Rotary engine control device

Abstract

To achieve both suppression of breakage associated with reverse rotation of a rotary engine and suppression of erroneous determination of reverse rotation of the rotary engine.SOLUTION: A control device for a rotary engine 3 includes a motor mechanically connected to the shaft of the rotary engine, a controller (motor ECU 26) that controls energization to the motor so that the rotary engine is started by driving of the motor, and a sensor (motor rotation sensor SN4). When starting the rotary engine, based on the electric signal of the sensor, the controller stops energization to the motor, if the shaft of the rotary engine reversely rotates by a predetermined angle or more and then the rotary engine continues to rotate reversely for a predetermined time.SELECTED DRAWING: Figure 7

Description

[Technical field]

[0001] The technology disclosed herein relates to a control device for a rotary engine. [Background technology]

[0002] Patent Document 1 describes an engine that performs idling stop. When this engine is restarted, if a sensor detects reverse rotation of the engine, a controller stops fuel injection and ignition into the cylinders. This prevents damage to the engine.

[0003] Patent Document 2 describes a rotary engine. The intake port of this rotary engine opens to a side housing. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2014-47746 A [Patent Document 2] JP 2010-174740 A Summary of the Invention [Problem to be solved by the invention]

[0005] When the rotary engine rotates in reverse, the edge of the side seal may interfere with the opening of the intake port formed in the side housing, causing the side seal to be damaged. Damage to the side seal reduces the fuel efficiency and emission performance of the rotary engine. When the rotary engine rotates in reverse, it is desirable to stop the rotary engine as soon as possible.

[0006] In order to quickly stop the reverse rotation of a rotary engine, it is necessary to quickly detect that the shaft has rotated in the reverse direction. However, if the shaft has rotated in the reverse direction by only a very small angle and / or for only a very small period of time, determining that the shaft has rotated in the reverse direction is likely to result in an erroneous determination.

[0007] The technology disclosed herein achieves both prevention of damage caused by reverse rotation of a rotary engine and prevention of erroneous determination of reverse rotation of a rotary engine. [Means for solving the problem]

[0008] The present disclosure relates to a control device for a rotary engine. A rotary engine having an intake port opening in a side housing; a motor mechanically connected to a shaft of the rotary engine; a controller that controls current supply to the motor so that the rotary engine is started by driving the motor; a sensor that outputs an electrical signal related to a rotation direction of the rotary engine to the controller; When starting the rotary engine, the controller stops the supply of electricity to the motor if the shaft of the rotary engine rotates in reverse by a predetermined angle or more and the rotary engine continues to rotate in reverse for a predetermined period of time based on the electrical signal of the sensor.

[0009] According to this configuration, when the rotary engine is started, the controller determines that the rotary engine has rotated in reverse if the following condition is met: the shaft of the rotary engine has rotated in reverse by a predetermined angle or more, and the rotary engine has continued to rotate in reverse for a predetermined period of time.

[0010] The controller obtains information about the rotation of the rotary engine based on the electrical signal of the sensor, which outputs an electrical signal related to the direction of rotation of the rotary engine.

[0011] When the motor functions as a starter to start the rotary engine, the rotary engine may vibrate in both forward and reverse rotation directions. Even if the engine starts, if the rotation angle of the shaft is less than a predetermined angle, the controller does not determine that the rotary engine has rotated in reverse.

[0012] Furthermore, noise in the sensor's electrical signal may lead to an erroneous judgment by the controller. Even if noise occurs, the controller will not judge that the rotary engine has rotated in reverse unless the rotary engine continues to rotate in reverse for a predetermined period of time. The controller judges that the rotary engine has rotated in reverse based on a condition that combines two parameters, the rotation angle of the shaft and the time that reverse rotation continues, thereby preventing erroneous judgment.

[0013] When the above condition is met, the controller stops the supply of electricity to the motor. This makes it possible to stop the reverse rotation of the rotary engine before the edge of the side seal interferes with the opening of the intake port formed in the side housing. This prevents damage to the rotary engine caused by the reverse rotation of the rotary engine.

[0014] Therefore, with the above-described configuration, it is possible to both prevent damage caused by reverse rotation of the rotary engine and prevent erroneous determination of reverse rotation of the rotary engine.

[0015] The controller may stop the supply of electricity to the motor so that the shaft of the rotary engine stops before it starts to rotate in reverse and reaches 70 degrees.

[0016] When a rotary engine that was in operation stops, the rotor stops when one of the working chambers is in the middle to late stage of the compression stroke. When the motor is de-energized and the rotary engine is rotating by inertia, the pressure in the working chamber increases as the compression stroke progresses from the early stage to the middle stage and then to the late stage, which creates rotational resistance for the rotary engine. More specifically, the rotary engine stops at a rotational position of approximately ATDC-90deg.

[0017] In addition, in a rotary engine having a rotor with a substantially triangular shape, the rotor housing is divided by the major axis into an intake stroke / exhaust stroke region and a compression stroke / expansion stroke region. The intake port opens into the side housing in the region corresponding to the intake stroke. The inventors of the present application have found the following regarding reverse rotation of a rotary engine. That is, if the shaft of a rotary engine stopped at the above-mentioned rotation position ATDC-90deg rotates in the reverse direction by 135deg or more, there is a risk that the edge of the side seal will interfere with the opening of the intake port.

[0018] Therefore, taking into consideration a safety factor, if the power supply to the motor is stopped so that the rotary engine shaft stops before it reaches 70 degrees after it starts to rotate in reverse, damage to the rotary engine due to reverse rotation can be suppressed. As mentioned above, the rotary engine shaft continues to rotate due to inertia even after the power supply to the motor is stopped. Power supply to the motor is stopped so that the rotary engine shaft stops before it reaches 70 degrees after it starts to rotate in reverse, including the continued rotation due to inertia.

[0019] The predetermined angle may be 5 degrees within 10 msec from the start of reverse rotation.

[0020] Based on this condition, the controller can distinguish between vibrations that occur when the rotary engine is started and the shaft of the rotary engine rotating in reverse.

[0021] The predetermined time period may be 5 msec.

[0022] Based on this condition, the controller can determine that the rotary engine is rotating in reverse while eliminating the effects of noise in the sensor's electrical signal.

[0023] the controller estimates a rotation angle of the shaft when power supply to the motor is stopped 15 msec after the start of reverse rotation, based on a maximum starting torque of the motor and an inertia of the rotary engine; The controller may also use the motor to change the rotational position of the shaft in a positive rotation direction before starting the rotary engine if the estimated angle exceeds 70 degrees.

[0024] Assuming that the motor rotates in the reverse direction when the rotary engine is started and the power supply to the motor continues for 15 msec before stopping, the angle through which the rotary engine shaft rotates can be calculated from the maximum starting torque of the motor and the inertia of the rotary engine. If the rotation angle of the shaft exceeds 70 degrees, there is a concern that the edge of the side seal may interfere with the opening of the intake port formed in the side housing.

[0025] If the estimated shaft rotation angle exceeds 70 degrees, the controller uses the motor to change the shaft's rotational position before starting the rotary engine to the forward rotation direction. This causes the shaft's rotational position at the time the rotary engine is started to be more advanced than the aforementioned ATDC-90 degrees. This prevents the edge of the side seal from interfering with the opening of the intake port even if the shaft rotates in reverse beyond 70 degrees when the rotary engine is started. This both prevents damage caused by the reverse rotation of the rotary engine and prevents erroneous determination of the reverse rotation of the rotary engine.

[0026] the controller estimates a rotation angle of the shaft when power supply to the motor is stopped 15 msec after the start of reverse rotation, based on a maximum starting torque of the motor and an inertia of the rotary engine; The controller may also use the motor to change the rotational position of the shaft to a forward rotation direction before starting the rotary engine if the end of a side seal of the rotary engine would interfere with the opening of the intake port if the shaft rotates in the reverse direction by the estimated angle.

[0027] As before, the controller estimates the rotation angle of the rotary engine shaft if the motor were to rotate in reverse and continue to rotate in reverse for 15 msec.

[0028] Unlike the above configuration, the controller determines whether the end of the side seal will interfere with the opening of the intake port when the shaft rotates in the reverse direction by an estimated angle based on the rotational position of the shaft at the time the rotary engine is started. This is because rotary engines do not always stop at a fixed position. If the controller determines that interference will occur, it uses the motor to change the rotational position of the shaft to the forward rotation direction.

[0029] By doing this, when the rotary engine is started, the rotational position of the shaft has progressed further in the forward direction. When the rotary engine is started, the motor is energized for 15 msec. Even if the shaft rotates in reverse during this period, the edge of the side seal is prevented from interfering with the opening of the intake port formed in the side housing. This achieves both prevention of damage caused by the reverse rotation of the rotary engine and prevention of erroneous determination of the reverse rotation of the rotary engine. Effect of the Invention

[0030] As described above, the control device for a rotary engine can simultaneously prevent damage caused by reverse rotation of the rotary engine and prevent erroneous determination of reverse rotation of the rotary engine. [Brief description of the drawings]

[0031] [Figure 1] FIG. 1 illustrates an exemplary electric vehicle control system. [Diagram 2] FIG. 2 illustrates an exemplary rotary engine. [Diagram 3] FIG. 3 illustrates the operation of an exemplary rotary engine. [Figure 4] FIG. 4 shows an example of interference between a side seal and an intake port of a rotary engine. [Diagram 5] FIG. 5 illustrates an example battery management procedure and an example motor control procedure. [Figure 6] FIG. 6 shows an example engine control procedure. [Figure 7] FIG. 7 illustrates an exemplary engine starting procedure. [Figure 8] FIG. 8 shows simulation results for an exemplary reverse rotation. [Figure 9] FIG. 9 shows a procedure of a modified engine control. [Figure 10] FIG. 10 shows a procedure of a modified engine control. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0032] Hereinafter, an embodiment of a control device for a rotary engine will be described with reference to the drawings. The control device for a rotary engine described here is an example.

[0033] (Overall configuration of electric vehicle) 1 shows a control system for an electric vehicle. The electric vehicle 1 is equipped with a traction motor 11 for driving. The traction motor 11 is mechanically connected to drive wheels 14, 14 via a reduction gear 13. The reduction gear 13 reduces the output of the traction motor 11. When the output of the traction motor 11 is transmitted to the drive wheels 14, 14, the electric vehicle 1 starts to drive.

[0034] The electric vehicle 1 includes a high-voltage battery 23. The high-voltage battery 23 stores electric power for traveling. The high-voltage battery 23 is, for example, a lithium-ion battery.

[0035] The traveling motor 11 is electrically connected to the high-voltage battery 23 via a first inverter 21. The traveling motor 11 and the first inverter 21 are electrically connected via a harness wire shown by a dashed line in FIG. 1, and the first inverter 21 and the high-voltage battery 23 are electrically connected via a harness wire. The traveling motor 11 receives power supply from the high-voltage battery 23 and performs power running. The traveling motor 11 also performs power generation operation when the electric vehicle 1 is decelerating. The first inverter 21 supplies regenerative power of the traveling motor 11 to the high-voltage battery 23. The high-voltage battery 23 is charged by the regenerative power of the traveling motor 11.

[0036] The electric vehicle 1 is equipped with a range extender device 30. The range extender device 30 includes a generator motor 12 for generating electricity, and an internal combustion engine that drives the generator motor 12. In the electric vehicle 1 illustrated here, the internal combustion engine is a rotary engine 3.

[0037] The shaft of the rotary engine 3 is mechanically connected to the generator motor 12. When the rotary engine 3 operates, the generator motor 12 operates to generate electricity. The configuration of the rotary engine 3 will be described in detail later.

[0038] The generator motor 12 is connected to the high-voltage battery 23 via the second inverter 22. The generator motor 12 and the second inverter 22 are electrically connected via a harness wire shown by a dashed line in FIG. 1, and the second inverter 22 and the high-voltage battery 23 are electrically connected via a harness wire. The second inverter 22 supplies the power generated by the generator motor 12 to the high-voltage battery 23. The high-voltage battery 23 is charged by the power generated by the generator motor 12. As will be described later, the generator motor 12 may also be powered by receiving power from the high-voltage battery 23. The generator motor 12 also functions as a starter. The generator motor 12 applies a cranking torque to the rotary engine 3 to start the rotary engine 3.

[0039] The electric vehicle 1 includes an engine ECU (Electric Control Unit) 25, a motor ECU 26, and a battery ECU 27. The engine ECU 25, the motor ECU 26, and the battery ECU 27 are each a controller based on a well-known microcomputer. Each ECU includes a central processing unit (CPU), a memory, and an I / F circuit. The CPU executes a program. The memory is composed of, for example, a random access memory (RAM) or a read only memory (ROM). The memory stores programs and data. The I / F circuit inputs and outputs electric signals.

[0040] The engine ECU 25, the motor ECU 26, and the battery ECU 27 are connected to each other via a Car Area Network (CAN) communication line 28. The engine ECU 25, the motor ECU 26, and the battery ECU 27 can transmit and receive signals to and from each other via the CAN communication line 28.

[0041] The engine ECU 25 is electrically connected to the rotary engine 3 via a signal line indicated by a two-dot chain line. The engine ECU 25 controls the rotary engine 3. An eccentric angle sensor SN1 is connected to the engine ECU 25. The eccentric angle sensor SN1 outputs a signal related to the rotation of an eccentric shaft 35, which is the output shaft of the rotary engine 3. The engine ECU 25 can obtain information on the rotational position of the rotary engine 3 based on the signal of the eccentric angle sensor SN1.

[0042] The engine ECU 25 has, as functional blocks, an engine operating point setting unit 251 and an engine control unit 252. The control of the rotary engine 3 by the engine ECU 25 will be described in detail later.

[0043] The motor ECU 26 is electrically connected to the first inverter 21 and the second inverter 22 via signal lines indicated by dashed double-dashed lines. The motor ECU 26 controls the travel motor 11 through the first inverter 21. The motor ECU 26 controls the generator motor 12 through the second inverter 22.

[0044] An accelerator opening sensor SN2, a vehicle speed sensor SN3, and a motor rotation sensor SN4 are connected to the motor ECU 26. The accelerator opening sensor SN2 outputs a signal corresponding to the depression amount of the accelerator pedal to the motor ECU 26. The vehicle speed sensor SN3 outputs a signal corresponding to the speed of the electric vehicle 1 to the motor ECU 26.

[0045] The motor rotation sensor SN4 outputs a signal related to the rotation of the generator motor 12 to the motor ECU 26. The motor rotation sensor SN4 includes photointerrupters arranged at different positions around the shaft of the generator motor 12. Since the output signals of the photointerrupters have different phases, the motor ECU 26 can determine the rotation direction of the generator motor 12, that is, whether it is forward rotation or reverse rotation. Based on the signal from the motor rotation sensor SN4, the motor ECU 26 can also determine the rotation angle of the eccentric shaft 35 of the rotary engine 3 to which the generator motor 12 is mechanically connected.

[0046] The motor rotation sensor SN4 also outputs a signal related to the rotation of the travel motor 11 to the motor ECU .

[0047] The motor ECU 26 has, as functional blocks, a generator motor control section 261 and a travel motor control section 262. The generator motor control section 261 has a start control section 263, a generator control section 264, and a stop position control section 265. The control of the generator motor 12 by the generator motor control section 261 will be described in detail later.

[0048] The traveling motor control unit 262 controls the traveling motor 11 based on signals from the accelerator opening sensor SN2, the vehicle speed sensor SN3, and the motor rotation sensor SN4, thereby causing the electric vehicle 1 to accelerate or decelerate in response to the driver's operation of the accelerator pedal.

[0049] A voltage / current sensor SN5 is connected to the battery ECU 27. The voltage / current sensor SN5 outputs signals related to the output voltage and output current of the high-voltage battery 23 to the battery ECU 27. The battery ECU 27 has, as functional blocks, a SOC calculation unit 271 and a generated power calculation unit 272. The SOC calculation unit 271 calculates the SOC (State Of Charge) of the high-voltage battery 23 based on the signal from the voltage / current sensor SN5. The generated power calculation unit 272 calculates a target amount of power generation based on the SOC of the high-voltage battery 23 when charging of the high-voltage battery 23 is required.

[0050] A warning light 41 on the meter panel is electrically connected to the motor ECU 26. The warning light 41 is turned on upon receiving a signal from the motor ECU 26 to warn the driver.

[0051] (Rotary engine configuration) Fig. 2 illustrates the rotary engine 3. Fig. 2 illustrates the internal configuration of the rotary engine 3 as viewed from the front. The front-rear direction of the rotary engine 3 is the axial direction of the eccentric shaft 35, and is a direction perpendicular to the plane of Fig. 2.

[0052] The rotary engine 3 has one rotor 34 and a rotor accommodating chamber 31. The rotor accommodating chamber 31 is formed by a rotor housing 32 and a side housing 33. The rotor housing 32 has a trochoidal inner circumferential surface 321. The rotor 34 is accommodated in the rotor accommodating chamber 31. The rotor 34 has a roughly triangular shape. The rotor accommodating chamber 31 is partitioned by the rotor 34 into three working chambers: a first chamber 361, a second chamber 362, and a third chamber 363.

[0053] The eccentric shaft 35 is provided to pass through the rotor accommodating chamber 31. The rotor 34 is supported to perform planetary rotation with respect to the eccentric shaft 35. The rotor 34 rotates around the eccentric shaft 35 such that the three apexes move along the trochoid inner peripheral surface 321.

[0054] 4, an apex seal 341 is attached to each apex of the rotor 34. Furthermore, substantially cylindrical corner seals 342 are provided at both front and rear ends of each apex seal 341. Furthermore, side seals 343 are provided on both front and rear side surfaces of the rotor 34. The side seals 343 connect the corner seals 342 to each other substantially parallel to the outer periphery of the rotor 34.

[0055] The apex seal 341 abuts against the trochoid inner peripheral surface 321 of the rotor housing 32. As a result, the apex seal 341 maintains airtightness of the working chamber. The side seal 343 abuts against the side housing 33. As a result, the side seal 343 maintains airtightness of the working chamber. The corner seal 342 maintains airtightness at the joint between the side seal 343 and the apex seal 341.

[0056] 2, the first chamber 361, the second chamber 362, and the third chamber 363 move around the eccentric shaft 35, and the intake, compression, expansion, and exhaust strokes are performed in the first chamber 361, the second chamber 362, and the third chamber 363, respectively. The rotational force generated by this is output from the eccentric shaft 35.

[0057] More specifically, the rotor 34 rotates in the clockwise direction in Fig. 2. The rotor accommodating chamber 31 is divided into an upper left region, an upper right region, a lower right region, and a lower left region by a major axis Y and a minor axis Z passing through the rotation axis X. Each working chamber generally performs an intake stroke in the upper left region, generally performs a compression stroke in the upper right region, generally performs an expansion stroke in the lower right region, and generally performs an exhaust stroke in the lower left region.

[0058] An injector 37, a first spark plug 381, and a second spark plug 382 are attached to the rotor housing 32. The injector 37 is attached to the top of the rotor housing 32. The injector 37 injects fuel into the working chamber during the intake stroke or the compression stroke.

[0059] The first spark plug 381 is attached to the right side wall of the rotor housing 32. The second spark plug 382 is also attached to the right side wall of the rotor housing 32. The second spark plug 382 is located on the leading side of the rotor 34 relative to the first spark plug 381. The first spark plug 381 and the second spark plug 382 each ignite the air-fuel mixture in the working chamber during the compression stroke.

[0060] An intake port 391 and an exhaust port 392 are open in the side housing 33. The opening of the intake port 391 is located in the upper left region of the rotor accommodating chamber 31. The intake port 391 extends horizontally leftward from this opening in a substantially straight line inside the side housing 33. The opening of the intake port 391 opens and closes with the rotation of the rotor 34. The intake port 391 communicates with the inside of the working chamber during the intake stroke. The intake port 391 is connected to an intake passage. A throttle valve 394 is disposed in the intake passage. The throttle valve 394 is a throttle valve that adjusts the amount of air supplied to the rotary engine 3.

[0061] The opening of the exhaust port 392 is located in the lower left region of the rotor accommodating chamber 31. The opening of the exhaust port 392 is located below the opening of the intake port 391. The exhaust port 392 extends horizontally leftward from this opening in a substantially straight line inside the side housing 33. The opening of the exhaust port 392 opens and closes in accordance with the rotation of the rotor 34. The exhaust port 392 communicates with the inside of the working chamber during the exhaust stroke.

[0062] FIG. 3 shows the transition of the strokes of each working chamber of the rotary engine 3. One stroke of one working chamber corresponds to a period in which the eccentric shaft 35 rotates 270 degrees. P31 is the rotary engine 3 in which the first chamber corresponds to the start of the intake stroke. P32 is the rotary engine 3 in which the first chamber corresponds to the end of the intake stroke and the start of the compression stroke. P33 is the rotary engine 3 in which the first chamber corresponds to the end of the compression stroke and the start of the expansion stroke. P33 is the compression top dead center of the first chamber. P34 is the rotary engine 3 in which the first chamber corresponds to the end of the expansion stroke and the start of the exhaust stroke. P35 is the rotary engine 3 in which the first chamber corresponds to the end of the exhaust stroke. P35 and P31 are the same.

[0063] One cycle including the intake stroke, compression stroke, expansion stroke, and exhaust stroke of one working chamber corresponds to a period in which the eccentric shaft 35 rotates by 1080 degrees. Also, the second chamber 362 has a phase delay of 360 degrees relative to the first chamber 361. The third chamber has a phase delay of 360 degrees relative to the second chamber 362.

[0064] (Power generation control for electric vehicles) Next, power generation control of the electric vehicle 1 will be described with reference to Figures 5 and 6. First, the left flowchart in Figure 5 shows the management procedure of the high-voltage battery 23 executed by the battery ECU 27.

[0065] First, in step S51 after starting, the SOC calculation unit 271 of the battery ECU 27 calculates the SOC of the high-voltage battery 23 based on the signal of the voltage / current sensor SN5. In the following step S52, the battery ECU 27 determines whether the calculated SOC is less than the first reference SOC1. If step S52 is YES, the process proceeds to step S53. The battery ECU 27 determines that the high-voltage battery 23 needs to be charged. If step S52 is NO, the process returns to step S51.

[0066] In step S53, the battery ECU 27 calculates the decrease rate of the SOC, and in the following step S54, the power generation calculation unit 272 of the battery ECU 27 calculates the target power generation amount according to the calculated decrease rate of the SOC. The battery ECU 27 increases the target power generation amount as the decrease rate increases.

[0067] Once the target power generation amount is calculated, the battery ECU 27 outputs a power generation request to each of the engine ECU 25 and the motor ECU 26 via the CAN communication line 28 in step S55.

[0068] In step S56, the battery ECU 27 determines whether or not the rotary engine 3 has started based on information from the engine ECU 25. The process repeats step S56 until the starting of the rotary engine 3 is completed, and when the starting of the rotary engine 3 is completed, the process proceeds to step S57.

[0069] When the rotary engine 3 starts and the generator motor 12 starts generating electricity, the SOC calculation unit 271 of the battery ECU 27 calculates the SOC of the high-voltage battery 23 in step S57. In the following step S58, the battery ECU 27 determines whether the calculated SOC exceeds the second reference SOC2. If step S58 is NO, the process returns to step S57, and the battery ECU 27 continues generating electricity. If step S58 is YES, the process proceeds to step S59. In step S59, the battery ECU 27 determines that charging of the high-voltage battery 23 is complete, and outputs a power generation end signal to each of the engine ECU 25 and the motor ECU 26 via the CAN communication line 28.

[0070] The flowchart on the right side of Fig. 5 shows the control procedure for the generator motor 12 during power generation, executed by the motor ECU 26. First, in step S510 after starting, the motor ECU 26 determines whether or not power generation is in progress in response to a power generation request from the battery ECU 27. If power generation is not in progress, the process repeats step S510, and if power generation is in progress, the process proceeds to step S511.

[0071] In step S511, the power generation control unit 264 of the motor ECU 26 reads the target power generation amount calculated by the battery ECU 27, and in the following step S512, the power generation control unit 264 sets an operating point of the generator motor 12 based on the target power generation amount. In addition, in step S513, the power generation control unit 264 controls the second inverter 22 so that the generator motor 12 operates at the set operating point.

[0072] In step S514, the power generation control unit 264 of the motor ECU 26 judges whether or not a command to stop power generation has been issued. While a command to stop power generation has not been issued, the process repeats step S513. The power generation motor 12 continues the power generation operation. If a command to stop power generation has been issued, the process proceeds to step S515. In step S515, the power generation control unit 264 stops inverter control.

[0073] 6 shows a control procedure for the rotary engine 3 executed by the engine ECU 25. First, in step S61 after starting, the engine ECU 25 determines whether or not there has been a power generation request from the battery ECU 27. If there has been no power generation request, the process repeats step S61, and if there has been a power generation request, the process proceeds to step S62.

[0074] In step S62, the engine ECU 25 reads the target power generation amount calculated by the battery ECU 27, and in the following step S63, the engine operating point setting unit 251 of the engine ECU 25 sets the operating point of the rotary engine 3 based on the target power generation amount. In addition, in step S64, the engine control unit 252 of the engine ECU 25 sets the opening degree of the throttle valve 394 and the fuel injection amount so that the rotary engine 3 operates at the set operating point.

[0075] In step S65, engine start control is executed. This engine start control is executed using the generator motor 12 as a starter. Therefore, as described later, this engine start control is executed in cooperation with the engine ECU 25 and the motor ECU 26. The details of the engine start control will be described later with reference to FIG. 7.

[0076] In step S66, the engine ECU 25 determines whether or not the starting of the rotary engine 3 is completed. If the starting is not completed, the process returns to step S65, and if the starting is completed, the process proceeds to step S67.

[0077] In step S67, the engine control unit 252 of the engine ECU 25 operates the rotary engine 3 at the set operating point. In the following step S68, the engine ECU 25 judges whether or not an instruction to stop power generation has been issued. If an instruction to stop power generation has not been issued, the process returns to step S67, and the engine control unit 252 continues to operate the rotary engine 3. If an instruction to stop power generation has been issued, the process proceeds from step S68 to step S69. In step S69, the engine ECU 25 stops the rotary engine 3.

[0078] (Rotary engine start control) Fig. 7 illustrates an example of the procedure of engine start control in step S65 of the flow in Fig. 6. The generator motor 12 performs both power running and power generating operations, and therefore may rotate in reverse when power is supplied due to its structure. The generator motor 12 and the eccentric shaft 35 of the rotary engine 3 are mechanically connected, and when the generator motor 12 rotates in reverse, the rotary engine 3 also rotates in reverse. When the rotary engine 3 rotates in reverse, an end of the side seal 343 may interfere with the opening of the intake port 391 formed in the side housing 33, and the side seal 343 may be damaged.

[0079] 4 illustrates an example of interference between the end of the side seal 343 and the opening of the intake port 391. The side seal 343 is attached to a side surface of the rotor 34. The side seal 343 is disposed along the outer periphery of the triangular rotor 34 so as to span between the apexes of the roughly triangular rotor 34.

[0080] When the rotary engine 3 is rotating forward, the trajectory of the tip of the side seal 343 does not intersect with the edge of the opening of the intake port 391, as shown by the dashed double-dashed arrow in the upper diagram of Fig. 4. When the rotary engine 3 is rotating forward, there is no interference between the tip of the side seal 343 and the opening of the intake port 391. However, when the rotary engine 3 is rotating reversely, the trajectory of the tip of the side seal 343 intersects with the edge of the opening of the intake port 391, as shown by the dashed double-dashed arrow in the upper diagram of Fig. 4. The tip of the side seal 343 when the rotor 34 is rotating reversely is the opposite end to the tip of the side seal 343 when the rotor 34 is rotating forward.

[0081] The lower diagram of Fig. 4 is a cross-sectional view taken along line AA of the upper diagram. As illustrated in the lower diagram of Fig. 4, a groove 344 is formed in the side surface of the rotor 34. A spring 345 disposed in this groove 344 presses the side seal 343 toward the side housing 33. Therefore, when the tip of the side seal 343 overlaps with the opening of the intake port 391, the tip of the side seal 343 is pressed by the spring 345 toward the inside of the intake port 391, that is, protrudes upward from the paper surface in the lower diagram of Fig. 4.

[0082] Therefore, if the reverse rotation of rotor 34 causes the trajectory of the tip of side seal 343 to intersect the edge of the opening of intake port 391, the protruding tip of side seal 343 may collide with vertical wall 393 of the opening of intake port 391, which may result in damage to side seal 343.

[0083] Therefore, when the rotary engine 3 is started, the motor ECU 26 prevents the rotor 34 from rotating in the reverse direction significantly.

[0084] Incidentally, even when the rotor 34 is rotating in the forward direction, when the rear end of the side seal 343 overlaps with the opening of the intake port 391, it is pushed by the spring 345 and protrudes inward of the intake port 391. However, in this case, the rear end of the side seal 343 moves from left to right on the page in the lower drawing of FIG.

[0085] Returning to the flow of FIG. 7, in step S71, the engine ECU 25 determines whether or not an abnormality has been reported so far regarding the start of the engine. The abnormality here is an abnormality in which the generator motor 12 that starts the rotary engine 3 rotates in reverse. If no abnormality has been reported, the process proceeds to step S72. If an abnormality has been reported, the process ends. The restart of the rotary engine 3 is stopped.

[0086] In step S72, the start control unit 263 of the motor ECU 26 controls the second inverter 22 so that a starting torque is applied to the rotary engine 3.

[0087] In step S73, the start control unit 263 reads the signal of the motor rotation sensor SN4. In the following step S74, the motor ECU 26 judges, based on the signal of the motor rotation sensor SN4, whether the eccentric shaft 35 mechanically connected to the generator motor 12 rotates in reverse in association with the reverse rotation of the generator motor 12 and whether the eccentric shaft 35 rotates in reverse by 5 degrees or more within 10 msec from the start of reverse rotation. The output signal of the motor rotation sensor SN4 indicating that the eccentric shaft 35 has rotated in reverse by 5 degrees or more within 10 msec does not mean that vibration is simply occurring. In other words, the output signal indicating that the eccentric shaft 35 has rotated in reverse by 5 degrees or more within 10 msec means that the generator motor 12 is rotating in reverse and, accordingly, the rotary engine 3 is also rotating in reverse. By employing this judgment condition, the motor ECU 26 can suppress erroneous judgment regarding the reverse rotation of the rotary engine 3.

[0088] If the determination in step S74 is NO, the generator motor 12 and the rotary engine 3 are not rotating in reverse, and the process proceeds to step S78. On the other hand, if the determination in step S74 is YES, there is a possibility that the generator motor 12 and the rotary engine 3 are rotating in reverse, and the process proceeds to step S75.

[0089] In step S75, the start control unit 263 determines, based on the output signal of the motor rotation sensor SN4, whether the generator motor 12 and the rotary engine 3 have rotated in reverse for 5 degrees or more in 10 msec and the reverse rotation has continued for an additional 5 msec. The output signal of the motor rotation sensor SN4 indicating that the reverse rotation has continued for an additional 5 msec eliminates the influence of noise in the sensor's electrical signal and makes it possible to determine that the generator motor 12 and the rotary engine 3 are actually rotating in reverse.

[0090] If the determination in step S75 is NO, it can be determined that neither the generator motor 12 nor the rotary engine 3 are rotating in reverse, and the process proceeds to step S78. In step S78, the start control unit 263 determines whether or not the start of the rotary engine 3 has been completed. If the start has not been completed, the process returns to step S73. If the start has been completed, the process proceeds to step S77.

[0091] On the other hand, if the determination in step S75 is YES, it can be determined that both the generator motor 12 and the rotary engine 3 are rotating in reverse, and the process proceeds to step S76.

[0092] In step S76, the start control unit 263 notifies the driver of the abnormality through the warning light 41 on the meter panel. In the following step S77, the motor ECU 26 stops the second inverter 22, and stops the generator motor 12.

[0093] Here, the determinations in steps S74 and S75 indicate that at least 15 msec has passed since the generator motor 12 and the rotary engine 3 started to rotate in reverse. The power supply from the second inverter 22 to the generator motor 12 is stopped after 15 msec has passed. The rotary engine 3 continues to rotate in reverse due to inertia even after the power supply is stopped.

[0094] In this rotary engine 3, the rotational position of the rotor 34 before starting is such that one of the working chambers is in the middle of the compression stroke, as shown by P37 in Fig. 3. This is because, in a state in which the rotary engine 3 is rotating by inertia just before stopping, the pressure in the working chamber increases as the compression stroke progresses from the early, middle, and late stages, i.e., P32, P36, and P37, which causes rotational resistance of the rotary engine 3. More specifically, the rotary engine 3 stops at a rotational position of approximately ATDC-90 deg. In Fig. 3, TDC is 540 deg.

[0095] If the eccentric shaft 35 rotates 135 degrees in the reverse direction from this position, the end of the side seal 343 will interfere with the opening of the intake port 391. In order to reliably avoid interference between the end of the side seal 343 and the opening of the intake port 391, it is preferable to stop the eccentric shaft at a position where it has rotated 70 degrees in the reverse direction, which is approximately half of 135 degrees, taking into account a safety factor, even if the rotary engine 3 continues to rotate in the reverse direction due to inertia after the power supply to the generator motor 12 is stopped.

[0096] FIG. 8 illustrates an example of a simulation result in which the rotational position at which the eccentric shaft 35 stops is calculated when the timing at which the power supply is stopped is changed. The vertical axis of FIG. 8 is the angle of the eccentric shaft 35. Zero on the vertical axis is the angle of the eccentric shaft 35 before the rotary engine 3 is started (see P37 in FIG. 3). Negative angles indicate angles in the direction of reverse rotation. As described above, the angle of -135 deg is the angle at which the end of the side seal 343 interferes with the opening of the intake port 391. The angle of -70 deg is the target stop position of the eccentric shaft 35. The horizontal axis of FIG. 8 is time. Zero on the horizontal axis is the timing at which the reverse rotation of the generator motor 12 begins. Time progresses from left to right in FIG. 8.

[0097] The two-dot chain line in Fig. 8 shows an example in which the power supply to the generator motor 12 is not stopped after the generator motor 12 starts to rotate in reverse. The generator motor 12 and the rotary engine 3 rotate in reverse by 5 degrees for 10 msec. After that, power is still supplied to the generator motor 12. In this case, the angle of the eccentric shaft 35 exceeds -135 degrees, causing interference between the end of the side seal 343 and the opening of the intake port 391.

[0098] The dashed line in FIG. 8 shows an example in which the generator motor 12 starts rotating in reverse, rotates 5 degrees in reverse for 10 msec, and then power supply to the generator motor 12 is continued for another 10 msec, after which power supply to the generator motor 12 is stopped. After 20 msec has elapsed, the rotary engine 3 continues rotating in reverse due to inertia. In this case, the eccentric shaft 35 rotates to approximately -90 degrees. The eccentric shaft 35 exceeds the target stop angle.

[0099] The solid line in Fig. 8 shows an example in which the generator motor 12 starts rotating in the reverse direction, rotates in the reverse direction by 5 degrees for 10 msec, and then power supply to the generator motor 12 is continued for another 5 msec, after which power supply to the generator motor 12 is stopped. This condition corresponds to the conditions in steps S74 and S75 in the flow in Fig. 7. In this case, the eccentric shaft 35 rotates to approximately -50 degrees. The eccentric shaft 35 does not exceed the target stop angle.

[0100] The dashed line in FIG. 8 shows an example in which the power supply to the generator motor 12 is stopped after the generator motor 12 starts rotating in reverse and rotates 5 degrees in reverse for 10 msec. This condition corresponds to a condition in which step S75 in the flow in FIG. 7 is omitted. In this case, the eccentric shaft 35 rotates to approximately -20 degrees. The eccentric shaft 35 does not exceed the target stop angle. However, by omitting step S75, there is a risk that the motor ECU 26 will make an erroneous judgment due to the influence of noise from the motor rotation sensor SN4.

[0101] If the power supply to the generator motor 12 is stopped early, the reverse rotation of the eccentric shaft 35 is stopped early, and interference between the side seal 343 and the opening of the intake port 391 can be avoided. However, there is a risk that the motor ECU 26 will make an erroneous judgment. According to the simulation result of FIG. 8, even if the power supply to the generator motor 12 is continued for 15 msec, interference between the side seal 343 and the opening of the intake port 391 can be avoided. In other words, the motor ECU 26 can use the 15 msec time to determine reverse rotation. By using the 15 msec time to determine reverse rotation, the motor ECU 26 can simultaneously prevent damage caused by reverse rotation of the rotary engine and prevent erroneous determination of reverse rotation of the rotary engine.

[0102] In addition, when the eccentric shaft 35 rotates in reverse by 5 degrees within 10 msec, the motor ECU 26 can distinguish between vibration occurring when the rotary engine 3 is started and the generator motor 12 and the rotary engine 3 actually rotating in reverse.

[0103] Therefore, by combining the two conditions of step S74 and step S75 in Figure 7, the motor ECU 26 can stop the reverse rotation of the rotary engine 3 before the end of the side seal 343 interferes with the opening of the intake port 391 formed in the side housing 33, while suppressing erroneous judgment.

[0104] (Modification of engine control) 7 are conditions that are set based on a predetermined maximum starting torque of the generator motor 12 and a predetermined inertia of the rotary engine 3. If the specifications of the generator motor 12 and / or the specifications of the rotary engine 3 change, the angle of reverse rotation of the eccentric shaft 35, including rotation due to inertia, may become larger even if the generator motor 12 is energized for the same period of time. Even if the power supply to the generator motor 12 is stopped according to the conditions of steps S74 and S75, there is a risk that the end of the side seal 343 will interfere with the opening of the intake port 391.

[0105] 9 relates to engine control for adjusting the stop position of the rotary engine 3 in accordance with the motor specifications and / or engine specifications. First, in step S91 after starting, the stop position control unit 265 of the motor ECU 26 judges whether the rotary engine 3 has stopped. If the engine has not stopped, the process repeats step S91. If the engine has stopped, the process proceeds to step S92.

[0106] In step S92, the stop position control unit 265 estimates, from the motor specifications and / or engine specifications, the rotation angle α of the eccentric shaft 35 when power supply to the generator motor 12 is continued for 15 msec from the start of reverse rotation and then the power supply to the generator motor 12 is stopped. The motor specifications include the maximum starting torque of the generator motor 12, and the engine specifications include the inertia of the rotary engine 3. The rotation angle α also includes the rotation due to the inertia of the rotary engine 3.

[0107] Then, in step S93, the stop position control unit 265 judges whether the estimated angle α exceeds 70 degrees. If it does not exceed 70 degrees, it is expected that the eccentric shaft 35 will stop at less than 70 degrees if the power supply to the generator motor 12 is stopped according to the conditions of steps S74 and S75 in the flowchart of Fig. 7. The process returns from step S93 without correcting the stop position of the rotary engine 3.

[0108] On the other hand, if the stop position control unit 265 determines in step S93 that the estimated angle α exceeds 70 degrees, it is expected that the eccentric shaft 35 will stop at an angle exceeding 70 degrees when the power supply to the generator motor 12 is stopped according to the conditions in steps S74 and S75 of the flowchart in FIG. 7. Since the eccentric shaft 35 does not stop at the target position, the stop position control unit 265 corrects the stop position of the rotary engine 3. Specifically, the process moves from step S93 to step S94, and the stop position control unit 265 powers the generator motor 12 to advance the rotation position of the stopped rotary engine 3 by α-70 degrees in the forward direction. The rotation position of the rotary engine 3 changes to a position in the forward direction from P37 in FIG. 3. As a result, even if the generator motor 12 rotates in reverse the next time the rotary engine 3 is started, the motor ECU 26 can stop the reverse rotation of the eccentric shaft 35 before the end of the side seal 343 interferes with the opening of the intake port 391, according to the flowchart of Figure 7.

[0109] (Second Modification of Engine Control) The flowchart in FIG. 10 relates to engine control that can accommodate various motor specifications and / or engine specifications. First, in step S101 after starting, the stop position control unit 265 of the motor ECU 26 acquires engine rotational position information from the engine ECU 25. In the following step S102, the stop position control unit 265 determines the relative positional relationship between the rotary engine 3 and the generator motor 12 based on the engine rotational position information acquired in step S101. Since the eccentric shaft 35 of the rotary engine 3 and the generator motor 12 are mechanically connected, the relative positional relationship between the rotational position of the rotary engine 3 and the rotational position of the generator motor 12 confirmed while the rotary engine 3 is operating and the generator motor 12 is generating electricity does not change even after the rotary engine 3 is stopped. Therefore, after the relative positional relationship is determined, the motor ECU 26 can acquire the rotational positions of the rotary engine 3 and the generator motor 12 based only on the output signal of the motor rotation sensor SN4.

[0110] In step S103, the motor ECU 26 determines whether the rotary engine 3 has stopped. The motor ECU 26 can determine that the rotary engine 3 has stopped, for example, based only on the output signal of the motor rotation sensor SN4. If the determination in step S103 is NO, the process repeats step S103, and if the determination in step S103 is YES, the process proceeds to step S104.

[0111] In step S104, the motor ECU 26 checks the stop position of the rotary engine 3 based on the output signal of the motor rotation sensor SN4 when the rotary engine 3 stops. Just before the engine stops when the rotation speed of the rotary engine 3 decreases, it is difficult for the engine ECU 25 to accurately grasp the rotation position of the rotary engine 3 based on the signal of the eccentric angle sensor SN1. This is because the sampling frequency of the engine ECU 25 is relatively low. In contrast, the sampling frequency of the motor ECU 26 is relatively high. Based on the previously determined relative positional relationship between the rotation position of the rotary engine 3 and the rotation position of the generator motor 12 and the signal of the motor rotation sensor SN4, the motor ECU 26 can accurately grasp the rotation position of the rotary engine 3 even just before the engine stops.

[0112] In step S105, the stop position control unit 265 estimates the angle β of the rotor 34 from the motor specifications and / or engine specifications when power supply to the generator motor 12 is continued for 15 msec from the start of reverse rotation and then the power supply to the generator motor 12 is stopped. Unlike step S82 in which the angle α of the eccentric shaft 35 is estimated, the motor ECU 26 estimates the angle β of the rotor 34.

[0113] In the next step S106, the motor ECU 26 calculates the angle γ between the end of the side seal 343 and the opening of the intake port 391 at the stop position of the rotary engine 3 confirmed in step S104, based on the engine specifications. The angle γ corresponds to the allowable angle until the end of the side seal 343 and the opening of the intake port 391 interfere with each other when the generator motor 12 rotates in reverse.

[0114] Then, in step S107, the motor ECU 26 judges whether the angle β estimated in step S105 is greater than half the angle γ calculated in step S96. The reason for using γ / 2 here is to correspond to setting the target stop position to 70 degrees, which is approximately half of the above-mentioned 135 degrees. If the judgment in step S107 is NO, interference between the end of the side seal 343 and the opening of the intake port 391 can be avoided by stopping the power supply to the generator motor 12 according to the conditions in steps S74 and S75 of the flowchart in FIG. 7. The process returns from step S107 without correcting the stop position of the rotary engine 3.

[0115] In step S107, if the motor ECU 26 determines that the estimated angle β exceeds γ / 2, it is expected that the edge of the side seal 343 will interfere with the opening of the intake port 391 when the power supply to the generator motor 12 is stopped according to the conditions in steps S74 and S75 of the flowchart in FIG. 7. Therefore, the motor ECU 26 corrects the stop position of the rotary engine 3. Specifically, the process moves from step S107 to step S108, and the motor ECU 26 uses the generator motor 12 to advance the rotation position of the rotary engine 3 by β-γ / 2 in the forward direction. As a result, even if the generator motor 12 rotates in the reverse direction when the rotary engine 3 is next started, the motor ECU 26 can suppress interference between the edge of the side seal 343 and the opening of the intake port 391 according to the flowchart in FIG. 7.

[0116] Note that the above-mentioned flows do not necessarily define the order of steps. The order of steps can be changed to the extent possible, and multiple steps can be executed simultaneously. Also, in each flow, some steps can be omitted, and new steps can be added.

[0117] 1 is just an example, and the system to which the technology disclosed herein is applicable is not limited to the system shown in Fig. 1. The technology disclosed herein is widely applicable to control systems for rotary engines, and the structure of the rotary engine is not limited to the structure shown in Fig. 2. [Explanation of symbols]

[0118] 12 Generator motor 26 Motor ECU (controller) 3. Rotary engine 33 Side housing 343 Side seal 35 Eccentric Shaft 391 Intake port SN4 Motor Rotation Sensor

Claims

1. A rotary engine having an intake port opening in a side housing; a motor mechanically connected to a shaft of the rotary engine; a controller that controls current supply to the motor so that the rotary engine is started by driving the motor; a sensor that outputs an electrical signal related to a rotation direction of the rotary engine to the controller; the controller, when starting the rotary engine, stops energizing the motor when the shaft of the rotary engine rotates in reverse by a predetermined angle or more and the rotary engine continues to rotate in reverse for a predetermined period of time based on the electrical signal of the sensor; Rotary engine control device.

2. 2. The rotary engine control device according to claim 1, the controller stops energization of the motor so that the shaft of the rotary engine starts to rotate in reverse and stops before reaching 70 degrees; Rotary engine control device.

3. 3. The rotary engine control device according to claim 1, The predetermined angle is 5 degrees within 10 msec from the start of reverse rotation. Rotary engine control device.

4. The rotary engine control device according to any one of claims 1 to 3, The predetermined time is 5 msec. Rotary engine control device.

5. 5. The rotary engine control device according to claim 4, the controller estimates a rotation angle of the shaft when power supply to the motor is stopped 15 msec after the start of reverse rotation, from a maximum starting torque of the motor and an inertia of the rotary engine; The controller also changes the rotational position of the shaft to a forward rotational direction using the motor before starting the rotary engine if the estimated angle exceeds 70 degrees. Rotary engine control device.

6. 5. The rotary engine control device according to claim 4, the controller estimates a rotation angle of the shaft when power supply to the motor is stopped 15 msec after the start of reverse rotation, from a maximum starting torque of the motor and an inertia of the rotary engine; The controller also uses the motor to change the rotational position of the shaft to a forward rotation direction before starting the rotary engine when an end of a side seal of the rotary engine interferes with an opening of the intake port when the shaft rotates in the reverse direction by the estimated angle. Rotary engine control device.

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