical fiber 14 and the control part 15 judges the ignition time or fuel jet time of a specific cylinder.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a rotational position detection device, and more particularly to a rotational position detection device for dividing a plurality of channels from a rotating body and obtaining a rotational signal as an optical signal.

Conventionally, in a multi-cylinder internal combustion engine, in order to detect the ignition timing of each cylinder or the opening timing of the fuel injection valve of each cylinder,
There is one that obtains two-channel frequency division and rotation signals from a distributor. In this case, a light-emitting element and a light-receiving element are arranged on both sides of a rotating body having a slit, and two-channel division and rotation signals are obtained by transmitting and blocking light between the pixel elements. However, in such conventional technology, the light emitting element, the light receiving element, the driving circuit, and the light receiving circuit are generally built into the distributor, and the semiconductor element is exposed to harsh conditions such as heat, vibration, and electrical noise. Since it needs to be placed near the internal combustion engine body, there are many restrictions in terms of layout and element selection.

The purpose is to provide a detection device.

Hereinafter, one embodiment of the present invention will be described with reference to the drawings.First, in FIG. A signal indicating the timing or fuel injection timing and a signal indicating the ignition timing or fuel injection timing of the remaining three cylinders are obtained from the rotational position detection device 1.

A disk-shaped rotating body 3 is fixed to the rotating shaft 2, and on one surface of the rotating body 3, optical signal absorbing parts and reflecting parts are arranged on a plurality of virtual circles having different radii around the rotational axis. are provided alternately in the circumferential direction. That is, in this embodiment, the reflective part 5 is provided on a part of the virtual circle 4 having the radius R1 in the circumferential direction, and the absorbing part 6 is provided in the remaining part. The reflecting portion 5 and the absorbing portion 6 are formed, for example, by applying paint of a color that reflects light and a color that absorbs light to the surface of the rotating body 3. Also, the radius R1
On the imaginary circle 7 with a radius R2 that is larger than 1, there are four reflecting portions 8α spaced at equal intervals in the circumferential direction.

9b, QC, and 13d are provided, and their reflecting portions 8a to 13d are provided.
Absorbing portions 9 are provided between each portion 8d. Moreover, the reflecting portions 5 and 8α are arranged at the same position in the circumferential direction of the rotating body 30, and this position is at the 0 ignition timing 67 of the specific cylinder.
+ui'! , indicates the fuel injection timing; and the remaining reflecting portions 8h to 8d indicate the ignition timing or fuel injection timing of the remaining cylinders.

Referring also to FIG. 2, a demultiplexer/mixer DM including two dichroic ink mirrors 10 and 11 is arranged opposite to one surface of the rotating body 3. Moreover, each dichroic mirror io, 1i is located at a position corresponding to each virtual circle 4, 7,
It is arranged at an angle of 45 degrees with respect to the rotating body 3. Such dichroic mirrors 10 and 11 are formed, for example, on the joint surface and one end surface of a prism assembly 12 formed by adhering or mechanically bonding two prisms, and one dichroic mirror 10 receives light of wavelength λ1. signal,
The other dichroic ink mirror 11 has a function of reflecting an optical signal of wavelength λ2.

At a position facing the other end face of the prism assembly 12,
A collimating lens 13 is used to form an optical path at an angle of 45 degrees with respect to each of the dichroic mirrors io and ii.
will be placed. An end face of an optical fiber 14 is arranged opposite to the focal position of the collimating lens 13, and this optical fiber 14 is connected to a control section 15.

The control unit 15 includes a light-emitting element and a light-receiving element, and is arranged at a position separated from the internal combustion engine main body. Moreover, this control unit 15 controls the wavelength λ1. It has a function of emitting an optical signal containing λ2 on and off at very short regular intervals and emitting it to the optical fiber 14, and detecting the wavelength of the optical signal input via the optical fiber 14 when the optical signal is not emitted. have

Next, the operation of this embodiment will be explained.
The optical signal emitted in blinking light from reflected towards. Therefore, when the reflecting portions 5 and 8α come to the positions corresponding to both dichroic ink mirrors 10°11, the wavelength λ1
. The optical signal including the wavelengths λ1 and λ2 is transmitted to the control unit 15 via the optical fiber 14, and the control unit 15 determines that it is the ignition timing or fuel injection timing for a specific cylinder.

Furthermore, when the reflecting portions 9b, 13C, and 8cj respectively come to positions corresponding to one dichroic mirror 11,
At the position corresponding to the other dichroic ink mirror 10,
An absorption section 6 is located, and only the optical signal of wavelength λ2 returns to the control section 15 via the optical fiber 14. Thereby, the control unit 15 can detect the ignition timing or fuel injection timing of each remaining cylinder.

Although the above embodiments have been described in relation to a distributor, the present invention can be widely implemented as a rotational position detection device for a rotating body. Furthermore, although the above-described embodiments have been described as obtaining frequency division and rotation signals of two channels, the present invention can also be used to obtain division and rotation signals of three or more channels. Furthermore, the reflecting part and the absorbing part may be reversed, and the position may be detected by the absorbing part. Furthermore, the dichroic ink mirror 10 that is farthest from the control unit 15 may be replaced with a simple reflecting mirror.

As described above, according to the present invention, on one surface of the rotating body,
Optical signal absorption parts and reflection parts are provided alternately on a plurality of virtual circles having different radii around the axis of rotation, and optical signals containing a plurality of different wavelengths are demultiplexed for each virtual circle. A demultiplexer and a mixer for mixing the optical signals emitted toward the rotating body and reflected by the reflecting section are disposed opposite to the -1 side of the rotating body, and a mixer is arranged to face the -1 side of the rotating body, and outputs a plurality of optical signals having different wavelengths. Since the control unit in charge of light emission and light reception is connected to the demultiplexer and mixer via an optical fiber, frequency division and rotation signals of multiple channels can be obtained as optical signals.
Moreover, the control unit including the light emitting element and the light receiving element can be placed at any position, making it easy to use in terms of layout and element selection.
It's advantageous.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, and FIG. 1 is a perspective view, and FIG. 2 is a simplified enlarged sectional view taken along line 1--2 in FIG. DESCRIPTION OF SYMBOLS 1... Rotation position detection device, 3... Rotating body, 4,1.
...Virtual circle, 5,8a-8d...Reflection part, 6,9...
・Absorption section, io, it-... dichroic ink mirror, 13... collimating lens, 14... optical fiber, 15... control section, DM... demultiplexer, mixer Fig. 1 δ Figure 2

Claims (1)

[Claims] On one surface of the rotating body, optical signal absorbing parts and reflecting parts are alternately provided on a plurality of virtual circles having different radii around the axis of rotation, and are used to separate optical signals containing a plurality of different wavelengths. A plurality of demultiplexers and mixers are disposed opposite to the one surface of the rotary body, and mix the optical signals that are emitted toward the rotating body in each of the virtual circles and are reflected by the reflecting section. A rotary position detection device characterized in that a control section that controls emission and reception of optical signals having different wavelengths is connected to the demultiplexer and mixer via an optical fiber.