JP2016023622A - Crankshaft position controller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a crankshaft position controller capable of accurately displacing a crankshaft to a position suited for restarting an engine when the engine is stopped.SOLUTION: A crankshaft position controller comprises: a power generation unit 10 generating electric power by revolution of an engine 70 at a time of driving the engine 70; and control units 50 to 52 controlling the power generation unit 10 to be driven, a first pulley 71 rotating along with a crankshaft of the engine 70 and a second pulley 11 of the power generation unit 10 are coupled to each other via a belt 73 and are configured so that one of the first pulley 71 and the second pulley 11 generates a torque to rotate the other pulley by the torque, and the control units 50 to 52 rotate the second pulley 11 so as to displace the crankshaft to a position suited for restarting the engine 70 when the engine 70 is stopped.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a crankshaft position control device that includes a power generation unit that generates electric power by rotation of an engine and a control unit that controls driving of the power generation unit.

  As disclosed in Patent Document 1, a four-cycle multi-cylinder engine starter configured to automatically restart an engine by performing combustion in a cylinder in an expansion stroke is known. The engine starter adjusts the intake air flow rate of the cylinder in the compression stroke so that the piston of the cylinder in the expansion stroke is stopped within an appropriate range suitable for restart when the engine automatically stops. The engine starter then creates a distribution map showing the correlation between the top dead center rotation speed during the engine stop operation period and the piston stop position of the cylinder during the expansion stroke, and based on this, the power generation amount of the alternator is calculated. adjust. This adjusts the rotational resistance of the crankshaft and stops the piston within an appropriate range suitable for restarting.

Japanese Patent No. 3772891

  As described above, in the engine starter disclosed in Patent Document 1, the amount of inertial rotation of the crankshaft connected to the piston is adjusted by adjusting the intake flow rate into the cylinder and the rotational resistance of the crankshaft. As a result, the piston is stopped at a position suitable for restarting the engine. However, elements such as an A / C compressor and an oil pump are usually connected to the engine via a belt. Since the engine rotates against the resistance of these elements, the correlation between the top dead center rotation speed and the piston stop position may vary due to these resistances. Therefore, in the configuration described in Patent Document 1, the accuracy of the stop position of the piston (crankshaft) may be reduced.

  In view of the above problems, an object of the present invention is to provide a crankshaft position control device that accurately displaces a crankshaft to a position suitable for restarting the engine when the engine is stopped.

  The first invention for achieving the above object includes a power generation unit (10) that generates electric power by rotation during driving of the engine (70), and a control unit (50 to 52) that controls driving of the power generation unit. The first pulley (71) rotating with the crankshaft (72) of the engine and the second pulley (11) of the power generation unit are connected via the belt (73), and either the first pulley or the second pulley is connected. The other is rotated by the torque generated on one side, and the controller rotates the second pulley so that the crankshaft is displaced to a position suitable for restarting the engine when the engine is stopped. It is characterized by making it.

  Normally, pulleys (90, 91) of elements such as an A / C compressor and an oil pump are connected to the engine (70) via the belt (73). The engine (70) rotates against the resistance of these elements. For that purpose, when the engine (70) is stopped, the crankshaft (72) is stopped at a position suitable for restarting the engine (70) by adjusting the amount of inertial rotation of the crankshaft (72). Due to the resistance of the elements described above, the accuracy of the stop position of the crankshaft (72) may be reduced.

  On the other hand, in the present invention, the first pulley (72) of the crankshaft (72) is interposed via the belt (73) so that the crankshaft (72) is displaced to a position suitable for restarting the engine (70). 71) The 2nd pulley (11) of the electric power generation part (10) connected with 71) is rotated. Thus, since the second pulley (11) is rotated regardless of the resistance of the above-described elements, the crankshaft (72) is accurately displaced to a position suitable for restart regardless of the resistance of the above-described elements. be able to. Furthermore, unlike the configuration without an element for rotating the crankshaft (72), the rotation angle of the crankshaft (72) can be finely adjusted.

  The second invention has a first angle sensor (31) for detecting the rotation angle of the crankshaft and the cam of the engine, and a second angle sensor (32) for detecting the rotation angle of the second pulley. The angle sensor has a higher resolution for detecting the rotation angle than the first angle sensor, the control unit (52) stores the pulley ratio of the first pulley and the second pulley, and the control unit (52) stops the engine. At a predetermined timing based on the rotation angle of the crankshaft detected by the first angle sensor, the rotation angle of the second pulley detected by the second angle sensor after the predetermined timing, and the pulley ratio. A crankshaft rotation angle is calculated, and based on the calculated crankshaft rotation angle, the crankshaft is displaced to a position suitable for restarting the engine. Rotate the pulley.

  Since the first pulley (71) and the second pulley (11) are connected via the belt (73), the crank is determined based on the pulley ratio of both and the rotation angle of the second pulley (11) as described above. The rotation angle of the shaft (72) can be calculated.

  In the third invention, the first angle sensor generates a crank signal indicating the rotation angle of the crankshaft and a cam signal indicating the rotation angle of the cam, and the control unit (52) detects the crankshaft detected by the first angle sensor. In order to synchronize the calculated rotation angle with the calculated crankshaft rotation angle, the calculated crankshaft rotation angle is periodically matched with the detected crankshaft rotation angle based on the crank signal and the cam signal.

  Since the first pulley (71) and the second pulley (11) are connected via the belt (73) as described above, the first pulley (71) is also equivalent to the amount of rotation of the second pulley (11). Rotating, the rotation angle of both is related by the pulley ratio. However, if at least one of the two pulleys (11, 71) and the belt (73) slip for some reason, the first pulley (71) rotates as much as the second pulley (11) rotates. Disappear. Therefore, the rotation angles of the two pulleys (11, 71) are not related by the pulley ratio. Therefore, in order to cancel the difference in rotation due to the slip described above, the calculated crank angle is periodically made to coincide with the detected crank angle. As a result, the rotation angles of the two pulleys (11, 71) are related by the pulley ratio, and the accuracy of displacing the crankshaft (72) to a position suitable for restarting the engine (70) due to slippage is reduced. Is suppressed.

  The rotational speed of the crankshaft (72) varies depending on the rotational state of the engine (70). Therefore, the term “periodic” described above does not indicate a constant period of time, but indicates a period in which the rotation angle of the crankshaft (72) is constant.

  As described above, the elements described in the claims and the means for solving the problems are attached with parentheses, and the parentheses are described in the embodiment. These are for simply showing the correspondence with each of the constituent elements, and do not necessarily show the elements themselves described in the embodiments. The description of the reference numerals with parentheses does not unnecessarily narrow the scope of the claims.

It is a block diagram which shows schematic structure of a crankshaft position control apparatus. It is a mimetic diagram showing the state where the 1st pulley and the 2nd pulley are connected via the belt. It is a block diagram which shows a 1st angle sensor. It is a block diagram which shows a 2nd angle sensor. It is a timing chart which shows a crank signal, a cam signal, and a calculation signal. It is sectional drawing which shows the motion of the piston in a cylinder. It is a flowchart which shows the calculation process of a crank angle. It is a flowchart which shows the displacement process to the ideal position of a crankshaft. It is a flowchart which shows the modification of the calculation process of a crank angle.

Hereinafter, an embodiment when the present invention is applied to a four-cycle engine will be described with reference to the drawings.
(First embodiment)
A crankshaft position control device according to the present embodiment will be described with reference to FIGS. As shown in FIG. 1, the crankshaft position control device 100 includes a power generation unit 10, an angle sensor 30, and a control unit 50. The engine 70 is provided with a first pulley 71 that rotates together with the crankshaft 72, and the power generation unit 10 is provided with a second pulley 11 that rotates together with a rotor (not shown). The first pulley 71 and the second pulley 11 are mechanically connected via a belt 73, and the other is rotated by torque generated in one of the two pulleys 11 and 71. For example, when the first pulley 71 rotates when the engine 70 is driven, the second pulley 11 rotates thereby. On the contrary, when the second pulley 11 rotates when the engine 70 is stopped, the first pulley 71 rotates thereby.

  The angle sensor 30 includes a first angle sensor 31 that detects the rotation angle (crank angle) of the engine 70 and a second angle sensor 32 that detects the rotation angle of the second pulley 11. The control unit 50 includes a first control unit 51 that controls the driving of the engine 70 and a second control unit 52 that controls the driving of the power generation unit 10. The second control unit 52 calculates the crank angle with higher resolution than the first angle sensor 31 based on the signal sent from the first control unit 51 and the signal sent from the second angle sensor 32. The second control unit 52 causes the second pulley 11 to generate torque when the engine 70 is stopped, thereby rotating the first pulley 71 and displacing the crankshaft 72 to an ideal position suitable for restarting the engine 70. Hereinafter, the components of the crankshaft position control device 100 will be described individually.

  The power generation unit 10 generates power by the rotation of the engine 70 and the rotation of wheels (not shown). The power generation unit 10 according to the present embodiment also has a function of rotating the crankshaft 72 (engine 70) when the engine 70 is started, and specifically is an ISG (Integrated Starter Generator). As described above, the power generation unit 10 is provided with the second pulley 11, and the second pulley 11 is mechanically connected to the first pulley 71 via the belt 73 as shown in FIG. In addition to the pulleys 11 and 71 described above, pulleys 90 and 91 of an oil pump and an A / C compressor are connected to the belt 73, and the pulleys 90 and 91 rotate together with the pulleys 11 and 71. The belt 73 is fixed to the pulleys 11, 71, 90, 91 by three fixing portions 92 shown in FIG. 2, and the belt 73 is tensioned by the fixing portions 92. Due to such a connection structure, the pulleys 71, 90, and 91 are also rotated by the same distance as the second pulley 11 is rotated by a predetermined distance unless slipping occurs in contact with the belt 73. The diameter ip of the second pulley 11 is shorter than the diameter ep of the first pulley 71. Therefore, when the first pulley 71 rotates once, the second pulley 11 rotates more than one rotation. The rotation ratio of the two pulleys 11 and 71 is determined by the ratio of the diameters ip and ep (pulley ratio).

  The angle sensor 30 includes the first angle sensor 31 and the second angle sensor 32 as described above. As shown in FIG. 3, the first angle sensor 31 includes a crank angle sensor 33 that detects the rotation angle of the crankshaft 72 and a cam angle sensor 34 that detects the rotation angle of a cam (not shown). The crank angle sensor 33 includes a magnetoelectric conversion circuit 35 that converts a magnetic signal into an electric signal, and a processing circuit 36 that performs analog signal processing and digital signal processing on an output signal of the magnetoelectric conversion circuit 35. Similarly, the cam angle sensor 34 includes a magnetoelectric conversion circuit 37 that converts a magnetic signal into an electric signal, and a processing circuit 38 that performs analog signal processing and digital signal processing on the output signal of the magnetoelectric conversion circuit 37. Each of the magnetoelectric conversion circuits 35 and 37 has a plurality of magnetoresistive effect elements whose resistance values vary in accordance with the transmission direction of the magnetic flux passing through the magnetoelectric conversion circuits 35 and 37, and a bridge circuit is formed by the plurality of magnetoresistive effect elements. Although not shown, the magnetoelectric conversion circuit 35 has a bias magnet that transmits magnetic flux to the rotating body 74 provided on the crankshaft 72 via the bridge circuit described above, and the magnetoelectric conversion circuit 37 is camped via the bridge circuit. And a bias magnet that transmits the magnetic flux to the rotating body 75 provided on the rotating body 75. As shown in FIG. 3, protrusions are formed on the annular surface of the rotating body 74 at intervals of 30 °, and one protrusion is formed on the annular surface of the rotating body 75. When these rotators 74 and 75 rotate together with the crankshaft 72 and the cam, the protrusions formed on the rotators 74 and 75 also rotate, whereby the transmission direction of magnetic flux passing through the bridge circuit of the magnetoelectric conversion circuits 35 and 37 is changed. fluctuate. For this reason, electrical signals corresponding to fluctuations in the transmission direction are output from the magnetoelectric conversion circuits 35 and 37 to the processing circuits 36 and 38. The processing circuits 36 and 38 amplify the input output signals of the magnetoelectric conversion circuits 35 and 37 or remove noise to perform analog signal processing, and then perform binarization processing and digital signal processing based on a threshold value. . Therefore, as shown in FIG. 5, the processing circuit 36 outputs a pulse signal in which one pulse rises every time the crankshaft 72 rotates 30 °, and the processing circuit 38 rotates the crankshaft 72 by 720 ° (the engine 70 A pulse signal in which one pulse rises every time one rotation) is output. These two pulse signals are input from the processing circuits 36 and 38 to the first control unit 51 by at least one of wiring and communication. Hereinafter, the pulse signal output from the crank angle sensor 33 is referred to as a crank signal, and the pulse signal output from the cam angle sensor 34 is referred to as a cam signal.

  The second angle sensor 32 detects the rotation angle of the power generation unit 10 by detecting the rotation angle of the second pulley 11. As shown in FIG. 4, the second angle sensor 32 includes a magnetoelectric conversion circuit 39 and a processing circuit 40. No protrusion is formed on the second pulley 11 to be detected by the second angle sensor 32, and a magnet 76 composed of a pair of magnetic poles is provided on the second pulley 11. Therefore, the transmission direction of the magnetic flux passing through the magnetoelectric conversion circuit 39 is changed every rotation by the rotation of the second pulley 11. Therefore, an electrical signal corresponding to the rotation period of the second pulley 11 is output from the magnetoelectric conversion circuit 39. The magnetoelectric conversion circuit 39 according to the present embodiment has a Hall element. The processing circuit 40 calculates the rotation angle of the second pulley 11 according to the electrical signal (Hall voltage) output from the magnetoelectric conversion circuit 39. The processing circuit 40 outputs the calculated rotation angle of the second pulley 11 to the second control unit 52 by at least one of wiring and communication.

  The second angle sensor 32 has a higher resolution than the crank angle sensor 33. As described above, the resolution of the crank angle sensor 33 is 30 °, but the resolution of the second angle sensor 32 is several times that. In the present embodiment, the resolution of the second angle sensor 32 is 5 times, and is 6 ° when converted to the rotation angle of the crankshaft 72.

  As described above, the control unit 50 includes the first control unit 51 and the second control unit 52. The first control unit 51 controls the driving state of the engine 70 based on the first angle sensor 31 and sensor signals that detect the traveling state of various vehicles such as a vehicle speed sensor and a throttle opening (not shown). Since the engine 70 is a four-cycle engine, the engine 70 makes one rotation by performing a series of operations of suction, compression, explosion (expansion), and exhaust. In this series of operations, the crankshaft 72 rotates twice and the cam rotates once. The first control unit 51 calculates the crank angle based on the crank signal and the cam signal shown in FIG. Specifically, the first control unit 51 counts one time each time the pulse included in the crank signal rises, and resets the count of the crank signal counted so far when the pulse included in the cam signal rises. . As described above, the crank signal is a pulse signal that rises one pulse every time the crankshaft 72 rotates 30 °, and the cam signal is a pulse signal that rises one pulse every time the crankshaft 72 rotates 720 °. Accordingly, the first control unit 51 repeats canceling the above-mentioned pulse count to zero based on the rising edge of the cam signal pulse input every time the rising edge of the crank signal pulse is counted 24 times. The first control unit 51 calculates the crank angle based on the count number. For example, the count starts at time t2 in FIG. 5, 1 count is performed at time t3, and 2 counts are performed at time t4. Then, 22 counts at time t5, 23 counts at time t6, 24 counts at time t7, and the count number are cancelled. Therefore, the count number becomes zero at time t7, and the count number becomes 1 again at time t8. As described above, the count number is 2 at time t4. In this case, the first control unit 51 determines that the crank angle is 60 °. The crank angle calculated (detected) by the first control unit 51 is input to the second control unit 52.

  As shown in FIG. 6, the crankshaft 72 rotates as the piston 79 connected to the piston rod 78 moves up and down in the cylinder 77. The engine 70 has four cylinders 77, and one of the four cylinders 77 performs any one of intake, compression, explosion (expansion), and exhaust. The four pistons 79 provided in the above-described four cylinders 77 are interlocked with each other, and when suction, compression, explosion (expansion), and exhaust are sequentially performed in one of the four cylinders 77, In another cylinder 77, compression, explosion (expansion), exhaust, and suction are sequentially performed. Further, explosion (expansion), exhaust, suction, and compression are sequentially performed in a different cylinder 77, and exhaust, suction, compression, and explosion (expansion) are sequentially performed in the last remaining one cylinder 77.

  In the cylinder 77 in the intake stroke, the intake valve (not shown) is opened, and the piston 79 in the cylinder 77 moves from the top dead center to the bottom dead center side. By doing so, air is sucked into the cylinder 77. In the cylinder 77 in the compression stroke, the air in the cylinder 77 is compressed by moving the piston 79 in the cylinder 77 from the bottom dead center to the top dead center side. In the cylinder 77 in the explosion (expansion) stroke, fuel is applied in the cylinder 77 in the form of a mist and sparks are generated, thereby causing an explosion in the cylinder 77. This explosion energy causes the piston 79 in the cylinder 77 to move from the top dead center to the bottom dead center, and the air in the cylinder 77 is expanded. In the cylinder 77 in the exhaust stroke, an exhaust valve (not shown) is opened, and the piston 79 in the cylinder 77 moves from the bottom dead center to the top dead center side. By doing so, the exhaust gas in the cylinder 77 is exhausted.

  In this embodiment, when the engine 70 is restarted, the fuel is exploded in the cylinder 77 in the explosion (expansion) stroke, and the piston 79 is moved from the top dead center to the bottom dead center side. However, when the piston 79 is located near the top dead center, the air in the cylinder 77 cannot be sufficiently secured, and the crankshaft 72 cannot be sufficiently rotated by the energy (explosion energy) generated by the fuel. On the contrary, when the piston 79 is located near the bottom dead center, there is no room for the piston 79 to be displaced by the explosion of the fuel, and therefore the crankshaft 72 cannot be sufficiently rotated by the explosion energy. Thus, when the engine 70 is restarted, in order to sufficiently rotate the crankshaft 72 by fuel combustion (explosion), it is suitable for the crankshaft 72 to rotate between the top dead center and the bottom dead center. It is necessary to arrange at an ideal position (position where rotation is most likely). This ideal position is a predetermined range between the top dead center and the bottom dead center, and is a position where the crankshaft 72 can be sufficiently rotated by the above-described explosion energy. When the crank angle at the bottom dead center is 0 ° and the crank angle at the top dead center is 180 °, the ideal position is, for example, a range of 90 ° ± 30 °. The displacement of the crankshaft 72 to the ideal position is performed by the second control unit 52 controlling the driving of the power generation unit 10. Although the crankshaft 72 rotates inertially after the engine 70 is stopped, the above-described displacement of the crankshaft 72 to the ideal position may be performed while the crankshaft 72 is inertially rotated. It may be done after a complete stop.

  The second control unit 52 controls the driving state of the power generation unit 10. When the engine 70 is in a driving state, the second pulley 11 is rotated by the rotational force transmitted through the belt 73, and the power generation unit 10 generates power. In contrast, when the engine 70 is stopped, the second control unit 52 rotates the second pulley 11 to rotate the first pulley 71 via the belt 73, and the engine 70 is restarted. The crankshaft 72 is displaced to a suitable position. When the engine 70 is started, the second control unit 52 assists the rotation of the crankshaft 72 by rotating the second pulley 11 of the power generation unit 10. As described above, since the crankshaft 72 is displaced to a position suitable for restarting the engine 70, the second control unit 52 explodes the assistance of the crankshaft 72 due to the rotation of the second pulley 11 in the cylinder 77. To be done after Thereby, compared with the structure which cranks the engine 70 only by rotation of the 2nd pulley 11, the electric power consumed in the 2nd pulley 11 for the restart of the engine 70 is reduced.

  As described above, the first pulley 71 and the second pulley 11 are connected via the belt 73. Therefore, the first pulley 71 is also rotated by the amount that the second pulley 11 is rotated, and the rotation angles of both are related by the pulley ratio. The relationship between the two is expressed as P1 = P2 × (ip / ep) where P1 is the rotation angle of the first pulley 71 (crankshaft 72) and P2 is the rotation angle of the second pulley 11. Further, every time the first control unit 51 calculates (detects) the crank angle, the second control unit 52 receives the crank angle from the first control unit 51, and the second control unit 52 calculates the pulley ratio described above. I remember it. The second control unit 52 sequentially calculates the crank angle by substituting the crank angle input at a predetermined timing and the rotation angle of the second pulley 11 detected by the second angle sensor 32 after the predetermined timing into the above relational expression. . For example, when information about the crank angle of 30 ° is input from the first control unit 51 to the second control unit 52, the second control unit 52 sequentially calculates P1 and adds it to 30 °, thereby sequentially adding the crank angle. calculate. As described above, the second angle sensor 32 has a higher resolution than the crank angle sensor 33, and is 6 ° when converted to the rotation angle of the crankshaft 72. Therefore, the second control unit 52 sequentially calculates the crank angle as 36 °, 42 °, 48 °, and 54 °.

  In addition, as described above, as long as no slip occurs in contact with the belt 73, the first pulley 71 connected via the belt 73 is also rotated by the same distance as the second pulley 11 is rotated by a predetermined distance. However, if slippage occurs in contact with the belt 73 for some reason, the first pulley 71 does not rotate the same distance by the amount that the second pulley 11 has rotated a predetermined distance. Therefore, as described above, the rotation angles of the first pulley 71 (crank angle) and the second pulley 11 cannot be related based on the relationship of the pulley ratio. Therefore, the second control unit 52 detects the calculated crank angle based on the crank signal and the cam signal in order to synchronize the crank angle detected by the first control unit 51 with the crank angle calculated by itself. To match periodically. FIG. 5 shows the crank angle calculated by the second control unit 52 as a calculation signal. As shown by the broken line and the alternate long and short dash line in FIG. 5, the second control unit 52 matches the calculated crank angle with the detected crank angle every time one pulse included in the crank signal rises. By doing so, the calculated crank angle and the detected crank angle are synchronized. Thereafter, the second control unit 52 calculates the rotation angle ΔP2 of the second pulley 11 each time the rotation angle of the second pulley 11 is detected by the second angle sensor 32. Next, the second control unit 52 calculates the crank angle ΔP1 = ΔP2 × (ip / ep) per detection period of the rotation angle of the second pulley 11 based on the calculated rotation angle ΔP2 and the above-described relational expression. Finally, the second control unit 52 sequentially adds the calculated rotation angle ΔP1 to the crank angle at the time of synchronization. When the crank angle at the time of synchronization is P0, the crank angle is expressed as P1 = P0 + ΣΔP1 by the processing of the second control unit 52 described above. By performing this calculation, the crank angle is calculated by the second control unit 52. For example, when synchronization is made at time t1 shown in FIG. 5, P0 is 30 °. Thereafter, the second control unit 52 sequentially calculates the crank angle P1 as 36 °, 42 °, 48 °, and 54 °. When time t2 is reached, synchronization is again performed, and P0 becomes 60 °. Thereafter, the second control unit 52 sequentially calculates the crank angle P1 as 66 °, 72 °, 78 °, and 84 °. Therefore, in the present embodiment, the above-mentioned predetermined timing is the edge rising timing of the pulse of the crank signal.

  Note that Σ is a symbol indicating that the calculated ΔP1 is sequentially added. In FIG. 5, the sequential addition of ΔP <b> 1 is shown by the sequential rise of pulses having a middle voltage level in the calculation signal. This calculation signal is shown in order to simplify the description of the synchronization and calculation of the crank angle, and is not actually generated.

  Next, the crank angle calculation process will be described with reference to FIG. First, in step S10, the second control unit 52 detects whether a pulse of the crank signal has risen. When the crank signal pulse rises, the second control unit 52 proceeds to step S20, and when the crank signal pulse does not rise, the second control unit 52 proceeds to step S30.

  In step S20, the second control unit 52 synchronizes the calculated crank angle with the detected crank angle, and matches the calculated crank angle with the detected crank angle. By doing so, the difference in rotation due to the slip of the belt 73 is canceled, and the second pulley 11 and the crank angle are related by the pulley ratio. Thereafter, the second controller 52 ends the crank angle calculation process once and returns to step S10 again.

  In step S30, the second control unit 52 calculates the rotation angle ΔP2 of the second pulley 11 per detection period of the rotation angle of the second pulley 11. Then, the second control unit 52 proceeds to step S40.

  In step S40, the second control unit 52 calculates the crank angle ΔP1 per detection period of the rotation angle of the second pulley 11 based on the calculated rotation angle ΔP2 and the relational expression ΔP1 = ΔP2 × (ip / ep). To do. Then, the second control unit 52 proceeds to step S50.

  In step S50, the second control unit 52 adds the rotation angle ΔP1 calculated in step S40 to the crank angle synchronized in step S20. By doing so, the second control unit 52 calculates the crank angle. Thereafter, the second controller 52 ends the crank angle calculation process once and returns to step S10 again.

  The second control unit 52 repeats steps S10 to S50 described above to cancel the slip of the belt 73 and sequentially updates and calculates the crank angle.

  Next, the displacement process to the ideal position of the engine 70 will be described based on FIG. First, in step S110, the second control unit 52 calculates the current crank angle in the stopped state. The second control unit 52 calculates the difference between the stored ideal position (ideal angle) of the crankshaft 72 and the current crank angle (current angle) calculated in steps S10 to S50. In step S110, the second controller 52 calculates the difference between the ideal angle of the crankshaft 72 and the current angle during the explosion (expansion) stroke. After performing the above processing, the second control unit 52 proceeds to step S120.

  In step S120, the second control unit 52 calculates the minimum amount of rotation of the second pulley 11 (minimum rotation angle) in order to displace the crankshaft 72 to the ideal position. As described above, the four cylinders 77 are in one of the strokes of suction, compression, explosion (expansion), and exhaust. For example, it is conceivable that the crankshaft 72 of the cylinder 77 in the compression stroke is rotated halfway to make an explosion (expansion) stroke, and then the crankshaft 72 is displaced to an ideal position. However, in this process, the second pulley 11 is rotated excessively. Therefore, as described above, the minimum rotation of the second pulley 11 means that the crankshaft 72 of the cylinder 77 in the explosion (expansion) stroke is displaced to the ideal position. The second control unit 52 calculates an angle necessary for displacing the crankshaft 72 of the cylinder 77 in the explosion (expansion) stroke to the ideal position. Next, the second control unit 52 proceeds to step S130. In the above-described explosion (expansion) process, the crankshaft 72 rotates by a crank angle of 180 °. Therefore, the minimum rotation angle described above is a value greater than 0 ° and less than 180 ° when converted to a crank angle.

  If it progresses to step S130, the 2nd control part 52 will determine whether the crankshaft 72 exists in an ideal position. In other words, the second control unit 52 determines whether or not the difference between the ideal angle calculated in step S110 and the current angle is within an allowable range for starting the engine 70. When it determines with it being in the tolerance | permissible_range, the 2nd control part 52 complete | finishes the displacement process to the ideal position of the engine 70. FIG. On the other hand, if it is determined that it is outside the allowable range, the second control unit 52 proceeds to step S140.

  In step S140, the second control unit 52 calculates how much torque must be generated in the second pulley 11 to stop the crankshaft 72 at the ideal position. The second controller 52 calculates the torque (stop position adjustment torque) for adjusting the stop position of the crankshaft 72, and then proceeds to step S150.

  If it progresses to step S150, the 2nd control part 52 will rotate the 1st pulley 71 by actually rotating the 2nd pulley 11 based on the calculated torque, and will displace the crankshaft 72 to an ideal position. Thereby, the stop position of the crankshaft 72 is adjusted. Thereafter, the second control unit 52 proceeds to step S160. For example, as described above, when the crank angle at the bottom dead center is 0 °, the crank angle at the top dead center is 180 °, and the crankshaft 72 is 150 ° at the time of stopping, the ideal position is 90 ° ± 30. The crankshaft 72 is rotated forward by 30 ° to 90 ° and moved to the bottom dead center side so as to be located in the range of ° (allowable range). Alternatively, when the crankshaft 72 is positioned at 160 °, the crankshaft 72 is reversely rotated by 40 ° to 100 ° and moved to the top dead center side so as to be positioned within the above-described allowable range. Thus, by rotating the crankshaft 72 by less than a half rotation, the crankshaft 72 is displaced to a position suitable for restarting the engine 70.

  In step S160, the second control unit 52 calculates the stop position of the crankshaft 72 based on the relational expression between the output signal of the second angle sensor 32 (rotation angle of the second pulley 11) and the pulley ratio, and this stop It is determined whether or not the position is an ideal position. When it determines with it being an ideal position, the 2nd control part 52 complete | finishes the displacement process to the ideal position of the engine 70. FIG. On the other hand, if it is determined that the second pulley 11 does not rotate as calculated in step S120 and the stop position of the crankshaft 72 is not the ideal position, the second control unit 52 returns to step S140, Steps S140 to S160 are sequentially repeated. Thus, the stop position of the crankshaft 72 is finely adjusted by rotating the second pulley 11 after the engine 70 is stopped.

  Next, the effect of the crankshaft position control apparatus 100 according to the present embodiment will be described. As described above, the first pulley 71 of the engine 70 is connected to the pulleys 90 and 91 of the oil pump and the A / C compressor via the belt 73 in addition to the second pulley 11 of the power generation unit 10. Therefore, the engine 70 rotates against the resistance of these oil pumps and A / C compressors. Therefore, when the engine is stopped, the crankshaft is stopped at a position suitable for restarting the engine by adjusting the rotation amount of the inertial rotation of the crankshaft. This is due to the resistance of the oil pump and A / C compressor. There is a possibility that the accuracy of the stop position of the crankshaft 72 is lowered.

  On the other hand, in this embodiment, the power generation unit connected to the first pulley 71 of the crankshaft 72 via the belt 73 so that the crankshaft 72 is displaced to a position suitable for restarting the engine 70. Ten second pulleys 11 are rotated. Thus, since the second pulley 11 is rotated regardless of the resistance of the oil pump or the A / C compressor, the crankshaft 72 can be accurately restarted regardless of the resistance of the oil pump or the A / C compressor. Can be displaced. Furthermore, unlike the configuration without the element for rotating the crankshaft, the rotation angle of the crankshaft 72 can be finely adjusted. For example, as shown in FIG. 8, in this embodiment, the stop position of the crankshaft 72 is finely adjusted by repeating steps S140 to S160.

  Since the first pulley 71 and the second pulley 11 are connected via the belt 73 as described above, the rotation angle of the crankshaft 72 is calculated based on the pulley ratio between them and the rotation angle of the second pulley 11. be able to.

  In order to synchronize the detected crank angle with the calculated crank angle, the calculated crank angle is periodically matched with the detected crank angle based on the crank signal and the cam signal. As described above, since the first pulley 71 and the second pulley 11 are connected via the belt 73, the first pulley 71 also rotates as much as the second pulley 11 rotates. Is related by However, when at least one of the two pulleys 11 and 71 and the belt 73 slip for some reason, the first pulley 71 does not rotate as much as the second pulley 11 rotates. Therefore, the rotation angles of the two pulleys 11 and 71 are not related by the pulley ratio. Therefore, in order to cancel the difference in rotation due to the slip described above, the calculated crank angle is periodically made to coincide with the detected crank angle. As a result, the rotation angles of the two pulleys 11 and 71 are related by the pulley ratio, and it is possible to prevent the accuracy of displacing the crankshaft 72 to a position suitable for restarting the engine 70 due to slipping.

  In addition, the second control unit 52 according to the present embodiment makes the calculated crank angle coincide with the detected crank angle each time one pulse included in the crank signal rises, and calculates the calculated crank angle and the detected crank angle. Synchronize According to this, each time the pulse included in the cam signal rises or falls, the rotation due to slippage of the pulleys 11 and 71 and the belt 73 is compared with the configuration in which the calculated crank angle is made to coincide with the detected crank angle. The difference can be canceled frequently. Therefore, it is possible to more effectively suppress the accuracy of displacing the crankshaft 72 to a position suitable for restarting the engine 70 due to slipping.

  The second control unit 52 calculates ΔP1 = ΔP2 × (ip / ep) and calculates the crank angle by sequentially adding the calculated ΔP1 to the crank angle P0 at the time of synchronization. According to this, compared with the structure which detects a crank angle only by the output signal of the 1st angle sensor 31, a crank angle can be detected with high resolution.

  The second control unit 52 rotates the second pulley 11 by a minimum rotation angle (less than half rotation) to displace the crankshaft 72 to the ideal position. Since the crankshaft 72 rotates, there are several positions where the crankshaft 72 is suitable when the engine 70 is restarted. On the other hand, as described above, the crankshaft 72 is displaced to a position suitable for restarting the engine 70 by the minimum rotation of the second pulley 11. According to this, for example, the power consumption required for the rotation of the second pulley 11 is reduced as compared with a configuration in which the crankshaft is displaced to a position suitable for restarting the engine by making one extra rotation.

  The preferred embodiments of the present invention have been described above. However, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention.

  In the present embodiment, an example in which the crankshaft position control device 100 is applied to a four-cycle engine is shown. However, the application of the crankshaft position control device 100 is not limited to the above example, and can be applied to, for example, a two-cycle engine. In this case, the crankshaft 72 also makes one revolution while the engine 70 makes one revolution.

  Each of the magnetoelectric conversion circuits 35 and 37 has a plurality of magnetoresistive effect elements, and an example is shown having a bridge circuit assembled by these plurality of magnetoresistive effect elements. However, the magnetoelectric conversion circuits 35 and 37 can also employ a configuration having Hall elements.

  Moreover, the example in which the magnetoelectric conversion circuits 35 and 37 have a bias magnet was shown. However, if the rotating bodies 74 and 75 apply a magnetic flux to the magnetoelectric conversion circuits 35 and 37, the magnetoelectric conversion circuits 35 and 37 may not have a bias magnet.

  In the present embodiment, an example is shown in which protrusions are formed at intervals of 30 ° on the annular surface of the rotating body 74 provided on the crankshaft 72. However, the interval between the protrusions formed on the rotating body 74 is not limited to the above example, and for example, 15 ° may be employed.

  In the present embodiment, an example in which one protrusion is formed on the annular surface of the rotating body 75 provided on the cam is shown. However, the number of protrusions formed on the rotating body 75 is not limited to the above example, and for example, four protrusions may be formed at 90 ° intervals. However, when the plurality of protrusions are formed on the rotating body 75 in this way, one of the plurality of protrusions has a shape different from that of the other protrusions to indicate that the rotating body 75 has made one rotation. .

  In the present embodiment, the processing circuits 36 and 38 show an example in which the output signals of the input magnetoelectric conversion circuits 35 and 37 are subjected to analog signal processing and then digital signal processing is performed. However, the processing circuits 36 and 38 may only perform analog signal processing on the output signals of the input magnetoelectric conversion circuits 35 and 37. In this case, the digital signal processing is performed by the first control unit 51.

  In the present embodiment, an example is shown in which the resolution of the second angle sensor 32 is 6 ° when converted to a crank angle. However, the resolution of the second angle sensor 32 is not limited to the above example. It can be changed as appropriate according to the adjustment accuracy of the stop position of the crankshaft 72. For example, when a resolver is employed as the second angle sensor 32, higher resolution can be achieved.

  In the present embodiment, the first control unit 51 counts up every time a pulse included in the crank signal rises, and when the pulse included in the cam signal rises, the count number (crank angle) of the crank signal counted so far. An example of resetting was shown. However, the first control unit 51 counts up every time the pulse included in the crank signal falls, and when the pulse included in the cam signal falls, even if the count number of the crank signal counted so far is reset. Good. In other words, the trigger for counting and resetting may be either rising or falling of a pulse.

  In this embodiment, if the crank angle at the bottom dead center is 0 ° and the crank angle at the top dead center is 180 °, the ideal position suitable for the rotation of the crankshaft 72 is a range of 90 ° ± 30 ° ( An example of an allowable range is shown. However, this allowable range is only an example, and may be 90 ° ± 15 °, for example.

  In the present embodiment, an example is shown in which the second control unit 52 assists the rotation of the crankshaft 72 (engine 70) by rotating the second pulley 11 of the power generation unit 10 when the engine 70 is started. However, since the crankshaft 72 is displaced to a position suitable for restarting the engine 70 by the second pulley 11, the second control unit 52 does not have to rotate the second pulley 11 of the power generation unit 10 when the engine 70 is started. Good.

  In this embodiment, the 2nd control part 52 showed the example which synchronizes the detected crank angle and the calculated crank angle. However, the detected crank angle and the calculated crank angle need not be synchronized. In this case, the second controller 52 determines the crankshaft 72 based on the crank angle input from the first controller 51, the output signal of the second angle sensor 32 (rotation angle of the second pulley 11), and the pulley ratio. Adjust the stop position.

  In the present embodiment, the second control unit 52 synchronizes the calculated crank angle with the detected crank angle by matching the calculated crank angle with the detected crank angle each time one pulse included in the crank signal rises. An example to do. However, the second control unit 52 may synchronize the calculated crank angle with the detected crank angle every time at least one of the plurality of pulses included in the crank signal rises. For example, as shown in step S10 of FIG. 9, the second control unit 52 calculates the crank angle calculated when the crank angle is 30 ° (in FIG. 5, at the rising timing of the pulse of the crank signal at time t3). The detected crank angle may be synchronized. Further, the calculated crank angle may be synchronized with the detected crank angle even when the crankshaft 72 rotates once and the crank angle is 390 °. That is, you may synchronize every time the crankshaft 72 rotates once. The frequency of synchronization can be determined as appropriate.

  In this embodiment, as shown in FIG. 8, in step S160 of the displacement process of the engine 70 to the ideal position, the second control unit 52 determines whether or not the stop position of the crankshaft 72 is the ideal position. It was. However, this step S160 may be omitted.

  In this embodiment, the 2nd control part 52 showed the example which rotates the 2nd pulley 11 minimum rotation angle, in order to displace the crankshaft 72 to an ideal position. That is, the example in which the second control unit 52 rotates the crankshaft 72 of the cylinder 77 in the explosion (expansion) stroke to the ideal position is shown. However, the second control unit 52 may displace the crankshaft 72 to an ideal position after the crankshaft 72 of the cylinder 77 in the compression stroke is set to an explosion (expansion) stroke, for example.

DESCRIPTION OF SYMBOLS 10 ... Power generation part 11 ... 2nd pulley 50 ... Control part 51 ... 1st control part 52 ... 2nd control part 70 ... Engine 71 ... 1st pulley 72 ... Crankshaft 73 ... Belt 100 ... Crankshaft position control apparatus

Claims (7)

A power generation unit (10) that generates electric power by rotation during driving of the engine (70);
A control unit (50 to 52) for controlling the driving of the power generation unit,
A first pulley (71) that rotates together with the crankshaft (72) of the engine and a second pulley (11) of the power generation unit are connected via a belt (73), and the first pulley and the second pulley are connected to each other. The other is rotated by the torque generated in either one,
The crankshaft position control device, wherein the control unit rotates the second pulley so that the crankshaft is displaced to a position suitable for restarting the engine when the engine is stopped. . A first angle sensor (31) for detecting a rotation angle of the crankshaft and the cam of the engine;
A second angle sensor (32) for detecting a rotation angle of the second pulley,
The second angle sensor has a higher resolution for detecting the rotation angle than the first angle sensor,
The control unit (52) stores a pulley ratio of the first pulley and the second pulley,
The control unit (52)
The rotation angle of the crankshaft detected by the first angle sensor at a predetermined timing when the engine is stopped, the rotation angle of the second pulley detected by the second angle sensor after the predetermined timing, and the pulley A rotation angle of the crankshaft after the predetermined timing based on the ratio,
2. The second pulley is rotated based on the calculated rotation angle of the crankshaft so that the crankshaft is displaced to a position suitable for restarting the engine. The crankshaft position control device described in 1. The first angle sensor generates a crank signal indicating a rotation angle of the crankshaft and a cam signal indicating a rotation angle of the cam;
The control unit (52) calculates based on the crank signal and the cam signal so as to synchronize the rotation angle of the crankshaft detected by the first angle sensor and the calculated rotation angle of the crankshaft. The crankshaft position control device according to claim 2, wherein the rotation angle of the crankshaft is periodically matched with the detected rotation angle of the crankshaft. The crank signal is a pulse signal in which a pulse rises and falls a plurality of times during one revolution of the engine,
The cam signal is a pulse signal that contains fewer pulses than the crank signal during one revolution of the engine,
The control unit (52) is detected by making the calculated rotation angle of the crankshaft coincide with the detected rotation angle of the crankshaft each time one pulse included in the crank signal rises or falls. The crankshaft position control device according to claim 3, wherein the rotation angle of the crankshaft is synchronized with the calculated rotation angle of the crankshaft.   The control unit (52) matches the calculated rotation angle of the crankshaft with the detected rotation angle of the crankshaft, and then detects the rotation angle of the second pulley by the second angle sensor. Further, based on the rotation angle of the second pulley and the pulley ratio, the rotation angle of the crankshaft per detection cycle of the rotation angle of the second pulley is calculated, and the crank per detection cycle is calculated. The rotation angle of the crankshaft is sequentially calculated by sequentially adding the rotation angle of the shaft to the calculated rotation angle of the crankshaft that matches the detected rotation angle of the crankshaft. The crankshaft position control device according to claim 3 or claim 4.   The position suitable for restarting the engine on the crankshaft is between a top dead center and a bottom dead center in a cylinder (77) of the engine. The crankshaft position control device according to claim 1.   The said control part displaces the said crankshaft to the position suitable for the said engine to restart by rotating the said crankshaft less than a half rotation, when the said engine stops. The crankshaft position control device described in 1.

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