JP2009180153A - Engine ignition timing detector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an engine ignition timing detector in which stability and certainty at the start-up the engine are retained, engine efficiency during normal operation is improved, and the cost is reduced. <P>SOLUTION: An engine ignition timing detector for detecting engine ignition timing having projections mounted to a rotational drive body to which sensors fixed to a static member are corresponded, making the sensors generating sensing signals by the projections to detect the engine ignition timing, in which the plurality of projections are angularly asymmetrically placed in the circumference of the rotationally drive body, and the projection near the top dead point of the engine corresponds to the sensor to make the position being the ignition position at the engine start-up, and the projection at the position advanced from the start-up position corresponds to the sensor to make the position being a basic ignition position during normal operation of the engine. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention is mainly provided in an ignition timing detection device of a small single cylinder engine, and a sensor fixed to a stationary member is made to correspond to a protrusion attached to a rotary drive body, and the sensor generates a sensing signal by the protrusion. The present invention relates to an engine ignition timing detection device for detecting an engine ignition timing.

The ignition timing control of a single cylinder engine is based on a transistor ignition device that uses power generated by a flywheel magnet as a power source and a transistor as a switching element, or a pulsar coil signal (1 pulse / rev) CDI type ignition timing control device that discharges using
Such an electric ignition timing control device is often used in a multi-cylinder engine for automobiles, and for example, there is a patent document (Japanese Patent Laid-Open No. 60-169664).

In this technique, a crank angle sensor, ignition timing adjustment voltage setting means for setting an ignition timing adjustment voltage of the engine, correction crank angle calculation means for calculating a correction crank angle using the ignition timing adjustment voltage, Basic ignition timing calculation means for calculating the basic ignition timing of the engine in accordance with a predetermined operating state parameter of the engine at every predetermined timing, and basic ignition for adjusting the basic ignition timing by adding the correction crank angle to the basic ignition timing Timing adjustment means and ignition timing correction means for correcting the adjusted basic ignition timing according to a predetermined operating state parameter of the engine are provided.
This eliminates the need for mechanical adjustment of the setting deviation of the initial ignition timing of the crank angle sensor, and can ease the mounting accuracy of each component of the crank angle sensor.

Japanese Patent Application Laid-Open No. 60-169664

In a small single-cylinder engine, the ignition timing at the time of starting should be ignited in the vicinity of the top dead center to be stably started. However, during rated operation, it is necessary to ignite at a more advanced position in order to improve engine efficiency.
If the reference pulse position of the ignition timing is set to the advance side, the accuracy of the ignition timing control at the rated operation is improved, but the accuracy of the ignition timing at the start is deteriorated.
Since the rotational speed is low (100 to 800 RPM) and the rotational fluctuation is large at the start, it is difficult to calculate the ignition timing on the retard side from the reference pulse signal position on the advance side with software because accuracy is not obtained. . Therefore, when starting the engine, it is necessary to mechanically use the reference pulse signal of the sensor as an ignition signal instead of software calculation.

  From the above point of view, the technology of the patent document (Japanese Patent Laid-Open No. 60-169664) is an electric ignition timing control device applied to a multi-cylinder engine for automobiles. In addition, since both a crank sensor and a cam sensor are required, the cost is high, and it is unsuitable for application to a general-purpose small single cylinder engine that is conscious of lower costs.

  In view of the problems of the prior art, the present invention maintains stability and certainty when starting an engine, improves engine efficiency during normal operation, and uses one of a cam sensor and a crank sensor for ignition timing control. An object of the present invention is to provide an ignition timing detection device for an engine that is reduced in cost.

  The present invention achieves such an object. A sensor fixed to a stationary member is made to correspond to a protrusion attached to a rotary drive body, and a sensing signal is generated by the protrusion to detect the ignition timing of the engine. In the engine ignition timing detection device, the plurality of protrusions are arranged angularly asymmetrically in the circumferential direction of the rotary drive body, and the protrusion closer to the top dead center of the engine is made to correspond to the sensor to start the engine. The ignition position at the time is set, and a protrusion at a position advanced from the starting position is made to correspond to the sensor to be a reference ignition position during normal operation of the engine (claim 1).

  In this invention, specifically, the rotational drive body is a disc body provided on the camshaft of the engine, and the projection closer to the top dead center of the engine is made to correspond to the sensor so that the ignition position at the start of the engine And a means for calculating an ignition timing during normal operation based on the reference ignition position of the protrusion at a position advanced from the start position and the sensor.

  Further, in this invention, preferably, the rotation drive body provided with a protrusion at the time of starting the engine, the rotation drive body provided with a protrusion at the ignition timing during normal operation, and the rotation drive body corresponding to each of the rotation drive body A sensor is provided (claim 3).

Further, the present invention can be configured as follows.
A sensor fixed to a stationary member is made to correspond to a protrusion attached to a rotary drive body fixed to the crankshaft of the engine, and a sensor generates a sensing signal by the protrusion to detect the ignition timing of the engine. In the ignition timing detection device, the two protrusions are arranged in an angularly asymmetric manner in the circumferential direction of the rotary drive body, and the protrusion closer to the top dead center of the engine is made to correspond to the sensor, so that ignition at the time of engine start is performed. And a protrusion at a position advanced from the starting position is made to correspond to the sensor to serve as a reference ignition position during normal operation of the engine (claim 4).

Specifically, the invention is configured as follows.
(1) The flywheel fixed to the crankshaft is used as the rotary drive body, and the rotary drive body is provided with a projection for setting an ignition position at the start and a projection for setting a reference ignition position during normal operation of the engine. (Claim 5).

(2) In an engine provided with a generator that is directly connected to a crankshaft, the rotor of the generator is the rotary drive body, the rotary drive body has a projection for setting an ignition position at startup, and normal operation of the engine And a projection for setting the reference ignition position at the time.

  According to the present invention, a plurality of protrusions are arranged angularly asymmetrically in the circumferential direction of the rotary drive body, and the protrusion closer to the top dead center of the engine is made to correspond to the sensor as the ignition position at the start of the engine, A protrusion at a position advanced from the starting position is made to correspond to the sensor as a reference ignition position during normal operation of the engine (Claim 1), and the rotary drive body is a disc body provided on the camshaft. The projection closer to the top dead center is made to correspond to the sensor to be the ignition position at the time of starting the engine, and the ignition at the time of normal operation is based on the reference ignition position of the projection at a position advanced from the starting position and the sensor. Since means for calculating the timing is also provided (Claim 2), it is possible to switch the ignition timing control value between the start time and the normal operation with one sensor, and at the start time, a pulse signal near the top dead center start time. Can be used with an ignition signal. It becomes possible to stably start a large state of the rotational fluctuation of the time.

In addition, during normal operation, the ignition timing can be controlled to the advance side with high accuracy by using the pulse signal of the advance position relative to the start position, that is, the maximum advance position, so that the engine efficiency is improved. Control for the purpose of improvement becomes possible.
Accordingly, it is possible to obtain an ignition timing control position that can simultaneously realize stability at the start and efficiency improvement during normal operation.

  In addition, the ignition position at the start of the engine is mechanically set, and the ignition timing control during normal operation is controlled by means that calculates based on the reference ignition position, so at low cost and during normal operation The ignition timing can be controlled.

  Further, the rotary drive body provided with a projection at the time of starting the engine, the rotary drive body provided with a projection at the ignition timing during normal operation, and the sensor corresponding to each of the rotary drive body are provided. (Claim 3), even if the pulse signal is skipped due to the influence of noise, it can be controlled by other protrusions and sensors.

A sensor fixed to a stationary member is made to correspond to a protrusion attached to a rotary drive body fixed to the crankshaft of the engine, and provided with the same configuration as above (Claim 4), and a fly fixed to the crankshaft If the wheel is a rotational drive body, and the rotational drive body is provided with a projection for setting an ignition position at the time of starting and a projection for setting a reference ignition position at the time of normal operation of the engine (Claim 5), a four-cycle engine In this case, since the camshaft rotates once and the crankshaft rotates twice, the angular pitch of the protrusions for starting and normal operation can be doubled, so that the protrusions can be easily machined.
Moreover, the number of parts can be reduced by processing the protrusion by using the flywheel as a rotary drive body.

  Further, in an engine equipped with a generator, the rotor of the generator is a rotational driving body, and the rotational driving body has a projection for setting an ignition position at the time of starting, and a projection for setting a reference ignition position during normal operation of the engine. (Claim 6), the rotating shaft of the generator is also used as a rotary drive body provided with a projection, so that parts can be shared and the cost is reduced.

Hereinafter, the present invention will be described in detail with reference to the embodiments shown in the drawings. However, the dimensions, materials, shapes, relative arrangements, and the like of the component parts described in this example are not intended to limit the scope of the present invention only to specific examples unless otherwise specified. Only.
(First embodiment)

FIG. 1 is a schematic side view of an ignition timing detection apparatus for a single cylinder engine according to a first embodiment of the present invention.
In FIG. 1, reference numeral 100 denotes a single cylinder four-cycle engine, a crankshaft 6, a generator 8 that is directly connected to the crankshaft 6, and a direct drive that is driven to the crankshaft 6 and rotates by a half rotation of the crankshaft 6. The cam shaft 1 etc. in which the cam 2 was formed are provided. Reference numeral 8 a denotes a rotating shaft of the generator 8.

A rotating disk 3 is fixed to the shaft end of the cam shaft 1, and two protrusions 5 a and 5 b are fixed to the outer periphery of the rotating disk 3. The protrusions 5a and 5b are provided with cam sensors 4 supported by a fixing member 9 fixed to the engine body.
As shown in FIG. 3, the protrusions 5 a and 5 b are arranged in an angle asymmetrical manner in the circumferential direction of the rotating disk 3 with respect to the top dead center of the engine.
FIG. 3 shows the circumferential arrangement of the protrusions 5a and 5b.
The protrusions 5a and 5b are arranged on the outer periphery of the rotating disk 3 as shown by the solid line in FIG. 1 and on the cam gear 50 driven by the crankshaft (not shown) as shown by the broken line in FIG. Protrusions 5a and 5b may be provided on the side portions, and the cam sensor 4 may correspond to the protrusions 5a and 5b. In any case , the cam sensor 4 generates a sensing signal 4s by the protrusions 5a and 5b and sends it to the controller 11. The controller 11 sends an ignition signal 11a to a spark plug (not shown) of the engine based on the sensing signal 4s from the cam sensor 4.

As shown in FIG. 3, one of the protrusions is a protrusion 5a for starting ignition position setting for setting the ignition position at the time of starting, and the protrusion 5a is set at T1 before the top dead center of the engine. The other protrusion is a normal operation setting protrusion 5b corresponding to the normal operation of the engine, and the protrusion 5b is set at a position T2 advanced from the protrusion 5a.
The starting point fire position setting protrusion 5a preferably has an angle T1 = 20 ° ± 5 ° before top dead center, and the normal operation setting protrusion 5b sets its maximum reference ignition position T2 to T2 = 40. A degree of about ± 5 ° is preferred.

  Then, the rotational speed of the engine is detected by a rotational speed detector 12 and input to the controller 11, and the controller 11 determines the position of the projection 5b set during normal operation based on the detected value of the rotational speed of the engine. An amount of delay from the maximum reference ignition position T2 of the engine 100 is calculated.

Specifically, as shown in FIG. 5, when the engine is driven to rotate from the outside by a starter or the like, the pulse signals ΔT1 and ΔT2 of the cam sensor 4 are measured, and ΔT1 <ΔT2 is set as the starting point fire position. The protrusion 5a and the protrusion 5b set during normal operation are recognized.
In this case, for example, there are the following methods.
(Before engine start)
1) The reference position recognition is confirmed if ΔT1 <ΔT2 continuously 10 times of the cam angle.
2) Count and compare the number of pulses of another sensor for detecting the engine speed.
3) Create a logic circuit that automatically determines the input of the cam signal and rotation signal.
(When starting the engine)
When the engine is started, an ignition signal is output at the starting ignition reference position to ignite.
(During normal engine operation)
During normal engine operation, the time from the maximum reference ignition position T2 to the desired ignition timing is calculated from the current engine speed, and an ignition signal is output for ignition.

FIG. 6 shows a flow of the engine ignition timing detecting means as described above.
In FIG. 6, in the absolute cam angle setting algorithm (1), the interval time of the cam pulse signal during engine rotation is measured by a starter, and the absolute cam angle of each pulse is determined by determining whether the time is long or short. .
In the starting ignition control (2), ignition control is performed at the starting cam pulse position (T1).
In the normal ignition control (3), the normal cam pulse position is set to the maximum reference ignition position T2. Using this maximum reference ignition position T2 as a reference, a delay time from the detected value of the engine speed to the target ignition timing is calculated, and ignition is performed using this calculated value.

  According to the above embodiment, the two protrusions are arranged in an angularly asymmetric manner in the circumferential direction of the rotating disk 3, and the protrusion 5a closer to the top dead center of the engine is made to correspond to the cam sensor 4 when starting the engine. The ignition position (T1) of the engine, and the projection 5b at a position advanced from the start position is made to correspond to the cam sensor 4 as the reference ignition position (T2) during normal operation of the engine, and is more than the start position (T1). Since a means for calculating the ignition timing during normal operation based on the reference ignition position of the protrusion 5b at the advanced position and the cam sensor 4 is also provided, the cam sensor 4 with a pair of rotating disks 3 is used for starting and normal operation. It is possible to switch the ignition timing control value with the time, and since the pulse signal near the top dead center start time can be used as the ignition signal (T1) at the start, it is stable even in a state where the rotation fluctuation at the start is large Start is possible.

In addition, during normal operation, the ignition timing can be controlled to the advanced angle side with high accuracy by using the pulse signal of the position advanced from the starting position, that is, the maximum advanced angle position (T2) as a reference. This makes it possible to perform control aimed at improving engine efficiency.
Accordingly, it is possible to obtain an ignition timing control position that can simultaneously realize stability at the start and efficiency improvement during normal operation.

In addition, since the ignition position (T1) at the time of starting the engine is mechanically set, and the ignition timing control during normal operation is controlled by means that calculates based on the reference ignition position (T2), the cost can be reduced. It is possible to control the ignition timing during start-up and during normal operation.
(Second embodiment)

FIG. 7 is a schematic side view of an ignition timing detection apparatus for a single cylinder engine according to a second embodiment of the present invention.
In the second embodiment, a projection 5a for setting an ignition position at start-up, which is attached to a flywheel 7 fixed to the crankshaft 6 of the engine 100 in the same manner as in the first embodiment, and during normal operation of the engine The cam sensor 4 fixed to the fixing member 9 is provided in correspondence with the reference ignition position setting projection 5b. The projections 5a and 5b cause the cam sensor 4 to generate a sensing signal 4a to detect the ignition timing of the engine.
Other configurations are the same as those of the first embodiment, and the same members are denoted by the same reference numerals.

In the case of a 4-cycle engine, since the crankshaft 6 rotates twice with one rotation of the camshaft, the angular pitch of the protrusions 5a and 5b for starting (T1) and normal operation (T2) can be doubled. Is easy to machine.
Moreover, the number of parts is reduced by processing the protrusions 5a and 5b by using the flywheel 7 as a rotary drive body.
(Third embodiment)

In the third embodiment, as shown by a two-dot chain line in FIG. 1, in the engine 100 including the generator 8 that is directly connected to the crankshaft 6, the ignition position at the start of the rotor 8a of the generator 8 is set. A setting protrusion 5a and a reference ignition position setting protrusion 5b during normal operation of the engine are provided. A cam sensor 4 supported by a fixing member is attached to the protrusions 5a and 5b .
Also in this case, the crankshaft 6 is rotated twice by one rotation of the camshaft, and the angular pitch of the protrusions 5a and 5b for starting (T1) and normal operation (T2) can be doubled. Machining becomes easy. The cam sensor 4 is connected to the controller 11 .
In this case, since the rotor 8a of the generator 8 is also used as a rotating disk provided with the protrusions 5a and 5b, the parts can be shared and the cost can be reduced.
Other configurations are the same as those of the first embodiment, and the same members are denoted by the same reference numerals.
(Fourth embodiment)

FIG. 2 is a schematic partial side view of an ignition timing detection apparatus for a single cylinder engine according to a fourth embodiment of the present invention. In the fourth embodiment, the rotating disks 3a and 3b supported by the support member 9 are provided at the shaft end of the cam shaft 1, and the cam sensors 4a and 4b are provided corresponding to the rotating disks 3a and 3b, respectively. Provided.
In this case, even when the pulse signal is skipped due to the influence of noise, it can be controlled by the other protrusions 5a and 5b and the sensor. And can be controlled by sensors.
Other configurations are the same as those of the first embodiment, and the same members are denoted by the same reference numerals.
(Other examples)

8 to 10 are diagrams showing the relationship between the protrusion of the ignition timing detection device and the cam sensor.
In the case of FIG. 8, the protrusion 5 a is protruded from the rotating disk 3, and the cam sensor 4 is oriented at a right angle to the rotating disk 3.
In the case of FIG. 9, the protrusion 5 a protrudes upward from the rotating disk 3, and the cam sensor 4 is directly above the rotating disk 3.
In the case of FIG. 10, the protrusion 5 a is protruded from the rotating disk 3 to the side surface, and the cam sensor 4 faces the rotating disk 3 at a right angle.

  According to the present invention, it is possible to provide an ignition timing detection device for an engine that maintains stability and certainty when the engine is started, improves engine efficiency during normal operation, and is reduced in cost.

It is a schematic side view of the ignition timing detection apparatus of the single cylinder engine which concerns on 1st Example of this invention, and 3rd Example. It is A arrow directional view of FIG. 1 in 1st Example. FIG. 3 is a timing diagram of protrusions in the first embodiment (No. 1). FIG. 6 is a timing diagram of protrusions in the first embodiment (No. 2). The flow of the engine ignition timing detection means in the first embodiment is shown. It is a schematic side view of the ignition timing detection apparatus of the single cylinder engine which concerns on 2nd Example of this invention. It is a schematic partial side view of the ignition timing detection apparatus of the single cylinder engine which concerns on 4th Example of this invention. FIG. 4 is a first diagram illustrating a relationship between a protrusion of an ignition timing detection device and a cam sensor. FIG. 6 is a relationship diagram (part 2) between the protrusion of the ignition timing detection device and the cam sensor. FIG. 6 is a third diagram illustrating the relationship between the protrusion of the ignition timing detection device and the cam sensor.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Cam shaft 2 Cam 3, 3a, 3b, 3s Rotating disc 4, 4a, 4b Cam sensor 4s Sensing signal 5a, 5b Protrusion 6 Crankshaft 7 Flywheel 8 Generator 8a Generator rotor 9 Fixed member 11 Controller 12 Rotation detection 100 engine

Claims (6)

  In the engine ignition timing detection device for detecting the engine ignition timing by causing a sensor fixed to the stationary member to correspond to the protrusion attached to the rotary drive body and generating a sensing signal to the sensor by the protrusion. The protrusions are arranged in an angularly asymmetric manner in the circumferential direction of the rotary drive body, and the protrusion closer to the top dead center of the engine is made to correspond to the sensor as the ignition position at the start of the engine. An engine ignition timing detection apparatus characterized in that a protrusion at an advanced position is made to correspond to the sensor and used as a reference ignition position during normal operation of the engine.   The rotational drive body is a disc body provided on the camshaft of the engine, and the projection closer to the top dead center of the engine is made to correspond to the sensor to be an ignition position at the time of starting the engine. 2. The engine ignition timing detection device according to claim 1, further comprising means for calculating an ignition timing during normal operation based on the reference ignition position of the protrusion at the position and the sensor.   A rotary drive body provided with a projection at the time of starting the engine, a rotary drive body provided with a projection at an ignition timing during normal operation, and the sensor provided for each of the rotary drive bodies The engine ignition timing detection device according to claim 1.   A sensor fixed to a stationary member is made to correspond to a protrusion attached to a rotary drive body fixed to the crankshaft of the engine, and a sensor generates a sensing signal by the protrusion to detect the ignition timing of the engine. In the ignition timing detection device, the two protrusions are arranged in an angularly asymmetric manner in the circumferential direction of the rotary drive body, and the protrusion closer to the top dead center of the engine is made to correspond to the sensor, so that ignition at the time of engine start is performed. An ignition timing detection device for an engine, characterized in that a projection at a position advanced from the start position is made to correspond to the sensor to serve as a reference ignition position during normal operation of the engine.   A flywheel fixed to a crankshaft is used as the rotary drive body, and the rotary drive body is provided with a projection for setting an ignition position at the time of starting and a projection for setting a reference ignition position during normal operation of the engine. 5. The engine ignition timing detection device according to claim 4, wherein   In an engine having a generator that is directly coupled to a crankshaft, the rotor of the generator is the rotary drive body, and the rotary drive body has a projection for setting an ignition position at the start, and a reference for normal operation of the engine 5. The engine ignition timing detection device according to claim 4, further comprising an ignition position setting projection.

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