JP5353511B2 - Hybrid car - Google Patents

Description

  The present invention relates to a hybrid vehicle including an engine and a motor as a power source for the vehicle.

  As a hybrid vehicle, there is known a parallel hybrid vehicle in which a motor generator is disposed downstream of a power transmission system with respect to a clutch interposed between a vehicle engine and a transmission (Patent Documents 1 and 2). etc).

  According to such a hybrid vehicle, at the time of deceleration braking, the clutch is disengaged and the engine is disconnected from the wheel, the braking energy of the wheel is collected by the motor generator and stored in the battery, and the clutch is connected at the time of starting or acceleration The motor generator can generate driving force to assist the driving of the wheels by the engine and reduce the engine load, thereby improving fuel efficiency.

JP 2003-129878 A JP-A-11-280513

  According to the system described above, the braking energy is recovered (regenerated) by the motor generator during deceleration braking of the vehicle, and the motor load is reduced (acceleration assistance) by the motor generator during start and acceleration to reduce the engine load. However, it is not sufficient, and further improvement in fuel efficiency has been demanded.

  Accordingly, an object of the present invention is to provide a hybrid vehicle that improves fuel efficiency by performing electric traveling under predetermined conditions while traveling.

  In order to achieve the above object, the present invention provides a power transmission system between a clutch interposed between an engine of a vehicle and a transmission, and wheels driven by the output shaft of the transmission. A hybrid vehicle having a motor disposed therein, an opening sensor for detecting the opening of the accelerator, a rotation sensor for detecting the rotation speed of the clutch, and an accelerator detected by the opening sensor and the rotation sensor And a control unit that controls the amount of fuel injected to the clutch, the motor, and the engine according to the opening and the number of revolutions of the clutch. An engine no-load line in which the output of the engine is balanced with the friction applied to the engine and does not contribute to driving the wheel, and the engine no-low line A control map in which an electric travel region set in a predetermined range is written on the side adjacent to the line and the accelerator opening is larger than that, and the accelerator opening detected by the opening sensor and the rotation sensor and When the clutch rotational speed is in the electric travel region of the map, the clutch is disengaged, the fuel injection amount to the engine is decreased to lower the engine rotational speed, and the motor is operated to electrically drive the vehicle. .

  The controller outputs the vehicle based on the accelerator opening detected by the opening sensor and the clutch rotational speed detected by the rotation sensor when the vehicle is electrically driven in the electric driving region. The engine torque may be predicted, and the motor may be operated with an output corresponding to the torque with the clutch disengaged.

  The controller may lower the engine speed to idling when the vehicle is electrically driven in the electric travel region.

  According to the hybrid vehicle of the present invention, it is possible to improve the fuel consumption by performing the electric driving under a predetermined condition where the required power is small during the driving.

It is explanatory drawing which shows the outline | summary of the power transmission system of the hybrid vehicle which concerns on one Embodiment of this invention. FIG. 2 is an enlarged view of the transmission of FIG. 1 and the vicinity thereof. It is explanatory drawing which shows a control map. It is explanatory drawing which shows the relationship between an accelerator opening, an engine speed (clutch speed), and an engine torque. It is a flowchart at the time of performing electric travel.

  Preferred embodiments of the present invention will be described with reference to the accompanying drawings.

  As shown in FIG. 1, the hybrid vehicle according to the present embodiment is driven by a clutch C interposed between an engine E and a transmission TM mounted on the vehicle, and an output shaft of the clutch C and the transmission TM. And a motor generator MG disposed in a power transmission system between the wheels T. In the present embodiment, a fluid coupling FC is interposed between the crankshaft of the engine E and the input shaft of the transmission TM in addition to the clutch C. When starting, the transmission TM is geared into the starting gear, and the clutch C The fluid coupling FC is started by creep of the fluid coupling FC, but the fluid coupling FC may be omitted and the clutch C may be started by half-clutch control. Here, the fluid coupling FC is a concept including a torque converter, the clutch C is a wet clutch, and the engine E is a diesel engine.

  As shown in FIG. 2, the fluid coupling FC includes a pump impeller 1 connected to the crankshaft of the engine E, a turbine impeller 2 connected to the input shaft of the clutch C, and a transmission case via a one-way clutch 3. And a stator impeller 4 supported by a fixed system such as the above. A lockup clutch RC is interposed between the member to which the pump impeller 1 is attached and the member to which the turbine impeller 2 is attached. When the vehicle speed falls below a predetermined vehicle speed, the lock-up clutch RC is disconnected to avoid engine stall. After that, when the vehicle speed rises above another predetermined vehicle speed higher than the predetermined vehicle speed, the slip-up clutch RC avoids slipping and increases efficiency. Bordered to enhance.

  The clutch C has an input plate 5 provided on the input shaft connected to the turbine impeller 2 of the fluid coupling FC, and an output plate 6 provided on the output shaft connected to the input shaft 7 of the transmission TM. When the plate 5 and the output plate 6 are relatively pressed by the clutch actuator CA, they are brought into contact with each other, and when the pressing is released, the plates are disconnected. The clutch C is disengaged when a speed change operation is performed by the transmission TM, and is brought into contact after completion of the speed change.

  The transmission TM includes an input shaft 7 connected to the output shaft of the clutch C, a main shaft 8 disposed coaxially with a distance from the shaft end, and a sub shaft 9 disposed in parallel with the input shaft 7 and the main shaft 8. Each shaft is rotatably supported by a transmission case via a bearing. An input gear 10 is provided on the input shaft 7 so as not to rotate. The sub-shaft 9 rotates with an input sub-gear 11 meshing with the input gear 10, a reverse sub-gear CR, a first-speed sub-gear C1, a second-speed sub-gear C2, a third-speed sub-gear C3, and a fourth-speed sub-gear C4. Impossibly, a 6-speed auxiliary gear C6 is rotatably provided. The main shaft 8 includes a reverse main gear MR meshing with an idle gear IR meshed with a reverse sub gear CR, a first speed main gear M meshing with a first speed sub gear C1, and a second speed main gear meshing with a second speed sub gear C2. M2, a 3-speed main gear M3 that meshes with the 3rd-speed sub gear C3, and a 4-speed main gear M4 that meshes with the 4-speed sub-gear C4, and a 6-speed main gear M6 that meshes with the 6-speed sub-gear C6, respectively. It is provided so that it cannot rotate. The main shaft 8 is provided with a 1-speed / reverse hub H1R, a 2-speed / 3-speed hub H23, and a 4-speed / 5-speed hub H45, respectively. The hub H6 is provided so as not to rotate.

  When the 1st speed / reverse sleeve SR1 spline-engaged with the 1st speed / reverse hub H1R is engaged with the reverse dog DR provided on the reverse main gear MR, the main shaft 8 rotates reversely, and the 1st speed / reverse sleeve When SR1 is meshed with a first speed dog D1 provided on the first speed main gear M1, the main shaft 8 rotates at a gear ratio of the first speed. When the 2-speed / 3-speed sleeve S23 that is spline-engaged with the 2-speed / 3-speed hub H23 is engaged with the 2-speed dog D2 provided in the 2-speed main gear M2, the main shaft 8 rotates at a 2-speed gear ratio. When the 2nd / 3rd speed sleeve S23 is engaged with the 3rd speed dog D3 provided on the 3rd speed main gear M3, the main shaft 8 rotates at a gear ratio of 3rd speed. When the 4-speed / 5-speed sleeve S45 that is spline-engaged with the 4-speed / 5-speed hub H45 is engaged with the 4-speed dog D4 provided on the 4-speed main gear M4, the main shaft 8 rotates at a 4-speed gear ratio. When the 4-speed / 5-speed sleeve S45 is engaged with the 5-speed dog D5 provided on the input shaft 7, the main shaft 8 is directly connected to the input shaft 7 (5-speed gear ratio) and rotates. When the 6-speed sleeve S6 spline-engaged with the 6-speed hub H6 is engaged with the 6-speed dog D6 provided on the 6-speed auxiliary gear C6, the main shaft 8 rotates at a gear ratio of 6-speed. Each sleeve is provided with a synchro mechanism.

  A motor generator MG is connected to the transmission TM via a side PTO mechanism P. The side PTO mechanism P includes an idle gear 15 meshed with the third speed sub gear C3 of the counter shaft 9, a PTO gear 16 meshed with the idle gear 15, a dog 18 provided on the rotation shaft 17 of the PTO gear 16, and a rotation shaft 17 A drive shaft 19 disposed coaxially with the drive shaft 19, a hub 20 provided at one end of the drive shaft 19, a sleeve 21 spline-engaged with the hub 20, a reduction gear 22 provided at the other end of the drive shaft 19, and a reduction gear 22 The pinion 23 of the motor generator MG engaged is provided. The rotary shaft 17 is rotatably supported via a bearing on a PTO case 29 (see FIG. 1) that accommodates the PTO gear 16, dog 18, hub 20, and sleeve 21, and the drive shaft 19 incorporates a universal joint. Thus, one end is rotatably supported by the PTO case 29 via a bearing, and the other end is rotatably supported by a reduction gear case 36 (see FIG. 1) accommodating the reduction gear 22 and the pinion 23 via a bearing. Yes.

  According to this PTO mechanism P, when the sleeve 21 is engaged with the dog 18, the rotation of the third speed sub gear C3 is transmitted to the motor generator MG, and when the sleeve 21 is detached from the dog 18, the motor generator MG is transmitted to the third speed sub gear C3. Disconnected from the rotation. The dog 18, the hub 20, and the sleeve 21 constitute a PTO clutch PC. The PTO clutch PC is normally engaged, and is disconnected to reduce the synchronization burden of each sleeve when the transmission TM performs a shift operation. Also when the engine E runs alone, the drag torque of the motor generator MG is used. Refused to avoid.

  An inverter IV for adjusting the output is connected to the motor generator MG, and a battery (lithium ion battery or the like) BT as a power source is connected to the inverter IV.

  As shown in FIG. 2, the hybrid vehicle includes an opening sensor 26 that detects the opening of the accelerator pedal 25, a rotation sensor 27 that detects the number of rotations of the clutch C, the opening sensor 26, and the rotation sensor. And a control unit (ECU: electronic control unit) 28 for controlling the fuel injection amount to the clutch C, the motor generator MG, and the engine E according to the accelerator opening degree and the clutch rotational speed detected at 27.

  The opening sensor 26 is an angle sensor that detects the angle of the accelerator pedal 25, and obtains the accelerator opening from the angle.

  The rotation sensor 27 detects the rotation of the input gear 10 provided on the input shaft 7 of the transmission TM, and the rotation speed of the input gear 10 matches the rotation speed of the output shaft of the clutch C. That is, the clutch rotational speed detected by the rotation sensor 27 means the rotational speed of the output shaft of the clutch C. The rotational speed of the output shaft of the clutch C matches the rotational speed of the crankshaft of the engine E (engine speed) if the clutch C is engaged and the lockup clutch RC is engaged.

  Here, after the start of the vehicle, the lockup clutch RC is engaged when the vehicle speed is such that creep is not required, and thereafter, the lockup clutch RC remains in contact unless the vehicle speed drops to the extent that it is stalled. Since the clutch C is engaged except when a speed change operation is performed in the transmission TM, the rotational speed of the output shaft of the clutch C coincides with the engine speed during normal running other than at the time of start and gear shift. . Therefore, hereinafter, the clutch rotational speed is also referred to as engine rotational speed.

  As shown in FIG. 3, the control unit 28 drives the wheel T so that one shaft is a map of the accelerator opening and the other shaft is a map of the clutch rotational speed, and the output of the engine E is balanced with the friction applied to the engine E. A control map M1 in which an engine no-load line 30 that does not contribute to the engine and an electric traveling region 31 that is adjacent to the engine no-load line 30 and that is set in a predetermined range on the side where the accelerator opening is larger than that are written. When the accelerator opening degree and the clutch rotational speed detected by the degree sensor 26 and the rotational sensor 27 are in the electric travel region 31 of the control map M1, the clutch C is disengaged and the fuel injection amount to the engine E is decreased to reduce the engine rotational speed. The motor generator MG is operated as a motor to drive the vehicle electrically.

  The friction is a sliding resistance generated in a sliding portion such as between the piston cylinders in the engine during operation of the engine E, or driving when the engine E drives auxiliary equipment such as a power steering pump or an air conditioner compressor. If the output of the engine E balances with the friction, such as resistance, the output of the engine E is consumed only by the friction, the rotational force is not transmitted to the transmission TM, and does not contribute to the driving of the wheels T at all. The engine no-load line 30 is a line that connects points where the output of the engine E balances the friction at that time. Therefore, on the engine no-load line 30, the output from the engine E to the transmission TM becomes zero while the vehicle is traveling, and the engine E does not work on the wheels T at all.

  On the side where the accelerator opening is smaller than the engine no-load line 30 (the left side in FIG. 3), the output of the engine E is smaller than the output that balances the friction, so that it becomes a deceleration region. On the contrary, on the side where the accelerator opening is larger than the engine no-load line 30 (the right side in FIG. 3), the output of the engine E becomes larger than the output balanced with the friction, so that it becomes an acceleration region. In this acceleration region, if it is a point in the vicinity of the engine no-load line 30 (a certain accelerator opening and clutch rotational speed), the engine output and the friction are balanced on the engine no-load line 30 while the vehicle is running. Thus, the driving state of the acceleration region can be maintained with a small force.

Therefore, the present invention sets an electric traveling region 31 within a predetermined range adjacent to the engine no-load line 30 and on the side where the accelerator opening is larger than that, and in the electric traveling region 31, the clutch C is disengaged to disengage the engine. E was disconnected from the transmission TM, and the motor generator MG was operated as a motor. As a result , in the parallel hybrid type in which the motor output of the motor generator MG is designed to be low in order to reduce the cost, the engine can be used while traveling even in an acceleration region that is generally recognized as not performing electric traveling. temporarily electric drive in electric drive area 31 set in the acceleration region side of the no-load line 30 Ru is executed. Since the output of the engine E does not have to be consumed for driving the wheels T during the electric running, fuel efficiency is improved.

  In the present embodiment, when the vehicle is electrically driven in the electric traveling region 31, the control unit 28 disengages the clutch C by the clutch actuator CA to separate the engine E from the transmission TM and the wheels T, and to each cylinder of the engine E. By controlling the fuel injection control unit 34 of the injector 33 that injects fuel, the rotational speed of the engine E is reduced to idling regardless of the accelerator opening, thereby improving fuel efficiency. Note that if the engine E is stopped, the fuel consumption becomes zero. In this case, auxiliary equipment such as a power steering pump and an air conditioner compressor driven by the crankshaft of the engine E is stopped, and the power assist of the steering wheel and the cab Because the air conditioning and the like will stop, it is idle. However, if the compressor and the power steering pump of these air conditioners are driven electrically, the engine E may be stopped when the electric running is performed.

  When the vehicle is switched from engine driving to electric driving, the wheels T that have been driven by the engine E until then are switched to driving by the motor generator MG. Therefore, in order to avoid a shock at the time of switching, the motor generator MG at the time of switching is changed. It is necessary to match the output of the engine E when the output is switched. Therefore, in the present embodiment, when the vehicle is electrically driven in the electric travel region 31, based on the accelerator opening detected by the opening sensor 26 and the clutch rotational speed detected by the rotation sensor 27. The output torque of the engine E is predicted, and with the clutch C disengaged, the motor generator MG is operated as a motor with an output corresponding to the torque.

  More specifically, as shown in FIG. 4, the control unit 28 stores a so-called engine lever schedule map M2 in which the relationship between the accelerator opening, the clutch rotational speed (engine rotational speed), and the engine torque is written. Has been. When the vehicle is electrically driven in the electric travel region 31, the accelerator opening detected by the opening sensor 26 and the clutch rotational speed detected by the rotation sensor 27 are input to the engine lever schedule map M2, and at that time Is determined by the control unit 28. If the torque is Te (Nm), the output W (kW) of the motor generator MG commensurate with the torque can be calculated as W = Ne × Te × 2π / 60 using the engine speed Ne (rpm). In addition, a proportionality coefficient a and an addition constant b may be added for adjustment, and calculation may be performed using an equation of W = a × Ne × Te × 2π / 60 + b.

  The upper limit line 31L on the accelerator opening large side of the electric travel region 31 adjacent to the engine no-load line 30 shown in FIG. 3 is the performance (output) of the motor generator MG mounted on the vehicle, the capacity of the battery BT that is the power source, etc. Determined by. That is, if the upper limit line 31L is excessively moved to the right side of FIG. 3 and the electric travel region 31 is excessively expanded to the right side of the acceleration region, the limit electric travel capability determined from the performance of the motor generator MG mounted on the vehicle and the capacity of the battery BT. However, even if the electric running is impossible or possible, the battery BT is quickly depleted. Therefore, the upper limit line 31L of the electric travel region 31 is set to a slow acceleration region near the right side of the engine no-load line 30 so that the electric travel is performed only in the region where the limit electric travel capability is not exceeded and the battery BT is not rapidly consumed. I made it.

  The electric travel region 31 is set so as to spread from the engine no-load line 30 to the acceleration region side as the clutch rotational speed (engine rotational speed) shifts from high to low. The reason for this is that when the clutch rotational speed (engine rotational speed) is high, the limit electric running capacity is reached at a point slightly away from the engine no-load line 30 toward the acceleration region, whereas the clutch rotational speed (engine rotational speed) This is because, if the number) is low, the limit electric travel capability is reached at a point further away from the engine no-load line 30 on the acceleration region side. In the present embodiment, the upper limit line 31L of the electric travel region 31 is set such that the output of the motor generator MG is a certain value determined by the limit electric travel capability.

  On the other hand, braking energy is recovered (regenerated) when the vehicle decelerates, when the accelerator opening is zero or when the accelerator pedal is zero and the brake pedal is depressed, the clutch C is disengaged and the rotation of the wheel T is performed by the engine. The rotation of the wheel T is transmitted to the motor generator MG via the transmission TM, and is not transmitted to E. That is, in the control map M1 of FIG. 3, the braking regeneration region 35 is set in a region where the accelerator opening is zero and the clutch rotational speed (engine rotational speed) is higher than the engine idling rotational speed. When both the accelerator opening detected by the opening sensor 26 and the clutch rotational speed (engine rotational speed) detected by the rotation sensor 27 are within the braking regeneration region 35, the clutch C is disconnected and the motor generator is disconnected. The braking energy is recovered (regenerated) by MG. Note that, as described above, in addition to the accelerator opening being zero, the regenerative condition may be that the brake pedal is depressed.

  The electric travel control of the hybrid vehicle according to the present embodiment will be described based on the flowchart of FIG.

  As shown in step S1, during rotation of the vehicle, the rotation speed of the clutch 27 (engine speed) is detected by the rotation sensor 27 shown in FIG. 2, and the accelerator opening degree is detected by the opening degree sensor 26. In step S2, the detected clutch rotational speed (engine rotational speed) and accelerator opening are input to the control map M1 in FIG. 3, and it is determined whether or not they are within the electric travel region 31. If no, head to the end without performing electric driving, and if yes, in step S3, the clutch C is disengaged and the engine speed is reduced to idling. In step S4, the clutch rotational speed (engine rotational speed) detected in step S1 and the accelerator opening are input to the lever schedule map M2 in FIG. 4, and the engine torque at that time is obtained, which is commensurate with the engine torque. The target output of the motor generator MG is calculated. In step S5, the calculated target output is commanded to the motor controller, and the output of the motor generator MG is controlled to the target output by the inverter IV.

  As described above, during vehicle traveling, electric traveling is performed in the electric traveling region 31 of FIG. 3, and engine traveling is performed in other regions. During electric travel, the output of the engine E does not have to be consumed for driving the wheels T, and the engine E is in an idling state, so that fuel efficiency is improved.

  As described above, the recovery (regeneration) of braking energy when the vehicle decelerates is obtained when the accelerator opening detected by the opening sensor 26 is zero and the clutch rotational speed (engine rotational speed) detected by the rotation sensor 27 is shown in FIG. 3 is achieved by disengaging the clutch C and transmitting the rotation of the wheel T not to the engine E but to the motor generator MG.

  In the hybrid vehicle according to the present embodiment, torque assist (acceleration assist) is not performed by the motor generator MG when starting and accelerating. When the energy regenerated as described above at the time of vehicle deceleration is used for both acceleration assist at the time of start and acceleration and electric traveling in the electric traveling region 31, the consumption amount of the battery BT exceeds the regeneration amount, and the system It is because there is a possibility that it may not be established.

  However, if the regenerative amount of the motor generator MG can be balanced with the consumption amount of the battery BT by increasing the performance of the motor generator MG and the capacity of the battery BT, the acceleration assist and the electric travel area at the start and acceleration You may perform both with 31 electric running.

  The present invention is not limited to the above embodiment.

  In this embodiment, the motor generator MG is connected to the auxiliary shaft 9 of the transmission TM via a gear (side PTO type), but the motor generator MG may be provided on the input shaft 7 of the transmission TM (front PTO type). ) A motor generator MG may be provided on the output shaft of the transmission TM (rear PTO type).

  In the case of the side PTO type and the front PTO type, the output of the motor generator MG is transmitted to the wheels T via the transmission ratio in the transmission TM, so that the capacity of the motor generator MG can be made relatively small, whereas the rear PTO In the case of the equation, since the output of the motor generator MG is transmitted to the wheels T without passing through the gear ratio in the transmission TM, in principle, the capacity of the motor generator MG needs to be relatively large.

  However, in the present invention, the acceleration assist by the motor generator MG is not performed, and the motor generator MG is used only for the electric traveling in the electric traveling region 31 in which a large output is not required. Therefore, the capacity of the motor generator MG can be made smaller than that of the conventional rear PTO type, and the cost can be reduced.

  Further, the motor generator MG may be a motor, and a regeneration generator may be separately provided somewhere in the power transmission system.

E Engine TM Transmission C Clutch T Wheel MG Motor (motor generator)
26 Opening sensor 27 Rotation sensor 28 Control unit 30 Engine no-load line 31 Electric travel region M1 Control map

Claims (3)

A hybrid vehicle having a clutch interposed between an engine of a vehicle and a transmission, and a motor disposed in a power transmission system between the clutch and a wheel driven by an output shaft of the transmission There,
A opening sensor for detecting an accelerator opening, a rotation sensor for detecting a rotational speed of the engine, the clutch in accordance with the accelerator opening and the engine rotational speed detected by these opening sensor and the rotation sensor, the motor And a controller for controlling the fuel injection amount to the engine,
The control unit
One axis and the other axis in the accelerator opening a map of the engine speed, the accelerator opening and the engine speed which do not contribute to the driving of the wheels output commensurate with the friction exerted on the engine of the engine an engine no-load line which defines an electric accelerator opening is set in a predetermined range of the upper-limit line or less that defines the limit electric travel capability for the output of the engine no-than load line rather come large, and the motor for the engine rotational speed It has a control map in which the driving area is written,
When the accelerator opening and the engine speed detected by the opening sensor and the rotation sensor are in the electric travel region of the map, the clutch is disengaged and the fuel injection amount to the engine is reduced to lower the engine speed. , a hybrid vehicle, wherein the Ru motor to actuate the by electric vehicle to travel. The control unit detects the accelerator opening detected by the opening sensor and the rotation sensor before the clutch is disengaged when the clutch is disengaged and the vehicle is electrically driven in the electric travel region. 2. The hybrid according to claim 1, wherein the engine torque output at that time is predicted based on the engine speed, and the motor is operated with an output corresponding to the torque when the clutch is disengaged. Automobile.   3. The hybrid vehicle according to claim 1, wherein the control unit is configured to reduce the number of revolutions of the engine to idling when the vehicle is electrically driven in the electric traveling region. 4.

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