JP5998429B2 - Hybrid vehicle - Google Patents

Description

  The present invention relates to a hybrid vehicle.

  As an engine, a spark ignition gaseous fuel engine that is supplied with gaseous fuel such as hydrogen or LPG and ignited by a spark plug has been put into practical use. In addition, the number of hybrid vehicles equipped with an engine and a driving motor tends to increase. Patent Document 1 discloses an engine for a hybrid vehicle. An apparatus using a spark ignition type gas fuel engine is disclosed. Patent Document 2 discloses that in a hybrid vehicle, engine rotation is performed within a high efficiency range.

  In a gaseous fuel engine in which gaseous fuel is supplied and combustion is performed, an air-fuel ratio sensor such as a linear oxygen sensor is provided in the exhaust passage in the same manner as a liquid fuel engine to which liquid fuel is supplied. The fuel injection amount is also feedback controlled so that the detected actual air-fuel ratio becomes the target air-fuel ratio.

JP 2006-250024 A JP 2007-195334 A

  By the way, in a gaseous fuel engine, since a lot of water vapor is generated by combustion, the water vapor is liquefied in the exhaust passage and the air-fuel ratio sensor is flooded especially during cold operation, which causes an abnormality in the air-fuel ratio sensor. Become. Even if the actual air-fuel ratio is, for example, the target air-fuel ratio, the abnormality of the air-fuel ratio sensor due to the flooded water is erroneously detected as being leaner than the target air-fuel ratio (the detected value is shifted to the lean side). On the other hand, even if the actual air-fuel ratio is the target air-fuel ratio, for example, it is erroneously detected that the actual air-fuel ratio is richer than the target air-fuel ratio (the rich deviation in which the detected value shifts to the rich side). Such an abnormal state of undesirable output characteristics of the air-fuel ratio sensor, such as lean deviation or rich deviation, will continue as it is.

  If engine control is continued using the output of the air-fuel ratio sensor that has become abnormal as it is, the engine output will differ from the desired state (target value), for example, the generator power generation may be excessive or insufficient, or the battery An unfavorable situation occurs in the entire hybrid vehicle system, such as excessive or insufficient charge / discharge amount. Further, when viewed as a single engine, if the air-fuel ratio sensor is deviated lean, the fuel injection amount is increased to make the air-fuel ratio rich, and fuel consumption deterioration and abnormal combustion (backfire) are likely to occur. Further, when the air-fuel ratio sensor is shifted to the rich side, the fuel injection amount is reduced to make the air-fuel ratio lean, and the output becomes insufficient. In order to prevent the occurrence of such an abnormality in the air-fuel ratio sensor, the air-fuel ratio sensor is also protected with a waterproof cover or the like, but this is not always sufficient, and the occurrence of an abnormality in the air-fuel ratio sensor can be completely avoided. The fact is that it is difficult.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a hybrid vehicle capable of detecting an abnormality of an air-fuel ratio sensor.

In order to achieve the above object, the following solution is adopted in the present invention. That is, as described in claim 1 in the claims,
Driven by receiving power from at least one of an engine to which gaseous fuel is supplied, a generator that is driven by the engine to generate electric power, a battery that stores electric power generated by the generator, and the generator A hybrid motor, wherein the engine drives the generator but does not drive the driving wheels,
An air-fuel ratio sensor provided in the exhaust passage of the engine;
Target fuel consumption rate setting means for setting a target fuel consumption rate based on the target output of the engine;
Target air-fuel ratio setting means for setting a target air-fuel ratio based on the target fuel efficiency set by the target fuel efficiency setting means;
Feedback control means for feedback-controlling the fuel injection amount to the engine so that the air-fuel ratio detected by the air-fuel ratio sensor becomes the target air-fuel ratio set by the target air-fuel ratio setting means;
An actual fuel consumption rate determining means for determining an actual fuel consumption rate from the output of the generator and the consumption of gaseous fuel;
An abnormality determination that determines an abnormality that has caused a deviation in the output of the air-fuel ratio sensor by comparing the actual fuel consumption rate determined by the actual fuel consumption rate determination unit with the target fuel consumption rate set by the target fuel consumption rate setting unit Means,
It is supposed to be equipped with.

  According to the above solution, the output of the generator (corresponding to torque or power generation amount) reflects the engine output, so the actual fuel consumption rate of the engine is determined from the consumption of gaseous fuel and the output of the generator. be able to. Then, by comparing the actual fuel consumption rate with the target fuel consumption rate, it is determined whether the amount of fuel supplied based on the output of the air-fuel ratio sensor is appropriate, that is, whether the air-fuel ratio sensor is normal or abnormal. It becomes possible to judge whether or not.

A preferred mode based on the above solution is as described in claim 2 and the following claims. That is,
Abnormality determination by the abnormality determination means is performed at least in a cold state of the engine (corresponding to claim 2). In this case, the abnormality determination of the air-fuel ratio sensor can be performed at an early stage from the start of the engine in the cold state. Further, when the air conditioner is cold, the air-fuel ratio sensor is likely to be wet, and an environment in which the air-fuel ratio sensor is likely to be abnormal is likely to occur.

  The apparatus further comprises correction means for performing correction so as to compensate for a deviation in the output of the air-fuel ratio sensor when the abnormality determination means determines that an abnormality has occurred (corresponding to claim 3). In this case, the system of the hybrid vehicle can be properly operated by the correction by the correction means.

  The correction means is set so as to correct the output characteristic of the air-fuel ratio sensor in accordance with the deviation of the air-fuel ratio (corresponding to claim 4). In this case, since the output characteristic itself of the air-fuel ratio sensor is corrected, that is, by correcting the output characteristic so that the air-fuel ratio sensor is operating normally, the abnormality of the air-fuel ratio sensor is fundamentally eliminated. Is preferable. In particular, it is preferable to correct during the steady operation of the engine so that the output characteristic after the correction is effectively used for the subsequent engine control or the like.

  The correction means is set to increase / decrease the engine output in accordance with the deviation of the air / fuel ratio (corresponding to claim 5). In this case, by correcting the engine output changed based on the output of the air-fuel ratio sensor, it is possible to obtain substantially the same effect as that corresponding to the fourth aspect. In particular, this is preferable as a correction during a transition such as when the engine is accelerated.

  The correction means is set so as to correct the charge / discharge amount of the battery according to the deviation of the air-fuel ratio (corresponding to claim 6). In this case, the deviation of the engine output from the desired state can be eliminated by correcting the charge / discharge amount of the battery, and the system of the hybrid vehicle can be operated appropriately.

An actual excess air ratio determining means for determining an actual excess air ratio from the intake air amount and the fuel injection amount;
By comparing the actual excess air ratio determined by the actual excess air ratio determining means with the target excess air ratio, the magnitude of the deviation of the air / fuel ratio detected by the air / fuel ratio sensor is determined.
(Corresponding to claim 7). In this case, the magnitude of the air-fuel ratio deviation can be accurately determined.

  The abnormality determination by the abnormality determination means is executed on the assumption that the output of the generator deviates by a predetermined value or more set in advance with respect to the target output (corresponding to claim 8). In this case, it is preferable to prevent the air-fuel ratio sensor abnormality from being unnecessarily determined.

  According to the present invention, an abnormality of the air-fuel ratio sensor can be detected.

The simplified top view which shows an example at the time of applying this invention to a hybrid vehicle. The system diagram which shows an example of a spark ignition type gaseous fuel engine. The figure which shows an example when driving | running | working, using the driving | running | working using only battery power, and generating electric power with an engine. The figure which shows the example of a control system of this invention in a block diagram. The characteristic view which shows the relationship between an air fuel ratio and an engine fuel consumption rate. The characteristic view which shows the relationship between an engine speed and a fuel consumption rate. The time chart which shows a mode that various control values change by correct | amending the output characteristic of an air fuel ratio sensor at the time of a steady operation of an engine. The time chart which shows a mode that various control values by correcting an engine output change at the time of engine acceleration. The characteristic view which shows the specific example which correct | amends the output characteristic of an air fuel ratio sensor according to the deviation | shift of an air fuel ratio. The characteristic view which shows the specific example which correct | amends an engine output according to the deviation | shift of an air fuel ratio. The flowchart which shows the example of control of this invention.

  In FIG. 1, an automobile V as a vehicle has a body (vehicle body) indicated by reference numeral 1, left and right front wheels indicated by reference numeral 2, and left and right rear wheels indicated by reference numeral 3. A traveling motor 4 is connected to the left and right front wheels 2 via a differential gear 5A and a drive shaft 5B. In other words, in the embodiment, a front-wheel drive vehicle in which only the left and right front wheels 2 are driven.

  In addition to the traveling motor 4, an engine 6, a generator 7, and an inverter 8 are disposed at the front portion of the body 1. A battery 9 and a fuel tank 10 are disposed below the floor surface of the body 1 from the middle part in the front-rear direction to the rear part. The engine 6 is a spark ignition type gaseous fuel engine, and is supplied with hydrogen as gaseous fuel stored in the fuel tank 10.

  The generator 7 is driven by the engine 6 to generate electric power, and also functions as a starting motor for starting the engine 6 by receiving electric power from the battery 9. The battery 9 is composed of, for example, a lithium ion battery, and has a high voltage (for example, 300 to 500 V) and a large capacity. The electric power stored in the battery 9 is supplied to the traveling motor 4 and travels, and the electric power stored only in the battery 9 in the maximum power storage state can travel several tens km (for example, 30 to 60 km). Further, a low-voltage (for example, 12V) battery 11 is mounted on the rear end of the body 1, and this battery 11 is used for various on-vehicle electric devices such as a spark plug, a fuel injection valve, a headlight, a wiper, and an audio. Power is supplied.

  FIG. 2 shows an example of the engine 6 and its intake / exhaust system. In the embodiment, the engine 6 is a Wankel type rotary piston engine, and has two cylinders of a first cylinder RA and a second cylinder RB in series. Branch intake passages 21A and 21B that are individually connected to the intake ports of the cylinders RA and RB are connected to one common intake passage 22. A throttle valve 23 is disposed in the common intake passage 22. Further, first fuel injection valves 24A and 24B for port injection are disposed in the respective branch intake passages 21A and 21B. As the fuel injection valve, second fuel injection valves 25A and 25B that directly inject fuel into the cylinder (working chamber) are further provided.

  Branch exhaust passages 26 </ b> A and 26 </ b> B that are individually connected to the exhaust ports of the cylinders RA and RB are connected to one common exhaust passage 27. An air-fuel ratio sensor 28 is disposed in the common exhaust passage 27, and an exhaust gas purification catalyst (NOx catalyst in the embodiment) 29 is disposed on the downstream side of the air-fuel ratio sensor 28.

  The common intake passage 22 and the common exhaust passage 27 are connected by an EGR passage 30, and an EGR valve 31 is connected to the EGR passage 30. The EGR passage 30 is opened to the common intake passage 22 on the downstream side of the throttle valve 23, and is opened to the common exhaust passage 27 on the upstream side of the air-fuel ratio sensor 28.

  Each cylinder RA, RB has two spark plugs 33A, 33B. The fuel injection from the first fuel injection valves 24A and 24B is executed at a relatively low rotation and low load. The fuel injection from the second fuel injection valves 25A and 25B is performed at a relatively high rotation or high load. A mixture of air and hydrogen as fuel injected from the fuel injection valve is ignited by the spark plugs 33A and 33B. Combustion is performed by igniting the air-fuel mixture.

  FIG. 3 shows how the traveling state of the vehicle V is changed according to the amount of power stored in the battery 9. That is, when the charged amount of the battery 9 is large (for example, until the charged amount is reduced to 40%), the engine 6 is stopped (automatically stopped), and the traveling motor 4 is driven only by the power supply from the battery 9. (So-called plug-in travel). On the other hand, when the storage amount of the battery 9 is small (for example, when the storage amount is less than 40%), the engine 6 is started (automatic start), and the generator 7 generates power, and the generator 7 generates power. Electric power is supplied to the traveling motor 4 and surplus power is supplied to the battery 9. When the amount of electricity stored in the battery 9 is increased by the power generated by the generator 7 (for example, when the amount of electricity stored reaches 70%), the engine 4 is automatically stopped (resumption of plug-in travel). As described above, the engine 6 automatically repeats stop and start according to the amount of power stored in the battery 9, and when the engine 6 is started, the generator 7 generates power and travels and stores power in the battery 9. Is done. Note that when the vehicle V is decelerated, regeneration is performed by the traveling motor 4, and electric power generated by regeneration is stored in the battery 9.

  FIG. 4 is a block diagram showing an example of the control system of the present invention. In the figure, U is a controller (control unit) configured using a microcomputer. The controller U controls the traveling motor 4, the engine 6 (particularly the fuel injection valve), the generator 7, and the inverter 8. Power transfer between the battery 9 and the travel motor 4 via the inverter 8, power transfer between the generator 7 and the battery 9, power supply from the generator 7 to the travel motor 4, and from the battery 9 to the battery 11 is supplied with electric power.

  The controller U performs normal engine control such as fuel injection amount control and ignition timing control, and also performs control for determining abnormality of the air-fuel ratio sensor 28 and correction control when it is determined as abnormal. A signal from the air-fuel ratio sensor 28 is input to the controller U. The air-fuel ratio sensor 28 is a linear sensor and detects an excess air ratio λ as an air-fuel ratio. In addition, the controller U receives signals from various sensors or switches S1 to S8. The sensor S1 detects the vehicle speed. The sensor S2 detects the accelerator opening. The sensor S3 detects the engine coolant temperature. The sensor S4 detects the engine speed. The switch S5 detects that the brake pedal has been depressed. The sensor S6 detects the intake air amount. The sensor S7 detects the gaseous fuel consumption, but may be calculated based on the actually injected fuel injection amount (a fuel injection amount signal corresponding thereto). The sensor S8 detects the output of the generator 7 (the function of the sensor can also be used with the amount of power generation).

  The automatic stop and automatic start of the engine 6 by the controller U are performed according to the following conditions, for example. First, as described above, automatic stop and automatic start according to the charged amount of the battery 9 are performed. Even under the condition that the engine is automatically started according to the amount of power stored in the battery 9, automatic stop and automatic start by idle stop are performed. That is, for example, when the accelerator opening is 0, the vehicle speed is 0, and the brake switch S5 is ON (when the brake pedal is depressed), the engine 6 is automatically stopped. When the brake switch S5 is turned off from the automatic stop state, the engine 6 is automatically started.

  Here, in a state where the engine 6 is in operation, the air-fuel ratio at this time is, for example, 2.2 with the excess air ratio λ (the throttle opening is, for example, 80% in order to reduce the pumping loss). It is said that the opening degree is large. Note that the excess air ratio λ during engine operation is preferably set in the range of 2.2 to 2.5 in order to reduce Raw / NOx. The excess air ratio λ is set to 2.2. In the case of steady operation, the engine speed is, for example, constant rotation of 200 rpm at a low speed, constant rotation of, for example, 3000 rpm at a medium speed, and constant rotation of, for example, 4000 rpm at a high speed. I try to drive. Of course, the fuel injection amount is feedback-controlled based on the output of the air-fuel ratio sensor 28 so as to become the target air-fuel ratio (target air excess ratio).

  Here, the engine 6 is operated so as to have a target output. The target output is determined based on, for example, the engine speed and the accelerator opening, and this basic output is charged to the battery 9. The final target output is determined by correcting according to the amount (power storage amount). That is, the basic output is an output that can sustain the current running only with the power generation amount of the generator 7. When the charge amount of the battery 9 is small, the amount corresponding to the charge amount is required to charge the battery 9. The engine output is corrected to increase. On the contrary, when the charge amount of the battery 9 is large, the battery 9 is discharged for power feeding to the traveling motor 4 and the engine output is corrected to decrease by an amount corresponding to the discharge amount. From the target output determined as described above, the target fuel efficiency is determined so that the engine is operated with the highest possible thermal efficiency, and the target air-fuel ratio is determined according to this target fuel efficiency. Then, the fuel injection amount is feedback-controlled so that the air-fuel ratio detected by the air-fuel ratio sensor 28 becomes the target air-fuel ratio.

  FIG. 6 is a characteristic diagram showing the relationship between the air-fuel ratio of the engine and the thermal efficiency, and shows that the thermal efficiency is reduced when the excess air ratio becomes larger or smaller than the excess air ratio at which the thermal efficiency becomes maximum. Show. FIG. 7 is a characteristic diagram showing the relationship between the engine speed and the thermal efficiency. The solid line indicates the normal state in which the output characteristic of the air-fuel ratio sensor 28 does not deviate, and the broken line indicates the case where the output characteristic deviates to the rich side A one-dot chain line shows a case where the output characteristic is shifted to the lean side. As can be seen from FIG. 6, the high thermal efficiency point shifts to the low rotation side in the case of rich shift, and the high thermal efficiency point shifts to the high rotation side in the case of lean shift.

  FIG. 7 shows a method for correcting the output characteristics when a deviation occurs in the output characteristics of the air-fuel ratio sensor 28. In FIG. 7, as an output characteristic of the air-fuel ratio sensor 28, a solid line indicates a normal case, a broken line indicates a lean characteristic that is shifted (offset) to a lean side with respect to a normal output characteristic, and is indicated by a one-dot chain line. Indicates a rich characteristic that is shifted (offset) from the normal output characteristic to the rich side. When an abnormality occurs in the air-fuel ratio sensor 28 and the detected air-fuel ratio is a lean deviation indicating the lean side of the actual air-fuel ratio, the actual fuel injection amount is increased so as to be on the rich side. In this case, the output characteristic is corrected to the rich characteristic indicated by the alternate long and short dash line. Conversely, when an abnormality occurs in the air-fuel ratio sensor 28 and the detected air-fuel ratio is a rich shift that indicates a richer side than the actual air-fuel ratio, the actual fuel injection amount is reduced so as to be on the lean side. Therefore, in this case, the output characteristic is corrected to the lean characteristic indicated by the broken line. By correcting the output characteristics of the air-fuel ratio sensor 28 as described above, the subsequent control can be performed in exactly the same manner as when the air-fuel ratio sensor 28 is normal. Such correction of the output characteristic itself is preferably performed during steady operation where the engine operating state is stable.

  In the correction of the output characteristic, the correction degree is determined according to the deviation degree of the output characteristic of the air-fuel ratio sensor 28. The degree of deviation of the output characteristics of the air-fuel ratio sensor 28 is calculated by, for example, calculating the actual excess air ratio λ from the intake air amount detected by the sensor S6 and the consumption amount of gaseous fuel (fuel injection amount signal). The actual excess air ratio can be determined by comparing the excess air ratio detected by the air-fuel ratio sensor sensor 28.

  FIG. 9 shows how the air-fuel ratio sensor 28 is returned to the same control state as when the air-fuel ratio sensor 28 is normal by correcting the output characteristics of the air-fuel ratio sensor 28 as described above. In FIG. 9, the two-dot chain line indicates a normal state, the broken line indicates a lean shift, and the solid line indicates a rich shift. Until the time t1, the output of the air-fuel ratio sensor 28 is in a state of deviation, and the deviation judgment and deviation of the output characteristics of the air-fuel ratio sensor 28 described above are performed between the time t1 and the time t2 after the deviation is detected. Corresponding output characteristics are corrected. Then, after the time point t2, control based on the corrected output characteristics is executed, and the control state is returned to the same control state as when the air-fuel ratio sensor 28 is normal.

  FIG. 8 shows a case where the engine speed (that is, engine output) is corrected to be increased or decreased when an abnormality occurs in the air-fuel ratio sensor 28 and the output characteristics are shifted. In FIG. 8, the target output is indicated by a solid line, the output characteristic of rich deviation is indicated by a one-dot chain line, and the output characteristic of lean deviation is indicated by a broken line. In order to obtain the target output, it is understood that the engine speed may be decreased in the case of lean deviation, and it is understood that the engine speed may be increased in the case of rich deviation. As described above, the engine output can be set as the target output by correcting the increase / decrease of the engine speed according to the deviation of the output characteristic of the air-fuel ratio sensor 28. Such correction of the engine speed is preferably performed during engine transition such as acceleration.

  FIG. 10 shows a case where the engine speed is corrected according to the deviation in the output characteristics of the air-fuel ratio sensor 28 described above so that the engine output can maintain the target output. In FIG. 10, time t11 corresponds to time t1 in FIG. 9, and time t12 corresponds to time t2 in FIG. Until the time t12, the engine output is not corrected because the engine speed is not corrected. However, after the time t12 when the correction of the engine speed is executed, the engine output is the target output. Will match.

  FIG. 11 is a flowchart showing an example of control performed by the controller U in response to a deviation in the output characteristics of the air-fuel ratio sensor 28. This flowchart will be described below. In the following description, Q indicates a step. Further, the control of FIG. 11 is executed immediately after the engine is started (executed from the cold time). First, in Q1, signals from various sensors and switches 28, S1 to S8 are read. Thereafter, in Q2, it is determined whether or not the difference between the output of the generator 7 and the target output is larger than an allowable range (for example, whether or not there is a deviation of 2% or more). If the determination at Q2 is NO, the air-fuel ratio sensor 28 is assumed to be normal, and the process returns to Q1.

  If YES in Q2, the air-fuel ratio sensor 28 is considered abnormal. At this time, in Q3, the actual fuel consumption rate is calculated from the output of the generator 7 and the consumption amount of gaseous fuel. Thereafter, in Q4, it is determined whether or not the actual fuel consumption rate is larger than the target fuel consumption rate (whether or not the actual consumption amount is larger than the target fuel amount). If the determination in Q4 is NO, the fuel efficiency is not deteriorated. At this time, the air-fuel ratio sensor 28 is assumed to be normal, and the process returns to Q1. In the determination of Q4, a value obtained by subtracting a predetermined allowable fuel consumption rate (for example, 2%) from the target fuel consumption rate may be used as a comparison value with the actual fuel consumption rate.

  If YES in Q4, this is a case where it is determined that there is an abnormal time in which the output of the air-fuel ratio sensor 28 has shifted. At this time, in Q5, the actual excess air ratio λ is calculated from the intake air amount and the gaseous fuel consumption (fuel injection amount). Thereafter, at Q6, it is determined whether or not the actual excess air ratio is smaller than the target excess air ratio. When the determination in Q6 is YES, the actual excess air ratio is richer than the target excess air ratio (lean deviation occurs). At this time, the correction process of Q8 to Q10 is performed. That is, after the degree of richness of the excess air ratio is determined in Q7, it is determined in Q8 whether the engine speed is constant (almost constant) or not. If YES in Q8, the output characteristic of the air-fuel ratio sensor 28 is corrected in Q9 in accordance with the richness determined in Q7 (execution of correction explained in FIGS. 7 and 9). . Thereafter, in Q10, it is determined whether or not the actual fuel consumption rate is larger than the target fuel consumption rate. If YES in Q10, the process returns to Q6. If YES in Q10, the process returns to Q1.

  When NO in Q8, that is, during acceleration, the engine speed is corrected to decrease in Q11 in accordance with the degree of richness determined in Q7 (the correction described in FIGS. 8 and 10). Thereafter, at Q12, it is determined whether or not the output of the generator 7 matches the target engine output. If the determination in Q12 is NO, the process returns to Q11. If YES in Q12, the process proceeds to Q10.

  If NO in Q6, it is determined in Q13 whether the actual excess air ratio is greater than the target excess air ratio. When the determination in Q13 is YES, correction according to the rich deviation of the air-fuel ratio sensor 28 is performed by the processing of Q14 to Q18. In addition, since the process of Q14-Q18 respond | corresponds to the process of Q7-Q12, the duplicate description is abbreviate | omitted.

  If the determination in Q13 is NO, it is caused by deterioration of the fuel consumption rate due to secular change, and the air-fuel ratio sensor 28 is returned as it is, assuming that it is normal. It may be set so that the step of Q2 is eliminated and the process immediately shifts from Q1 to Q3. However, the provision of the step Q2 is preferable in reducing the chance of performing abnormality determination of the air-fuel ratio sensor 28, which increases the processing load.

Although the embodiment has been described above, the present invention is not limited to the embodiment, and can be appropriately changed within the scope described in the scope of claims. For example, the invention includes the following cases. . First, the charge / discharge amount of the battery 9 may be corrected according to the deviation in the output of the air-fuel ratio sensor 28. That is, in the case of the rich shift, the engine output is insufficient, and in this case, the shortage may be compensated by discharging from the battery 9. Conversely, if the lean side, the engine output is excessive, this time, to absorb the output of an excessive amount, have good if so to charge the battery 9. Engine 6 may be a reciprocating engine. Of course, the object of the present invention is not limited to what is explicitly stated, but also implicitly includes providing what is substantially preferred or expressed as an advantage.

  The present invention is suitable for application to, for example, a hybrid vehicle using hydrogen as fuel.

V: Vehicle 4: Driving motor 6: Engine 7: Generator 9: Battery 10: Fuel tank 24A, 24B: Fuel injection valve (for point injection)
25A, 25B: Fuel injection valve (for direct injection)
28: Air-fuel ratio sensor 33A, 33B: Spark plug U: Controller

Claims (8)

Driven by receiving power from at least one of an engine to which gaseous fuel is supplied, a generator that is driven by the engine to generate electric power, a battery that stores electric power generated by the generator, and the generator A hybrid motor, wherein the engine drives the generator but does not drive the driving wheels,
An air-fuel ratio sensor provided in the exhaust passage of the engine;
Target fuel consumption rate setting means for setting a target fuel consumption rate based on the target output of the engine;
Target air-fuel ratio setting means for setting a target air-fuel ratio based on the target fuel efficiency set by the target fuel efficiency setting means;
Feedback control means for feedback-controlling the fuel injection amount to the engine so that the air-fuel ratio detected by the air-fuel ratio sensor becomes the target air-fuel ratio set by the target air-fuel ratio setting means;
An actual fuel consumption rate determining means for determining an actual fuel consumption rate from the output of the generator and the consumption of gaseous fuel;
An abnormality determination that determines an abnormality that has caused a deviation in the output of the air-fuel ratio sensor by comparing the actual fuel consumption rate determined by the actual fuel consumption rate determination unit with the target fuel consumption rate set by the target fuel consumption rate setting unit Means,
It is supposed to be equipped with.
In claim 1,
A hybrid vehicle characterized in that abnormality determination is performed by the abnormality determination means at least in a cold state of the engine. In claim 1 or claim 2,
A hybrid vehicle, further comprising: a correction unit that performs correction so as to compensate for a deviation in the output of the air-fuel ratio sensor when the abnormality determination unit determines that an abnormality has occurred. In claim 3,
The hybrid vehicle according to claim 1, wherein the correction means is set to correct an output characteristic of the air-fuel ratio sensor in accordance with an air-fuel ratio shift. In claim 3,
The hybrid vehicle according to claim 1, wherein the correction means is set to increase or decrease the engine output in accordance with a deviation of the air-fuel ratio. In claim 3,
The hybrid vehicle according to claim 1, wherein the correction unit is set to correct a charge / discharge amount of the battery in accordance with an air-fuel ratio shift. In any one of Claims 1 thru | or 6,
An actual excess air ratio determining means for determining an actual excess air ratio from the intake air amount and the fuel injection amount;
By comparing the actual excess air ratio determined by the actual excess air ratio determining means with the target excess air ratio, the magnitude of the deviation of the air / fuel ratio detected by the air / fuel ratio sensor is determined.
A hybrid vehicle characterized by that. In any one of Claims 1 thru | or 7,
The hybrid vehicle, wherein the abnormality determination by the abnormality determination means is executed on the assumption that the output of the generator is deviated by a predetermined value or more set in advance with respect to the target output.

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