JP2005030344A - Signal generator for internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a signal generator for an internal combustion engine, accurately obtaining the rotational information including the information on the rotating direction of an engine even at a very low speed of the internal combustion engine. <P>SOLUTION: This signal generator 1 for an internal combustion engine is composed of: a rotor 3 provided with two reluctors R1, R2, fitted with a ring gear 302, and rotated synchronously with the engine; a first signal generator SG1 for detecting the edges of the reluctors R1, R2 to generate an edge detection pulse; and a second signal generator SG2 for detecting the tooth part of the ring gear 302 to generate a crank angle detection pulse. The pole arc angles of the reluctors R1, R2 and the position relationship between both reluctors are set to obtain the information on the rotating direction of the engine and the cylinder discrimination information from the number of crank angle detection pulses generated by the signal generator SG2 while the signal generator SG1 sequentially generates pulses. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a signal generator for an internal combustion engine that generates a signal including cylinder discrimination information and rotation direction information of the internal combustion engine.

  2. Description of the Related Art A two-cycle internal combustion engine is often used as a drive source in vehicles such as scooters, snowmobiles, and buggies that emphasize simplicity. Further, in this type of vehicle, a centrifugal clutch type continuously variable transmission that does not have a reverse gear is often used as a transmission provided between the crankshaft of an engine and a drive wheel. However, even in a vehicle using a simple transmission of this type, it is desirable to retreat with the help of the engine when the vehicle body is heavy or when a snowmobile that has plunged into snow is retreated. .

  Therefore, when a two-cycle internal combustion engine is used as a drive source, the direction of rotation of the engine is reversed in accordance with a driver's command using the characteristic of the two-cycle internal combustion engine that can be rotated in both forward and reverse directions. It is considered that the engine can be operated both in the normal rotation state and in the reverse rotation state.

  As a method of reversing the rotational direction of the two-cycle internal combustion engine, the engine rotational speed is set to the idling speed by a method such as fuel cut, engine misfire, or ignition timing retardation when a reversal command is given by the driver. After the engine speed is reduced to less than the set rotational speed, the ignition timing is over-advanced to reverse the rotation direction of the engine, and after confirming that the rotation direction of the engine is reversed, the engine ignition timing is rotated. There is known a method of shifting to a time suitable for maintaining the operation of the engine with the direction reversed.

  In order to reverse the rotation direction of the internal combustion engine by such a method and operate the engine in the normal rotation state and the reverse rotation state, it is essential to obtain information on the rotation direction of the engine.

  In addition, in an internal combustion engine mounted on a vehicle or the like using a transmission equipped with a reverse gear, it is sometimes necessary to obtain information on the rotational direction of the engine in order to prevent reverse rotation of the engine.

  Further, when the ignition timing of the internal combustion engine is controlled by the microprocessor, a predetermined crank angle position (crankshaft rotation angle position) of the engine is set as the reference crank angle position, and the crank angle position is set to the reference crank angle. The ignition timing is calculated based on the timing coincident with the position, and when the crank angle position coincides with the set reference crank angle position, measurement of the calculated ignition timing is started. Therefore, in this case, it is necessary to be able to detect that the crank angle position matches the reference crank angle position, and for this purpose, it is necessary to be able to detect the reference crank angle position.

  Further, when the engine is extremely low in speed, the rotational speed of the crankshaft varies finely due to changes in the engine stroke, making it difficult to accurately measure the ignition timing calculated by the microprocessor. For this reason, it is preferable that ignition is performed at a predetermined constant ignition timing instead of ignition at the ignition timing calculated by the microprocessor at an extremely low engine speed. As described above, when ignition is performed at a constant ignition timing when the engine is extremely slow (when the crank angle position coincides with the constant ignition position), the crank angle position is set to the ignition timing when the engine is extremely slow. It is necessary to be able to detect that it matches the corresponding position.

  When the ignition timing is controlled by the microprocessor, the rotation speed of the engine is detected by measuring the time required for the crankshaft to rotate at a certain angle with a timer. In order to detect the rotational speed by such a method, it is necessary to be able to detect a specific crank angle position that causes a timer to measure time.

  To obtain various rotation information such as information on the rotation direction of the internal combustion engine, information on the reference crank angle position of the crankshaft, information on the crank angle position corresponding to the ignition timing at engine start and extremely low speed, and rotation speed information As a signal generator used in the above, when an inductor-type rotor provided with a reluctator and provided to rotate synchronously with the engine, and an edge on the front end side and a rear end side in the rotation direction of the reluctator of the rotor are respectively detected A signal generator including a signal generator for generating a front edge detection pulse and a rear edge detection pulse having different polarities, and a waveform shaping circuit for converting an output pulse of the signal generator into a waveform that can be recognized by a CPU. Many are used.

As a method for obtaining information on the rotational direction of the engine using such a signal generator, a method disclosed in Patent Document 1 is known. In this prior art, two signal generators are arranged at a predetermined interval around an inductor-shaped rotor having two relaxors, and one of the signal generators is connected to the rear end of one of the relaxors of the rotor. The time from when the side edge is detected and the trailing edge detection pulse is generated until the other signal generator detects the leading edge of the one reluctator and generating the leading edge detection pulse, and the other signal After the generator detects the trailing edge of the other reluctator and generates a trailing edge detection pulse, until one signal generator detects the leading edge of one of the relaxors and generates a leading edge detection pulse By utilizing the fact that the long-short relationship between the time and the difference between the normal rotation and the reverse rotation of the engine is different, it is possible to obtain information on whether the engine is rotating forward or reverse.
US Pat. No. 5,794,574 and drawings

  When the rotational speed of the crankshaft of the engine is almost constant, the rotational direction of the engine can be reliably determined by comparing the generation intervals of specific pulses as in the method described in the above-mentioned US patent. Can do. However, when the engine is at a very low speed, the rotational speed of the crankshaft fluctuates finely during one rotation of the crankshaft due to a change in the stroke of the engine.

  Further, the internal combustion engine is a multi-cylinder internal combustion engine having two or more cylinders, and a reference set for each cylinder in order to perform ignition of each cylinder at an ignition timing calculated with respect to various control conditions. When starting the ignition timing measurement at the crank angle position or when performing fuel synchronous injection at the reference crank angle position set for each cylinder, the reference crank angle position corresponding to each cylinder, etc. It is necessary to obtain information for detection (cylinder discrimination information), but such a cylinder discrimination information cannot be obtained when a signal generator as shown in the above-mentioned US patent is used.

  An object of the present invention is to generate a signal for accurately obtaining rotation information including information on the rotation direction of the engine and cylinder discrimination information even at an extremely low speed of the engine with a large fluctuation in the rotation speed of the crankshaft. Another object of the present invention is to provide a signal generator for an internal combustion engine.

  The present invention provides a signal generator for an internal combustion engine that generates a signal including engine rotation information in synchronization with the rotation of a multi-cylinder two-cycle internal combustion engine.

  A signal generator for an internal combustion engine according to the present invention detects a front end edge detection pulse having different polarities by detecting a front end side edge and a rear end side edge in a rotation direction of each of a plurality of reluctors rotating synchronously with a crankshaft of the internal combustion engine. A first signal generator for generating a trailing edge detection pulse, and a second signal generator for generating a crank angle detection pulse each time the crankshaft rotates by a unit angle set to be sufficiently small, From the number of crank angle detection pulses generated by the second signal generator while the first signal generator sequentially generates edge detection pulses, the pulse generated sequentially by the first signal generator is determined by any of the reluctators. In order to obtain information for determining whether the pulse corresponds to the edge and information on the rotational direction of the internal combustion engine, the positional relationship between the plurality of reluctors and the position of the plurality of reluctors are obtained. And the pole arc angle of, respectively has been set.

  When the signal generator is configured as described above, the number of crank angle detection pulses generated by the second signal generator is counted while the first signal generator sequentially generates the edge detection pulses, and then sequentially counted. By comparing these numbers, information on the rotational direction of the engine can be obtained. In this case, since it is not necessary to measure the time between pulses, information on the rotational direction of the engine can be obtained accurately even at the extremely low speed of the engine where the rotational speed of the crankshaft fluctuates finely.

  Further, when configured as described above, the number of crank angle detection pulses generated by the second signal generator while the first signal generator sequentially generates the edge detection pulses is counted and the number is viewed, or By comparing the sequentially counted numbers, it is possible to determine which of the reluctator edges corresponds to the pulse generated sequentially by the first signal generator. Since the relationship between the position of the edge of each reluctator and each cylinder of the engine (for example, the relationship between the top dead center position of each cylinder) is known in advance, as described above, the pulses generated sequentially by the first signal generator Can be determined which pulse corresponds to which edge of the reluctator, based on the determination result, the ignition timing calculated for various control conditions when controlling the ignition timing of each cylinder is determined. It is possible to detect a reference crank angle position at which measurement is started, an ignition position at the start for each cylinder, or a crank angle position used as a position for performing synchronous injection of fuel for each cylinder. Also in this case, since it is not necessary to measure the time between pulses, a series of pulses generated by the signal generator can be accurately determined even at an extremely low engine speed.

  It is preferable that at least one of the plurality of relaxors is provided so as to correspond to a specific cylinder of the internal combustion engine.

  In a preferred aspect of the present invention, the reluctator is provided on the outer periphery of a rotor provided to rotate synchronously with the crankshaft. The second signal generator is configured to generate a crank angle detection pulse by detecting crank angle detection convex portions provided so as to be arranged at equal angular intervals on the outer periphery of the rotor.

  The rotor can be directly attached to the crankshaft of the internal combustion engine. When the rotor is attached to the crankshaft in this way, a ring gear meshed with a pinion gear driven by an internal combustion engine starting electric motor is fitted on the outer periphery of the rotor, and the teeth of the ring gear are fitted to the convex for detecting the crank angle. It is preferable to use it as a part.

  In another preferred embodiment of the present invention, two of the above-described reluctors are provided, and the two reluctors are disposed at asymmetric positions.

  In still another preferred aspect of the present invention, two of the above-mentioned relucters are provided with different polar arc angles.

  When the internal combustion engine is a two-cylinder internal combustion engine, it is preferable that the two reluctators are provided in correspondence with the two cylinders of the internal combustion engine. In this case, the two reluctors are detected by the first signal generator at the positions before and after the crank angle position corresponding to the top dead center of the cylinder to which each reluctator corresponds in each circumferential direction. Arranged so that.

  When the internal combustion engine is a two-cylinder internal combustion engine, three or more reluctors can be provided. In this case, it is preferable that two of the three or more reluctors are the reluctors respectively corresponding to the two cylinders of the internal combustion engine, and the two reluctors are arranged at symmetrical positions with the same polar arc angles. In this case, the two reluctors arranged at the symmetrical positions are such that the edges of both ends in the circumferential direction have the first signal at positions before and after the crank angle position corresponding to the top dead center of the cylinder to which each reluctator corresponds. Position to be detected by the generator.

  As described above, according to the present invention, the number of crank angle detection pulses generated by the second signal generator while the first signal generator sequentially generates the edge detection pulses is counted and sequentially counted. By comparing these numbers, it is possible to obtain information on the rotational direction of the engine, and it is not necessary to measure the time between pulses, so even at the extremely low speed of the engine where the rotational speed of the crankshaft varies finely, There is an advantage that information on the rotation direction of the engine can be obtained accurately.

  According to the present invention, the number of crank angle detection pulses generated by the second signal generator is counted while the first signal generator sequentially generates edge detection pulses, and the number is viewed or sequentially. By comparing the counted numbers, it is possible to determine which of the relucter edges corresponds to the pulse generated sequentially by the first signal generator, and based on the determination result, each cylinder The reference crank angle position for starting the measurement of the ignition timing calculated for various control conditions when controlling the ignition timing of the engine, the ignition position at the start for each cylinder, or the synchronous injection of fuel for each cylinder Since it is possible to detect the crank angle position used as the position for performing the engine, there is an advantage that the cylinder discrimination information can be obtained together with the information on the rotational direction of the engine.

  Embodiments of the present invention will be described below with reference to the drawings.

[First Embodiment]
1A and 1B show a configuration of a signal generator 1 used in the first embodiment of the present invention. In this embodiment, an internal combustion engine (not shown) has two cylinders. Assumes that.

  The signal generator 1 according to this embodiment includes an inductor-shaped rotor 3 attached to a crankshaft of an internal combustion engine, and first and second signal generators SG1 and SG2.

  The rotor 3 is formed in a cup shape with a ferromagnetic material such as iron, and has a rotating body 301 in which the first and second retractors R1 and R2 are formed on the peripheral wall portion 301a, and an outer periphery of the peripheral wall portion of the rotating body 301. The ring gear 302 is fitted by shrink fitting or the like, and is rotated clockwise in the direction of the arrow in FIG. 1A when the internal combustion engine rotates forward.

  Retractors R1 and R2 are formed of arc-shaped protrusions extending in the circumferential direction of rotating body 301, and polar arc angle α2 of relaxor R2 is set to be larger than polar arc angle α1 of relaxor R1.

  Further, the edges e11 and e21 on one end side in the circumferential direction of the reluctors R1 and R2 are arranged at asymmetric positions, and the rear end edges e12 and e22 in the circumferential direction of both reluctors are arranged at 180 ° symmetrical positions.

  The illustrated reluctors R1 and R2 are formed by punching the peripheral wall portion of the rotating body 301 from the inner side to the outer side in the radial direction.

  In the present embodiment, the polar arc angle α1 of the first reluctator R1 is set to 24 °, and the polar arc angle α2 of the second reluctator R2 is set to 60 °.

  A boss portion 303 is riveted to the center portion of the bottom wall portion 301b of the rotating body 301, and a tip end portion of a crankshaft of an internal combustion engine (not shown) is fitted into a tapered hole provided in the shaft core portion of the boss portion 303. Thus, the rotor 3 is attached to the crankshaft of the engine.

  The ring gear 302 is provided to mesh with a pinion gear driven by an internal combustion engine starting electric motor, and has a large number of tooth portions (convex portions) 302a at equal angular intervals.

  The reluctors (inductor magnetic pole portions) R1 and R2 are portions that abruptly change the air gap between the magnetic pole portion a of the first signal generator SG1 and the rotor 3. In the illustrated example, these reluctors are Although it consists of an arc-shaped protrusion, each reluctator may consist of a groove extending in an arc shape in the circumferential direction of the rotor.

  At the time of normal rotation of the engine, the edges e11 and e21 on the one end side of the first and second reluctators R1 and R2 shown in FIG. e12 and e22 are edges on the rear end side in the rotation direction of the respective reluctors.

  Also, during reverse rotation of the internal combustion engine, the edges e12 and e22 on the other end side of the retractors R1 and R2 shown in FIG. It becomes an edge on the rear end side in the rotation direction.

  The first signal generator SG1 includes an iron core having a magnetic pole part a facing the surface of the rotor 3 on which the reluctors R1 and R2 are provided, a signal coil wound around the iron core, and a magnetic coupling to the iron core. It is a well-known thing which accommodated the made permanent magnet in the casing. This signal generator is arranged in a state where the magnetic pole part a is oriented in the radial direction of the rotor 3 and located at a position where it can face the reluctors R1 and R2, and is attached to a fixed part such as a case or cover of the internal combustion engine. It is fixed to the provided signal generator mounting part.

  The signal coil in the first signal generator SG1 is configured such that when the magnetic pole portion at the tip of the iron core of the signal generator starts to face the retractors R1 and R2 (the front end side edges in the respective rotation directions of the retractors R1 and R2). Front ends having different polarities in response to changes in the magnetic flux generated in the iron core when the opposite ends (when the rear end edges in the respective rotation directions of the reluctors R1 and R2 are detected). An edge detection pulse and a trailing edge detection pulse are output.

  In FIG. 1A, TDC1 indicates the outer peripheral position of the rotor facing the magnetic pole part a of the first signal generator SG1 when the piston of the first cylinder of the engine reaches the top dead center (corresponding to the top dead center of the first cylinder of the rotor). TDC2 is the outer peripheral position of the rotor (the top dead center of the second cylinder of the rotor) facing the magnetic pole part a of the signal generator SG1 when the piston of the second cylinder of the engine reaches the top dead center. Corresponding position). In the case of the two-cylinder internal combustion engine that is the subject of the present embodiment, the first cylinder top dead center corresponding position TDC1 and the second cylinder top dead center corresponding position TDC2 of the rotor are at target positions that are 180 ° apart from each other.

  In this example, the first and second retractors R1 and R2 are provided so as to correspond to the first cylinder and the second cylinder of the internal combustion engine, respectively, and the first cylinder top dead center corresponding position TDC1 and the second cylinder of the rotor are provided. The respective reluctors are provided such that the top dead center corresponding position TDC2 is located between the front end side edge and the rear end side edge in the rotational direction of each of the first and second reluctators R1 and R2.

  In the example shown in the drawing, a position 9 ° from the edge e12 on the other end side in the circumferential direction of the first reluctator R1 to the edge e11 side on the one end side becomes the first cylinder top dead center corresponding position TDC1 of the rotor, and the second reluctator R2 Retractors R1 and R2 are provided so that the position shifted by 9 ° from the edge e22 on the other end side in the circumferential direction to the edge e21 side on the one end side becomes the second cylinder top dead center corresponding position TDC2 of the rotor.

  In the following description, the front edge detection pulse generated when the first signal generator SG1 detects the front edge of each of the reluctors R1 and R2 is V1f, and the first signal generator SG1 is the reluctor R1, R2. Let V1r be the trailing edge detection pulse generated when each trailing edge is detected.

  The second signal generator SG2 is configured in the same manner as the first signal generator SG1, and the magnetic pole part b is oriented in the radial direction of the rotor 3 and can be opposed to the tooth part of the ring gear 302. It is arranged in a positioned state and is fixed to a signal generator mounting portion provided at a fixing location such as an engine case or a cover.

  The signal coil in the second signal generator SG2 is configured so that the magnetic pole portion at the tip of the iron core of the signal generator starts to face each tooth portion 302a of the ring gear 302 (the front end side in the rotation direction of each tooth portion). Crank angle detection with different polarities in response to changes in the magnetic flux generated in the iron core when detecting edges) and when ending the facing (when detecting the trailing edge of the rotation direction of each tooth) Output a pulse.

  In the following description, the crank angle detection pulses generated when the second signal generator SG2 detects the front end side edge and the rear end side edge of the tooth portion of the ring gear are referred to as V2f and V2r, respectively.

  In the present embodiment, when the first signal generator SG1 detects the front end edge of each of the reluctators R1 and R2 in the rotation direction, it outputs a negative front end edge detection pulse V1f, and the first signal generator SG1 The winding direction of the signal coil of the signal generator SG1 is set so that the positive end trailing edge detection pulse V1r is output when the trailing edge of the rotation direction of the reluctors R1 and R2 is detected.

  Similarly, when the second signal generator SG2 detects an edge on the front end side in the rotation direction of each tooth portion of the ring gear, a negative crank angle detection pulse V2f is output, and the second signal generator SG2 The winding direction of the signal coil of the signal generator SG2 is set so that a positive crank angle detection pulse V2r is output when the trailing edge of the rotation direction of R1 and R2 is detected.

  In the present embodiment, the crank angle that is generated every time the crankshaft rotates by a unit angle, the pulse V2r that is generated when the second signal generator SG2 detects the rear end side edge of the tooth portion of the ring gear in the rotation direction. Used as a detection pulse.

  The output pulses of the first signal generator SG1 and the second signal generator SG2 shown in FIGS. 1A and 1B are fed into an electronic control unit (ECU) that controls the internal combustion engine as shown in FIG. The signal is input to the CPU 10 of the provided microprocessor through a waveform shaping circuit.

  In the example shown in FIG. 2, the negative polarity front end edge detection pulse V1f and the positive polarity rear end edge detection pulse V1r output from the first signal generator SG1 are input to the CPU 10 through the waveform shaping circuits 11 and 12, respectively. A positive crank angle detection pulse V2r output from the second signal generator SG2 is input to the CPU 10 through the waveform shaping circuit 13.

  The waveform shaping circuit 11 converts the negative front edge detection pulse V1f output from the first signal generator SG1 into an interrupt signal S1f having a waveform that can be recognized by the CPU, and inputs the interrupt signal S1f to the interrupt signal input terminal IN1 of the CPU 10. The waveform shaping circuit 12 converts the positive trailing edge detection pulse V1r output from the first signal generator SG1 into an interrupt signal S1r having a waveform that can be recognized by the CPU, and inputs the interrupt signal S1r to the interrupt signal input terminal IN2 of the CPU 10. .

  The waveform shaping circuit 13 converts the positive polarity crank angle detection pulse V2r output from the second signal generator SG2 into a waveform interrupt signal S2r that can be recognized by the CPU each time the crankshaft rotates by a unit angle, and converts the CPU 10 To the interrupt signal input terminal IN3.

  The first signal generator SG1 and the waveform shaping circuits 11 and 12 detect the front end side edge and the rear end side edge in the rotational direction of each of the plurality of reluctors R1 and R2 that rotate synchronously with the crankshaft of the internal combustion engine. A first signal generator for generating a front edge detection pulse and a rear edge detection pulse having different polarities is configured. Each time the crankshaft rotates by a unit angle by the second signal generator SG2 and the waveform shaping circuit 13. A second signal generator for generating a crank angle detection pulse is configured.

  The unit angle can be set any number of times, but is set sufficiently smaller than the minimum value of the polar arc angles of the reluctors R1 and R2 (24 ° in the present embodiment). In this embodiment, the unit angle is set to 12 °. That is, the second signal generator generates a crank angle detection pulse every time the crankshaft rotates 12 °. The number of crank angle detection pulses V2r generated by the second signal generator during one rotation of the crankshaft is thirty.

  In this embodiment, the edge detection pulses V1f and V1r generated by the first signal generator SG1 and the crank angle detection pulse V2r generated by the second signal generator SG2 when the engine is rotating forward are shown in FIG. As shown in (A) and (B), the pulses V1f and V1r generated by the first signal generator SG1 and the crank angle detection pulse V2r generated by the second signal generator SG2 when the engine is rotating in reverse are shown. These are shown in FIGS. 4 (A) and 4 (B), respectively.

  3 and 4, the symbols # 1 and # 2 mean that the symbols with these symbols are related to the first cylinder and the second cylinder of the engine, respectively. BTDC means the position before the top dead center position (crank angle position when the piston reaches top dead center), and ATDC means the position after the top dead center position of the engine. is doing. For example, # 1ATDC9 ° means a crank angle position of 9 ° after the top dead center position of the first cylinder, and # 1BTDC15 ° and # 2BTDC51 ° respectively indicate a crank angle position of 15 ° before the top dead center position of the first cylinder and This means a crank angle position of 51 ° before the top dead center position of the second cylinder.

  In the present embodiment, as shown in FIG. 3A, the crank angle position of the internal combustion engine when the engine is rotating forward is the top dead center position of the first cylinder (when the piston in the first cylinder reaches the top dead center position). When the first signal generator SG1 is rotated by the set angle (15 ° in the illustrated example) (# 1BTDC15 °) with respect to the crank angle position) # 1TDC, the first signal generator SG1 rotates the first retractor R1. The front edge of the direction is detected and a negative front edge detection pulse V1f is generated, and the crank angle position is delayed by a set angle (9 ° in the illustrated example) with respect to the top dead center position # 1 TDC of the first cylinder. When the first signal generator SG1 detects the rear end side edge in the rotation direction of the first reluctator R1 when it coincides with the angled position (# 1ATDC 9 °), the rear end edge detection pulse V1r is generated. Between the first signal generator SG1 and the rotor 3; Location relation has been set.

  In the present embodiment, the first signal generator SG1 determines from the number of crank angle detection pulses generated by the second signal generator SG2 while the first signal generator SG1 sequentially generates edge detection pulses. In order to obtain information for determining which one of the plurality of reluctors R1 and R2 corresponds to the edge of the reluctator and information on the rotational direction of the internal combustion engine, the sequentially generated pulses can be obtained. The positional relationship between R1 and R2 and the respective polar arc angles of the retractors R1 and R2 are set.

  In the illustrated example, the first signal generator SG1 detects the front end side edge of the reluctator R1 corresponding to the first cylinder of the engine and generates the pulse V1f during the forward rotation of the engine, and then the rear end of the reluctator. The first signal generator SG1 detects the rear end side edge of the retractor R1 corresponding to the first cylinder until the side edge is detected and the pulse V1r is generated, and then the reluctator R2 corresponding to the second cylinder is detected. Until the first signal generator SG1 detects the front end side edge of the retractor R2 corresponding to the second cylinder until the front end side edge is detected and the pulse V1f is generated, the rear end side edge of the reluctator R2 is detected. Until the pulse V1r is detected and the first signal generator SG1 detects the rear end side edge of the reluctor R2 corresponding to the second cylinder, generates the pulse V1r, and then corresponds to the first cylinder. The front edge of the reluctator R1 The number of crank angle detection pulses V2r generated by the second signal generator SG2 before the detection of the pulse V1f is 2, 10, 5, and 13 respectively. The positional relationship between the reluctors R1 and R2 and the polar arc angles of the reluctors R1 and R2 are set.

  In this case, during reverse rotation of the engine, the first signal generator SG1 detects the front end side edge of the retractor R1 corresponding to the first cylinder of the engine and generates the pulse V1f, and then The first signal generator SG1 detects the rear end side of the relaxor R1 corresponding to the first cylinder until the rear end side edge is detected and the pulse V1r is generated, and then the retractor corresponding to the second cylinder. Until the first signal generator SG1 detects the front end side edge of the R2 corresponding to the second cylinder until the R1 front end side edge is detected and the pulse V1f is generated, the rear end side of the R2 The first cylinder after the edge is detected and the pulse V1r is generated, and after the first signal generator SG1 detects the trailing edge of the reluctor R2 corresponding to the second cylinder and generates the pulse V1r. Reactor R1 corresponding to The number of crank angle detection pulses V2r generated by the second signal generator SG2 from the detection of the front end side edge to the generation of the pulse V1f is 2, 13, 5, and 10, respectively.

  If comprised as mentioned above, the information of the rotation direction of an engine can be obtained by comparing the number of crank angle detection pulses counted while the first signal generator sequentially generates pulses. For example, after the number of crank angle detection signals counted between the time when the first signal generator generates the front edge detection pulse V1f and the time when the rear edge detection pulse V1r is generated is 2, When the number of crank angle detection pulses counted until the front edge detection pulse V1f is generated is 10, it can be determined that the engine is rotating forward, and the first signal generator After the number of crank angle detection signals counted between the generation of the front edge detection pulse V1f and the generation of the rear edge detection pulse V1r is 2, until the next front edge detection pulse V1f is generated. When the number of crank angle detection pulses counted during this period is 13, it can be determined that the engine is rotating in reverse.

  Further, the pulse generated by the first signal generator is detected by detecting the edge of any reluctor from the number of crank angle detection pulses counted while the first signal generator SG1 sequentially generates edge detection pulses. It is possible to discriminate whether or not it is a pulse. For example, during the normal rotation of the engine, the number of crank angle detection signals V2r generated between the time when the first signal generator generates the front edge detection signal V1f and the time when the rear edge detection signal V1r is generated is 2. At a certain time, it is possible to determine that the front end side edge and the rear end side edge of the reluctator detected by the first signal generator SG1 this time are the edges of the reluctator corresponding to the first cylinder, and the first signal generator When the number of crank angle detection signals V2r generated between SG1 generating the front edge detection signal V1f and the generation of the rear edge detection signal V1r is 5, the first signal generator SG1 this time It can be determined that the detected front end side edge and rear end side edge of the reluctator are edges of the reluctator R2 corresponding to the second cylinder.

  In this way, when it is possible to determine which reluctator edge the pulse generated by the first signal generator is generated, the reference crank set for each cylinder is determined. Detection of the angular position and the like can be performed.

  For example, the crank angle position when the front edge in the rotation direction of the first reluctator R1 is detected by the first signal generator SG1 is set as the reference crank angle position for the first cylinder, and the rotation direction of the second reluctator R2 is If the crank angle position when the front end edge is detected by the first signal generator SG1 is the reference crank angle position for the second cylinder, the first signal generator SG1 generates the front end edge detection signal V1f. When the number of crank angle detection signals V2r generated during the period from the generation of the rear edge detection signal V1r to 2 is 2, the position of the front edge of the retractor detected by the first signal generator SG1 this time is It is possible to detect the reference crank angle position for one cylinder, which is generated after the first signal generator generates the front end edge detection signal V1f until it generates the rear end edge detection signal V1r. When the number of detected crank angle detection signals V2r is 5, it is detected that the position of the front end edge of the reluctator detected by the first signal generator SG1 this time is the reference crank angle position for the second cylinder. Can do.

  In addition, after the first signal generator SG1 generates the positive trailing edge detection pulse, the first edge generator detects the leading edge detection pulse generated by the first signal generator SG1 after the ten crank angle detection pulses are counted. After determining that the pulse corresponds to the front end side edge of the 2 reluctator R2, and after the first signal generator SG1 generates the positive end edge detection pulse, the 13 crank angle detection pulses are counted. The front edge detection pulse generated by the first signal generator SG1 may be determined as a pulse corresponding to the front edge of the first reluctator R1.

  Note that the reference crank angle position is not limited to the crank angle position when the front end edge of the reluctator is detected, and a predetermined number of positions from the position at which the front end edge or the rear end side edge of the specific reluctator is detected. The position when the crank angle detection pulse is detected can be set as the reference crank angle position.

  For example, in the example shown in FIG. 3, two more crank angle detection pulses are detected from the crank angle position when the first signal generator SG1 detects the front end side edge of the retractor R2 corresponding to the second cylinder. The crank angle position at that time can also be used as the reference crank angle position for the second cylinder.

  In the example shown in FIG. 3, if the ignition position at the start of the engine is the top dead center position of each cylinder, two crank angle detection pulses are counted after the front edge of the first reluctator is detected. The crank angle position of the engine can be detected as the ignition position at the start of the first cylinder of the engine, and when the front end side edge of the second reluctator is detected, five crank angle detection pulses are counted. The crank angle position can be detected as the ignition position when starting the second cylinder of the engine.

  Similarly, during the reverse rotation of the engine, it is possible to determine which edge of each reluctator the pulse generated by the first signal generator SG1 is generated.

  When the signal generator is configured as described above, by comparing the number of crank angle detection pulses generated by the second signal generator SG2 while the first signal generator SG1 sequentially generates the edge detection pulses, Information on the direction of rotation of the engine can be obtained. In this case, since it is not necessary to measure the time between pulses, information on the rotational direction of the engine can be obtained accurately even at the extremely low speed of the engine where the rotational speed of the crankshaft fluctuates finely.

  Further, when configured as described above, the number of crank angle detection pulses generated by the second signal generator while the first signal generator SG1 sequentially generates the edge detection pulses is counted and the number is viewed. Alternatively, by comparing the sequentially counted numbers, it is possible to determine which of the relucter edges corresponds to the pulse generated sequentially by the first signal generator, and based on the determination result, The crank angle position set for each cylinder can be detected. Also in this case, since it is not necessary to measure the time between pulses, a series of pulses generated by the signal generator can be accurately determined even at an extremely low engine speed.

  FIGS. 5A and 5B show the configuration of another embodiment of the present invention. In these drawings, parts equivalent to those in FIGS. 1A and 1B are denoted by the same reference numerals. Also in this embodiment, the internal combustion engine is a two-cycle two-cylinder internal combustion engine.

  In the embodiment shown in FIG. 5A and FIG. 5B, on the outer periphery of the peripheral wall portion of the rotating body 301 that constitutes the rotor 3, there are provided three retractors R1 to R3 made of arcuate protrusions extending in the circumferential direction of the rotating body. ing. In this example, the first and third reluctors R1 and R3 are provided so as to correspond to the first and second cylinders of the internal combustion engine, respectively, and these reluctors are arranged at 180 ° symmetrical positions. The second reluctator R2 is positioned in a state where its one end edge e21 in the circumferential direction is shifted by 84 ° in the reverse rotation direction of the crankshaft with respect to the edge e12 on one end side in the circumferential direction of the first reluctator R1. , And provided between the first and third relaxors R1 and R3.

  The polar arc angles of the first to third reluctors R1 to R3 are set to be equal (= 24 °).

  Also in this example, at the time of forward rotation of the engine, the edges e11, e21 and e31 on one end side of the first to third retractors R1 to R3 become the edges on the front end side in the rotation direction of the respective relaxors, and Edges e12, e22, and e32 on the other end side become edges on the rear end side in the rotation direction of the respective reluctors.

  At the time of reverse rotation of the internal combustion engine, the edges e12, e22 and e32 on the other end sides of the reluctors R1 to R3 serve as front end edges in the rotation direction of the respective reluctors, and the edges e11, e21 and e31 on the one end sides respectively. It becomes the edge of the rear end side of the rotation direction of each reluctator. Other points are the same as those of the embodiment shown in FIG.

  FIGS. 6 and 7 show the waveforms of signals generated by the first signal generator SG1 and the second signal generator SG2 when the signal generator of the embodiment shown in FIGS. 5A and 5B is used. . FIG. 6 shows a waveform during forward rotation of the engine, and FIG. 7 shows a waveform during reverse rotation of the engine.

  At the time of forward rotation of the internal combustion engine, the first signal generator SG1 moves the front end side edge of the first retractor R1 at a position advanced by 15 ° with respect to the top dead center position of the first cylinder (position of # 1 BTDC 15 °). A front end edge detection pulse V1f is detected and a rear end side edge of the first reluctator R1 is detected by detecting a rear end side edge of the first reluctator R1 at a position 9 ° behind the top dead center position of the first cylinder (position of # 1ATDC 9 °). An edge detection pulse V1r is generated.

  The first signal generator SG1 also detects the front end side edge of the second reluctator R2 at a position advanced by 87 ° (# 2 BTDC 87 ° position) with respect to the top dead center position of the second cylinder during normal rotation of the engine. Then, a front end edge detection pulse V1f is generated, and the rear end side edge of the second reluctator R2 is detected at a position advanced by 63 ° relative to the top dead center position of the second cylinder (position of # 2BTDC 63 °). An edge detection pulse V1r is generated.

  The first signal generator SG1 also detects the front edge of the third reluctator R3 at a position advanced by 15 ° (# 2 BTDC 15 ° position) with respect to the top dead center position of the second cylinder during normal rotation of the engine. Then, a front end edge detection pulse V1f is generated, and the rear end side edge of the third reluctator R3 is detected at a position delayed by 9 ° with respect to the top dead center position of the second cylinder (position of # 2ATDC 9 °). An edge detection pulse V1r is generated.

  Also, during reverse rotation of the internal combustion engine, the first signal generator SG1 moves the front end side edge of the third reluctator R3 at a position advanced by 9 ° relative to the top dead center position of the second cylinder (position of # 1 BTDC 9 °). Detecting and generating a front edge detection pulse V1f, detecting the rear edge of the third reluctor R3 at a position delayed by 15 ° from the top dead center position of the second cylinder (position of # 1ATDC 15 °) An edge detection pulse V1r is generated.

  The first signal generator SG1 also detects the front end edge of the second reluctator R2 at a position delayed by 63 ° with respect to the top dead center position of the second cylinder (position of # 2ATDC 63 °) during reverse rotation of the engine. Then, the front edge detection pulse V1f is generated, and the rear edge of the second reluctator R2 is detected at a position delayed by 87 ° (position of # 2ATDC 87 °) with respect to the top dead center position of the second cylinder. A rear edge detection pulse V1r is generated.

  The first signal generator SG1 also detects the front-end edge of the first reluctator R1 at a position advanced by 9 ° (# 2BTDC 9 ° position) with respect to the top dead center position of the first cylinder during engine reverse rotation. Then, a front edge detection pulse V1f is generated, and the rear edge of the first reluctator R1 is detected at a position delayed by 15 ° relative to the top dead center position of the first cylinder (position of # 2ATDC 15 °). An edge detection pulse V1r is generated.

  When configured as shown in FIG. 5A and FIG. 5B, during the forward rotation of the engine, the first signal generator SG1 detects the front end side edge of the first reluctator R1 until the rear end side edge is detected. During the period from the detection of the rear end edge of the first reluctator R1 to the detection of the front end side edge of the second reluctator R2, after the detection of the front end side edge of the second reluctator R2, Until the end edge is detected, the first end edge of the third reluctator R3 is detected after the rear end edge of the second reluctator R2 is detected until the front end edge of the third reluctator R3 is detected. Crank angle counted until the rear end edge of the third reluctator R3 is detected and between the time when the rear end side edge of the third reluctator R3 is detected and the time when the front end side edge of the first reluctator R1 is detected Detection Pal The number of V2r becomes the 2,7,2,4,2,13.

  Further, during reverse rotation of the engine, the first signal generator SG1 detects the rear end side edge of the third reluctator R3 until the rear end side edge is detected after the detection of the front end side edge of the third reluctator R3. Until the front end side edge of the second reluctator R2 is detected, and until the rear end side edge of the second reluctator R2 is detected after the front end side edge of the second reluctator R2 is detected. Between the time when the rear end edge of R2 is detected and the time when the front end edge of the first reluctator R1 is detected, and the time after the front end edge of the third reluctator R3 is detected and the time when the rear end edge of the third reluctator R3 is detected. , And the number of crank angle detection pulses V2r counted between the detection of the rear end edge of the third reluctator R3 and the detection of the front end side edge of the first reluctator R1 are 2, 7, 2, 4, 2, 13 and That.

  In the embodiment shown in FIGS. 5A and 5B, the number of crank angle detection pulses counted while the first signal generator SG1 sequentially generates edge detection pulses is 7, 2, 4, 2, 13,. It can be determined that the engine is rotating forward at the time of change, and the number of crank angle detection pulses counted while the first signal generator SG1 sequentially generates edge detection pulses is 7, It can be determined that the engine is rotating in the reverse direction when it changes like 2, 13, 2, 4,.

  When the engine is rotating forward, the crank angle detection pulse counted between the time when the first signal generator SG1 generates the rear end edge detection pulse V1r and the time when the front end edge detection pulse V1f is generated. The front end edge detection pulse V1f generated after the number is 13 can be determined to be a pulse generated by detecting the front end side edge of the first reluctator R1 corresponding to the first cylinder of the engine. The front edge detection pulse generated after the number of crank angle detection pulses counted from when the signal generator SG1 generates the rear edge detection pulse V1r to when the signal generator SG1 generates the front edge detection pulse V1f is four. It can be determined that V1f is a pulse generated by detecting the front edge of the third reluctor R3 corresponding to the second cylinder of the engine.

  Further, at the time of reverse rotation of the engine, the number of crank angle detection pulses counted from when the first signal generator SG1 generates the rear end edge detection pulse V1r to when it generates the front end edge detection pulse V1f is 13. It is possible to determine that the front edge detection pulse V1f generated after the detection is a pulse generated by detecting the front edge of the first reluctator R3 corresponding to the second cylinder of the engine, and the first signal generator The front edge detection pulse V1f generated after the number of crank angle detection pulses counted from the time SG1 generates the rear edge detection pulse V1r to the generation of the front edge detection pulse V1f is seven. It can be determined that the pulse is generated by detecting the front end side edge of the first reluctator R1 corresponding to the first cylinder.

  As shown in FIG. 5A and FIG. 5B, the reluctors R1 and R3 corresponding to the first and second cylinders of the engine, respectively, are provided, the polar arc angles of these reluctors are made equal, and both reluctors are placed in symmetrical positions When arranged, the angle between the crank angle position at which the first signal generator SG1 detects the front end side edge in the rotational direction of the reluctors R1 and R3 and the top dead center positions of the first cylinder and the second cylinder are made the same. (15 ° in the above example), so these positions can be used as the reference crank angle position where the measurement of the ignition timing of the first cylinder and the second cylinder is started and the position where the fuel is synchronously injected. A convenient position can be set, and the detection of the reference crank angle position for each cylinder and the synchronous injection position can be facilitated.

  In the above example, the ring gear 302 having 30 teeth is used. However, the ring gear 302 is not limited to the above example as long as the number of teeth of the ring gear is sufficiently larger than the number of relaxors. The first signal generator SG1 detects a plurality of reluctors, and is not limited to the above example. In the example shown in FIG. 5A and FIG. 5B, three relaxors are provided for a two-cylinder internal combustion engine, but more relaxors can be provided.

  In the above example, the pulse V2r generated when the second signal generator SG2 detects the trailing edge of each tooth of the ring gear 302 is used as the crank angle detection pulse. Both the pulses V2f and V2r generated when the generator SG2 detects the front end edge and the rear end edge of each tooth of the ring gear may be used as the crank angle detection pulse. With this configuration, since the angular interval (unit angle) between the crank angle detection pulses can be reduced, the reference is obtained by counting the crank angle detection pulse from the crank angle position corresponding to the edge of one of the reluctors. When obtaining the crank angle position, the ignition position at the start of the engine, etc., the detection accuracy can be increased by increasing the resolution of the crank angle detection.

  In the above example, the second signal generator SG2 detects the teeth of the ring gear and generates a crank angle detection pulse. However, the second signal generator SG2 generates a crank angle every unit angle. Therefore, the convex portion detected by the second signal generator SG2 is not limited to the teeth of the ring gear.

  The second signal generator SG2 only needs to generate a pulse each time the crankshaft rotates by a unit angle, so that a pulse is generated by detecting a series of convex portions provided on the outer periphery of the rotor. It is not limited to, a magnetic encoder that detects a magnetic pattern provided on the outer periphery of the rotor and generates a pulse for each unit angle, a code plate having a large number of slits arranged in the circumferential direction, You may make it use the optical encoder etc. which combined the optical sensor which detects the slit of this code | symbol plate as a 2nd signal generator.

  In the example shown in FIGS. 1A, 1B, 5A, and 5B, the second signal generator SG2 is arranged at a position 180 ° away from the first signal generator SG1, but the second signal generator The position of the vessel SG2 is not limited to the above example.

  In the above embodiment, the two-cycle two-cylinder internal combustion engine is taken as an example. However, the present invention can be applied to a multi-cylinder two-cycle internal combustion engine based on the same concept.

It is the front view which showed the structural example of the signal generator used in the 1st Embodiment of this invention. It is a longitudinal cross-sectional view of the signal generator used in the 1st Embodiment of this invention. FIG. 2 is a block diagram schematically showing a configuration example of a circuit for inputting output pulses of first and second signal generators of the signal generator shown in FIG. 1 to a CPU of a microprocessor. FIG. 2 is a waveform diagram showing a waveform of a pulse obtained by a signal generator of the signal generator shown in FIG. 1 when the engine is rotating forward. FIG. 2 is a waveform diagram showing a waveform of a pulse obtained by the signal generator of the signal generator shown in FIG. 1 when the engine is rotating in reverse. It is the front view which showed the structure of the 2nd Embodiment of this invention. It is the longitudinal cross-sectional view which showed the structure of the 2nd Embodiment of this invention. FIG. 6 is a waveform diagram showing waveforms of signals output from the first and second signal generators when the engine rotates forward in the embodiment of FIG. 5. FIG. 6 is a waveform diagram illustrating waveforms of signals output from the first and second signal generators when the engine rotates reversely in the embodiment of FIG. 5.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Signal generator for internal combustion engines, 3 ... Rotor, 301 ... Rotating body, 302 ... Ring gear, R1-R3 ... 1st thru | or 3rd retractor, SG1 ... 1st signal generator, SG2 ... 2nd signal generation vessel.

Claims (8)

A signal generator for an internal combustion engine that generates a signal including engine rotation information in synchronization with the rotation of a multi-cylinder two-cycle internal combustion engine,
A first end detection pulse and a rear end edge detection pulse having different polarities are detected by detecting front end side edges and rear end side edges in the rotation direction of a plurality of reciprocators rotating synchronously with the crankshaft of the internal combustion engine. A signal generator;
A second signal generator for generating a crank angle detection pulse each time the crankshaft rotates by a unit angle set to be sufficiently small,
From the number of crank angle detection pulses generated by the second signal generator while the first signal generator sequentially generates edge detection pulses, the plurality of pulses sequentially generated by the first signal generator are the plurality of pulses. The positional relationship between the plurality of reluctors, and the information for determining which one of the reluctors corresponds to the edge of the reluctor and the information on the rotational direction of the internal combustion engine are obtained, and The polar angle of each of the plurality of reluctors is set,
A signal generator for an internal combustion engine.   The signal generator for an internal combustion engine according to claim 1, wherein the plurality of relaxors include at least one relaxor provided corresponding to a specific cylinder of the internal combustion engine. The reluctator is provided on the outer periphery of a rotor provided to rotate synchronously with the crankshaft,
The second signal generator is configured to generate a crank angle detection pulse by detecting a crank angle detection convex portion provided so as to be arranged at equal angular intervals on the outer periphery of the rotor;
The signal generator for an internal combustion engine according to claim 1 or 2, characterized in that. The rotor is attached to a crankshaft of the internal combustion engine, and a ring gear meshing with a pinion gear driven by an internal combustion engine starter motor is fitted to the outer periphery of the rotor,
The teeth of the ring gear are used as the convex portions for detecting the crank angle;
The signal generator for an internal combustion engine according to claim 3.   The signal generator for an internal combustion engine according to any one of claims 1 to 4, wherein the two reluctors are provided, and the two reluctors are disposed at asymmetric positions.   The signal generator for an internal combustion engine according to any one of claims 1 to 5, wherein two of the reluctors are provided, and the two reluctors are provided with different polar arc angles. The internal combustion engine is a two-cylinder internal combustion engine, and the two reluctors are provided corresponding to two cylinders of the internal combustion engine,
The two reluctors are detected by the first signal generator at the positions before and after the crank angle position corresponding to the top dead center of the cylinder to which each reluctator corresponds in each circumferential direction. To be arranged as
The signal generator for an internal combustion engine according to claim 5 or 6. The internal combustion engine is a two-cylinder internal combustion engine;
Three or more of the reluctors are provided, and two of the three or more reluctors are provided respectively corresponding to two cylinders of the internal combustion engine,
The two reluctors are arranged at symmetrical positions with the same polar arc angle,
The two reciprocators arranged at the symmetric positions are configured such that the edges at both ends in the circumferential direction are the first signal generation at positions before and after the crank angle position corresponding to the top dead center of the cylinder to which each reluctor corresponds. Arranged to be detected by the instrument,
The signal generator for an internal combustion engine according to any one of claims 1 to 4, characterized in that:

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