JP3564272B2 - Gas engine ignition system - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an ignition device for a gas engine, and more particularly, to a technology for attaching an ignition timing detection device to an engine.
[0002]
[Prior art]
Conventionally, the detection of the ignition timing in a four-cycle gas engine is performed by a crankshaft rotation detecting device for detecting the rotation of the crankshaft and a camshaft rotation detecting device for detecting a half rotation of the crankshaft.
The crankshaft rotation detecting device has been configured to include a crank rotor mounted on a crankshaft, a crank sensor for detecting a rotational position of the crank rotor, and a crank sensor bracket for fixing the crank sensor.
[0003]
Further, the camshaft rotation detecting device includes a camshaft that rotates at half the crankshaft, a cam rotor mounted on the other, a cam sensor that detects the rotational position of the cam rotor, and a cam sensor bracket that fixes the cam sensor. Was composed.
The operation of the above device will be described with reference to FIG. 7. The crank sensor Mc outputs a rotation signal Sc six times per rotation of a crank rotor Rc having the same number of protrusions as the number of cylinders provided on the crankshaft of a six-cylinder engine. To detect. Further, the cam sensor Mk detects a rotation signal Sk once for one rotation of the cam rotor Rk provided on the cam shaft.
[0004]
The ignition timing is confirmed by the rotation signal Sc described above, and the basic cylinder for ignition is determined by Sk.
As for the ignition timing, the crank BTDC angle is basically determined by the intake pressure Ps, and the adjustment of the ignition timing by the fuel type and the adjustment of the ignition timing by the knock state are performed by the electronic control unit ECU, and the ignition plug Ip is instructed. You.
[0005]
As described above, the crankshaft rotation detecting device and the camshaft rotation detecting device for transmitting the basic information for controlling the ignition timing are each supported by separate brackets having high rigidity because detection accuracy is required.
[0006]
[Problems to be solved by the invention]
However, in the conventional technology, the crankshaft rotation detecting device and the camshaft rotation detecting device are mounted at separate places, and it is difficult to perform initial adjustment of the rotation angle detection related to each other. There were multiple brackets, which caused problems in weight, layout, and cost.
[0007]
A technique relating to a magnetic disc mounting structure for giving the ignition timing of each cylinder corresponding to the rotation angle of the crankshaft has been disclosed (see Japanese Patent Application Laid-Open No. Hei 6-73375), but a technique for solving the above-mentioned problems. is not.
The present invention, as described above has been made to solve the conventional problems, and the crankshaft rotation detecting apparatus, by mounting the cam shaft rotation detection device to one axis, the rotation angle of interrelated An object of the present invention is to provide a gas engine ignition device which can facilitate initial adjustment of detection and is advantageous in weight, layout, and cost.
[0008]
[Means for Solving the Problems]
Therefore, the invention according to claim 1 is
The ignition device for four-cycle gas engines, against the cam rotor for detecting the reference position of the crank rotor and the cylinder for detecting the ignition timing of each cylinder, one axis to synchronize the half rotation of the crankshaft In a state where the crank rotor is integrally connected to the cam rotor in a predetermined rotational positional relationship, the crank rotor and the cam sensor for detecting the rotation of the crank rotor and the cam sensor for detecting the rotation of the cam rotor are attached to the outer wall of the cylinder block while being connected. Mounted on a single bracket.
[0009]
As described above, according to the present invention, the crank rotor for detecting the rotation angle of the crankshaft for determining the ignition timing, and the cam rotor for detecting the reference position of the cylinder as the reference for the rotation of the crankshaft, are provided with a half of the crankshaft . Attached to one shaft rotating at speed . The crank rotor and the cam rotor were attached to this one shaft in a state where they were integrally connected in a predetermined rotational positional relationship.
Also, a crank sensor for detecting rotation of the crank rotor, and a cam sensor for detecting the rotation of the cam rotor, a more fixed to one bracket attached to the cylinder block outer wall.
[0010]
Thus, against the crank rotor and cam rotor one axis, by mounting in a state of being coupled together, Interactions position can accurately easily set, also the installation space can be reduced.
Further, since the crank rotor and the cam rotor are close to each other, the crank sensor and the cam sensor can be arranged and fixed on one bracket. In addition, by combining the brackets into one, rigidity can be increased, and weight and cost can be reduced.
[0011]
The invention according to claim 2 is
The crank rotor has protrusions twice as many as the number of cylinders arranged in the circumferential direction. As described above, in the present invention, the crank rotor is attached to a shaft that is synchronized with a half rotation of the crankshaft. Therefore, in a four-stroke engine, the ignition timing is detected by a crank rotor having a projection twice as many as the number of cylinders. I made it.
[0012]
Therefore, the signal due to the projection of the crank rotor is completely synchronized with the rotation of the crankshaft, and is more reliable than the method of determining the signal by software.
[0013]
BEST MODE FOR CARRYING OUT THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings for a four-cycle six-cylinder gas engine.
FIG. 1 functionally shows a configuration in which a device that detects rotation of a crankshaft and a device that detects rotation of a shaft that is synchronized with a half rotation of the crankshaft are integrated in one place.
[0014]
However, the device configuration is roughly divided into a rotating part Rb including a rotating part and its supporting part, and a detecting part Sb including the rotation detecting part and its supporting part. The device will be described.
1 and 5, the rotating portion Rb is supported rotatably by the plate-shaped support 1 fixed to the cylinder block E, the drive support 2 fixed to the support 1, and the drive support 2. A drive shaft 3, a rectangular coupling 5 fixed to a tip end of the drive shaft 3 with a key and a coupling bolt 6, a crank rotor 8 fixed to the coupling 5 so as to be adjustable in a rotational direction, and a crank. And a cam rotor 9 fastened to the rotor 8.
[0015]
The support 1 has a high rigidity so that the drive support 2 is fixed and a torque reaction force of a crankshaft (not shown) that drives the drive shaft 3 is provided.
The drive support 2 is configured to support the drive shaft 3 as a cantilevered rotation shaft by a plurality of radial bearings.
[0016]
The drive shaft 3 is configured to rotate in the same direction as the crankshaft at a half of the crankshaft by a gear train driven by the crankshaft.
The coupling 5 is formed so that a ring-shaped convex portion 5a is formed in the axial direction, and the crank rotor 8 and the cam rotor 9 are fixed by the rotor fixing bolt 7 through two long holes 5b which are long in the circumferential direction. Have been.
[0017]
As shown in FIG. 3, the crank rotor 8 has a disk shape, an inner hole 8a is provided so as to be fitted to the convex portion 5a, and twelve protrusions 8b are provided on the outer periphery in the circumferential direction. It is provided in the arrangement. The position of the bolt hole 8 c provided at the center of the crank rotor 8 so as to be opposed to the axis is determined from the position of the projection 8 a and the relationship with the cam rotor 9.
[0018]
As shown in FIG. 4, the cam rotor 9 has a drum shape with one end open, a projection 9b provided on the outside of the open end of the main body 9a, and an inner hole 9c fitted to the projection 5a at a closed end. A bolt hole 9d facing the axis is provided. The position of the bolt hole 9d is determined in relation to the projection 9b.
As shown in FIGS. 1 and 5, the detection portion Sb includes a bracket 10 bolted to the cylinder block E, and first and second bolts bolted to a sensor mounting portion 10a formed at the outer end of the bracket 10. Second holders 13 and 14, a crank sensor 11 fixed to the first holder 13 so as to be vertically adjustable, a cam sensor 12 fixed to the second holder 14 so as to be vertically adjustable, and a safety cover. 15 are included.
[0019]
The bracket 10 has a flat plate portion 10b which is bolted to the cylinder block E, and a sensor mounting portion 10a which fixes the first and second holders 13 and 14. The sensor mounting portion 10a includes a crank sensor 11 and a cam sensor 12. Is strictly supported with high rigidity.
The first holder 13 is formed so that the crank sensor 11 can be adjusted vertically by a holder hole 13a, and the air gap between the crank sensor 11 and the projection 8b can be minutely adjusted.
[0020]
The relationship between the second holder 12 and the cam sensor 12 is exactly the same as that of the first holder 13, so that the cam sensor 12 can be adjusted vertically by the holder hole 14a, and the air gap between the cam sensor 12 and the projection 9b is minutely adjusted. It is formed to be possible.
Further, the crank sensor 11 and the cam sensor 12 are configured to be linearly arranged in the radial direction with the projections 8b and 9a with respect to the axis of the drive shaft 3, respectively.
[0021]
Both the crank sensor 11 and the cam sensor 12 are electromagnetic sensors and are configured to output the interruption of the magnetic field by the projections 8b and 9b as a voltage change. In this example, the output voltage of the crank sensor 11 is set to 500 mV or more and the output voltage of the cam sensor 12 is set to 200 mV or more when the air gap is adjusted and the engine is 500 rpm or less.
[0022]
In addition, at the time of maximum engine rotation, both the crank sensor 11 and the cam sensor 12 are set to 50 V or less.
The positional relationship between the protrusions 8b and 9b, the crankshaft position, and the crank sensor 11 and the cam sensor 12 is set as follows.
One of the protrusions 8 b is provided so as to face the crank sensor 11 at a BTDC of 10 degrees of the first cylinder. BTDC10 degrees is the ignition timing for idling rotation.
[0023]
Next, the projection 9b is installed so as to face the cam sensor 12 at a position, for example, 30 degrees BTDC, in which the ignition timing is advanced when the BTDC of the first cylinder is 10 degrees or more. This opposing position is located between the protrusion next to the protrusion 8b in the case of engine reverse rotation.
The positions of the bolt holes 8c and 9d are determined by the relationship between the protrusions 8b and 9b and the rotational positions of the crank sensor 11, the cam sensor 12, and the coupling 5. The slot 5b is configured to easily perform the above-described position adjustment. The safety cover 15 is formed so as to cover the rotating coupling 5, the crank rotor 8, and the cam rotor 9 and be bolted to the bracket 10.
[0024]
FIG. 2 shows the arrangement of the support 1, the bracket 10, and the safety cover 15 mounted on the front side of the cylinder block E so that the installation position of the entire apparatus can be overviewed.
Next, the operation will be described.
In FIGS. 1 and 5, first, a support 1 and a drive shaft 3 supported by a drive support 2 are rotated in the same direction as the crankshaft by a crankshaft and a gear train (not shown).
[0025]
The drive shaft 3 rotates the coupling 5 fixed by the key 4 and the coupling bolt 6.
By the rotation of the coupling 5, the crank rotor 8 and the cam rotor 9 fixed by penetrating the bolt holes 8c and 9d with the rotor fixing bolt 7 are rotated.
[0026]
The cover 15 protects rotating bodies such as the coupling 5, the crank rotor 8, and the cam rotor 9 from interfering with the operator or external parts.
As shown in FIG. 6B, the rotation of the crank rotor 8 causes the crank sensor 11 to output a crank signal as an output voltage V as shown in FIG.
[0027]
Further, as shown in FIG. 6A, a cam signal from the projection 9b of the cam rotor 9 is output from the cam sensor 12 as an output voltage v.
As described above, in this example, the ignition timing BTDC of 10 degrees at 500 rpm is set as the basic ignition timing.
Then, the type of fuel, occurrence of knock, and other operating conditions are calculated and examined by an electronic control unit (not shown), and the ignition timing is optimally adjusted and changed.
[0028]
【The invention's effect】
As described above, according to claim 1 of the present invention, against the crank rotor and cam rotor one axis, so wearing them in a state of being coupled together, the relevant position of mutual accuracy easily It can be set, the crank rotor and the cam rotor are brought close to each other, and the crank sensor and the cam sensor can be mounted side by side on one bracket.
[0029]
Accordingly, high rigidity can be achieved by using only one bracket instead of two, and weight and cost can be reduced.
According to the second aspect, since the number of protrusions of the crank rotor is twice the number of cylinders, the mutual relationship between the rotation of the cam rotor and the rotation of the cam rotor can be clarified.
[Brief description of the drawings]
FIG. 1 is a device configuration diagram showing an example of an ignition timing detection device of the present invention. FIG. 2 is a perspective view showing a state of being mounted on an engine of the same. FIG. 3 is a front view of a crank rotor of the present invention. FIG. 5A is a front view, FIG. 5B is a sectional side view, and FIG. 5B is a view showing the relationship between the crank rotor, the cam rotor and each sensor as viewed from the rear of the engine. FIG. 7 is a diagram showing an output state of a cam signal.
E Cylinder block C Ignition coil 1 Support 2 Drive support 3 Drive shaft 4 Key 5 Coupling 6 Coupling bolt 7 Rotor fixing bolt 8 Crank rotor 9 Cam rotor 10 Bracket 11 Crank sensor 12 Cam sensor

Claims (2)

In an ignition device for a four-cycle gas engine,
A cam rotor for detecting the reference position of the crank rotor and the cylinder for detecting the ignition timing of each cylinder, against the one axis to synchronize the half rotation of the crankshaft, rotating crank rotor is given to the cam rotor In a state where they are joined together in a positional relationship ,
An ignition device for a gas engine, wherein a crank sensor for detecting rotation of the crank rotor and a cam sensor for detecting rotation of the cam rotor are mounted on a single bracket attached to an outer wall of a cylinder block. 2. The ignition device for a gas engine according to claim 1, wherein the crank rotor is provided with protrusions twice as many as the number of cylinders arranged in a circumferential direction. 3.

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