JP2011020561A - Hybrid car - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a hybrid car having both coasting control and EV control. <P>SOLUTION: When a plot point crosses an EV upper limit line from a larger accelerator opening to a smaller one or when it crosses an EV lower limit line from a smaller accelerator opening to a larger one, a clutch is disengaged, the fuel injection quantity to an engine is reduced to reduce the engine rotational speed, and the EV control is started to start a motor generator. During the EV control, if the plot point crosses a coasting control start threshold line of a map from a larger accelerator opening to a smaller one, the hybrid car stops operation of the motor generator while maintaining the clutch disengaged and decreasing the engine rotational speed, and starts the coasting control. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

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

  As a hybrid vehicle, a parallel hybrid vehicle is known 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 start or acceleration The driving power is generated by the motor generator to assist the driving of the wheels by the engine to reduce the engine load, thereby improving the fuel consumption.

  In addition, coasting control is known as control for improving fuel efficiency (see, for example, Patent Document 3).

  The coasting control is a method of improving fuel efficiency by automatically disengaging the clutch when a predetermined condition is satisfied and setting the engine speed to idle or an equivalent speed in a vehicle equipped with a mechanism that can automatically connect and disconnect the clutch. It is.

  In this coasting control, it is only necessary to be able to automatically cut off the output of the engine to the drive wheel side. Therefore, in addition to the above-described clutch automatic connecting / disconnecting mechanism, the same effect can be obtained in ordinary torque converter, AT, and AMT systems. can get.

  This coasting control is executed, for example, based on a coasting control map as shown in FIG.

  In the coasting control map of FIG. 9, reference numeral 51 denotes a no-load line. The no-load line 51 is obtained by plotting the accelerator opening and the clutch rotational speed when the output of the engine 2 and the friction are balanced on the coasting control map.

  Reference numeral 52 denotes a coasting control start threshold line. The coasting control start threshold line 52 is a threshold line for determining the start of coasting control, and is set by offsetting the no-load line 51 to the side where the accelerator opening is small. According to the coasting control start threshold line 52, the point at which the accelerator opening and the clutch rotational speed are plotted on the coasting control map (hereinafter referred to as plot point) is the coasting control start threshold line 52 with a small accelerator opening. The coasting control is started when straddling from the side to the larger side.

  Reference numeral 53 denotes an acceleration 0 threshold line. The acceleration 0 threshold line 53 is a threshold line for determining the end of coasting control, and is set by offsetting the no-load line 51 to the side where the accelerator opening is larger. According to the acceleration 0 threshold line 53, the coasting control is ended when the plot point crosses the acceleration 0 threshold line 53 from the small accelerator opening to the large side during the execution of the coasting control.

  Reference numeral 54 denotes a deceleration 0 threshold line. The deceleration 0 threshold line 54 is a threshold line for determining the end of coasting control, and is set by offsetting the no-load line 51 to the side where the accelerator opening is smaller than the coasting control start threshold line 52. According to this deceleration 0 threshold line 54, coasting control is terminated when the plot point crosses the deceleration 0 threshold line 54 from the larger accelerator opening to the smaller side during execution of the coasting control.

  Reference numeral 55 denotes a coasting control lower limit line. The coasting control lower limit line 55 is a line that defines the lower limit of the clutch rotational speed at which coasting control is performed, and is a straight line with a constant clutch rotational speed (referred to as a clutch rotational speed threshold). The clutch rotational speed threshold is set near the idling rotational speed and higher than the idling rotational speed.

  The region on the side (right side) where the accelerator opening is larger than the acceleration 0 threshold line 53 is the acceleration region, the region between the acceleration 0 threshold line 53 and the deceleration 0 threshold line 54 is the coasting control possibility region 56, and deceleration. A region on the side (left side) where the accelerator opening is smaller than the 0 threshold line 54 is referred to as a deceleration region.

JP 2003-129878 A JP-A-11-280513 JP 2006-342832 A

  By the way, the inventors of the present application have devised a hybrid vehicle in which the fuel efficiency is improved by performing electric traveling under predetermined conditions during traveling.

  The hybrid vehicle has an EV traveling map similar to the coasting control map described above (that is, one axis is the accelerator opening and the other axis is the map of the clutch rotational speed).

  As shown in FIG. 10, the EV travel map is written with a no-load line 51 and an EV travel area 57 that is adjacent to the no-load line 51 and is set within a predetermined range on the side where the accelerator opening is larger. Yes.

  In this hybrid vehicle, when the accelerator opening and the clutch rotational speed are in the EV travel area 57 of the EV travel map, the clutch is disengaged, the fuel injection amount to the engine is decreased to lower the engine rotational speed, and the motor generator is operated as a motor. The vehicle is allowed to travel by EV.

  When this hybrid vehicle technology is used in the coasting control vehicle described above, it is possible to further improve fuel efficiency, but a simple effect cannot provide a sufficient effect. This is because the coasting control energy non-input region cannot be secured unless the establishment of the coasting control is positioned above the clutch disengagement-EV traveling (hereinafter referred to as normal EV traveling control).

  FIG. 11 is obtained by superimposing the EV traveling map of FIG. 10 on the coasting control map of FIG. An area 58 in FIG. 11 is an area obtained by removing the coasting control possibility area 56 from the EV travel area 57. If coasting control is established, it is not necessary to input energy in the region 56 (also referred to as an energy non-input region) during EV traveling, and wasteful input of electric power can be reduced, and an increase in fuel efficiency can be expected.

  Therefore, in order to secure this energy non-input region 56, it is conceivable to prioritize coasting control over normal EV traveling control.

  However, in this case, only the EV running effect after the coasting control establishment condition (condition that the accelerator is returned and the plot point crosses the coasting control start threshold line 52 from the no-load line 51) is obtained, and the operation frequency of the EV running is reduced. The effect is reduced as compared with the normal EV traveling control described above.

  FIG. 12 is obtained by adding lines 59 and 60 indicating an operation example of an accelerator pedal to the map of FIG. These lines 59, 60 consist of the locus of plot points.

  First, when coasting control is at the upper level, EV traveling cannot be used when the accelerator opening changes in a state as shown by line 59 or line 60 in FIG.

  On the other hand, when the normal EV traveling control is in the higher rank, the coasting control energy non-input area 56 cannot be used, and the power cannot be reduced.

  Therefore, an object of the present invention is to provide a hybrid vehicle that achieves both coasting control and EV traveling control.

  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 a wheel driven by the output shaft of the transmission. A hybrid vehicle having a motor generator disposed therein, wherein the engine is disengaged when the engine is in a no-load state and coasting control is performed to reduce the engine speed, and the accelerator opening is detected. An opening sensor, a rotation sensor that detects the rotation speed of the clutch, and fuel to the clutch, the motor generator, and the engine according to the accelerator opening and the clutch rotation speed detected by the opening sensor and the rotation sensor A control unit for controlling the injection amount, wherein the control unit is a map of an accelerator opening degree and the other axis is a clutch rotational speed, A no-load line that balances the engine output with the friction applied to the engine and does not contribute to the driving of the wheel, and a coasting control start threshold line set on the side adjacent to the no-load line and having a smaller accelerator opening. And an EV lower limit line set on the side where the accelerator opening is smaller than that adjacent to the coasting control start threshold line, and a side where the accelerator opening is larger than that adjacent to the no-load line. The EV upper limit line has a control map in which the accelerator opening degree and clutch rotational speed detected by the opening degree sensor and the rotation sensor are plotted on the map, and the EV upper limit line is opened. When straddling from a large side to a small side, or straddling the EV lower limit line from a side with a small accelerator opening to a large side, the The EV running control for operating the motor generator is started by lowering the fuel injection amount to the engine to lower the engine speed, and during the execution of the EV running control, the plot point is When the control start threshold line is straddled from the side where the accelerator opening is large to the small side, the operation of the motor generator is stopped while maintaining the state where the clutch is disengaged and the state where the engine speed is lowered. The coasting control is started.

  Preferably, during execution of EV travel control, the control unit operates the motor generator as a motor when the plot point is between the EV lower limit line and the no-load line of the map, When the plot point is between the EV upper limit line and the no-load line of the map, the motor generator is operated as a generator.

  The hybrid vehicle according to the present invention can achieve both coasting control and EV traveling control.

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 an operation explanatory view of this embodiment, and shows an operation example on the acceleration side. It is an operation explanatory view of this embodiment, and shows an operation example on the acceleration side. It is an operation explanatory view of this embodiment, and shows an operation example on the deceleration side. It is an operation explanatory view of this embodiment, and shows an operation example on the deceleration side. It is a lever schedule which shows the relationship between an accelerator opening, an engine speed (clutch speed), and an engine torque. It is explanatory drawing which shows the control map of coasting control. It is explanatory drawing which shows the control map of EV traveling control. It is a figure for demonstrating the problem of coasting control + EV traveling control. It is a figure for demonstrating the problem of coasting control + EV traveling control.

  An embodiment 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 vehicle wheel T and the vehicle wheel T. The coasting control is performed to disengage the clutch C and reduce the engine speed when the engine E is in a no-load state. It is a thing. 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. On the countershaft 9, the input subgear 11 meshing with the input gear 10, the reverse sub gear CR, the first speed sub gear C1, the second speed sub gear C2, the third speed sub gear C3, and the fourth speed sub gear C4 rotate. 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 A pinion 23 of the meshed motor generator MG 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 moved 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, and the drag torque of the motor generator MG is also used when the engine E runs alone. Refused to avoid.

  The motor generator MG is connected to an inverter IV for adjusting the output thereof, 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. 27, a control unit (ECU: electronic control unit) 28 that controls the fuel injection amount to the clutch C, the motor generator MG, and the engine E according to the accelerator opening and the clutch rotational speed detected at 27 is provided.

  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 has a control map in which one axis is the accelerator opening and the other axis is the clutch rotational speed. This control map is created based on the coasting control map of FIG. 9 and the EV travel map of FIG. 9 are the same as those in the coasting control map in FIG. 9 and the EV traveling map in FIG.

  In the control map, the output of the engine E is balanced with the friction applied to the engine E, and the no-load line 51 that does not contribute to the driving of the wheel T is set adjacent to the no-load line 51 and the accelerator opening is smaller. The coasting control start threshold line 52, the EV lower limit line 54 that is adjacent to the coasting control start threshold line 52 and is set on the side where the accelerator opening is smaller, and the no-load line 51 are adjacent thereto. Also, the EV upper limit line 61 set on the side where the accelerator opening is larger is written.

  As the EV lower limit line 54, the same line as the deceleration 0 threshold line 54 in the coasting control map of FIG. 9 is used.

  On the other hand, the EV upper limit line 61 is formed by combining the acceleration side upper limit line 571 of the EV travel region 57 in the EV travel map of FIG. 10 and the acceleration 0 threshold line 53 in the coasting control map of FIG.

  More specifically, the acceleration upper limit line 571 of the EV travel region 57 is a boundary line on the side where the accelerator opening is large, and the accelerator opening is higher than the acceleration 0 threshold line 53 in the region where the clutch rotational speed is low. It is located on the larger side, intersects with the acceleration 0 threshold line 53 in the vicinity of about 3500 rpm, and is located on the side where the accelerator opening is smaller than the acceleration 0 threshold line 53 in a region where the clutch rotational speed is higher than the intersection 62.

  The EV upper limit line 61 includes an acceleration upper limit line 571 in a region where the clutch rotational speed is lower than the intersection 62 between the acceleration side upper limit line 571 and the acceleration 0 threshold line 53, and acceleration in a region where the clutch rotational speed is higher than the intersection 62. This is a line obtained by combining the 0 threshold line 53.

  The controller 28 plots the EV upper limit line 61 from the larger accelerator opening to the smaller one by plotting the accelerator opening and the clutch rotational speed detected by the opening sensor 26 and the rotation sensor 27 on the control map. Or when the EV lower limit line 54 is straddled from the side where the accelerator opening is small to the large side, the clutch C is disengaged, the fuel injection amount to the engine E is reduced, and the engine speed is lowered. EV traveling control for operating the MG (hereinafter referred to as EV traveling control before coasting) is started.

  In addition, the control unit 28 applies the clutch C when the plot point crosses the coasting control start threshold line 52 of the control map from the larger accelerator opening to the smaller side during execution of the EV traveling control before coasting. The operation of motor generator MG is stopped and coasting control is started while maintaining the cut state and the state where the engine speed is lowered.

  The operation of this embodiment will be described with reference to FIGS. In the following description, the acceleration side refers to the side where the accelerator pedal 25 is depressed (side where the accelerator opening increases), and the deceleration side refers to the side where the accelerator pedal 25 returns (side where the accelerator opening decreases). .

  First, FIG. 4 and FIG. 5 show the operation in the situation of entering the control of the present embodiment on the acceleration side. FIGS. 4 and 5 show operation examples 65 and 66 when the accelerator pedal 25 is depressed in the control map of FIG.

  Step A1 As shown in FIG. 4, the control of Step A2-A8 is entered when the change in accelerator opening exceeds the set change amount on the acceleration side and the accelerator opening changes more slowly than a certain set value. More specifically, the control unit 28 detects the depression speed (accelerator opening speed) of the accelerator pedal 25 when the accelerator pedal 25 is depressed, and the accelerator opening speed is within a predetermined range (for example, 1 second). Step A2 is executed when it is within the range of about 3% to about 10%.

  Step A2 When the plotted point enters the EV lower limit line 54, the EV traveling control before coasting is started to perform the EV traveling. In the EV traveling, control unit 28 disconnects clutch C, matches the engine speed to the idling speed, and operates motor generator MG. Whether the motor generator MG is operated as a motor or a generator is determined by the following steps A3-A5. Further, the driving force (or regenerative braking force) for operating motor generator MG is also determined by steps A3-A5.

  Step A3 An asymptotic line 67 of the accelerator opening speed at the time of entry is drawn to the no-load line 51. The asymptote 67 is a straight line having a plot point 68 (hereinafter referred to as an entry point) on the EV lower limit line 54 as a start point and an accelerator opening speed at the entry point 68 as an inclination.

  Step A4 The difference between the entry point 68 on the asymptotic line 67 and the intersection 69 of the asymptotic line 67 and the no-load line 51 is converted to KW (kilowatts, that is, to work power or power). For example, KW conversion is performed according to a labor schedule as shown in FIG.

  More specifically, as shown in FIG. 8, the control unit 28 stores a so-called lever schedule in which the relationship between the accelerator opening, the clutch rotational speed (engine rotational speed), and the engine torque is written. .

  Here, when obtaining the KW converted value at the entry point 68, first, the accelerator opening and the clutch rotational speed at the entry point 68 are input to the lever schedule, and the engine torque at that time is obtained. When the torque is Te (Nm), a conversion value (output) W0 corresponding to the torque is calculated as W0 = Ne × Te × 2π / 60 using the clutch rotational speed Ne (rpm).

  On the other hand, the KW conversion value at the intersection 69 between the asymptotic line 67 and the no-load line 51 becomes 0 because the engine torque on the no-load line 51 is 0.

  From the above, the KW conversion value of the difference between the entry point 68 and the intersection 69 of the asymptotic line 67 and the no-load line 51 is W0.

  Step A5 Motor generator MG is operated with the KW converted value (absolute value) calculated in step A4.

  As shown in FIG. 5, + output (EV acceleration) is performed between the no-load line 51 and the EV lower limit line 54, and −output (EV deceleration) is performed between the no-load line 51 and the EV upper limit line 61. .

  More specifically, when the plot point is located between the no-load line 51 and the EV lower limit line 54, the control unit 28 operates the motor generator MG as a motor and outputs the driving force (output) to the step. Set to KW converted value calculated in A4.

  On the other hand, when the plot point is located between the no-load line 51 and the EV upper limit line 61, the control unit 28 operates the motor generator MG as a generator and calculates its regenerative braking force (output) in step A4. Set to the converted KW value.

  By the operation of step A5 (from EV acceleration to EV deceleration), as shown by reference numeral 70 in FIG. 5, even when the plot point enters the coasting control possibility region 56 from the acceleration side, coasting control is started by EV traveling control. The condition is easily established.

  Step A6 After that, when the coasting control start condition is satisfied during EV traveling, the coasting control is entered, and the motor output is not input in the coasting range (coasting control possibility region 56). Control unit 28 stops the operation of motor generator MG by inverter IV.

  Step A7 After entering the coasting control in Step A6, when the acceleration 0 threshold line 53 of the coasting control is exceeded from the side where the accelerator opening is small to the large side, the EV traveling control based on the EV traveling map of FIG. (Referred to as travel control).

  Step A8 On the other hand, if the plot point does not exceed the acceleration 0 threshold line 53 and is in the EV travel region (see reference numeral 57 in FIG. 10) after entering the coasting control in Step A6, the coasting control is continued, or The control returns to step A5.

  That is, when the coasting control is entered, the coasting control is maintained during the EV traveling range. In this case, the control program becomes complicated and difficult to create. Further, when the plot point falls within the EV travel range during the coasting control, the control may be returned to the control of step A5. In this case, some energy loss occurs, but the control program is easy to create.

  By performing the operations in the order of steps A1-A8 described above, it is possible to enter EV traveling control from outside the coasting control establishment condition and from outside the EV traveling condition, and to make the movement in accordance with the transition to coasting control, It is easy to establish the condition of coasting control + EV traveling.

  Next, FIG. 6 and FIG. 7 show the operation in the situation of entering the control of the present embodiment on the deceleration side. 6 and 7 show operation examples 75 and 76 when the accelerator pedal 25 is returned to the control map of FIG. In the following steps R1-R8, basically the same operations as those in steps A1-A8 described above are performed.

  Step R1 As shown in FIG. 6, when the change rate of the accelerator opening exceeds the set change rate on the deceleration side and the change amount of the accelerator opening is a gradual change from a certain set value, the process proceeds to Step R2.

  Step R2 When the EV upper limit line 61 is entered (the entry point 77), EV traveling by the EV traveling control before coasting is performed.

  Step R3 An asymptotic line 79 of the accelerator opening speed at the time of entry (when the plot point is located on the EV upper limit line 61) is drawn to the no-load line 51.

  Step R4 The difference between the entry point 77 on the asymptote 79 and the no-load line 51 (intersection 78) is converted to KW.

  Step R5 As shown in FIG. 7, motor generator MG is operated with the KW converted value calculated in step R4. At this time, negative output (EV deceleration) is performed between the no-load line 51 and the EV upper limit line 61. On the other hand, + output (EV acceleration) is performed between the no-load line 51 and the EV lower limit line 54. However, there is almost no need for EV acceleration.

  Step R6 After that, when the coasting control start condition is satisfied during EV traveling, the coasting control is entered, and the motor output is not turned on in the coasting range (coasting control possibility region 56).

  Step R7 After entering the coasting control in Step R6, when the acceleration 0 threshold line 53 of the coasting control is exceeded from the small accelerator opening to the large side, the normal EV traveling control based on the EV traveling map of FIG. 10 is performed. To do.

  Step R8 If the condition of Step R7 is not satisfied and the coasting control is entered, the coasting control is maintained during the EV traveling range. In this case, the control program becomes complicated and difficult to create. Further, when the plot point enters the EV traveling range during the coasting control, the control may be returned to the control of step R5. In this case, some energy loss occurs, but the control program is easy to create.

  By performing the operations in the order of steps R1 to R8 described above, the EV traveling control can be entered even from outside the coasting control establishment condition, and the movement to the coasting control can be achieved by the EV deceleration control. It is easy to establish the condition of control + EV traveling.

  That is, as indicated by reference numeral 80 in FIG. 7, when the plot point enters the coasting control possibility region 56 from the deceleration side, even if the accelerator opening stops on the EV upper limit line 61 side from the no-load line 51, The coasting control entry condition (between the no-load line 51 and the coasting control start threshold line 52) is easily established by the EV deceleration output.

  Thus, according to this embodiment, it is possible to achieve both coasting control and EV traveling control.

  Next, the normal EV traveling control in step A7 and step R7 described above will be described in detail.

  As shown in FIG. 10, the control unit 28 has a control map for normal EV traveling control, and when performing normal EV traveling control, the accelerator opening detected by the opening sensor 26 and the rotation sensor 27 and When the clutch rotational speed is in the EV traveling region (electric traveling region) 57 of the control map, the clutch C is disengaged, the fuel injection amount to the engine E is decreased to lower the engine rotational speed, and the motor generator MG is operated as a motor. The vehicle is driven electrically.

  The friction is caused by sliding resistance generated in a sliding portion such as between piston cylinders in the engine E as the engine E is operated, or 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 is balanced with this friction, the output of the engine E is consumed only by the friction, no rotational force is transmitted to the transmission TM, and does not contribute to driving the wheels T at all. The no-load line 51 is a line that connects points where the output of the engine E balances the friction at that time. Therefore, on the no-load line 51, the output from the engine E to the transmission TM becomes zero during traveling of the vehicle, and the engine E does not work on the wheels T at all.

  On the side where the accelerator opening is smaller than the no-load line 51 (the left side in FIG. 10), 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 no-load line 51 (the right side in FIG. 10), 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 no-load line 51 (a certain accelerator opening and clutch rotational speed), the engine output and the friction are balanced on the no-load line 51 while the vehicle is running. The operating state of the point in the acceleration region can be maintained with force.

  Therefore, in the normal EV traveling control, the electric traveling region 57 is set within a predetermined range adjacent to the no-load line 51 and on the side where the accelerator opening is larger than that, and the clutch C is disengaged in the electric traveling region 57. The engine E is disconnected from the transmission TM, and the motor generator MG is operated as a motor to drive the vehicle electrically. As a result, even in a so-called parallel hybrid type, even a hybrid vehicle that is generally recognized as being incapable of electric traveling by designing the motor output of the motor generator MG to be low in order to reduce costs. The electric travel can be temporarily realized in the electric travel region 57 set on the acceleration side of the no-load line 51 inside. 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 normal EV traveling control, when the vehicle is electrically driven in the electric traveling region 57, 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 each cylinder of the engine E By controlling the fuel injection control unit 34 of the injector 33 that injects fuel at the same time, 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 running to electric running, 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 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 57, the vehicle is driven 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, the control unit 28 determines whether the accelerator opening detected by the opening sensor 26 and the clutch rotational speed detected by the rotation sensor 27 when the vehicle is electrically driven in the electric travel region 57. Enter the lever schedule and determine the engine torque at that time. When the torque is Te (Nm), the output W (kW) of the motor generator MG corresponding to 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 571 on the accelerator opening large side of the electric travel region 57 adjacent to the no-load line 51 shown in FIG. 10 depends on the performance (output) of the motor generator MG mounted on the vehicle, the capacity of the battery BT that is the power source, and the like. Determined. That is, if the upper limit line 571 is excessively moved to the right side of FIG. 10 and the electric travel region 57 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 571 of the electric travel region 57 is set to a gentle acceleration region near the right side of the no-load line 51 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. did.

  The electric travel region 57 is set so as to spread from the no-load line 51 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 travel capability is reached at a point slightly away from the no-load line 51 to the acceleration region side, whereas the clutch rotational speed (engine rotational speed). This is because the limit electric travel capability is reached at a point farther away from the no-load line 51 on the acceleration region side.

  In the normal EV traveling control, the upper limit line 571 of the electric traveling region 57 is set so that the output of the motor generator MG becomes a certain value determined by the limit electric traveling capability.

  Next, Table 1 shows the fuel efficiency improvement effect prediction of this embodiment by calculation of a certain vehicle type. In Table 1, “normal vehicle” is a non-hybrid vehicle and serves as a reference, so the improvement rate is 0%. “Acceleration assist / deceleration regenerative HEV equivalent” is a calculation improvement prediction result when starting and acceleration assist and braking regeneration when the accelerator opening is 0% in HEV. “Equivalent to HEV of clutch disengaged motor travel type” is a calculation improvement prediction result when the above-described normal EV travel control is performed in HEV, and “coast control + corresponding to HEV of motor travel type” is the control of this embodiment. It is a calculation improvement prediction result at the time of performing.

  As shown in Table 1, according to this embodiment, of course, “acceleration assist, deceleration regeneration type HEV equivalent” is naturally “clutch” in which the engine E is idling while the clutch C is disconnected during EV traveling. It can be seen that the fuel efficiency is improved even with respect to the “HEV equivalent of the intermittent motor running type”. In particular, since coasting control is applied, the fuel efficiency improvement rate increases when traveling in a city is assumed.

  Thus, according to the present embodiment, as shown in FIGS. 4 and 7, the EV of the no-load line 51 when the plot point enters the coasting control possibility region 56 from the acceleration side and from the deceleration side. By reversing the EV traveling movement (driving and braking) with respect to the accelerator opening movement (acceleration and deceleration) on the upper limit line 61 side and the EV lower limit line 54 side, it becomes easier to shift to coasting control and coasting. By switching to the driving state of control + EV traveling, efficient EV traveling can be realized and fuel consumption can be improved.

  The present invention is not limited to the above embodiment.

  In the present 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).

E Engine TM Transmission
C Clutch T Wheel MG Motor generator 26 Opening sensor 27 Rotation sensor 28 Control unit 51 No-load line 57 EV travel region

Claims (2)

A clutch interposed between the engine of the vehicle and the transmission, and a motor generator disposed in a power transmission system between the clutch and wheels driven by the output shaft of the transmission, A hybrid vehicle configured to perform coasting control to disengage the clutch and reduce the engine speed when the engine is in a no-load state,
An opening sensor for detecting the opening of the accelerator, a rotation sensor for detecting the rotation speed of the clutch, the clutch, and the motor according to the accelerator opening and the clutch rotation speed detected by the opening sensor and the rotation sensor. A generator and a control unit for controlling a fuel injection amount to the engine,
The controller is
One axis is a map of the accelerator opening and the other axis is a map of the clutch rotational speed, the engine output balances with the friction applied to the engine and does not contribute to driving the wheel, and adjacent to the no-load line The coasting control start threshold line set on the side where the accelerator opening is smaller than that, and the EV lower limit line set adjacent to the coasting control start threshold line and on the side where the accelerator opening is smaller than that And an EV upper limit line set on the side where the accelerator opening is larger than that adjacent to the no-load line,
When the plot point in which the accelerator opening and the clutch rotational speed detected by the opening sensor and the rotation sensor are plotted on the map crosses the EV upper limit line from the side where the accelerator opening is large to the small side, or When the EV lower limit line is straddled from the side where the accelerator opening is small to the large side, the clutch is disengaged, the fuel injection amount to the engine is lowered, the engine speed is lowered, and the motor generator is operated. Start
During execution of the EV traveling control, when the plot point crosses the coasting control start threshold line of the map from the side where the accelerator opening is large to the small side, the clutch is disengaged and the engine speed A hybrid vehicle characterized in that the coasting control is started by stopping the operation of the motor generator while maintaining the lowered state. The control unit operates the motor generator as a motor when the plot point is between the EV lower limit line and the no-load line of the map during execution of EV traveling control,
On the other hand, the hybrid vehicle according to claim 1, wherein the motor generator is operated as a generator when the plot point is between the EV upper limit line and the no-load line of the map.

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