JPH04116247A - Rotation angle detecting device for internal combustion engine - Google Patents

Abstract

PURPOSE:To miniaturize a detecting device and obtain high precision by shaping the detected signal of a light detection section having a light interrupting means concurrently detecting the reference position and angle position into the optional reference position signal and angle position signal with a calculating circuit. CONSTITUTION:A series of slits of a rotor plate 1 are provided coaxially with unit angle detecting slits, and the length of the slits is increased only at the reference position portion. The reference position and unit angle are detected by a terminal P2 picking and outputting only the reference position portion of the rotation of a shaft fitted with the rotary plate 1 and a terminal P1 detecting and outputting the unit angle in a detection section 2 when the light is interrupted in response to the rotation of the rotary plate 1. The detected wave-form is converted into a square wave by a wave-form shaping circuit 3, and only necessary elements are extracted in a logical circuit 4 to form and output the wave-form. Rising edge sections of the terminals P1, P2 are picked from the same side of the same hole of the rotor plate 1, the light of light emitting diodes is used, thus the structural phase drift can be suppressed to the utmost.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a rotation angle detection device that optically detects the rotation angle of a crankshaft or the like of an internal combustion engine. The present invention relates to a signal detection method suitable for a high-precision rotation angle detection device that uses the same phase.

[Conventional technology]

2. Description of the Related Art A system using a light emitting element, a light receiving element, and a light intermittent means is widely used as a detection section of a rotation angle detection device that photoelectrically detects the rotation angle of a rotating body such as a crankshaft of an internal combustion engine.

A method has also been invented in which a detection signal is used to form a waveform using an electric circuit and an arbitrary waveform is extracted. In related devices of this type, for example, as described in Japanese Patent Publication No. 61-27689, due to the structure, a mechanical phase occurs between the reference position and angle detection due to rotational fluctuations.

[Problem to be solved by the invention]

The above conventional technology has two signals, one for the reference position signal and one for the angle detection signal.
It has a series of slits, and therefore, due to manufacturing errors (9) deviation of the rotating shaft, etc., a time lag occurs between the two signals having different diameters from the center of the rotating shaft.

This signal deviation is not desirable for highly accurate engine control.

The present invention detects both the reference position and unit angle using the light of one light emitting diode from the same slit in the rotary plate, which is a light intermittent means, to detect mechanical deviation, and also to detect the waveform shape of the reference position and unit angle. If the circuit and circuit constants are the same,
Since the slit width is uniform, electrical deviations caused by temperature changes can theoretically be converted into heat.

[Means to solve the problem]

In order to achieve the above object, the shape of the rotor plate that is the light intermittent means, the shape of the detection part that supports the light receiving and emitting element that detects the intermittent light of the rotor plate, and the shape of the detecting part that supports the light receiving and emitting element that detects the intermittent light of the rotor plate, and the shape of the detecting part that processes the detected signal and generates an arbitrary reference signal. The above object is achieved by a suitable combination of the three elements of the electrical circuit and forming the unit angle signal.

[Effect]

One series of light intermittent means is used, and a plurality of signals are taken out from the same light intermittent means having reference position and unit angle elements, and the reference position and angle detection elements are extracted as necessary by performing logical operations. Thereby, the structural error between the reference position signal and the angle detection signal can be theoretically reduced to zero.

〔Example〕

Embodiments of the present invention will be described below with reference to FIGS. 1 to 5.

FIG. 1 is a conceptual diagram of the system according to the present invention.

The detecting unit 2 detects one of the shafts on which the rotor plate 1 is attached according to the intermittent light that corresponds to the rotation of the rotor plate 1.
The detected waveform is converted into a square wave by the waveform shaping circuit 3, which detects elements of the reference position and unit angle of rotation, and the logic circuit 4 extracts only the necessary elements, shapes the waveform, and outputs it.

FIG. 2 shows an example of a rotor plate, which is a light intermittent means,
One series of slits is made coaxial with the unit angle detection slit and the length of the slit is made longer only at the reference position portion. Third
The figure shows the relative configuration of the rotor plate 1 and the detection unit 2, which includes a P2 terminal that picks up and outputs only the reference position portion (hereinafter referred to as REF) and a P1 terminal that performs and outputs unit angle detection (hereinafter referred to as POS). . FIG. 4 is a configuration diagram of an electric circuit of the rotation angle detection device. The P2 terminal output is subjected to arithmetic processing in the logic circuit 4 via the waveform shaping circuit 3, and has an arbitrary waveform. It is output as a reference position signal REF.

FIG. 5 is a timing chart of waveforms at each part in FIG. 4.

Looking at point A in Fig. 5, the rising edges of Pl and P2 are picked up from the same side of the same hole in the rotor plate, and the light from the same light emitting diode is used, so there is a structural difference. Phase shift can be suppressed as much as possible.

If there is no deviation in the radial direction with respect to the shaft in the light receiving diodes 6A and 6B shown in FIG. 3, the phases of the reference position signal and unit angle signal can be set to zero.

〔Effect of the invention〕

According to the present invention, in a rotation angle detection device.

(1) By reducing the number of slits in the rotor plate, the detection device can be made smaller. In addition, (2) a plurality of output signals can be made completely in phase, and high accuracy can be achieved.

[Brief explanation of drawings]

Fig. 1 is a system configuration diagram of a rotation angle detection device that is an embodiment of the present invention, Fig. 2 is an external view showing the shape of a rotor plate for implementing the present invention, and Fig. 3 is a rotor plate and optical detection. Fig. 4 is a functional block diagram of the electrical circuit that performs waveform processing, and Fig. 5 is a structural diagram showing the relative positions of the parts.
It is an operation waveform diagram of the figure part. DESCRIPTION OF SYMBOLS 1... Rotor plate, 2... Detection part, 3... Waveform shaping circuit, 4... Logic circuit. Figure Figure Figure! Diagram

Claims (1)

[Claims] 1. The shape of the light intermittent means that can simultaneously detect the reference position and angular position from one light intermittent means in the photodetector, and the logic for shaping the detection signal into an arbitrary reference position signal and angular position signal. A rotation angle detection device for an internal combustion engine, characterized by having an arithmetic circuit.