JP3582800B2 - Single cylinder 4 cycle engine - Google Patents

Description

[0001]
[Industrial applications]
The present invention relates to an internal combustion engine in which a four-stroke spark ignition type reciprocating internal combustion engine is constituted by a single cylinder (referred to as a single cylinder four-cycle engine in the present invention).
[0002]
[Prior art]
The spark ignition in the reciprocating internal combustion engine uses a spark discharge type, that is, a spark gap type spark plug in which a high voltage is applied to a spark gap to perform a spark discharge, that is, a spark gap type ignition plug is rotated by a piston which reciprocates in a cylinder at an ignition point. An electronic ignition control system in which electronic control is performed in association with the rotation angle of a crankshaft has been put to practical use.
[0003]
In such an electronic ignition control system, the configuration of a transistor-type electronic spark discharge circuit that obtains an ignition voltage by boosting an impulse generated by turning on / off a DC voltage by a transistor with a high turn ratio transformer ( The first prior art) is disclosed in "Mechanical Engineering Handbook", published by the Japan Society of Mechanical Engineers, May 1991, p. 104, FIG.
[0004]
Also, the configuration of a transistor type electronic spark discharge circuit that obtains an ignition voltage by boosting an impulse generated by switching a voltage charged in a capacitor by an SCR element with a transformer having a high winding ratio (hereinafter, referred to as a second prior art) 251 is disclosed in the same document, the same edition, page 105, FIG. 251 and its description.
[0005]
Further, the ignition timing of such spark ignition is determined by the opening degree of a valve (in the present invention, referred to as an intake throttle) for controlling the supply amount of a mixture gas of combustion and air in the intake stroke, the rotational speed of the crankshaft, that is, the unit. In order to electronically control the number of revolutions per hour (referred to as the number of revolutions in the present invention), that is, an appropriate time corresponding to the state of the engine speed or the like, at a point before the ignition point, From the obtained pulse signal, electronic advancing control for obtaining a target ignition time point by advancing by a digital operation such as counting a clock pulse by a predetermined amount, that is, a configuration for performing computer advancing control (hereinafter, referred to as computer advancing control) A third prior art) is disclosed in the same document, the same edition, page 106, FIG. 255, and its description.
[0006]
In the case of a single-cylinder four-cycle engine, generally, an electronic spark discharge circuit (referred to as a CDI circuit in the present invention) according to the first prior art or the second prior art is obtained for each rotation of the crankshaft. In order to simplify the configuration, the configuration is such that spark ignition is performed twice in four cycles (hereinafter, referred to as a fourth conventional technique).
[0007]
The two spark ignitions are performed in each cycle of the four cycles, that is, in the intake stroke → compression stroke → explosion stroke → exhaust stroke, at a point near the end point of the compression stroke and at a point near the end point of the exhaust stroke. The former is called "regular ignition" because it performs regular ignition, and the latter is called "discarded fire" because spark ignition does not serve the role of actual combustion ignition.
[0008]
In the configuration according to the fourth prior art, generally, a "flywheel" directly rotated by a crankshaft, that is, a pulse for generating a pulse signal every time a predetermined position on the outer periphery of the flywheel rotates. The pulse generator includes a flywheel provided with magnetism and a pulse generating coil, for example, an electromagnet coil, provided on a fixed side facing the magnetically conductive piece. Type, and a conductive element piece is provided in place of the above-described magnetic conductive material piece, and a Hall element detection type in which a Hall effect element is provided in place of the above-described pulse generating coil is used. A piece of magnetic conductive material or a piece of conductive material that performs such an operation is called a reluctor.
Specifically, such a pulse generator will be described by taking a pulse coil detection type as an example. As shown in FIG. 6, a reluctor 13 is attached to an outer peripheral portion of a flywheel 12 which is directly rotated by a crankshaft 11. In addition, a pulse generator 16 having a configuration in which a pulse generating coil 14 is arranged at a position facing the reluctor 13 and attached to an appropriate fixed member 15 is used.
[0009]
This reluctor 13 generally corresponds to the uppermost point of the crank, that is, a position point where the cylinder volume in the compression stroke and the exhaust stroke becomes minimum (referred to as a top dead center TDC in the present invention) as shown in FIG. For example, a position at a rotation angle of 30 ° in the rotation direction of the flywheel 12 is defined as a front edge position point A1, and a position at a rotation angle of 10 ° in the rotation direction is defined as a rear edge position from a position point TDC on the outer periphery of the flywheel 12 to be rotated. B1 having a size ranging from A1 to B1 is attached.
[0010]
Therefore, if the pulse signal P0 generated from the pulse generator 16 generates a positive pulse signal a1 at the position point A1 as shown in FIG. 7, for example, a negative pulse b1 is generated at the position point B1. I do. Then, based on both the pulse signal a1 obtained on the leading edge side and the pulse signal b1 obtained on the trailing edge side, an ignition pulse for causing the ignition plug to perform an ignition operation is obtained.
[0011]
Further, in the case of the pulse generator 16 in the computer advance angle control in the third prior art, the reluctor 13 is moved from the position point TDC corresponding to the top dead center to, for example, the flywheel 12 as shown in FIG. In the rotation direction, a position point at a rotation angle of 50 ° is set as a front edge position point A2, and a position point at a rotation angle of 10 ° as a rear edge position point B1 is attached. As described above, a positive pulse signal a2 is generated at the position point A2, and a negative pulse signal b1 is generated at the position point B1. Based on the pulse signal a2 obtained on the leading edge side, the advance angle By performing the calculation, for example, assuming that the target ignition time is 30 ° from TDC, the time passes a suitable angle of about 20 ° from the position point A2, that is, the vicinity of the position point A1 in FIG. Proper It is configured to obtain an ignition pulse to the point.
[0012]
In the configuration for calculating the advance angle as described above, a disk having many slits on the outer circumference and a disk having one slit on the outer circumference are rotated by a crankshaft, and these slits are detected by a photoelectric element. A pulse generator is used to obtain a pulse signal at a reference point of ignition by the former disk, and to obtain a clock pulse for calculating the advance angle by the latter disk (hereinafter referred to as a fifth conventional technique). For example, Japanese Patent Application Laid-Open No. 63-266170.
[0013]
Further, in such a configuration in which a reference point pulse signal and a clock pulse for one rotation of the rotating shaft are obtained, a gear having a large number of teeth on the outer periphery and a gear having one tooth on the outer periphery are rotated on the rotating shaft, and these tooth shapes are rotated. Of a pulse generator in which a pulse generating coil is arranged in opposition to the above, that is, a pulse generator using a tooth profile provided for each unit angle of rotation and a tooth profile provided at a predetermined rotation position as a reluctor (hereinafter referred to as a sixth prior art) Is disclosed by Japanese Patent Publication No. 40-28819.
[0014]
[Problems to be solved by the invention]
In the configuration according to the fourth prior art described above, "discarded fire" is wasteful ignition, and there is a disadvantage that the life of the spark plug is shortened by the wasteful ignition. To solve this disadvantage, it is necessary to use a plurality of cylinders. In the same manner as in the above case, it is possible to obtain the ignition time point of only “regular ignition” by the rotation angle of the rotation shaft that is configured to obtain half the rotation of the crankshaft.
[0015]
However, in order to obtain such a 1/2 rotation shaft, it is necessary to provide a reluctor and a pulsar on a cam shaft having a rotation ratio of 1/2 to the crankshaft, so that the mechanism of the camshaft portion becomes complicated and large. Therefore, in order to reduce the size of the entire engine, there are disadvantages, such as a structural disadvantage.
[0016]
For this reason, there is a problem that it is desired to provide a single-cylinder four-cycle engine with a simple structure that does not have such a disadvantage.
[0017]
[Means for Solving the Problems]
The present invention
A single-cylinder four-cycle engine for obtaining an ignition pulse for performing ignition based on a first pulse signal obtained at each one predetermined rotation position in rotation of a crankshaft,
Angular velocity signal means for converting the frequency of the second pulse signal obtained for each unit angle of the rotation into a voltage to obtain an angular velocity signal representing the angular velocity of the rotation in voltage;
[0018]
Based on the first pulse signal corresponding to the time when the angular velocity signal having the smaller voltage value among the angular velocity signals obtained at each time based on the first pulse signal is obtained. Ignition pulse means for obtaining the above ignition pulse
A first configuration that provides
[0019]
In addition to this first configuration,
When the rotation is equal to or less than a predetermined rotation speed, all ignition pulse means for obtaining the ignition pulse from all of the first pulse signals regardless of the angular velocity signal
A second configuration for providing
[0020]
Instead of all the ignition pulse means in the second configuration,
When the angular velocity signal is equal to or less than a predetermined value, all ignition pulse means for selecting all of the first pulse signals and obtaining the ignition pulse regardless of the angular velocity signal
A third configuration for providing
[0021]
A single-cylinder four-cycle engine that obtains an ignition pulse for performing ignition based on a first pulse signal obtained by a pulse generator formed by a reluctor disposed at one position on the outer peripheral side of a flywheel directly rotated by a crankshaft. And
Angular velocity signal means for converting a second pulse signal obtained by a pulse generator having a gear portion provided on the outer periphery of the flywheel as a reluctor into a frequency / voltage to obtain an angular velocity signal representing the angular velocity of the rotation by voltage; ,
[0022]
On the basis of the first pulse signal corresponding to the time when the angular velocity signal having the smaller voltage value among the angular velocity signals detected at the time of the first pulse signal is obtained. Ignition pulse means for obtaining the above ignition pulse;
A fourth configuration for providing
[0023]
In addition to this fourth configuration,
A rotation speed signal representing the rotation speed of the rotation is obtained based on the first pulse signal, and when the rotation speed signal is equal to or less than a predetermined value, the first rotation speed signal is obtained regardless of the detection. All ignition pulse means for selecting all of the pulse signals to obtain the above ignition pulse
A fifth configuration for providing
[0024]
Instead of all the ignition pulse means in the fifth configuration,
When the detected angular velocity signal is equal to or less than a predetermined value, all ignition pulse means for selecting all of the first pulse signals to obtain the ignition pulse regardless of the selection.
The above-mentioned problem can be solved by the sixth configuration in which is provided.
[0025]
[Action]
Every rotation of the crankshaft, that is, the rotation of the engine, is accelerated during the explosion stroke and decelerated during the compression stroke, so that the angular velocity is large during the latter half of the explosion stroke until the end of the supply stroke, and during the compression stroke, As the angular velocity decreases, the angular velocity at the time of “discarding fire” is high, and the angular velocity at the time of “regular ignition” is low.
[0026]
Accordingly, if the second pulse signal obtained for each unit angle is frequency / converted into an angular velocity signal representing the angular velocity as a voltage, the voltage becomes small at the time when the angular velocity is small, and the first pulse corresponding to that time is reduced. By selecting a signal, that is, a pulse signal for ignition, and obtaining an ignition pulse, it is possible to obtain only an ignition pulse corresponding to the “regular ignition” point.
[0027]
The detection of the angular velocity and the selection of the pulse signal for ignition are performed by an electronic circuit configuration, for example, converting the repetition frequency of the pulse signal generated by a pulse generator using a gear portion provided on the outer periphery of the flywheel as a reluctor into a voltage. Frequency / voltage conversion circuit and comparison circuit, etc., so there is no mechanical consumable part, the degree of failure is small, and the occupying position for mounting is only required outside the engine, simplifying the device Act to be able to.
[0028]
Further, when the rotation of the crankshaft is equal to or less than a predetermined rotation speed or a predetermined angular velocity, regardless of the selection of the pulse signal, all of the ignition pulse signals, both the “regular ignition” and the “discard ignition” If the difference in angular velocity values is likely to be unclear when the rotation is unstable immediately after the start of operation of the engine, etc., select the "regular ignition". Acts so as not to stop the operation of the engine by mistake.
[0029]
【Example】
An embodiment will be described below with reference to FIGS. In FIGS. 1 to 5, portions denoted by the same reference numerals as those in FIGS. 6 to 9 are portions having the same functions as the portions denoted by the same reference numerals described with reference to FIGS. 6 to 9.
[0030]
[First embodiment]
First, a first embodiment will be described with reference to FIGS. In the first embodiment, signals of respective parts as shown in FIG. 4 are obtained by the pulse generators 16A and 16B of FIG. 1 and the circuit configuration of FIG. Then, a pulse signal corresponding to “regular ignition” and “disposal ignition” is obtained by a pulse signal obtained by the pulse generator 16A, and an angular velocity of the crankshaft 11 is obtained by a pulse signal obtained by the pulse generator 16B. Utilizing the fact that the angular velocity is different between the compression stroke side and the intake stroke side, the ignition pulse corresponding to the "regular ignition" time is obtained by determining the "regular ignition" time. Things.
[0031]
In FIG. 1, a gear portion 12A provided on the outer periphery of a flywheel 12 is engaged with a starting motor, that is, a gear 19 provided on a rotating shaft 18A of a starter motor 18 to start the engine, thereby rotating the crankshaft 11. It is for doing.
[0032]
The pulse generating coil 14B is disposed at a position facing the gear portion 12A and is attached to the fixed member 15. The pulse generating coil 14B and the gear portion 12A respectively form one tooth profile of the gear portion 12A. A second pulse generator 16B for generating a pulse signal PB is configured as a reluctor.
[0033]
As shown in FIG. 2, the pulse signal PB is generated for each tooth shape of the gear portion 12A, that is, for each unit angle, for example, when the number of teeth is 300, 1.2 ° is used as a unit angle and 1.2 ° is used. The pulse signal a3 has a positive polarity pulse signal a3 and a negative polarity pulse signal b3. The repetition frequency of the pulse signals a3 and b3 changes in proportion to the rotation speed of the crankshaft 11.
[0034]
The retractor 13 has a position point A1 on the leading edge side and a position point B1 on the trailing edge side which are the same as the reluctor 13 in FIG. In this embodiment, the pulse signals a1 and b1 are obtained for each predetermined rotation position, but the reluctor 13 is projected toward the center of the flywheel 12 in order to avoid interference with the pulse generator 16A.
[0035]
The second pulse generator 16B is constituted by the reluctor 13 and the pulse generating coil 14B arranged to face the reluctor 13, and generates a pulse signal Pb. The pulse signal PA is a signal having a pulse signal a1 of a positive polarity by the leading edge of the reluctor 13 and a pulse signal b1 by a trailing edge of the reluctor 13 alternately.
[0036]
3, a pulse generator 16A supplies a pulse signal PA to a polarity discrimination circuit 21. The polarity discriminating circuit 21 is a circuit that discriminates between the pulse signal a1 and the pulse signal b1 in the pulse signal PA. For example, a positive level voltage and the pulse signal a1 are supplied to an AND gate to detect only the pulse signal a1. The obtained pulse signal a1 is given to the alternate selection circuit 22, the low rotation speed detection circuit 30, and the selection switching circuit 31.
[0037]
The alternating selection circuit 22 is a circuit that obtains two pulse signals a11 and a12 that are alternately sorted for each of the next-order pulse signals a1, starting from the first applied pulse signal a1, and includes, for example, a flip-flop circuit. A signal obtained by selecting every other pulse signal a1 from the first pulse signal a1 is given to the first detection circuit 24 and the ignition selection circuit 27 as the first pulse signal a11 by the combination of A signal obtained by selecting every other pulse signal a1 from the pulse signal a1 next to the pulse signal a1 is given to the second detection circuit 25, the comparison selection circuit 26, and the ignition selection circuit 27 as the second pulse signal a12.
[0038]
On the other hand, the pulse signal PB of the pulse generator 16B is given to the angular velocity circuit 23. The angular velocity circuit 23 is a circuit that obtains a signal representing the angular velocity of the crankshaft 11, that is, the value θ / t of the rotation angle θ per unit time t, based on the pulse signal PB, for example, a frequency / voltage conversion circuit, The F / V conversion circuit supplies a signal having a voltage waveform as an angular velocity signal d1 to the first detection circuit 24 and the second detection circuit 25 in proportion to the repetition frequency of the pulse signals a3 and b3 of the pulse signal PB.
In other words, the angular velocity circuit 23 converts the pulse signal PB into a frequency / voltage to obtain an angular velocity signal d1 representing the angular velocity in voltage.
In the case of the frequency / voltage conversion, as can be easily understood from the pulse signal PB and the angular velocity signal f1 in FIG. 4, the voltage increases in proportion to the repetition frequency of the pulse signals a3 and b3 of the pulse signal PB. Therefore, if the rotation speed of the engine increases, the rotation of the crank 11 increases, and the repetition frequency of the pulse signals a3 and b3 increases, the voltage of the angular velocity signal d1 naturally increases.
[0039]
The first detection circuit 24 is a circuit that detects an angular velocity value corresponding to the time point of the first pulse signal a11. For example, the first detection circuit 24 is a sample and hold circuit that samples the voltage of the angular velocity signal d1 for each first pulse signal a11. A signal obtained by holding the voltage obtained until the next sampling point is given to the comparison detection circuit 26 as the first angular velocity signal e1. Here, the first pulse signal a11 and the first angular velocity signal e1 are signals that detect the point in time when the angular velocity signal d1 having the smaller voltage value of the angular velocity signals d1 is obtained as shown in FIG. ing.
[0040]
The second detection circuit 25 is a circuit that detects an angular velocity value corresponding to the time point of the second pulse signal a12. For example, the second detection circuit 25 is a sample and hold circuit that samples the voltage of the angular velocity signal d1 for each second pulse signal a12. A signal obtained by holding the obtained voltage until the next sampling point is provided to the comparison detection circuit 26 as the second angular velocity signal e2.
[0041]
The comparison detection circuit 26 is a circuit that obtains a signal corresponding to the smaller one of the two detected angular velocity values. For example, the comparison detection circuit 26 is a circuit that obtains signals that are compared and detected by a combination of two operational amplifier circuits, A positive level output obtained by comparing the second angular velocity signal e2 with the first angular velocity signal e1 as a reference signal is defined as a first comparison signal f1, and the first angular velocity signal e1 is compared with the second angular velocity signal e2 as a reference signal. The positive level output obtained as described above is obtained as a second comparison signal f2, and the first comparison signal f1 and the second comparison signal f2 are sampled by the pulse signal a12, and the first count is performed each time the first comparison signal f1 is present. A signal g1 (not shown) is output to the first counter, and a second count signal g2 (not shown) is output every time the second comparison signal f2 is received. Give to the counter. In order to prevent the sampling time of the pulse signal a12 in this circuit from being applied to the transient portion of the second angular velocity signal due to the sampling time in the second detection circuit 25, the pulse signal a12 is changed for a short time Td. For example, it is delayed by about one millisecond by a one-shot multivibrator or the like.
[0042]
When the first counter and the second counter count a predetermined number N, for example, 30, a positive level signal is sent to the ignition selection circuit 27 as a first selection signal h1 and a second selection signal h2, respectively. When one of the first counter and the second counter counts the predetermined number N, counting of both the first counter and the second counter is stopped. Further, the counting is reset when the apparatus is started or when a reset signal described later is given.
[0043]
Here, as the angular velocity signal d1, for example, when the engine speed is about 2000 rpm, a voltage representing an angular velocity value corresponding to about 500 rpm is obtained at TDC at the end of the compression stroke, as shown in FIG. At the time of TDC at the end of the exhaust stroke, a voltage representing an angular velocity corresponding to about 2000 rpm is obtained, so that the smaller one of the angular velocities can be detected without performing the counting of 30 by the first counter and the second counter. Although the first selection signal h1 and the second selection signal h2 may be output based on the first comparison signal f1 or the second comparison signal f2, the engine rotation may be unstable at the initial stage of the engine startup. , A function of majority selection based on 30 counts by the first counter and the second counter.
[0044]
The ignition selection circuit 27 selects either the first pulse signal a11 or the second pulse signal a12 as a pulse signal for “regular ignition” based on the first selection signal h1 and the second selection signal h2. For example, the output of an AND gate that ANDs the first selection signal h1 and the first pulse signal a11 and the output of the AND gate that ANDs the second selection signal h2 and the second pulse signal a12 are given to an OR gate. The obtained signal is supplied to CDI circuit 28 as selection pulse signal i1 via selection switching circuit 31.
[0045]
Also, when neither the first selection signal h1 nor the second selection signal h2 is supplied, that is, one of the first counter and the second counter of the comparison detection circuit 26 reaches N counts. If not, both the first pulse signal a11 and the second pulse signal a12 are supplied to the CDI circuit 28.
[0046]
Therefore, the pulse signal a1 corresponding to the smaller time point of the angular velocity value, that is, the pulse signal a11 corresponding to the pulse signal a1 at the end of the compression stroke is selected and selected as the selected pulse signal i1, and the CDI circuit 28 Is what you will give.
[0047]
The CDI circuit 28 is a circuit for giving an ignition pulse to the ignition plug described in the section of the prior art, and supplies an ignition pulse j1 to the ignition plug 29 by driving a semiconductor element by a selection pulse signal i1. is there.
[0048]
When the first pulse signal a1 is shifted by one and the second pulse signal in FIG. 4 becomes the first pulse signal a11, the operations of the above circuits are reversed, but as a result, The pulse signal a11 corresponding to the pulse point a1 at the smaller time point of the angular velocity value, that is, the pulse signal a1 at the end of the compression stroke, is selected and selected as the selection pulse signal i1 and supplied to the CDI circuit 28.
[0049]
The low rotation speed detection circuit 30 obtains a signal that detects that the rotation speed of the engine, that is, the rotation speed of the crankshaft 11 is equal to or lower than a predetermined rotation speed, and is obtained, for example, by an internal clock circuit. A digital signal rotation speed signal k1 obtained by counting a pulse signal a1 given for a unit time, for example, 1 second, by a counter is converted into a digital signal reference signal k2 (e.g., 200 rpm) corresponding to a predetermined rotation speed. ) To detect that the rotation speed is equal to or less than the predetermined rotation speed. For example, when the value of the rotation speed signal k1 is subtracted from the value of the reference signal k2 by a subtraction circuit and there is a remaining value, The level signal is supplied to the ignition selection circuit 30 as the low rotation signal m1, and the low rotation signal m1 is reset by the first counter and the second counter of the comparison detection circuit 26. Reset signal for it gives the comparison detection circuit 26.
[0050]
The selection switching circuit 31 is, for example, a combination circuit of an AND gate and an OR gate. When the low rotation signal m1 is not supplied, the selection switching circuit 31 supplies the selection pulse signal i1 from the ignition selection circuit 27 to the CDI circuit 28, Although the rotation signal m1 is provided, the switching operation is performed so that the pulse signals based on all the pulse signals a1 are supplied to the CDI circuit 28 irrespective of the selection pulse signal i1, and "regular ignition" and "discard ignition" are performed. To the ignition plug 23.
[0051]
The low rotation speed detection circuit 30 and the selection switching circuit 31 are not necessary if the rotation operation of the engine does not have the possibility of becoming unstable at low speed rotation, but the rotation operation becomes unstable at low speed rotation. In such a case, the detection of the comparison of the angular velocity values becomes unstable at the time of this unstable rotation, making the determination between “regular ignition” and “discard ignition” unstable, and operating the engine. It functions to prevent stopping.
[0052]
In the configuration of the above-described first embodiment, the components not interposing the low rotation speed detection circuit 30 and the selection switching circuit 31 are summarized as follows.
In a single-cylinder four-cycle engine that obtains an ignition pulse j1 for performing ignition based on one predetermined rotation position in rotation of the crankshaft 11, for example, a first pulse signal a1 obtained at each position point A1,
[0053]
The second pulse signal PB obtained at each unit angle of rotation of the crankshaft, for example, at every 1.2 °, is subjected to frequency / voltage conversion to convert the second pulse signal PB to the rotation of the crankshaft 11. Angular velocity signal means for obtaining an angular velocity signal representing the angular velocity θ / t of rotation by voltage, for example, a signal d1 obtained by F / V conversion of a pulse signal PB;
[0054]
For each time point based on the first pulse signal a1, for example, when the angular velocity signal d1 having a small angular velocity value is obtained among the angular velocity signals e1 and e2 obtained at each time point of the pulse signal a1, That is, as shown in FIG. 4, the first pulse signal a1 corresponding to the time point positioned at the angular velocity signal d1 having the smaller voltage value of the angular velocity signal d1, for example, the time point at the end side of the compression stroke. Ignition pulse means for obtaining the above-mentioned ignition pulse j1 based on
A first configuration that provides
[0055]
An ignition pulse j1 for performing ignition based on a first pulse signal a1 obtained by a pulse generator 16A of a reluctor 13 arranged at one position on the outer peripheral side of a flywheel 12 directly rotated by a crankshaft 11 is generated. In the obtained single-cylinder 4-cycle engine,
[0056]
The second pulse signal PB obtained by the pulse generator 16B having the gear portion 12A provided on the outer periphery of the flywheel 12 as a reluctor is subjected to frequency / voltage conversion, and the angular velocity θ / t of the rotation is represented by a voltage. Angular velocity signal means for obtaining a signal d1,
[0057]
For each time point of the first pulse signal a1, for example, the angle of the smaller one of the angular velocity signals d1 detected by the first detection circuit 24, the second detection circuit 25, and the comparison detection circuit 16 At the time when the velocity signal d1, that is, as shown in FIG. 4, the angular velocity signal d1 having the smaller voltage value is obtained, for example, the first pulse signal a1 corresponding to the end point of the compression stroke. Ignition pulse means for obtaining the above-mentioned ignition pulse j1 based on
And the fourth configuration in which is provided.
[0058]
In addition, when the entire first embodiment, that is, the configuration including the low rotation speed detection circuit 30 and the selection switching circuit 31 is summarized,
In addition to the above first configuration,
When the rotation, that is, the rotation of the crankshaft 11 is equal to or less than a predetermined rotation speed, for example, 200 rpm or less, regardless of the angular velocity signal, that is, the angular velocity circuit 23, the first detection circuit 24, and the second detection circuit. 25. All ignition pulse means for obtaining the above-mentioned ignition pulse j1 by the above-mentioned first pulse signal a1 irrespective of the angular velocity signal in the comparison detection circuit 26, for example, by the selection switching circuit 31
A second configuration for providing
[0059]
In addition to the above fourth configuration,
Based on the first pulse signal a1, the rotation, that is, a rotation speed signal representing the rotation speed of the crankshaft 11 is obtained, and the rotation speed signal is equal to or less than a predetermined value, for example, equal to or less than a value corresponding to 200 rpm. In this case, for example, by supplying the low rotation signal m1 to the selection switching circuit 31, all of the first pulse signal a1 is irrespective of the above-mentioned detection, that is, irrespective of the detection by the comparison circuit 26. All ignition pulse means for selecting and obtaining the above ignition pulse j1
And the fifth configuration in which is provided.
[0060]
[Second embodiment]
Next, a second embodiment will be described with reference to FIG. In FIG. 5, portions indicated by the same reference numerals as those in FIGS. 1 to 4 are portions having the same functions as the portions denoted by the same reference numerals described with reference to FIGS.
[0061]
In the second embodiment, a low angular velocity detection circuit 35 for detecting that the angular velocity value is equal to or less than a predetermined value is provided in place of the low rotational speed detection circuit 30 in the first embodiment.
[0062]
In FIG. 5, a first detection circuit 24 and a second detection circuit 25 supply a first angular velocity signal e1 and a second angular velocity signal e2 to a low speed detection circuit 35. The low angular velocity detection circuit 35 detects that both the first angular velocity signal e1 and the second angular velocity signal e2 are equal to or less than a predetermined value and obtains a low angular velocity signal n1, and for example, two operational amplifications A first operational amplifier circuit compares the first angular velocity signal e1 with a predetermined reference level, and a second operational amplifier circuit combines the second angular velocity signal e2. And a reference level signal as a predetermined value, so that a positive level output is obtained when the first angular velocity signal e1 and the second angular velocity signal e2 each have a reference level below, and these outputs are In each case, when the signal is at the positive level, a signal of the positive level is supplied from the AND gate to the selection switching circuit 31 as the low angular velocity signal n1.
[0063]
By performing the operation based on the low rotation signal m1 in the first embodiment with the low angular velocity signal n1, the pulse signals based on all the pulse signals a1 are given to the CDI circuit 28, so that "regular ignition" and " The ignition pulse j1 for both the "discarded fire" is given to the ignition plug 23.
[0064]
Therefore, the low angular velocity detection circuit 35 and the selection switching circuit 31 provide the angular velocity value equal to or less than the predetermined value when the rotational operation of the engine is at low speed. The function of preventing the comparison and detection of the angular velocity values from becoming unstable and making the discrimination between “regular ignition” and “discarding fire” unstable and stopping the operation of the engine is prevented.
[0065]
To summarize the configuration of the second embodiment,
Instead of the all ignition pulse means in the second configuration,
When the angular velocity signal d1 is equal to or less than a predetermined value, for example, when both the first angular velocity signal e1 and the second angular velocity signal e2 are equal to or less than the predetermined value and the low angular velocity signal n1 is obtained from the low angular velocity detection circuit 35. Irrespective of the angular velocity signal, that is, irrespective of the angular velocity signals in the angular velocity circuit 23, the first detection circuit 24, the second detection circuit 25, and the comparison detection circuit 26, for example, by the selection switching circuit 31, All ignition pulse means for obtaining the above-mentioned ignition pulse j1 by all of the first pulse signals a1
A third configuration for providing
[0066]
Instead of the all ignition pulse means in the fourth configuration,
If the detected angular velocity signal, for example, both the first angular velocity signal e1 and the second angular velocity signal e2 are equal to or less than a predetermined value and the low angular velocity signal n1 is obtained from the low angular velocity detection circuit 35, the above selection is performed. That is, regardless of the selection operation of the ignition selection circuit 27, for example, the switching selection circuit 31 selects all of the first pulse signals a1 to obtain the above-described ignition pulse j1.
And the sixth configuration in which is provided.
[0067]
(Deformation implementation)
The present invention includes the following modifications.
(1) The pulse signal b1 is applied instead of the pulse signal a1 applied to the rotation speed detection circuit 30.
[0068]
(2) The reluctor 13 is changed to the one for advancing operation shown in FIG. 8 to change the pulse signal a1 to the pulse signal a2 and the pulse signal b1 to the pulse signal b2, and the dotted line is shown in FIG. As described above, the pulse signal a2 is advanced at a position before the alternating selection circuit 22 to obtain a pulse signal representing an ignition time point instead of the pulse signal a1.
[0069]
(3) In the configuration of the above (2), the same operation is performed without using the polarity discrimination 21 by using only one side pulse, for example, the pulse of the positive polarity.
[0070]
(4) The pulse generator is of a Hall element detection type. In this case, since the signal obtained from the Hall effect element is often obtained as a rectangular wave signal extending from the leading edge side to the trailing edge side of the reluctor 13, in the case of such a square wave signal, the square wave signal is converted into a differentiating circuit. To obtain a leading edge pulse signal and a trailing edge pulse signal.
[0071]
(5) The regenerator of the pulse generator 16 </ b> B does not use the gear portion for the self-motor of the flywheel 12, but uses a gear having the same gear or a slit disk having slits with similar intervals attached to the crankshaft 11. Configure.
[0072]
(6) The fact that the rotation of the crankshaft 11, that is, the rotation of the engine is in an unstable state, is determined, for example, by the detection value of each time obtained by a circuit similar to the low rotation speed detection circuit 31 or the low angular velocity detection circuit 35. By providing a signal detected by a circuit for detecting a vertical fluctuation range or the like to the selection switching circuit 31, the comparison detection circuit 26 is provided with a discrimination by the N counter between the first counter and the second counter. Instead, a signal obtained each time the angular velocity values are compared is provided to the ignition selection circuit 27.
[0073]
(7) The control processing configuration in the first embodiment and the second embodiment is not limited to a discrete circuit configuration, but is configured by a control processing configuration using a microcomputer by converting each signal into a digital value signal.
[0074]
(8) The configuration of the angular velocity circuit 22 is made by a suitable clock circuit to create a very short repetition time Δt, for example, a time for repeating the update every 1/100 sec, and update the count every this repetition time Δt. A digital counter circuit configuration for obtaining an angular velocity value by the number of pulse signals a3 or b3 per unit time Δt based on a count value obtained by repeatedly counting the pulse signals a3 or b3 of the pulse signal PB by The first detection circuit 24, the second detection circuit 25, and the comparison detection circuit 26 are configured by changing to a circuit configuration using digital values.
[0075]
(9) In the configuration of (8), the number of the counters described above is n, and count values obtained by shifting the start point of each counter by Δt / n by Δt / n are sequentially output. Thus, by sequentially outputting angular velocity values measured at finer time intervals, the angular velocity values measured at finer time intervals are obtained.
[0076]
【The invention's effect】
As described above, the present invention performs frequency / voltage conversion of pulse signals at fine time intervals obtained by a pulse generator using a gear portion or the like on the outer periphery of a flywheel directly rotated by a crankshaft, A change in the angular velocity of the crankshaft is obtained by a change in the voltage, and the voltage representing this angular velocity differs between the "regular ignition" point and the "discard" point, and the voltage representing the angular velocity decreases at the "regular ignition" point By taking advantage of this fact, the pulse signal corresponding to the “regular ignition” point is selected, so that the purpose can be achieved only with an electronic configuration.
Also, since the change in angular velocity is obtained by the change in frequency / voltage converted voltage, even if the rotation speed is increased and the frequency is increased, only the voltage is increased as a whole, and the detection of the “regular ignition” point In addition, as described above, the purpose can be achieved only with the electronic configuration, so there is no mechanical consumable part, and the occupation position of the installation can be done only outside the engine, so that the device can be simplified. It has the advantage that it can be provided with less failure.
[0077]
Further, in the configuration using the gear portion on the outer periphery of the flywheel, the gear itself for the self-motor can be used as it is, so that the mechanical configuration can be simplified, and since there is no mechanical consumable portion, the degree of failure occurrence is small. In addition, since the occupied position for mounting is only required outside the engine, there is a feature that the apparatus can be simplified.
[0078]
Furthermore, when the rotation of the crankshaft, that is, the rotation of the engine is equal to or less than a predetermined rotation speed or equal to or less than a predetermined angular velocity value, an ignition pulse is obtained by a pulse signal of both “regular ignition” and “discard ignition”. Therefore, when the rotation is unstable immediately after the start of the operation of the engine or the like, it is possible to provide a system that does not erroneously select the “regular ignition” and stop the operation of the engine.
[Brief description of the drawings]
In the drawings, FIGS. 1 to 5 show an embodiment of the present invention, and FIGS. 6 to 9 show a prior art, and the contents of each drawing are as follows.
FIG. 1 is a front view and a side sectional view of a main part configuration.
FIG. 2 is a main part signal waveform diagram.
FIG. 3 is a block diagram of a main part.
FIG. 4 is a main part signal waveform diagram.
FIG. 5 is a block diagram of a main part.
FIG. 6 is a front view and a side sectional view of a main part configuration.
FIG. 7 is a main part signal waveform diagram.
FIG. 8 is a front view and a side sectional view of a main part configuration.
FIG. 9 is a main part signal waveform diagram.
[Explanation of symbols]
11 Crankshaft
12 Flywheel 12
12A gear part
13 Retractor
14 Pulse generating coil
14B Pulse generating coil
15 Fixed side member
16 pulse generator
16A pulse generator
16B pulse generator
18 cell motor
18A Rotary shaft
19 gears
21 Polarity discrimination circuit
22 Alternate sorting circuit
23 angular velocity circuit
24 First Detection Circuit
25 Second detection circuit
26 Comparison selection circuit
27 Ignition selection circuit
28 CDI circuit
29 Spark plug
30 Low speed detection circuit
31 Selection switching circuit
35 Low angular velocity detection circuit
A1 Position point
A2 Position point
B1 Position point
B3 Position point
P0 pulse signal
P0 'pulse signal
PA pulse signal
PB pulse signal
a1 pulse signal
a2 pulse signal
a3 pulse signal
a11 1st pulse signal
a12 2nd pulse signal
b1 pulse signal
b3 pulse signal
d1 Angular velocity signal
e1 First angular velocity signal
e2 Second angular velocity signal
f1 First comparison signal
f2 Second comparison signal
i1 selection pulse signal
j1 ignition pulse
m1 Low rotation signal
n1 Low angular velocity signal

Claims (6)

A single-cylinder four-cycle engine for obtaining an ignition pulse for performing ignition based on a first pulse signal obtained at each one predetermined rotation position in rotation of a crankshaft,
Angular velocity signal means for frequency / voltage converting a second pulse signal obtained for each unit angle of rotation to obtain an angular velocity signal representing the angular velocity of rotation in voltage;
The ignition pulse is generated based on the first pulse signal corresponding to the time when the angular velocity signal having the smaller voltage value of the angular velocity signals obtained at each time based on the first pulse signal is obtained. A single-cylinder four-stroke engine comprising: A single-cylinder four-cycle engine for obtaining an ignition pulse for performing ignition based on a first pulse signal obtained at each one predetermined rotation position in rotation of a crankshaft,
Angular velocity signal means for frequency / voltage converting a second pulse signal obtained for each unit angle of rotation to obtain an angular velocity signal representing the angular velocity of rotation in voltage;
The ignition pulse is generated based on the first pulse signal corresponding to the time when the angular velocity signal having the smaller voltage value of the angular velocity signals obtained at each time based on the first pulse signal is obtained. Ignition pulse means for obtaining
A single-cylinder four-cycle engine, comprising: all ignition pulse means for obtaining the ignition pulse by using all of the first pulse signals irrespective of the angular velocity signal when the rotation is equal to or lower than a predetermined rotation speed. . A single-cylinder four-cycle engine for obtaining an ignition pulse for performing ignition based on a first pulse signal obtained at each one predetermined rotation position in rotation of a crankshaft,
Angular velocity signal means for frequency / voltage converting a second pulse signal obtained for each unit angle of rotation to obtain an angular velocity signal representing the angular velocity of rotation in voltage;
The ignition pulse is generated based on the first pulse signal corresponding to the time when the angular velocity signal having the smaller voltage value of the angular velocity signals obtained at each time based on the first pulse signal is obtained. Ignition pulse means for obtaining
A single-cylinder unit that selects all of the first pulse signals and obtains the ignition pulse regardless of the angular velocity signal when the angular velocity signal is equal to or less than a predetermined value. 4 cycle engine. A single-cylinder four-cycle engine that obtains an ignition pulse for performing ignition based on a first pulse signal obtained by a pulse generator formed by a reluctor disposed at one position on the outer peripheral side of a flywheel directly rotated by a crankshaft. And
Angular velocity signal means for converting the frequency of a second pulse signal obtained by a pulse generator having a gear portion provided on the outer periphery of the flywheel as a reluctor into a voltage to obtain an angular velocity signal representing the angular velocity value of the rotation in voltage;
The ignition pulse is generated based on the first pulse signal corresponding to the time point at which the angular velocity signal having the smaller voltage value of the angular velocity signals detected at each time point of the first pulse signal is obtained. A single-cylinder four-stroke engine comprising: A single-cylinder four-cycle engine that obtains an ignition pulse for performing ignition based on a first pulse signal obtained by a pulse generator formed by a reluctor disposed at one position on the outer peripheral side of a flywheel directly rotated by a crankshaft. And
Angular velocity signal means for converting the frequency of a second pulse signal obtained by a pulse generator having a gear portion provided on the outer periphery of the flywheel as a reluctor into a voltage to obtain an angular velocity signal representing the angular velocity value of the rotation in voltage;
The ignition pulse is generated based on the first pulse signal corresponding to the time point at which the angular velocity signal having the smaller voltage value of the angular velocity signals detected at each time point of the first pulse signal is obtained. Ignition pulse means for obtaining;
A rotation speed signal representing the rotation speed of the rotation is obtained based on the first pulse signal, and when the rotation speed signal is equal to or less than a predetermined rotation speed, all of the first pulse signals are output regardless of the detection. A single-cylinder four-stroke engine, comprising: A single-cylinder four-cycle engine that obtains an ignition pulse for performing ignition based on a first pulse signal obtained by a pulse generator formed by a reluctor disposed at one position on the outer peripheral side of a flywheel directly rotated by a crankshaft. And
Angular velocity signal means for converting the frequency of a second pulse signal obtained by a pulse generator having a gear portion provided on the outer periphery of the flywheel as a reluctor into a voltage to obtain an angular velocity signal representing the angular velocity value of the rotation in voltage;
The ignition pulse is generated based on the first pulse signal corresponding to the time point at which the angular velocity signal having the smaller voltage value of the angular velocity signals detected at each time point of the first pulse signal is obtained. Ignition pulse means for obtaining;
When the detected angular velocity signal is equal to or less than a predetermined value, all ignition pulse means for selecting all of the first pulse signals and obtaining the ignition pulse, regardless of the selection, is provided. Single cylinder 4 cycle engine.

Images