JP2005180254A - Controlling equipment of power train equipped with electric supercharger - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To satisfy acceleration requirements by improving drive response of an electric supercharger in a control device of a power train equipped with the electric supercharger equipped for increasing engine output and a motor functioning as power source of a vehicle in parallel and switching those drive according to an operation state of the engine. <P>SOLUTION: Operation states of an engine are divided into a first zone X where natural aspiration operation of the engine 1 is performed, a second zone Y where supercharged operation (drive assist by supercharging) by an electric supercharger 5 is performed, and a third zone Z where drive assist with making a motor generator 11 function as a motor is performed in addition to supercharging operation by the electric supercharger 5 with setting engine speed and target torque as engine load as parameters, for example as indicated in Figure 2. The motor generator 11 functions as a generator and generated electric power is supplied to the electric supercharger 5 at the time of transient from the first zone X to the second zone Y due to acceleration demand. An engine cooling pump, an air conditioner pump (compressor) or the like are stopped to reduce load at the time of transient. Power generation capacity by the motor generator 11 is tentatively sufficiently increased due to drive torque increase accompanying load reduction, sufficient electric power is supplied to the electric supercharger 5. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention includes a control device for a vehicle including an engine with an electric supercharger, more specifically, an electric supercharger for increasing the output of the engine, and a motor that functions as a power source for the vehicle, The present invention relates to a control apparatus for a power train provided with an electric supercharger configured to switch these drives in accordance with an operating state of an engine.

  Conventionally, superchargers and turbochargers have been well known as means for increasing engine output, but both have the problem of insufficient supercharging pressure in the low engine speed range as a result of the supercharging capacity being greatly affected by the engine speed. There is. In contrast, an electric supercharger that drives a compressor with a motor can control the rotation speed of the compressor without being affected by the rotation speed of the engine, so that it can generate a sufficient boost pressure even in a low rotation speed region. Have.

  On the other hand, in recent years, environmentally friendly vehicles equipped with a motor that functions as a power source of the vehicle in addition to the engine have been known. For example, Patent Document 1 discloses a combination of such a motor and the electric supercharger. An engine is disclosed. However, Patent Document 1 discloses a motor generator (motor generator) that has a function as a power source of a vehicle and a function as a generator that is driven by an engine and generates power as a motor. .

  And, in this way, in a vehicle equipped with an electric supercharger that increases engine output and a motor generator, for example, rotation-related values such as engine speed and vehicle speed, accelerator opening, etc. Each region indicating the driving state of the electric supercharger and the motor generator is set in a map according to the operating state of the engine using a torque related value such as a representative engine load as a parameter. The engine output control is performed by applying the engine speed, the engine load, etc., and switching the driving of the electric supercharger and the motor generator according to the result.

  In this regard, according to Patent Document 1, as shown in FIG. 27, the low vehicle speed (low rotation) low load region is a motor travel region in which the vehicle travels only with the output of the motor, and the medium vehicle speed (medium rotation). The medium load region is a non-supercharging region where the vehicle is driven only by the output of the natural intake of the engine, the low vehicle speed (low rotation) high load region is a supercharging region for driving the electric supercharger, and The medium vehicle speed (medium rotation) high load region to the full vehicle speed (high rotation) region are motor assist regions that drive the motor in addition to the electric supercharger.

  On the other hand, a vehicle including an electric supercharger includes a power storage device that serves as a power supply source for a motor generator and the electric supercharger when functioning as a drive assist motor. When the vehicle decelerates, it is generally performed that the motor generator functions as a generator to store electric power in the power storage device (regenerative braking). Has also been done. A large battery may be used as the power storage device, but a capacitor (capacitor) type that can charge and discharge a large amount of power with high response is often used.

JP-A-11-332015

  As described above, in a vehicle including an electric supercharger, a motor generator, and a power storage device, when there is an acceleration request, supercharging by the electric supercharger is executed and the motor generator functions as a motor. And trying to get enough acceleration. However, in this case, it is necessary to supply driving power from the power storage device to the electric supercharger and the motor generator at a stroke, and therefore, the supply voltage from the power storage device temporarily decreases rapidly. As a result, a response delay occurs in the drive of the electric supercharger or motor generator, particularly the electric supercharger, and the subsequent power supply tends to be insufficient, and it is difficult to obtain the expected acceleration. .

  The present invention has been made in view of the above circumstances, and provides a powertrain control device equipped with an electric supercharger that enhances the drive response of the electric supercharger and satisfies the acceleration request. It is to provide.

In order to achieve the above object, the present invention provides the following as a first solution. That is, as described in claim 1 in the claims,
A motor generator that is connected to an engine serving as a drive source for vehicle travel, and that selectively performs a function as a travel motor that assists the driving force of the engine and a function as a generator driven by the engine;
An electric supercharger for supercharging the intake air of the engine;
An engine accessory driven by the engine;
Control means for controlling the motor generator and the electric supercharger;
With
The control means is configured to change the motor from a non-supercharged state in which the electric supercharger is stopped and the engine is naturally aspirated to a supercharged state in which the electric supercharger is operated by an acceleration request. The generator is set to function as a generator to supply the electric power generated by the motor generator to the electric supercharger and to control the load on the engine auxiliary machine,
It is like that.

In order to achieve the above object, the present invention provides the second solution as follows. That is, as described in claim 2 in the scope of claims,
A motor generator that is connected to an engine serving as a drive source for vehicle travel, and that selectively performs a function as a travel motor that assists the driving force of the engine and a function as a generator driven by the engine;
An electric supercharger for supercharging the intake air of the engine;
An engine accessory driven by the engine;
A power storage device that stores power generated by the motor generator and serves as a power supply source for the motor generator and the electric supercharger;
Load detection means for detecting parameters relating to engine load;
A rotational speed detecting means for detecting a parameter relating to the engine rotational speed;
Control means for controlling the motor generator and the electric supercharger based on the engine load detected by the load detection means and the engine speed detected by the rotation speed detection means;
With
The control means is configured to change the motor from a non-supercharged state in which the electric supercharger is stopped and the engine is naturally aspirated to a supercharged state in which the electric supercharger is operated by an acceleration request. The generator is set to function as a generator to supply the electric power generated by the motor generator to the electric supercharger and to control to reduce the load on the engine auxiliary machine.
It is like that.

  In both the first solution and the second solution, at the time of transition from a non-supercharged state where the electric supercharger is stopped to a supercharged state where the electric supercharger is driven by an acceleration request. The motor generator is caused to function as a generator, and this generated power is supplied to the electric supercharger. At this time, since the load on the engine auxiliary machine is reduced, the torque for driving the motor generator is temporarily increased by this load reduction, and the power generation capability of the motor generator is temporarily sufficiently increased. Thus, the electric supercharger can be started to drive with good response, and the subsequent power shortage is less likely to occur. Thereby, sufficient acceleration can be satisfied.

A preferable aspect based on at least one of the first solution technique and the second solution technique is as described in claim 3 and the following claims. That is,
A non-supercharging region in which the electric supercharger is stopped and the engine is naturally aspirated using the engine speed and engine load as parameters, and a supercharging region in which the engine is supercharged by operating the electric supercharger And are preset,
When the acceleration request is detected when the current operating state is in the vicinity of the supercharging region in the non-supercharging region, the control means determines that the motor generator is in transition. Is set to perform control to reduce the load of the engine accessory while supplying the generated power from the electric supercharger,
(Claim 3). In this case, it is preferable to quickly detect that the driving of the electric supercharger is started and to further increase the acceleration response.

  The control means may be set so as to perform control for causing the motor generator to generate power so as to consume an increase in torque due to a load reduction of the engine accessory. Correspondence). In this case, it is preferable to generate power by the motor generator as much as the load of the engine auxiliary machine is reduced, and to prevent torque shock at the time of transition.

  The control means is configured to store the generated surplus power in the power storage device when the generated power corresponding to the torque increase accompanying the load reduction of the engine accessory is larger than the power supplied to the electric supercharger. It can be set so as to be performed (corresponding to claim 5). In this case, power can be stored without wasting surplus power while preventing torque shock during transition.

  The control means performs control so that the supply power supplied from the motor generator to the electric supercharger is larger when the engine speed is large than when the engine speed is small. When the generated power of the machine is larger than the power supplied to the electric supercharger, it is set to perform control to store the generated surplus power in the power storage device (claim). 6 correspondence). In this case, when the engine speed is small, the intake air flow rate of the maximum supercharging is small and the load on the electric supercharger is small. Therefore, the power supplied to the electric supercharger is reduced and the rise of supercharging is weakened. (The reverse is true when the engine speed is high.) In this way, it is possible to store power without wasting surplus power while supplying appropriate electric power according to the engine speed to the electric supercharger.

  The control means is set to control so that the supply power supplied from the motor generator to the electric supercharger is larger when the power storage amount of the power storage device is small than when the power storage amount is large. It is possible to do so (corresponding to claim 7). In this case, when the power storage amount of the power storage device is small, the power supply from the power storage device to the electric supercharger is small, and the response delay of the electric supercharger is large (the opposite is true when the power storage amount is large), At this time, response delay can be prevented or reduced by increasing the power supplied from the motor generator to the electric supercharger.

The control means, during the transition,
Control for determining a load reduction degree that is a degree of load reduction that the engine auxiliary machine can take according to an operating state of the engine auxiliary machine;
Control for determining a target supply power to be supplied to the electric supercharger based on an operating state of the engine;
When the generated power of the motor generator obtained by the determined degree of load reduction is smaller than the target supply power, the load of the engine accessory is reduced by the determined degree of load reduction, and the engine empty Rich correction control for temporarily enriching the fuel ratio is performed so that the motor generator generates power so as to consume the torque increase obtained by reducing the load on the engine accessory and enriching the air-fuel ratio. Do control,
Is set to
(Claim 8). In this case, depending on the operating state of the engine accessory, it may be difficult or difficult to completely turn off the engine accessory (stop driving when shut off), but determine the extent to which the load can be reduced within a reasonable range. Since the determined load reduction is performed, it is preferable to prevent an adverse effect caused by the load reduction of the engine accessory. Further, the torque for power generation that is insufficient only by reducing the load of the engine auxiliary machine is compensated for by enriching the air-fuel ratio, and sufficient electric power can be supplied to the electric supercharger to satisfy the acceleration response. .

The control means, during the transition,
Control for determining a target supply power to be supplied to the electric supercharger during the transition based on an operating state of the engine;
Control for determining the generated power of the motor generator obtained corresponding to the torque increase due to the load reduction of the engine accessory;
When the generated power is larger than the target supply power, the power is supplied from the motor generator to the electric supercharger by the amount of the target supply power, and a margin that is the difference between the generated power and the target supply power Control for storing electric power in the power storage device;
When the generated power is smaller than the target supply power, the torque obtained by enriching the air-fuel ratio by temporarily setting the air-fuel ratio of the engine to be insufficient as the difference between the generated power and the target supply power A control for increasing the generated power by an increase and supplying the target power to the electric supercharger;
Is set to do,
(Corresponding to claim 9). In this case, while the effect corresponding to claim 8 is obtained, the generated surplus power can be stored without being wasted.

  The target supply power can be set with parameters of supply time and supply power for supplying the generated power from the motor generator to the electric supercharger (corresponding to claim 10). In this case, the target supply power to the electric supercharger can be accurately supplied by a simple method of power control within the supply time by setting the supply time and the supply power as parameters. it can.

  The supplied power may be set to a maximum value at the initial stage and to be gradually decreased thereafter (corresponding to claim 11). In this case, the supply power is increased at the initial stage when the most electric power is required to improve the drive response of the electric supercharger, and smooth operation to the steady state of the electric supercharger can be achieved without causing a torque shock or the like. This is preferable for the transition to (1).

The operating region is set in advance with the engine speed and the target torque as the engine load set according to the accelerator opening as parameters,
The operation region is divided into three regions: a first region where the target torque is low or high, a second region where the target torque is high and medium, and a third region where the target torque is high and low. And
The control means prohibits drive assist by the motor generator and the electric supercharger in the first region, executes drive assist only by the electric supercharger in the second region, and in the third region. It is set to control to execute the drive assist of both the motor generator and the electric supercharger,
(Corresponding to claim 12).

  In this case, problems such as knocking of the engine and surging of the electric supercharger that occur when the electric supercharger is driven in a high target torque and low rotation range are avoided. In addition, since the motor generator that assists driving is driven at a low rotation speed with a high target torque, the motor generator may be any motor generator that can be driven at a low rotation speed although it has a high torque. A small motor generator is sufficient, and the motor generator and the power storage device that supplies electric power to the motor generator can be reduced in size, so that mounting on these vehicles can be improved and the cost and size of the vehicles can be reduced. Can be planned.

  On the other hand, since the electric supercharger is driven with a high target torque and medium rotation, the torque from the low rotation region to the medium rotation region is combined with the driving of the motor generator with the high target torque and low rotation described above. The assist torque and the supercharging torque obtained by driving the motor generator and the electric supercharger can be secured. As a result, it is possible to shift the maximum torque generation speed (and the maximum output generation speed) of the engine, which can be obtained only by natural intake, to the high speed range (in other words, the torque in the high speed range is not excessive). Therefore, sufficient marginal torque (torque corresponding to the difference between engine torque and running resistance) not only in the low to medium rotation range but also in the high rotation range. Is obtained. As a result, the total gear ratio obtained from the gear ratio of the transmission and the final gear ratio can be set to a gear ratio that does not require much deceleration (a gear ratio with a small value), so that the same vehicle speed can be obtained. In this case, the engine speed can be reduced as much as the total gear ratio value is small. Therefore, the region on the lower rotation side becomes the frequently used region, and the fuel consumption is remarkably improved.

  Moreover, the shift of the maximum torque generation rotational speed (and the maximum output generation rotational speed) of the engine to a high rotational speed region increases the charging efficiency by, for example, extending the opening time of the intake valve (the fresh air sweeps out the exhaust gas). To improve the charging efficiency) and to design the engine specifications so as to obtain an inertial supercharging effect when the length of the intake passage is high. As a result, in the low-medium-rotation low-load region where the frequency of use is high, it is possible to obtain the specifications of the engine with high pumping loss, low effective compression ratio, high effective expansion ratio, and high thermal efficiency. Can improve fuel efficiency.

A first boundary characteristic line that is a boundary between the first region and the second region corresponds to a torque curve of an engine that is naturally aspirated without driving assist between the motor generator and the electric supercharger. Set to
The second boundary characteristic line that is the boundary between the second region and the third region is set so that the target torque increases rapidly as the engine speed increases.
(Claim 13).
In this case, the setting of the first boundary characteristic line increases the frequency with which the necessary torque is obtained only by the engine that is operated by natural intake without driving assistance by the electric supercharger, that is, driving by the electric supercharger. It is preferable in terms of fuel saving by preventing the assist from being performed as much as possible. In addition, by setting the second boundary characteristic line, the drive assist in the low rotation range is performed by the motor generator as much as possible, and the problem that is likely to occur when the electric supercharger is operated in the low rotation range is more fully satisfied. This is preferable for solving the problem.

The generation speed of the maximum torque of the engine that has been naturally aspirated without driving assist of the motor generator and the electric supercharger is set to be close to the maximum speed in the second region. (Corresponding to claim 14).
In this case, it is preferable that the maximum torque generation rotation speed of the engine that is operated by natural intake operation is sufficiently shifted to the high rotation side in order to achieve sufficient fuel saving.

  According to the present invention, when driving the electric supercharger in response to the acceleration request, the motor generator is caused to function as a generator and the generated electric power is supplied to the electric supercharger. In addition, since the load on the engine auxiliary machine is reduced, the power generated by the motor generator is sufficiently secured, the drive response of the electric supercharger can be sufficiently increased, and the acceleration response can be satisfied. The power shortage will be less likely to occur. In addition, the torque reduction caused by the power generation of the motor generator is offset by the torque increase due to the load reduction of the engine auxiliary machine. This is preferable in terms of prevention or reduction.

  As shown in FIG. 1, the vehicle according to this embodiment includes an engine 1 and a motor generator (a motor generator as a power source, a function of a motor as a power source of the vehicle, and power generation that is driven by the engine 1 to generate power). 11 which has a function as a machine) and a so-called low pollution vehicle or environment-friendly vehicle, and the crankshaft of the engine 1 and the rotating shaft of the motor generator 11 are They are interconnected by a belt or chain 12. The vehicle also has an electric supercharger 5 as means for increasing the output of the engine 1, and the supercharger 5 is disposed in the intake passage 2 of the engine 1 as a main component, for example, centrifugal. And a motor 4 that rotationally drives the compressor 3.

  Here, an intercooler 6 and an electric throttle valve 7 are arranged in this order in the intake passage 2 downstream of the compressor 3. A bypass passage (also referred to as a relief passage or a recirculation passage) 9 is provided between the upstream side of the compressor 3 and the downstream side of the intercooler 6. For example, when the flow rate of the gas passing through the compressor 3 of the electric supercharger 5 is low and the bypass passage 9 is low in rotation, in order to ensure the supercharging capability of the electric supercharger 5, the intercooler is temporarily used. For example, the gas exiting 6 is returned to the upstream side of the compressor 3 to ensure the flow rate of the gas passing through the compressor 3. The intake passage 2 is connected to the engine 1 via an intake manifold 8.

  On the other hand, the motor 4 of the electric supercharger 5 is connected to the power supply system 14 of the engine 1, the motor generator 11 is connected via an inverter 13, and a 12V lead battery 17 is connected to a DC / DC converter. The power supply system 14 is connected to the power supply system 14 through 16. When the electric supercharger 5 is driven and when the motor generator 11 is driven as a vehicle power source, power is supplied from the power storage device 15 of the power supply system 14, for example, 42V. Conversely, when the motor generator 11 is driven as a generator by the engine 1, the generated power is supplied to the power storage device 15 of the power supply system 14 via the inverter 13 and used for charging the power storage device 15. In the embodiment, the power storage device 15 is a capacitor (capacitor) type that can discharge and charge a large amount of power with high response (rapidly), but is not limited thereto. .

  In addition, power is supplied from a 12V lead battery (ordinary battery) 17 to a general electric component such as a headlight and an air conditioner, and an auxiliary starter 18 used at the time of cold start. The power of the power storage device 15 of the power supply system 14 is stepped down to 12V by the DC / DC converter 16 and is always applied.

  The control unit 50 includes a signal from the accelerator opening sensor 20 that detects the opening (depression amount) of the accelerator pedal 19 by the driver, a signal from the engine rotation sensor 21 that detects the rotation speed of the engine 1, a vehicle Of the current position, road map information, and traffic (congestion) information, a signal from the navigation system 30 that detects the state of the road ahead, and a signal from the power supply system 14 (related to the state of the power storage device 15, such as the amount of power storage). Signal), a signal from a motor temperature sensor (for example, composed of a thermistor) 22 for detecting the temperature of the motor 4 of the electric supercharger 5, and an intake air temperature immediately after exiting the intercooler 6 in the intake passage 2 are detected. The intake pressure sensor 24 detects the signal from the intake air temperature sensor 23 and the intake pressure immediately upstream of the throttle valve 7 in the intake passage 2. Signals and the like are input. The control unit 50 also includes an inverter 13 for driving the motor 4 of the electric supercharger 5 and the motor generator 11 as a vehicle power source, a throttle actuator 25 for driving the throttle valve 7 and an auxiliary starter according to the result of the input signal. 18. Output various control signals to the relief valve 10 for adjusting the opening degree of the bypass passage 9 (that is, the circulation amount of the intake air passing through the compressor 3), the automatic transmission 40, etc. Then, power generation control (charge control of the power storage device 15) by the motor generator 11 is executed.

  Although not shown, the engine 1 includes various auxiliary machines driven by the engine 1. Examples of the engine accessory include an air conditioner pump (compressor), a coolant pump for circulating engine coolant, and the like. The control unit 50 also performs control for shutting off (stopping) the driving of the engine auxiliary machine. For this driving cutoff, the control unit 50 performs intermittent control on the driving path between the engine auxiliary machine and the engine 1. An electromagnetic clutch or the like is interposed. In the case where the load on the engine accessory is reduced not by shutting off the drive but by reducing the drive level, the clutch may be controlled to a half-clutch state, for example. Further, as will be described later, the control unit 50 also performs temporary enrichment of the air-fuel ratio of the engine 1 and temporary upshift of the automatic transmission 40 in order to secure the generated power of the motor generator 11. It is to do.

  FIG. 2 is a map for separating the operating states of the motor generator 11, the electric supercharger 5, and the engine 1 (only), and the engine speed and the torque as the engine load are set as parameters, The torque as a parameter corresponds to the target torque corresponding to the accelerator opening. That is, as will be described later, a target torque corresponding to the accelerator opening is set, and by determining which position in the map of FIG. 2 the target torque corresponding to the current engine speed is, the motor generator 11, the operation state of the electric supercharger 5 and the engine 1 (only) is appropriately selected and executed. The map shown in FIG. 2 is stored in advance in a ROM (storage means) of the control unit 50.

  In FIG. 2, it is divided into three regions of a first region X, a second region Y, and a third region Z. The first region X (non-supercharging region) is a region extending from the full low load (low torque-low target torque) to the full high rotation, and this first region X is driven only by the engine 1 that is operated by natural aspiration. It is time to perform (drive assist of the motor generator 11 and the electric supercharger 5 is not performed). The second region (supercharging region) Y is a high load and medium rotation region and is a time when drive assist is performed by the electric supercharger (no drive assist by the motor generator). The third region Z is a high load and low rotation region, and is a time when the drive assist by the motor generator 11 is performed in addition to the drive assist by the electric supercharger 5.

  The three regions X to Z will be described in more detail. A first boundary characteristic line serving as a boundary between the first region X and the second region Y is indicated by a symbol β1. This first boundary characteristic line β1 corresponds to the torque curve of the engine 1 that is operated by natural intake (in the embodiment, it is completely coincident with the torque curve of the engine 1, and also refer to FIG. 5 described later). The maximum torque generation rotation speed of the engine 1 that is operated by natural intake is set to be considerably shifted to the high rotation side as compared with the natural intake engine for ordinary passenger cars. The maximum torque generation rotational speed indicated by the first boundary characteristic line β1 is set to be near the maximum rotational speed in the second region Y where the drive assist by the electric supercharger 5 is performed. That is, the first boundary characteristic line β1 is set so that the torque (target torque) gradually increases as the rotational speed increases, but the torque increase accompanying the increase in the rotational speed is relatively gradual. As understood from the first boundary characteristic line β1, in a high load state (driving state in the second region Y) in which drive assist by the electric supercharger 5 is performed, the engine rotational speed is from a small state to a large state. As the engine speed increases, the drive assist by the electric supercharger 5 gradually increases and then the drive assist by the electric supercharger 5 increases as the engine speed increases. The rotational speed in the vicinity of the first region X that gradually decreases and shifts to the first region X where the drive assist by the electric supercharger 5 becomes extremely small becomes the substantially maximum torque generation rotational speed of the engine 1 in which only the natural intake operation is performed.

  A boundary characteristic line indicating a boundary between the second region Y and the third region Z is indicated by a symbol β2. The second boundary characteristic line β2 is set so that the torque increase increases rapidly as the engine speed increases. That is, in the third region Z, when the engine speed is small, the drive assist by the motor generator 11 becomes extremely large (which is more clearly understood by comparing with the first boundary characteristic line β1). In the third region Z, when the engine speed is low, the drive assist by the motor generator 11 is extremely large, while the drive assist by the electric supercharger 5 is extremely small. As the engine speed increases, the ratio of drive assist by the electric supercharger 5 gradually increases, and in the vicinity of the maximum speed in the third region Z, there is almost only drive assist by the electric supercharger 5.

  The line connecting the maximum torques of the three regions X to Z described above is the total maximum torque of the engine 1 with the electric supercharger 5 and the motor generator 11. This total maximum torque is the motor generator 11. Is substantially constant in the low rotation range where the drive assist is performed, and in the middle rotation range where the drive assist by the electric supercharger 5 is performed, it gradually decreases as the rotational speed increases, and only the natural intake operation of the engine 1 is performed. In the high rotation region, which is the region, the value decreases as the rotational speed increases, but the degree of decrease is greater than in the middle rotation region. However, the total maximum torque can be obtained in the normal and low rotation range and in the middle rotation range, with a substantially constant large torque, and is very easy to use (almost ideal) for automobiles. It has become.

  In FIG. 2, a more specific numerical example will be described. First, at point a in FIG. 2, the accelerator opening is 100%, and the engine speed is about 5000 rpm. In FIG. 2, the accelerator opening is 100%, and the engine speed is set to a speed near the minimum speed at which the maximum boost pressure is obtained and near the minimum speed at which knocking is free ( Set within the range of 2000 to 3000 rpm). The point C in FIG. 3 is the idle speed, the accelerator opening is about 80%, and the engine speed is around 650 rpm.

  Next, regarding the example of output control of the engine 1 for switching the driving of the electric supercharger 5 and the motor 11 according to the operating state of the engine 1 and the power storage control to the power storage device 15 by the control unit 50 as described above, This will be described with reference to FIG. 3 and subsequent drawings, including control during transition from region X to supercharging region Y in response to an acceleration request.

  First, FIG. 3 shows the overall control. In step S1, various signals are input, and in step S2, the target torque To is calculated based on the accelerator opening α. At this time, the target torque To is generally calculated to be larger as the accelerator opening degree α is larger.

  Next, in step S3, it is determined whether or not the vehicle is currently in the non-supercharging region X and in the vicinity of the supercharging region Y. That is, it is determined whether or not the vehicle is currently in the supercharging region X but is located near the first boundary characteristic line β1. If the determination in step S3 is YES, it is determined in step S4 whether or not the amount of change in accelerator opening (the amount of change per unit time) is greater than or equal to a predetermined value set in advance. The determination in step S4 is to determine whether or not it is an acceleration request. The predetermined value is set in step S4 and the distance from the first boundary characteristic line β1 as the supercharging start line in step S3. If the determination in step S4 is YES, the process proceeds to the supercharging region Y. When the determination in step S4 is YES, in step S6, control at the time of starting to drive the electric supercharger 5 is performed as described below. Further, when NO is determined in step S3 and NO is determined in step S4, the process proceeds to step S5, and normal control described later is performed.

  The normal control in step S5 of FIG. 3 is performed as shown in FIG. 4, for example. In FIG. 4, in step S12, it is determined whether or not the current driving state is in the drive assist region. This determination is made by checking the current operating state against the map of FIG. When currently in the non-supercharging region X, the determination in step S12 is NO, and in this case, in step S13, it is determined whether or not the vehicle is decelerating. Whether or not the vehicle is decelerating can be determined, for example, when the accelerator opening is zero, or when the brake is operated in addition to the accelerator opening being zero.

  When the determination in step S13 is NO, that is, when the vehicle is not decelerating, power storage control to the power storage device 15 is performed in step S14 (control for causing the motor generator 11 to function as a power generator). This power storage control is performed, for example, such that the power storage amount of the power storage device becomes a target power storage amount (for example, 80%). Thereafter, in step S15, the target throttle opening TVO set according to the target torque To is set, and in step S16, feedback control is performed so that the throttle opening becomes the target throttle opening TVO.

  When the determination in step S13 is YES, that is, when the vehicle is decelerating, regenerative braking is performed in step S19, and the target throttle opening TVO is set to 0 at this time. This regenerative braking causes the motor generator 11 to function as a generator, applies a large resistance to the rotation of the engine 1 to promote deceleration, and stores power generated by the motor generator 11 in the power storage device 15. is there. In the power storage control at the time of regenerative braking, the target power storage amount is set to a large target power storage amount of, for example, 95% (can be a target power storage amount of 100% according to the degree of deterioration of the power storage device 15). Is called. Of course, since it is during braking, fuel cut is performed. After step S19, the process proceeds to step S16.

  If the determination in step S12 is YES, drive assist control is performed in step S17. That is, drive assist corresponding to the region set in the map of FIG. 2 is performed, the electric supercharger 5 is driven in the supercharge region Y (no drive assist by the motor generator 11), and the motor assist region. In Z, the motor generator 11 functions as a motor together with the driving of the electric supercharger 5. Of course, in the supercharging region Y, the electric supercharger 5 is driven by receiving power supply from the power storage device 15 (the motor generator 11 functions as a generator), and in the motor assist region Z, the electric supercharger 5 and Both the motor generator 11 receives power supply from the power storage device 15. In the region where the drive assist is performed, the target throttle opening TVO is set to 100% in step S18 in order to operate the engine 1 most efficiently. After step S18, the process proceeds to step S16.

  A detailed control example of step S6 in FIG. 3 will be described with reference to FIG. In S21 of FIG. 5, the throttle opening is set to fully open (100%). Next, in step S22, the driving of the engine accessory is stopped. Examples of the engine auxiliary machine to be stopped include, for example, an engine cooling water circulation pump (cooling water pump) and an air conditioner pump that are expected to have a large torque increase due to driving stoppage. By stopping the driving of the engine auxiliary machine, the load on the engine 1 is reduced and the torque is increased. However, this torque increase increases the power generation capacity of the motor generator 11. FIG. 6 shows an example of the relationship with the power generation capability (improvement) of the motor generator 11 obtained by increasing the torque when the engine accessory is stopped. That is, when driving of the cooling water pump is stopped, the generated power is increased by the amount indicated by the wavy line in FIG. 6 as compared with the normal generated power. When the driving of the air-conditioner pump is stopped in addition to the cooling water pump stop, the generated power of the motor generator 11 is further increased.

  After step S22, in step S23, the electric power generated by the motor generator 11 is increased corresponding to the torque increase of the engine auxiliary machine whose driving is stopped. Next, in step S24, a target supply power to the electric supercharger 5 is set. This target supply power is set using the supply time ts and the supply power Ps as parameters. The target supply power, particularly the supply power Ps, is changed by controlling the inverter on the electric supercharger 5 (the motor 4) side. The supply time ts and the supply power Ps will be described in detail later.

  After step S24, it is determined in step S25 whether, for example, the supply time ts has elapsed since the time of step S24. When the determination in S25 is NO, it is a time when power is supplied from the motor generator 11 to the electric supercharger 5 at the time of transition. In this case, in step S26, the electric power received by the motor generator 11 is received. The supercharger 5 is feedback controlled so as to reach the target rotational speed. More specifically, the supercharging torque (corresponding to the torque obtained by subtracting the maximum torque of the engine 1 from the target torque To) necessary for realizing the target torque To is determined, and the determined supercharging torque is obtained. The target intake pressure is set (in general, the target intake pressure is increased as the supercharging torque increases), and the rotational speed of the electric supercharger 5 is feedback controlled so that the actual intake pressure becomes the target intake pressure. Is done. Since the feedback control of the electric supercharger 5 is supplied with sufficient power from the motor generator 11 with good response, it is reliably performed with good response, and the rise of the supercharging is quick.

  When the determination in step S25 is YES, it is the time when a transient time for supplying the electric power generated by the motor generator 11 to the electric supercharger 5 has elapsed. In this case, in step S27, the motor generator 11 After power generation is returned to the normal power generation state (normal power generation in FIG. 6). Thereafter, in step S28, the driving of the engine auxiliary machine whose driving is stopped is resumed.

  Here, the generated power supply from the motor generator 11 to the electric supercharger 5 during the transition will be described in more detail. First, in FIG. 7A, when driving the electric supercharger 5 in response to an acceleration request, the generated power from the motor generator 11 is supplied to the electric supercharger 5 (the supplied power is hatched). Area), the motor generator 11 can generate sufficient electric power due to the torque increase due to the driving stop of the engine auxiliary machine, and increase the electric power supplied to the electric supercharger 5, particularly the electric power at the initial supply stage, The electric supercharger 5 can be driven with good response. As a result, as shown in FIG. 7B, the rise of the supercharging is quick, and the acceleration response is sufficiently satisfied. Of course, the torque drop accompanying the start of power generation by the motor generator 11 is compensated by the torque increase caused by the stop of the driving of the engine auxiliary machine, and the torque shock is prevented or reduced. When there is a margin in the power generated by the motor generator 11, the power storage device 15 is charged.

  FIG. 12 shows a comparative example, and shows a case in which the start of driving of the electric supercharger 5 is all covered by the power supply from the power storage device 15 when the acceleration request is in transition. In this case, when the supply of electric power to the electric supercharger 5 is started, the supply voltage temporarily decreases suddenly and then the supply voltage gradually recovers. However, it takes a long time to recover the voltage. As a result, the electric supercharger 5 is not driven with good response, and the rise of the supercharging is delayed. In the present invention, in particular, since the supply voltage is temporarily increased suddenly without causing a temporary rapid decrease in the supply voltage shown in FIG. 12, the rise of supercharging becomes extremely fast.

  FIG. 8 shows a preferable supply form of generated power from the motor generator 11 to the electric supercharger 5. That is, at the beginning of the supply of generated power to the electric supercharger 5, the supply power Ps is set to the largest value, and thereafter, the supply power Ps is gradually reduced. At the end of the power supply time ts, the motor is supplied. It is reduced to the same level as the normal power generated by the generator 11. When there is a margin in the power generated by the motor generator 11, the marginal power can be used for power storage in the power storage device 15 as shown in FIG.

  The power supplied from the motor generator 11 to the electric supercharger 5 increases as the supply time ts increases and the supply power Ps increases. The setting of the supply time ts and the supply power Ps is preferably set with the engine speed as a parameter, for example, as shown in FIG. That is, when the engine speed is high, the intake air flow rate at the time of maximum supercharging is larger than when the engine speed is small. Therefore, the supply time ts and the supply power Ps are set to increase as the engine speed increases.

  FIGS. 10 and 11 show another setting example of the supply time ts for setting the target supply power and the supply power Ps, and they are used instead of the setting example of FIG. 9 or the setting of FIG. 9 is corrected. Can be used to However, since the degree of request for setting the supply time ts and the supply power Ps according to the engine speed is high, the setting examples in FIGS. 10 and 11 are for correction (setting correction coefficients) with the settings in FIG. 9 as basic values. For use).

  FIG. 10 shows a case where the supply time ts and the supply power Ps are increased (corrected). That is, for example, when the acceleration request is predicted by the navigation system 30, for example, when the front road is an automobile-only road or a highway, or an entrance ramp to these roads, a straight line having a plurality of lanes In the case of a road or the like, it is assumed that the degree of acceleration request is high, and ts and Ps are set to large values (set as increase correction coefficients). When the setting example of FIG. 10 is used as the increase correction coefficient, the minimum value may be set to “1”, for example.

  In FIG. 10, when the internal resistance of the power storage device 15 is large, the degree of deterioration is large and the power storage capacity is low. As the internal resistance increases, ts and Ps are set to larger values (set as increase correction coefficients). ) Also, when the degree of heating of the power storage device 15 is large, ts and Ps are set to large values (set as increase correction coefficients).

  FIG. 11 shows a case where ts and Ps are decreased (decrease correction). That is, for example, the larger the degree of heating of the electric supercharger 5, the greater the degree of deterioration of the electric supercharger 5, and the greater the amount of electricity stored in the power storage device 15, the smaller the values ts and Ps are set ( Set as a reduction correction factor). As for the amount of electricity stored in the electricity storage device 15, the smaller the amount of electricity stored, the less power is supplied to the electric supercharger 5. Therefore, it is preferable to set ts and Ps to large values (set as increase correction coefficients). It will be a thing. When the setting example of FIG. 11 is used as the reduction correction coefficient, the maximum value may be set to, for example, “1” (the minimum value is set to be larger than 1).

  FIGS. 13 and 14 show a second embodiment of the present invention and correspond to the control contents at the time of transition in FIG. First, in step S31 in FIG. 13, after the throttle opening is set to full open, in step S32, an engine accessory that can be shut off, that is, stopped driving is selected based on the current operating state of the engine accessory. This selection is performed as follows, for example. For example, in the case of an air conditioner pump, if the deviation between the current temperature and the set temperature is large, it is not preferable to stop driving the air conditioner pump, and it is preferable to at least reduce the operating capacity. Moreover, it is not preferable to stop the cooling water pump when the temperature of the engine 1 exceeds the allowable temperature range. As described above, selection of an engine accessory that can reduce the drive level without stopping driving or stopping the driving from the current operating state of the engine accessory is performed.

  In step S33, the generated power E of the motor generator 11 corresponding to the torque increase obtained when the driving of the engine auxiliary machine selected in step S32 is stopped or the driving level is lowered is determined. Thereafter, in S33, the target supply power Eo (= ts, Ps setting) to the electric supercharger 5 is determined based on the engine speed (FIG. 9).

  In step S35, the load reduction of the engine accessory selected as described above is executed (some of the driving is stopped and some of the driving level is lowered). Thereafter, in step S36, it is determined whether or not the obtained supply power E is smaller than the target supply power Eo. When the determination in step S36 is NO, the generated power E obtained by reducing the load on the engine accessory is greater than or equal to the target supply power Eo. In this case, in step S37, for example, the supply time from the time of step S35. It is determined whether ts has elapsed. If the determination in step S37 is NO, the process proceeds to step S38 (corresponding to step S26 in FIG. 5). Further, when the determination in step S37 is YES, steps S39 and S40 are performed (corresponding to steps S27 and 28 in FIG. 5).

  When the determination in step S36 is YES, the target supply power Eo cannot be achieved only by reducing the load on the engine accessory. At this time, the process proceeds to step S51 in FIG. 14, and whether or not the engine coolant temperature is equal to or higher than a predetermined value (for example, 60 degrees CF at a predetermined temperature), that is, whether or not the engine 1 is sufficiently warmed up. Is determined. When the determination in step S51 is YES, the degree of air-fuel ratio enrichment is determined. The degree of enrichment is performed based on the deviation (absolute value) between the generated power E and the target supply power Eo obtained, and the degree of enrichment increases as the deviation increases. Thereafter, in step S53, after enrichment of the air-fuel ratio is executed, the process returns to step S37 in FIG.

  If NO in step S51, the target supply power Eo cannot be satisfied even when the air-fuel ratio is enriched. In this case, the process proceeds to step S54, and the shift-up shift degree Pg of the automatic transmission 40 is determined based on the deviation (absolute value) between the generated power E and the target supply power Eo obtained. That is, by shifting up, inertia (inertia) of the drive system is released and torque for driving the motor generator 11 is increased. Therefore, the shift degree Pg of the shift up is set to a larger value as the deviation is larger. Is done. Thereafter, in step S55, upshifting is performed. In the case where the automatic transmission 40 is a continuously variable transmission (CVT), it is preferable that the shift up shift degree Pg can be set finely. Of course, when the automatic transmission 40 is a multi-stage type (for example, forward four-speed shift, five-speed shift, etc.), the minimum value of the shift degree Pg is one stage upshift.

  FIG. 15 shows an example in which the upshift is performed by Pg when the automatic transmission 40 is a continuously variable transmission (CVT). It is also possible to perform both enrichment of the air-fuel ratio and shift-up gear shifting. In other words, the air-fuel ratio can be maximized, and the generated power that is insufficient only by the maximum enrichment can be compensated by the shift-up shift for Pg.

  When the routine proceeds to step S40 in FIG. 13 via step S53, the air-fuel ratio is returned to the normal value. Similarly, when the routine proceeds to step S40 in FIG. 13 via step S55, the upshift speed Pg is canceled and the original speed ratio is restored.

  Although the embodiment has been described above, the present invention is not limited to this, and includes the following cases, for example. The electric supercharger 5 is not limited to the case where the compressor 3 is driven only by a motor (electric motor), and the compressor 3 is compressed in an exhaust turbocharger connected to a turbine driven by exhaust energy. This includes the case where the machine is driven by a motor as appropriate (especially when the compressor is driven by the motor at low rotation and high load, and the motor is stopped in the high load range from medium to high rotation to exhaust energy. Etc. to drive the compressor). In other words, in the present invention, the non-supercharging state refers to a state where the motor 4 that drives the supercharging compressor 3 is not energized for driving.

  The setting of the drive region shown in FIG. 2 is merely an example, and the setting of the drive region of the electric supercharger 5 and the region in which the motor generator 11 functions as a motor can be changed as appropriate. As control by the control unit 50, shift control of an automatic transmission (which can be either a multi-stage transmission or a continuously variable transmission), change control of a shift characteristic, and the like can be performed together. For example, when the power storage amount of the power storage device 15 is small, control such as shifting the speed change characteristic to the low speed side (the gear ratio large side) can be performed together. In transient control where acceleration is requested, the magnitude of the power generated by the motor generator 11 is set to just the magnitude corresponding to the load reduction of the engine accessory so that the generated power is not excessive or insufficient. On the other hand, it is also preferable for effectively preventing torque shock.

1 is a vehicle control system diagram for carrying out the present invention. A map showing the control area of the engine. The flowchart which shows the example of control of this invention. The flowchart which shows the example of control of this invention. The flowchart which shows the example of control of this invention. The figure which shows an example of the electric power generated when an engine auxiliary machine stops driving. The figure which shows the relationship between the electric power supply from a motor generator to an electric supercharger, and the rise of supercharging. The figure which shows the example of a setting of the target supply electric power from a motor generator to an electric supercharger. The figure which shows the example of a setting of the target supply electric power according to an engine speed. The figure which shows another example of a setting of target supply electric power. The figure which shows another example of a setting of target supply electric power. The figure which shows a comparative example and corresponds to FIG. The flowchart which shows the example of control of 2nd Embodiment of this invention. The flowchart which shows the example of control of 2nd Embodiment of this invention. The figure which shows an example in the case of upshifting a continuously variable transmission in order to ensure generated electric power.

Explanation of symbols

1: Engine 4: Motor 5: Electric supercharger 11: Motor generator 15: Power storage device 20: Accelerator opening sensor 21: Engine rotation sensor 40: Automatic transmission 50: Control unit

Claims (14)

A motor generator that is connected to an engine serving as a drive source for vehicle travel, and that selectively performs a function as a travel motor that assists the driving force of the engine and a function as a generator driven by the engine;
An electric supercharger for supercharging the intake air of the engine;
An engine accessory driven by the engine;
Control means for controlling the motor generator and the electric supercharger;
With
The control means is configured to change the motor from a non-supercharged state in which the electric supercharger is stopped and the engine is naturally aspirated to a supercharged state in which the electric supercharger is operated by an acceleration request. The generator is set to function as a generator to supply the electric power generated by the motor generator to the electric supercharger and to control the load on the engine auxiliary machine,
A control apparatus for a power train provided with an electric supercharger. A motor generator that is connected to an engine serving as a drive source for vehicle travel, and that selectively performs a function as a travel motor that assists the driving force of the engine and a function as a generator driven by the engine;
An electric supercharger for supercharging the intake air of the engine;
An engine accessory driven by the engine;
A power storage device that stores power generated by the motor generator and serves as a power supply source for the motor generator and the electric supercharger;
Load detection means for detecting parameters relating to engine load;
A rotational speed detecting means for detecting a parameter relating to the engine rotational speed;
Control means for controlling the motor generator and the electric supercharger based on the engine load detected by the load detection means and the engine speed detected by the rotation speed detection means;
With
The control means is configured to change the motor from a non-supercharged state in which the electric supercharger is stopped and the engine is naturally aspirated to a supercharged state in which the electric supercharger is operated by an acceleration request. The generator is set to function as a generator to supply the electric power generated by the motor generator to the electric supercharger and to reduce the load on the engine accessory.
A control apparatus for a power train provided with an electric supercharger.
An electric supercharger for supercharging the intake air of the engine; In claim 2,
A non-supercharging region in which the electric supercharger is stopped and the engine is naturally aspirated using the engine speed and engine load as parameters, and a supercharging region in which the engine is supercharged by operating the electric supercharger And are preset,
When the acceleration request is detected when the current operating state is in the vicinity of the supercharging region in the non-supercharging region, the control means determines that the motor generator is in transition. Is set to perform control to reduce the load of the engine accessory while supplying the generated power from the electric supercharger,
A control apparatus for a power train provided with an electric supercharger. In any one of Claims 1 thru | or 3,
The electric supercharger is characterized in that the control means is set to perform control to cause the motor generator to generate power so as to consume an increase in torque due to load reduction of the engine auxiliary machine. Equipped with a powertrain control device. In claim 2 or claim 3,
The control means is configured to store the generated surplus power in the power storage device when the generated power corresponding to the torque increase accompanying the load reduction of the engine accessory is larger than the power supplied to the electric supercharger. A control apparatus for a power train provided with an electric supercharger, characterized in that In claim 2 or claim 3,
The control means performs control so that the supply power supplied from the motor generator to the electric supercharger is larger when the engine speed is large than when the engine speed is small. The electric supercharger is configured to perform control to store the generated surplus power in the power storage device when the generated power of the machine is larger than the power supplied to the electric supercharger Powertrain control device with In any one of Claims 2 thru | or 6,
It is set to control so that the supply power supplied from the motor generator to the electric supercharger is larger when the storage amount of the power storage device is smaller than when the storage amount is large. A control apparatus for a power train having an electric supercharger. In any one of Claims 1 thru | or 7,
The control means, during the transition,
Control for determining a load reduction degree that is a degree of load reduction that the engine auxiliary machine can take according to an operating state of the engine auxiliary machine;
Control for determining a target supply power to be supplied to the electric supercharger based on an operating state of the engine;
When the generated power of the motor generator obtained by the determined degree of load reduction is smaller than the target supply power, the load of the engine accessory is reduced by the determined degree of load reduction, and the engine empty Rich correction control for temporarily enriching the fuel ratio is performed so that the motor generator generates power so as to consume the torque increase obtained by reducing the load on the engine accessory and enriching the air-fuel ratio. Do control,
Is set to
A control apparatus for a power train provided with an electric supercharger. In any one of Claims 2 thru | or 7,
The control means, during the transition,
Control for determining a target supply power to be supplied to the electric supercharger during the transition based on an operating state of the engine;
Control for determining the generated power of the motor generator obtained corresponding to the torque increase due to the load reduction of the engine accessory;
When the generated power is larger than the target supply power, the power is supplied from the motor generator to the electric supercharger by the amount of the target supply power, and a margin that is the difference between the generated power and the target supply power Control for storing electric power in the power storage device;
When the generated power is smaller than the target supply power, the torque obtained by enriching the air-fuel ratio by temporarily setting the air-fuel ratio of the engine to be insufficient as the difference between the generated power and the target supply power A control for increasing the generated power by an increase and supplying the target supply power to the electric supercharger;
Is set to do,
A control apparatus for a power train provided with an electric supercharger. In claim 8 or claim 9,
The target supply power is set by using, as parameters, a supply time and supply power for supplying the generated power from the motor generator to the electric supercharger, and a power train having an electric supercharger Control device. In claim 10,
The power supply from the motor generator to the electric supercharger is initially set to the largest value and then gradually reduced, and the control of the power train with the electric supercharger is characterized in that apparatus. In any one of Claims 1 thru | or 11,
The operating region is set in advance with the engine speed and the target torque as the engine load set according to the accelerator opening as parameters,
The operation region is divided into three regions: a first region where the target torque is low or high, a second region where the target torque is high and medium, and a third region where the target torque is high and low. And
The control means prohibits drive assist by the motor generator and the electric supercharger in the first region, executes drive assist only by the electric supercharger in the second region, and in the third region. It is set to control to execute the drive assist of both the motor generator and the electric supercharger,
A control apparatus for a power train provided with an electric supercharger. In claim 12,
A first boundary characteristic line that is a boundary between the first region and the second region corresponds to a torque curve of an engine that is naturally aspirated without driving assist between the motor generator and the electric supercharger. Set to
The second boundary characteristic line that is the boundary between the second region and the third region is set so that the target torque increases rapidly as the engine speed increases.
A control apparatus for a power train provided with an electric supercharger. In claim 13,
The maximum rotational speed of the engine that has been naturally aspirated without driving assist of the motor generator and the electric supercharger is set to be close to the maximum rotational speed in the second region,
A control apparatus for a power train provided with an electric supercharger.

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