JPH0355799Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a rotation angle sensor device for an electronic fuel injection type double overhead cam type engine.

(Prior Art) Conventionally, this type of engine has a first rotation angle sensor that generates a signal once at a predetermined rotation angle position during one rotation of the camshaft, and a rotation angle sensor that generates a signal once at a predetermined rotation angle position during one revolution of the camshaft, and a rotation angle sensor that corresponds to the explosion interval between each cylinder of the engine. A second rotation angle sensor that generates a signal once each at an angular interval; a third rotation angle sensor that generates a signal once each at a predetermined unit rotation angle interval of the camshaft;
The piston position of each cylinder is determined by counting the number of signals generated from the second rotation angle sensor and the third rotation angle sensor based on the signal generated from the rotation angle sensor, and fuel injection to each cylinder is performed. It is known that the engine controls the advance angle of the ignition timing.

In this case, these sensors may be installed on one of the pair of camshafts to which the distributor is attached coaxially with the distributor; As proposed in , it is separated from the distributor and attached to the other camshaft.

(Problems to be solved by the invention) In all of the above, three sensors are attached to the camshaft as one unit, and the unit protrudes greatly in the axial direction, increasing the axial dimension of the entire engine. There is a problem in that the vibration of a rotor such as a reluctor that is prepared for this increases at the sensor on the axially distal end side, making it easy for noise to occur in the signal.

To solve this problem, it is conceivable to install these sensors separately on one camshaft where the distributor is attached and the other camshaft, but in this case, the relative relationship between the sensors would be The influence of angular displacement and voltage noise in the digital distributor on the sensor signal is a problem, and it is necessary to take this into consideration when determining the sensor placement.

(Means for Solving the Problems) In order to solve the above-mentioned problems, the present invention is an electronic fuel injection type double overhead cam type engine. a first rotation angle sensor that generates signals;
a second rotation angle sensor that generates one signal each at a rotation angle interval of the camshaft corresponding to the explosion interval between each cylinder of the engine; and a second rotation angle sensor that generates one signal each at a predetermined unit rotation angle interval of the camshaft. 3 rotation angle sensors are provided, and the second rotation angle sensor and the third rotation angle sensor are provided based on the signal generated from the first rotation angle sensor.
One of a pair of camshafts in which the piston position of each cylinder is determined by counting the number of signals generated from a rotation angle sensor to perform fuel injection to each cylinder and ignition timing control. The second and third rotation angle sensors are installed on the opposite end of the camshaft from the side where the cam drive pulley is located, coaxially with the distributor attached thereto, and It is characterized in that the first rotation angle sensor is attached to the end on the same side as the user.

(Example) Embodiments of the present invention will be described based on the drawings.

Referring to FIG.
The figure shows an engine equipped with four cylinders 2 ₁ , _{2 2} , 2 ₃ , 2 ₄ , and a fuel injection nozzle 3 is provided at the intake port of each of these cylinders 2 ₁ , 2 2 , 2 ₃ , 2 ₄ . A pair of camshafts 5, 5 are provided on the engine 4 to constitute an electronic fuel injection type double overhead cam type engine.

These cylinders 2 ₁ , 2 ₂ , 2 ₃ , 2 ₄ are arranged at intervals of 180° in terms of crank angle, that is, 90° in terms of rotation angle of the camshaft 5. For example, first cylinder 2 ₁ → third cylinder 2 ₃ → fourth cylinder
The cylinder 2 ₄ → the second cylinder 2 ₂ explodes evenly in the order, and as shown in _FIG . The first rotation angle sensor 6 generates one pulse signal at a certain angle before the intake stroke top dead center (hereinafter referred to as TDC), and the rotation angle interval of the camshaft 5 corresponds to the explosion interval between each cylinder. That is, the second rotation angle sensor 7 generates one pulse signal just before TDC of each cylinder at 90° intervals, and the predetermined unit rotation angle interval of the camshaft 5, e.g.
A third rotation angle sensor 8 that generates one pulse signal each at 15° intervals is provided, and these sensors 6, 7, 8
The piston position of each cylinder is determined based on the signal from the engine, and fuel injection to each cylinder and ignition timing advance control are performed.

To explain this in more detail, these sensors 6, 7,
The signal from 8 is input to a control device such as a microcomputer, and depending on the number of signals input from the second rotation angle sensor 7 after the signal input from the first rotation angle sensor 6, the next intake air signal is input. The cylinder that enters the stroke is determined and fuel is injected.

Further, in the advance angle control, the ignition is started when the number of signals from the third rotation angle sensor 8 is input after the signal is input from the second rotation angle sensor 7 according to the amount of advance set in advance according to the driving situation. This is done by setting whether it matches the timing, and energizing the ignition coil when this signal is input. Note that when the ignition timing is within the interval between the generation of signals from the third rotation angle sensor 8, the time difference obtained by proportionally distributing from the preceding generation period after inputting a predetermined number of signals from the third rotation angle sensor 8 is calculated. energize the ignition coil.

According to the present invention, as shown in FIG. 2, one of the pair of camshafts 5, 5 is provided with the above-mentioned second and third camshafts located coaxially with the distributor 9 attached thereto. Both rotation angle sensors 7, 8 are attached to the other camshaft 5, and a first rotation angle sensor 6 is attached to the other camshaft 5.To explain this in more detail, in the illustrated example, the drive pulley 5a of both camshafts 5, 5 is attached. , 5a are provided on the end wall portion of the cylinder head 4 on the opposite side to the side where the two camshafts 5, 5a are arranged, housings 12, 13 are provided which pivotally support rotating shafts 10, 11 connected to the two camshafts 5, 5, respectively, and are connected to one of the camshafts 5. A second rotation angle sensor 7, a third rotation angle sensor 8, and a distributor 9 are housed in order in the axial direction in a first housing 12 that pivotally supports a first rotation shaft 10, and the other camshaft 5, which pivotally supports the second rotating shaft 11 connected to
The first rotation angle sensor 6 was housed within the housing 13.

The distributor 9 is connected to the first rotating shaft 10.
A rotor 9a provided at the shaft end of the first housing 12, a central power supply terminal 9b connected to the secondary side of the ignition coil provided on the end wall of the first housing 12, and each cylinder 2 ₁ , 2 ₂ , 2 ₃ ,
It consists of four power receiving terminals 9c connected to the ignition plugs 2 _{and 4} , and as the rotor 9a rotates, power is sequentially supplied from the power feeding terminal 9b to each of the power receiving terminals 9c, causing discharge at each spark plug. Function as much as possible. In the drawing, 14 indicates a plug cord.

Each rotation angle sensor 6, 7, 8 is connected to an angular rotation axis 1.
The rotors 6a, 7a, 8a on the rotors 0, 11, and the protrusions 6b, 7b on the circumferential surface of each of the rotors 6a, 7a, 8a,
It consists of outer pickup coils 6c, 7c, and 8c that detect the approach of the rotor 8b and generate a pulse signal, and one pick-up coil is attached to the rotor 6a of the first rotation angle sensor 6 at a predetermined angular position as shown in the third figure. protrusion 6b
As shown in FIG. 4, protrusions 7b and 8b are formed on the rotor 7a of the second rotation angle sensor 7 and the rotor 8a of the third rotation angle sensor 8 at intervals of 90 degrees and 15 degrees, respectively. , signals are generated from each of the sensors 6, 7, and 8 as shown in FIG.

In the drawings, 6d, 7d, and 8d indicate mounting plates for pick-up coils 6c, 7c, and 8c, respectively.

(Function) When a relative angular displacement occurs between the second rotation angle sensor 7 and the third rotation angle sensor 8, a signal from the second rotation angle sensor 7 is originally generated from the third rotation angle sensor 8 prior to this signal. However, if the second and third rotation angle sensors 7 and 8 are installed on the same axis as in the present invention, the ignition timing may be significantly deviated due to the signal indicated by A in Fig. 5. , both sensors 7,
8 can be arranged without relative angular displacement, and accurate electronic advance angle control can be performed.

In addition, by providing the first rotation angle sensor 6 on a separate shaft, the axial extension space of both camshafts 5, 5 can be used equally, thereby shortening the axial dimension of the entire engine, and further reducing rotor runout as in the conventional case. It is also possible to prevent noise from occurring.

Note that the first rotation angle sensor 6 is provided to determine which cylinder enters the intake stroke by counting the number of signals generated from the second rotation angle sensor 7 based on the signal generated from the sensor 6. The signal from the first rotation angle sensor 6 corresponds to the generation interval of the signals generated from the second rotation angle sensor 6 before and after this signal, that is, the signal from the second cylinder in the embodiment.
It is sufficient that the signal be generated at any time within the generation interval between the signal immediately before TDC and the signal immediately before TDC of the first cylinder.
For example, the signal may be generated at a point C in FIG. 5, which is in the middle of this generation interval. Therefore, the generated angle difference between the signal of the first rotation angle sensor 6 and the signal of the second rotation angle sensor 7 can be relatively large, and as a result of providing both sensors 6 and 7 on different axes, some relative angular displacement occurs. Even if this occurs, there is no problem in controlling fuel injection.

The above describes the first to third rotation angle sensors 6, 7, 8.
This is an explanation of the advantage of separating the first rotation angle sensor 6 and the second and third rotation angle sensors 7 and 8 and attaching them to different camshafts 5. In this case, the first rotation angle sensor 6 is mounted on a disk. Triviewer 9
It is also possible to arrange the sensor coaxially with the first rotation angle sensor 6, but if a noise signal as shown in FIG. 5 is generated due to voltage noise from the first rotation angle sensor 6 to the distributor 9, cylinder discrimination becomes impossible This has a serious effect on the control, so it is better to arrange the second and third rotation angle sensors 7 and 8 coaxially with the distributor 9 as in the present invention.

Moreover, if the second rotation angle sensor 7 is arranged with the third rotation angle sensor 8 for the distributor 9 as in the embodiment, the second rotation angle sensor 7 is separated from the distributor 9. This is advantageous because generation of noise signals from the sensor 7 due to power supply noise is prevented as much as possible. Note that the third rotation angle sensor 8 continuously generates signals at small angle intervals.
Even if it is close to the distributor 9, it is not easily affected by noise, and even if a noise signal were to occur, there would be no particular problem as it would only shift the ignition timing of one cylinder.

(Effect of the invention) As described above, according to the invention, the second and third rotation angle sensors are provided coaxially with the distributor attached to one camshaft, and the first rotation angle sensor is provided to the other camshaft. ,
The second and third rotation angle sensors are installed without relative angular displacement, allowing accurate advance angle control to be performed, and the first rotation angle sensor generates a noise signal due to the influence of voltage noise in the distributor, allowing control. This also prevents problems that would occur when all the rotation angle sensors are installed on the same axis, i.e., the rotation angle sensor on the tip end side in the axial direction has a large rotor runout that causes the signal to be affected. Problems that occur when noise is likely to occur can be resolved. Furthermore, since the first rotation angle sensor is attached to the other camshaft at the end on the same side as the distributor, the first rotation angle sensor can be arranged space-efficiently by overlapping the axial space of the distributor. The distribution device and the first rotation angle sensor are placed on the side opposite to the cam drive pulley, where the transmission is usually placed, so the distribution device and the first rotation angle sensor are placed above the transmission. It fits in the space, does not increase the overall length of the engine including the transmission, and does not affect the layout of the auxiliary equipment normally placed on the cam drive pulley side, the pulleys and belts that drive them, etc. have an effect.

[Brief explanation of drawings]

Fig. 1 is a plan view of an example of an engine equipped with the device of the present invention, Fig. 2 is an enlarged cross-sectional plan view of its main parts, and Figs. 3 and 4 are the lines - and - of Fig. 2, respectively.
FIG. 5 is a line diagram showing signal generation characteristics from each rotation angle sensor. DESCRIPTION OF SYMBOLS 1...Engine, ₂₁ , ₂₂ , 23 _{, 24 ...} Cylinder, 5...Camshaft, 6...First rotation angle sensor, 7...Second rotation angle sensor, 8...Third rotation angle Sensor, 9...Distributor.

Claims (1)

[Claims for Utility Model Registration] 1. A double overhead cam type engine with electronic fuel injection, which generates one signal at a predetermined rotation angle position during one revolution of the camshaft.
a rotation angle sensor; a second rotation angle sensor that generates one signal each at a rotation angle interval of the camshaft corresponding to the explosion interval between each cylinder of the engine; and a third rotation angle sensor that generates a signal,
By counting the number of signals generated from the second rotation angle sensor and the third rotation angle sensor based on the signal generated from the first rotation angle sensor, the piston position of each cylinder is determined, and the piston position for each cylinder is determined. In a device that performs fuel injection and ignition timing control, a camshaft is installed at the end of one of the pair of camshafts on the opposite side from the side where the cam drive pulley is located, coaxially with the distributor attached to the camshaft. and attach the second and third rotation angle sensors to the end of the other camshaft on the same side as the distributor.
A rotation angle sensor device for an engine, characterized in that a rotation angle sensor is attached. 2. In the engine according to claim 1, wherein the distributor and the second rotation angle sensor are spaced apart in the axial direction, and the third rotation angle sensor is disposed between them. Rotation angle sensor device.