JPS60155919A - Apparatus for detecting rotary position - Google Patents

Abstract

PURPOSE:To make it possible to arrange a light emitting part and a light receiving part to arbitrary positions, by avoiding the arrangement of the light emitting part or the light receiving part in an atmosphere severe in conditions such as a high temp., vibration or electrical noise while obtaining frequency dividing signals and rotary signals of a plurality of CHs as optical signals. CONSTITUTION:An optical signal containing wavelengths lambda1, lambda2 is incident on a wave splitter 8 from a light emitting part 10 present at a position spaced part from an internal combustion engine main body through a first optical fiber 11 and light with the wavelength lambda1 is reflected toward a rotor 3 in one dichroic mirror 15 while light with the wavelength lambda2 is reflected toward the rotor 3 in the other dichroic mirror 16. When through-holes 5, 7a are positioned between the wave splitter 8 and a mixer 9 in this state, the optical signals with the wavelength lambda1, lambda2 transmit the through-holes 5, 7a to be incident to the mixer 9. Said optical signals are mixed in the mixer 9 and transmitted to a light receiving part 12 through a second optical fiber 13. By this mechanism, the light receiving part 12 decodes that the optical signal contains both wavelengths lambda1, lambda2 and reads the ignition time of a specific cylinder or a fuel jet time thereof.

Description

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

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 respectively arranged on both sides of a rotating body having a slit, and two-channel frequency 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. Because it needs to be placed near the internal combustion engine body, there are many restrictions in terms of layout and element selection.

The present invention was made in view of such circumstances, and it is possible to separate multiple channels by avoiding placing the light emitting part and the light receiving part in an atmosphere with severe conditions such as high temperature, vibration, and electrical noise. The present invention provides a rotational position detection device that obtains circumferential and rotational signals as optical signals. We are friends with
Hereinafter, one embodiment of the present invention will be described with reference to the drawings.First, in FIG. A signal indicating the ignition 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 one or more through holes are formed in each of the rotating bodies 3 on a plurality of virtual circles having different radii around the rotational axis. . That is, in this embodiment, a single through hole 5 is bored on an imaginary circle 4 with a radius R1, and on an imaginary circle 6 with a radius R2, which is larger than the radius R1, holes are formed at equal intervals in the circumferential direction. Four through holes Iα, 7b, 7-c, and 7d are bored through the hole. Furthermore, the through holes 5 and 7α are arranged at the same position along the circumferential direction of the rotating body 3, and this position indicates the ignition timing or fuel injection timing of a specific cylinder. In addition, the remaining through holes 7h, 7. The positions c and 7 cl indicate the ignition timing or fuel injection timing of the remaining cylinders.

Referring also to FIG. 2, a duplexer 8 is disposed opposite to one surface of the rotary body 3, and a mixer is disposed on the other surface of the rotary body 3 corresponding to the duplexer 8. 9 are arranged facing each other. Duplexer 8
A first optical fiber 11 that guides an optical signal from a light emitting section 10, which is a light emitting element, is connected in parallel to the mixer 9, and a second optical fiber that guides an optical signal to a light receiving section 12 that includes a light receiving element is connected to the mixer 9. 1
3 is connected. The light emitting section 1o and the light receiving section 12 are arranged apart from the internal combustion engine main body.

The demultiplexer 8 consists of a collimating lens 14 and two dichroic mirrors 15.16. They are arranged parallel to each other and inclined at an angle of 45 degrees. Such dichroic mirrors 15 and 16 are formed on the joint surface and one end surface of the prism assembly 17 formed by bonding or mechanically coupling two prisms, respectively.
The direction of inclination is set so that as it moves away from the collimating lens 14, it approaches the rotating body 3 side. Furthermore, each dichroic mirror 15, 16 has the function of reflecting light of a different wavelength and transmitting light of another wavelength. For example, dichroic mirror 15 reflects light of wavelength λ1, and dichroic mirror 16 reflects light of wavelength λ1. Reflects one light of λ2.

At the focal position of the collimating lens 14 in this demultiplexer 8, the end surfaces of the first optical fibers 11 are arranged opposite to each other.
, λ is input to the demultiplexer 8.

The mixer 9 consists of a condensing lens 18 and two dichroic mirrors 19.20, both of which are connected to each dichroic mirror 15.20 of the splitter 8.
arranged parallel to each other at a 90 degree inclination to 16;
The prism assembly 21 is formed by bonding or mechanically bonding two prisms, and is formed on the joint surface and one end surface, respectively.

Moreover, the dichroic mirror 19 has a function of reflecting light of wavelength λ1, and the dichroic mirror 20 has a function of reflecting light of wavelength λ.

The light reflected by each dichroic mirror 19, 20 is guided to the condenser lens 18, and at the focal position of the condenser lens 18, the end face of the second optical fiber (13) is arranged to face the second optical fiber.

Such a demultiplexer 8 and a mixer 9 are arranged at positions corresponding to the two virtual circles 4 and 6 of the rotating body 30 so that optical signals can be sent and received from the demultiplexer 8 to the mixer 9. . That is, a dichroic mirror 15 that reflects light of wavelength λ□.
19 is arranged corresponding to the virtual circle 6, and dichroic mirrors 16 and 20 that reflect light of wavelength λ2 are arranged corresponding to the virtual circle 4.

Next, the operation of this embodiment will be explained. From the light emitting section 10 located at a distance from the internal combustion engine main body, a wavelength of λ1 is emitted.
, λ is input to the demultiplexer 8 via the first optical fiber 11, and one dichroic mirror 15 reflects the light with the wavelength λ toward the rotating body 3, and the other dichroic mirror 15 reflects the light with the wavelength λ toward the rotating body 3. The loic mirror 16 reflects light with a wavelength λ toward the rotating body 3.

In such a situation, if the through hole 5.7α is located between the demultiplexer 8 and the mixer 9, the wavelength λ1. λ.

The optical signals are transmitted through the through holes 5 and 7α to the mixer 9.
is incident on the Therefore, the mixer 9 mixes these optical signals and transmits them to the light receiving section 12 via the second optical fiber 13. As a result, in the light receiving section 12, both wavelengths λ1. λ
2, and reads that it is the ignition timing or fuel injection timing for a specific cylinder.

Further, a through hole 7b is provided between the duplexer 8 and the mixer 9.

When 7c and 7d are located, only the light with wavelength λ1 is transmitted from the demultiplexer 8 to the mixer 9, and the second optical fiber 13
It is transmitted to the light receiving section 12 via. Accordingly, the light receiving section 12 can detect the ignition timing or fuel injection timing of the remaining cylinders based on the length of the optical signal having the wavelength λ.

Although the above embodiments have been described in connection with a distributor, the present invention can be widely used as a rotational position detecting device for a rotary or rotating body. , the rotation signal is obtained, but the present invention is also applicable to frequency division of multiple channels of three or more channels,
It can also be used to obtain rotation signals. Furthermore, it is also possible to provide a through hole in an area excluding the portion where the rotational position is to be detected, so that the rotational position can be detected when no optical signal passes through. Furthermore, the dichroic mirrors 16 and 20 that are farthest from the light emitting section 10 and the light receiving section 12 may be replaced with simple reflecting mirrors.

As described above, according to the present invention, the rotating body has a plurality of virtual circles having different radii around the axis of rotation of the rotating body.
A demultiplexer, each having one or more O through holes, which demultiplexes the optical signal into a plurality of types and outputs the optical signals in parallel corresponding to each of the virtual circles, faces one surface of the rotating body. arranged,
A mixer for mixing a plurality of types of optical signals transmitted through each of the through holes is disposed facing the other surface of the rotary body at a position corresponding to the splitter, and the splitter has a light emitting section to a light emitting section. A first optical fiber for guiding the optical signal is connected to the mixer, and a second optical fiber for guiding the optical signal to the light receiving section is connected to the mixer, so it is possible to obtain frequency division and rotation signals of multiple channels. Furthermore, the light emitting section and the light receiving section can be arranged at arbitrary positions, which is advantageous in terms of layout and element selection.

[Brief explanation of drawings]

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, 6.
...Virtual circle, 5,7α-7d...Through hole, 8...Demultiplexer, 9...Mixer, 10...Light emitting part, 11...First optical fiber, 12...・Light receiving part, 13...Second optical fiber patent applicant Toyodenso Co., Ltd.

Claims (1)

[Claims] One or more through holes are formed in the rotating body on a plurality of imaginary circles having different radii around the axis of rotation, and the optical signal is split into multiple types to correspond to each of the imaginary circles. A demultiplexer that emits light in parallel is disposed opposite to one surface of the rotating body, and a mixer that heats the plurality of types of optical signals transmitted through each of the through holes is attached to the demultiplexer. A first optical fiber is disposed facing the other surface of the rotating body at a corresponding position, a first optical fiber for guiding an optical signal from a light emitting part is connected to the splitter, and a first optical fiber for receiving an optical signal is connected to the mixer. 1. A rotational position detection device, characterized in that a second optical fiber is connected thereto.