JP2017202760A - Hybrid vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the fuel economy of a hybrid vehicle in auto-cruising.SOLUTION: A transmission 20 includes: a primary transmission mechanism 21 for reducing the speed of rotary driving of a diesel engine 10; and a secondary transmission mechanism 22 for adjusting speed reduction ratios of the primary transmission mechanism 21. A control apparatus 80 controls an operation of a hybrid vehicle 100 in an auto-cruise. A shift lever 81 allows a driver of the vehicle 100 to select a gear of the transmission 20 or cause the control apparatus 80 to control selection of a gear. A motor-generator 33 is connected to a propeller shaft 25 via a speed reduction mechanism 30. In a case where (1) the clutch 15 is in a connection state, (2) the secondary transmission mechanism 22 is in a non-neutral state and (3) the motor-generator 33 is in a regeneration state, the control apparatus 80 puts the secondary transmission mechanism 22 in a neutral state under the condition of the driver selecting to cause the control apparatus 80 to automatically select a gear, as trigger.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a hybrid vehicle using an engine and a motor as power sources.

  Hybrid electric vehicles equipped with an engine and a motor as a driving power source have been developed and are becoming popular. Some of such hybrid electric vehicles are equipped with auto-cruise control that keeps the vehicle speed between the upper limit speed and the lower limit speed centered on the target vehicle speed set by the driver (for example, patents) Reference 1).

Japanese Patent Laying-Open No. 2015-073347

  In order to respond to the increasing interest in environmental problems in recent years, improvement in fuel efficiency is also required in auto cruise control of vehicles. The same applies to a hybrid vehicle having relatively high fuel efficiency, and further improvement in fuel efficiency is required especially during auto-cruise where manual operation by the driver is not required.

  The present invention has been made in view of these points, and an object of the present invention is to provide a technique for improving fuel efficiency in auto cruising of a hybrid vehicle.

  One embodiment of the present invention is a hybrid vehicle having an engine and a motor generator as driving forces. The hybrid vehicle includes a clutch that controls power transmission of the engine, a main transmission mechanism that decelerates the rotational drive of the engine that is transmitted through the clutch, and a gear ratio of the main transmission mechanism. A transmission including a sub-transmission mechanism, a propeller shaft that transmits the power of the engine to drive wheels via the sub-transmission mechanism, a control device that controls the operation of the hybrid vehicle during auto-cruising, and the operation of the hybrid vehicle And a shift lever for switching whether a hand selects a gear of the transmission or causes the control device to automatically control the selection of the gear. Here, the motor generator is connected to the propeller shaft via a speed reduction mechanism, and the control device includes: (1) the clutch is in a connected state, (2) the auxiliary transmission mechanism is in a non-neutral state, and (3) the When the motor generator is in the regenerative state, the sub-transmission mechanism is set to the neutral state when the driver selects the control device to automatically control the selection of the gear.

  The control device sets the gear of the main transmission mechanism and the gear of the auxiliary transmission mechanism based on at least the vehicle speed of the hybrid vehicle and the rotational speed of the engine while the auxiliary transmission mechanism is in the neutral state. May be.

  ADVANTAGE OF THE INVENTION According to this invention, the technique which makes compatible the fuel consumption improvement in the auto cruising of a hybrid vehicle and the response speed of acceleration / deceleration can be provided.

It is a figure which shows the structure of the hybrid vehicle which concerns on embodiment. It is a figure which shows typically the internal structure of the transmission which concerns on embodiment. It is a figure for demonstrating operation | movement of the transmission which concerns on embodiment. It is a figure which shows the classification | category of the drive mode which HEV which concerns on embodiment can take. It is a figure which shows typically the function structure of the hybrid vehicle which concerns on embodiment.

<Outline of the embodiment>
An outline of the embodiment will be described. The embodiment of the present invention relates to a hybrid vehicle (Hybrid Electric Vehicle; hereinafter referred to as “HEV”) including a diesel engine and a motor generator as driving forces, and particularly to an HEV equipped with an auto-cruise mode.
Here, the “auto cruise mode” means that the diesel engine, the motor generator, the transmission, and the like are maintained so that the HEV vehicle speed set by the driver is maintained without the driver operating the accelerator or the shift lever. A mode that is automatically controlled. The auto cruise mode is mainly assumed to be used when the HEV travels on a highway.

  As will be described in detail later, the HEV auto-cruise mode uses both a “engine running mode” that uses only a diesel engine as a driving force, a “motor running mode” that uses only a motor generator, and uses both a diesel engine and a motor generator. There are four travel modes: an “assist travel mode” and an “inert travel mode” in which neither a diesel engine nor a motor generator is used and the vehicle travels with inertial force. The embodiment of the present invention mainly relates to control performed on the diesel engine, the motor generator, and the transmission when a travel mode in the auto-cruise mode transitions to another travel mode.

  Below, the outline | summary of HEV used as the premise of embodiment of this invention is demonstrated first, and the transmission with which HEV is mounted next is demonstrated. Then, the control apparatus responsible for the control of the HEV diesel engine, motor generator, and transmission will be described, and finally, the transition of the travel modes provided in the HEV will be described.

<Overview of hybrid vehicle>
First, an outline of a hybrid vehicle according to an embodiment of the present invention will be described.
FIG. 1 is a diagram showing a configuration of HEV 100 according to the embodiment. The HEV 100 shown in FIG. 1 is a large vehicle such as a bus or a truck. The HEV 100 includes a hybrid system having a diesel engine 10 and a motor generator 33. The diesel engine 10 and the motor generator 33 are combined and controlled by the control device 80 in accordance with the operating state of the HEV 100.

The HEV 100 is also configured to execute the auto cruise mode under the control of the control device 80 when the auto cruise operation switch 811 is turned on by the driver.
Here, the shift lever 81 is a lever for switching whether the driver of the HEV 100 manually selects the gear of the transmission 20 or causes the control device 80 to automatically control the selection of the gear of the transmission 20. The shift lever 81 is also used when the driver of the HEV 100 manually shifts the gear of the transmission 20.

  The diesel engine 10 rotationally drives the crankshaft 13 by heat energy generated by burning fuel in a plurality (six in the example shown in FIG. 1) cylinders 12 formed in the engine body 11. The rotational power of the crankshaft 13 is transmitted to the transmission 20 through the clutch 15. The clutch 15 is realized by using, for example, a fluid coupling and a wet multiple plate (not shown), a dry clutch, or the like.

  For example, when the driver depresses the clutch pedal, a clutch plate (not shown) is separated from the flywheel, and the rotational power of the diesel engine 10 is not transmitted to the transmission 20. In this sense, the clutch 15 is a member that controls power transmission of the diesel engine 10. Hereinafter, the state in which the clutch 15 is transmitting the rotational power of the diesel engine 10 to the transmission 20 may be referred to as a “clutch engaged state”, and the state in which the clutch 15 is not transmitted is referred to as a “clutch disengaged state”.

  The transmission 20 is connected to the diesel engine 10 via the clutch 15. The transmission 20 employs AMT (Automated Manual Transmission) in which the control device 80 automatically shifts to a preset target gear position based on the operating state of the HEV 100 and preset map data.

  The transmission 20 includes a main transmission mechanism 21 capable of shifting to a plurality of stages for decelerating the rotational drive of the diesel engine 10 transmitted via the clutch 15, and a sub-transmission mechanism for adjusting the transmission ratio of the main transmission mechanism 21. 22. The sub-transmission mechanism 22 further includes a first sub-transmission mechanism 22a that can transmit the rotational power transmitted from the diesel engine 10 via the clutch 15 to the main transmission mechanism 21 by shifting the rotational power between the low speed stage and the high speed stage, The second sub-transmission mechanism 22b is configured to be capable of shifting the rotational power transmitted from the main transmission mechanism 21 to two stages of a low speed stage and a high speed stage. The first sub-transmission mechanism 22a may be referred to as a “splitter” and the second sub-transmission mechanism 22b may be referred to as a “range”. Details of the transmission 20 will be described later.

  The propeller shaft 25 transmits the rotational power of the diesel engine 10 to the drive wheels 27 via the transmission 20. More specifically, the rotational power changed by the transmission 20 is first transmitted to the differential 26 through the propeller shaft 25 connected to the output shaft 23. The differential 26 distributes the driving force to a pair of driving wheels 27 made of double tires.

  The motor generator 33 is disposed on the opposite side of the diesel engine 10 across the transmission 20. The motor generator 33 is connected to the propeller shaft 25 via the speed reduction mechanism 30. The motor generator 33 is also electrically connected to the battery 35 through the inverter 34. The battery 35 is a known secondary battery such as a nickel metal hydride battery or a lithium ion battery. The battery 35 is a drive power source for the motor generator 33 and also functions as a power storage unit that stores the power generated by the motor generator 33.

  The propeller shaft 25 and the rotating shaft 32 of the motor generator 33 are connected via a speed reduction mechanism 30. The speed reduction mechanism 30 uses the rotating shaft 32 of the motor generator 33 as an input shaft and the propeller shaft 25 as an output shaft. In other words, in reduction mechanism 30, the reduction ratio (Nm / Np), which is the ratio of rotation speed Np of propeller shaft 25 to rotation speed Nm of motor generator 33, is greater than 1.0. Note that this reduction ratio may be set to either fixed or variable.

  Of the gears included in the speed reduction mechanism 30, the gear connected to the rotation shaft 32 may be fixed and released by a sleeve (not shown). The operation of the sleeve is performed by an actuator (not shown). May be controlled. When the fixing of the gear is released by the sleeve, the speed reduction mechanism 30 is in a neutral state, and power transmission between the propeller shaft 25 and the rotating shaft 32 is stopped.

  By providing the HEV 100 with the speed reduction mechanism 30, the regenerative braking torque of the motor generator 33 can be increased by the speed reduction mechanism 30 regardless of the gear stage of the transmission 20 during inertia traveling during high speed travel of the HEV 100. Thereby, regeneration efficiency can be improved. Further, when the state of charge (hereinafter referred to as “SOC”) of the battery 35 exceeds a predetermined threshold (for example, 90%), the speed reduction mechanism 30 is set to neutral so that the battery 35 is overcharged. Can be suppressed.

  HEV 100 according to the embodiment transmits the power of motor generator 33 to propeller shaft 25 through reduction mechanism 30. For this reason, the change of the layout of a powertrain component is small, and the conversion from the existing vehicle becomes easier than before.

  The combination switch 95 is a switch that the driver operates to control braking of the HEV 100. Examples of the braking means of the HEV 100 include an engine brake, a regenerative brake, a side brake, a foot brake, an exhaust brake, a compression release brake, and a retarder 28. The combination switch 95 is used by the driver to control the use of the exhaust brake, the compression release brake, and the retarder 28 which are auxiliary brakes.

  Although not shown, the combination switch can be set in four stages from 0 to 3. When the driver sets the combination switch 95 to 0, the exhaust brake, compression release brake, and retarder 28 of the HEV 100 do not operate. When the driver sets the combination switch 95 to 1, the exhaust brake of the HEV 100 is activated, and when the combination switch 95 is set to 2, the exhaust brake and the compression release brake of the HEV 100 are activated. Similarly, when the driver sets the combination switch 95 to 3, the exhaust brake, the compression release brake, and the retarder 28 of the HEV 100 are operated.

  When the driver sets the combination switch 95 to any one of 1 to 3, the valve 76 provided in the exhaust path 73 closes the exhaust path. Thereby, the friction of the diesel engine 10 increases and the exhaust brake operates. Further, when the driver sets the combination switch 95 to 3, resistance due to electromagnetic force is generated between the stator fixed to the transmission 20 and the rotor rotating together with the output shaft 23, and the retarder 28 that suppresses the rotation of the propeller shaft 25. Operates.

<Transmission>
Next, the transmission 20 will be described.
FIG. 2 is a diagram schematically illustrating an internal configuration of the transmission 20 according to the embodiment. The rotational drive of the diesel engine 10 is transmitted to the input shaft 29a via the clutch 15. The counter shaft 29b is disposed in parallel with the input shaft 29a, and rotational driving is transmitted from the input shaft 29a via the first auxiliary transmission mechanism 22a. The rotational drive of the countershaft 29b is transmitted to the main transmission mechanism 21. That is, the first auxiliary transmission mechanism 22 a is provided on a drive transmission path that transmits the rotational drive of the diesel engine 10 transmitted through the clutch 15 to the main transmission mechanism 21.

  The first auxiliary transmission mechanism 22 a is also called a splitter, and includes two gears, a low gear 221 and a high gear 222, and a first sleeve 223 for adjusting the transmission ratio of the main transmission mechanism 21. The low gear 221 includes a first low gear 221a disposed on the input shaft 29a and a second low gear 221b fixed to the counter shaft 29b. Similarly, the high gear 222 includes a first high gear 222a disposed on the input shaft 29a and a second high gear 222b fixed to the counter shaft 29b.

  The first sleeve 223 slides on the input shaft 29a by the first actuator 201a controlled by the control device 80. When the first sleeve 223 is connected to the first low gear 221a, the rotational drive of the input shaft 29a is transmitted to the counter shaft 29b via the low gear 221. Similarly, when the first sleeve 223 is connected to the first high gear 222a, the rotational drive of the input shaft 29a is transmitted to the counter shaft 29b via the high gear 222.

  FIG. 2 shows a state where the first sleeve 223 is not connected to any of the first low gear 221a and the first high gear 222a. In this case, the input shaft 29a idles with respect to any of the first low gear 221a and the first high gear 222a. For this reason, the rotational drive of the input shaft 29a is not transmitted to the counter shaft 29b. Hereinafter, in the present specification, the state in which the first sleeve 223 is not connected to any of the first low gear 221a and the first high gear 222a is referred to as “the neutral state of the auxiliary transmission mechanism 22”, “the neutral state of the splitter” or the like. May be described.

  When the splitter is in the neutral state, the power transmission path between the diesel engine 10 and the countershaft 29b is interrupted. This state has an effect equivalent to the state in which the clutch 15 is disconnected in the sense that the rotational power of the diesel engine 10 is not transmitted to the countershaft 29b. Therefore, hereinafter, in the present specification, the “neutral state of the splitter” may be described as “a state corresponding to the disconnection of the clutch 15” or the like.

Generally, when the transition between the disconnected state and the connected state of the clutch 15 is repeated, parts such as a clutch release bearing constituting the clutch 15 are worn. Therefore, by replacing the disconnected state of the clutch 15 with the neutral state of the splitter, consumption of the clutch 15 can be suppressed.
In particular, when the HEV 100 is traveling in the auto-cruise mode, a state in which the diesel engine 10 is stopped or idling and the motor generator 33 is powered is often generated. In such a case, the clutch 15 is generally disengaged in order to reduce the friction loss due to the diesel engine 10. By replacing this with the neutral state of the splitter, it is possible to reduce wear of the clutch 15 when the motor generator 33 is powered.

  The main transmission mechanism 21 includes a first speed gear 211, a second speed gear 212, a third speed gear 213, a second sleeve 214, and a third sleeve 215. The first speed gear 211 includes a first first speed gear 211a disposed on the output shaft 23 and a second first speed gear 211b fixed to the counter shaft 29b. Similarly, the second speed gear 212 includes a first second speed gear 212 a disposed on the output shaft 23 and a second second speed gear 212 b fixed to the counter shaft 29 b, and the third speed gear 213 is connected to the output shaft 23. It includes a first third speed gear 213a arranged and a second third speed gear 213b fixed to the counter shaft 29b.

  The second sleeve 214 and the third sleeve 215 slide on the output shaft 23 by the second actuator 201b whose operation is controlled by the control device 80, respectively. The second sleeve 214 can be connected to either the first first gear 211a or the first second gear 212a. The third sleeve 215 can be connected to the first third speed gear 213a, or the input shaft 29a and the output shaft 23 can be directly connected.

  When the second sleeve 214 is connected to either the first first gear 211a or the first second gear 212a, the third sleeve 215 cannot be connected to the first third gear 213a, and the input shaft 29a and the output shaft 23 cannot be directly connected. The reverse is also true, and when the third sleeve 215 is connected to the first third speed gear 213a or the input shaft 29a and the output shaft 23 are directly connected, the second sleeve 214 is connected to the first first speed gear. Neither 211a nor the first second gear 212a can be connected.

  When the second sleeve 214 or the third sleeve 215 is connected to any one of the first first speed gear 211a, the first second speed gear 212a, or the first third speed gear 213a, the rotational power of the counter shaft 29b is changed to each speed. It is decelerated according to the ratio and transmitted to the output shaft 23. When the third sleeve 215 directly connects the input shaft 29 a and the output shaft 23, the rotational power of the input shaft 29 a is directly transmitted to the output shaft 23.

  The second subtransmission mechanism 22 b is also called a range, and is provided on a drive transmission path that transmits the rotational drive of the output shaft 23 to the propeller shaft 25. The second sub-transmission mechanism 22b is a known planetary gear mechanism 224, and can change the reduction ratio to two stages of low speed and high speed. The switching between the low speed stage and the high speed stage in the second auxiliary transmission mechanism 22b is realized by the third actuator 201c that is driven under the control of the control device 80.

  FIGS. 3A to 3R are diagrams for explaining the operation of the transmission 20 according to the embodiment. In FIGS. 3A to 3R, in order to avoid complication, the reference numerals indicating the same members are attached to only one place. In FIGS. 3A to 3R, thick lines indicate power transmission paths. In particular, a gear indicated by a thick line indicates a state of being rotated by the rotational drive of the diesel engine 10.

  FIG. 3A to FIG. 3P show a state in which the transmission 20 is in the 1st speed to the 16th speed, respectively. For example, FIG. 3A illustrates a state in which the first subtransmission mechanism 22a is the low gear 221, the main transmission mechanism 21 is the first speed gear 211, and the second subtransmission mechanism 22b is in the low speed stage. The first speed of 20. FIG. 3B is the same as FIG. 3A except that the first auxiliary transmission mechanism 22 a is the high gear 222, and this state is the first speed of the transmission 20.

FIG. 3G shows that the input shaft 29 a and the output shaft 23 are directly connected, and the second auxiliary transmission mechanism 22 b is in the low speed stage, which is the seventh speed of the transmission 20. FIG. 3H shows a state where the input of the output shaft 23 is the low gear 221 of the first auxiliary transmission mechanism 22a, and this state is the eighth speed of the transmission 20.
FIGS. 3 (i) to 3 (p) are the same as FIGS. 3 (a) to (h), respectively, except that the second auxiliary transmission mechanism 22b is at a high speed. For example, when the second auxiliary transmission mechanism 22b is switched to the high speed stage while the transmission 20 is in the first speed, the transmission 20 becomes the ninth speed. By configuring the transmission 20 in multiple stages in this way, a rotational range with good engine efficiency in the diesel engine 10 can be maintained, which contributes to improving the fuel efficiency of the HEV 100.

FIG. 3 (q) shows that the clutch 15 is in a disengaged state. As shown in FIG. 3 (q), when the clutch 15 is in a disconnected state, the rotational drive of the diesel engine 10 is not transmitted to the countershaft 29b. FIG. 3 (r) shows that the splitter is in the neutral state, that is, the clutch 15 is in the disengagement equivalent state. As shown in FIG. 3 (r), the rotational drive of the diesel engine 10 is not transmitted to the countershaft 29b even when the clutch 15 is in the disengagement equivalent state.
For convenience of explanation, illustration of the reverse gear is omitted in FIGS. 2 and 3.

<Running mode of HEV>
A travel mode M that the HEV 100 can take will be described.
FIG. 4 is a diagram showing the classification of travel modes M that the HEV 100 according to the embodiment can take. As shown in FIG. 4, the travel modes M that the HEV 100 can take are roughly divided into a normal mode NM and an auto cruise mode AM.
The normal mode NM is a mode in which the driver of the HEV 100 operates while changing the speed of the HEV 100 by operating the accelerator pedal and the brake pedal. The normal mode NM is mainly used when the HEV 100 travels while frequently starting and stopping, such as in an urban area.

  The normal mode NM is further classified into an auto shift mode ASM and a manual shift mode MSM. In the automatic shift mode ASM, a map determined in advance based at least on the vehicle speed of the HEV 100, the engine speed Ne of the diesel engine 10 detected by the speed sensor 86, the gear of the main transmission mechanism 21, and the gear of the auxiliary transmission mechanism 22. In this travel mode, the control device 80 sets the gear of the main transmission mechanism 21 and the gear of the auxiliary transmission mechanism 22 based on the data.

  On the other hand, the manual shift mode MSM is a mode in which the driver of the HEV 100 operates the shift lever 81 to manually shift the gear of the transmission 20. In the example shown in FIG. 2, the transmission 20 can be switched between the first speed and the 16th speed. Even in the manual shift mode MSM, the operations of the clutch 15 and the actuator 201 are controlled by the control device 80. In other words, the manual shift mode MSM can also be said to be a mode in which the driver selects the shift timing of the transmission 20.

  When the driver of the HEV 100 turns on the auto cruise operation switch 811 provided in the shift lever 81, the HEV 100 enters the auto cruise mode AM. The auto cruise mode AM is a mode in which the control device 80 automatically controls the switching of the diesel engine 10 and the transmission 20 and the operation of the motor generator 33. In the auto cruise mode AM, the HEV 100 automatically runs the HEV 100 under the control of the control device 80 while maintaining the vehicle speed V acquired by the wheel speed sensor 84 within a preset target speed range. More specifically, the auto-cruise mode AM is further divided into an engine travel mode EDM, an assist travel mode ADM, a motor travel mode MDM, and an inertia travel mode IDM, and the control device 80 appropriately selects each travel mode, The vehicle speed V of the HEV 100 is maintained within a preset target speed range.

  Here, the target speed range is a range between the upper limit speed vb and the lower limit speed vc based on the target speed va. The target speed va, the upper limit speed vb, and the lower limit speed vc can be set to arbitrary values by the driver. For example, the target speed va is set to 70 km / h or more and 90 km / h or less, and the upper limit speed vb is the target speed vb. The speed va is set to a speed of 0 km / h or more and +10 km / h or less, and the lower limit speed vc is set to a speed of -10 km / h or more and 0 km / h or less with respect to the target speed va.

  In the engine travel mode EDM, the HEV 100 is traveled by the driving force Fe transmitted from the diesel engine 10 to the propeller shaft 25 via the clutch 15 and the transmission 20. In the engine running mode EDM, the speed reduction mechanism 30 is set to the neutral state, and the motor generator 33 is disconnected from the propeller shaft 25. For this reason, in the engine running mode EDM, the HEV 100 is accelerated only by the driving force of the diesel engine 10, and the driving force of the motor generator 33 is not used. In the engine running mode EDM, the regenerative brake of the motor generator 33 does not operate even when the HEV 100 is decelerated.

  In the motor travel mode MDM, the HEV 100 is traveled by the driving force Fm from the motor generator 33 with the clutch 15 in a state corresponding to disengagement, that is, the splitter in the neutral state. In the motor travel mode MDM, the driving force of the diesel engine 10 is not transmitted to the propeller shaft 25. Instead, in the motor travel mode MDM, the motor generator 33 is powered when the HEV 100 is accelerated, and the motor generator 33 is regeneratively generated when the HEV 100 is decelerated.

  In the assist travel mode ADM, the HEV 100 travels with both the driving force Fe from the diesel engine 10 and the driving force Fm transmitted from the motor generator 33 to the propeller shaft 25 via the speed reduction mechanism 30. In the assist travel mode ADM, both the driving force of the diesel engine 10 and the driving force of the motor generator 33 are transmitted to the propeller shaft 25.

  In the inertia traveling mode IDM, the HEV 100 is caused to travel in a state where the driving force of the diesel engine 10 and the motor generator 33 is not transmitted to the propeller shaft 25. In inertial running mode IDM, clutch 15 is equivalent to disengagement and deceleration mechanism 30 is in a neutral state. For this reason, both the diesel engine 10 and the motor generator 33 are disconnected from the propeller shaft 25.

  When the HEV 100 is in the motor traveling mode MDM or the inertia traveling mode IDM, the control device 80 sets the clutch 15 to a disconnected state or a state corresponding to the disconnected state, stops the fuel injection, stops the diesel engine 10 and sets the idling stop state. It may be maintained, or fuel may be injected in an amount that maintains idling of the diesel engine 10.

  When the HEV 100 is in the auto-cruise mode AM, the HEV 100 can be accelerated by the driving force from the diesel engine 10 when the accelerator opening sensor 92 detects the depression of the accelerator pedal. When the brake pedal depression sensor 93 detects the depression of the brake pedal, the clutch sensor 94 detects the depression of the clutch pedal, or the auto cruise operation switch 811 is released, the HEV 100 auto Cruise mode is canceled.

Next, the functional configuration of the HEV 100 according to the embodiment will be described.
FIG. 5 is a diagram schematically illustrating a functional configuration of the HEV 100 according to the embodiment. The HEV 100 according to the embodiment includes a diesel engine 10, a clutch 15, a transmission 20, an actuator 201, a control device 80, a shift lever 81, an auto cruise operation switch 811, a wheel speed sensor 84, a rotation speed sensor 86, and an accelerator opening sensor 92. A brake pedal opening sensor 93, a clutch sensor 94, and a combination switch 95. FIG. 4 shows a configuration for describing the HEV 100 according to the embodiment from the functional aspect, and other configurations are omitted.

The control device 80 controls the diesel engine 10, the disconnection and connection of the clutch 15, the switching of the transmission 20, and the operation of the motor generator 33. The control device 80 also controls the operation of the HEV 100 during auto cruise.
Specifically, the control device 80 determines the amount of fuel to be supplied to the cylinder 12 of the diesel engine 10 based on the engine speed Ne detected by the speed sensor 86 and the accelerator pedal depression amount detected by the accelerator opening sensor 92. Adjust the injection amount and injection timing. Control device 80 adjusts the frequency of inverter 34 and the current value between battery 35 and motor generator 33 in accordance with the SOC of battery 35 and the like. The control device 80 assists at least a part of the driving force by controlling the motor generator 33 when the HEV 100 starts or accelerates. On the other hand, the control device 80 causes the motor generator 33 to generate regenerative power during the inertial running or braking of the HEV 100, converts surplus kinetic energy into electric power, and charges the battery 35.

<Transition of driving mode>
As described above, the driving mode M of the HEV 100 is divided into two modes, the normal mode NM and the auto cruise mode AM. When HEV 100 is in auto cruise mode AM, control device 80 appropriately selects engine travel mode EDM, assist travel mode ADM, motor travel mode MDM, and inertia travel mode IDM. Below, the transition of the driving mode M of HEV100 is demonstrated.

[Transition from normal mode to auto cruise mode]
The control device 80 detects the operation of the shift lever 81 and the auto cruise operation switch 811 by the driver. When the driving mode M of the HEV 100 is the normal mode NM, when the driver turns on the auto cruise operation switch 811, the HEV 100 transitions to the auto cruise mode AM. At this time, if the vehicle speed of the HEV 100 does not reach the target speed range, the HEV 100 transits to the assist travel mode ADM that is driven by both the driving force of the diesel engine 10 and the driving force of the motor generator 33.

[Transition from assist mode to motor mode]
When the HEV 100 is in the assist travel mode ADM, the control device 80 controls the amount of fuel injected into the cylinder 12 of the diesel engine 10, the operation of the actuator 201 for switching the gear of the transmission 20, the operation of the clutch 15, and the motor generator 33. Power running is controlled so that the vehicle speed of the HEV 100 reaches the target speed range. At this time, if the vehicle speed of the HEV 100 is equal to or higher than a predetermined speed (for example, 60 kilometers per hour), the transmission 20 is at the highest stage. In the example shown in FIG. 2, when the HEV 100 transitions to the inertia running mode IDM, the gear of the transmission 20 is 16 speed.

  If the HEV 100 approaches, for example, an uphill during the assist travel mode ADM, the vehicle speed of the HEV 100 may fall below the target speed range set by the driver. In this case, the control device 80 (1) disengages the clutch 15 or corresponds to disengagement, (2) sets the fuel injection amount supplied to the diesel engine 10 to a predetermined value (for example, 40 millicubic per piston stroke) or less, and (3) A control for powering the motor generator 33 is executed. As a result, the HEV 100 transitions from the assist travel mode ADM to the motor travel mode MDM. As an example, the control device 80 causes the motor generator 33 to generate a torque of 50 Nm in terms of the propeller shaft 25 when the vehicle speed of the HEV 100 is 90 km / h.

  When the vehicle speed of the HEV 100 that is slightly below the target speed range is restored to the target speed range, generally a large driving force is not required. For this reason, if it is going to cover this driving force with the output of diesel engine 10, since diesel engine 10 will be used in the revolving region where engine efficiency is low, efficiency is bad. Therefore, the fuel consumption can be reduced by using the driving force of the motor generator 33 in such a case. Further, since the motor generator 33 has less annealing such as filter processing than the diesel engine 10, it can respond to the drive request of the control device 80 in a short time. As a result, the vehicle speed correction of the HEV 100 can be realized in a short time.

  Here, if the HEV 100 approaches a downhill, for example, during the assist travel mode ADM, the vehicle speed of the HEV 100 may exceed the target speed range set by the driver. In this case, the control device 80 (1) sets the clutch 15 to be disengaged or corresponds to disengagement, (2) sets the fuel injection amount supplied to the diesel engine 10 to a predetermined value or less, and (3) performs control to regenerate the motor generator 33. Run. As a result, the HEV 100 transitions from the assist travel mode ADM to the motor travel mode MDM. Although not limited, as an example, when the vehicle speed of HEV 100 is 90 km / h, control device 80 causes motor generator 33 to regenerate with a torque of 100 Nm in terms of propeller shaft 25.

This makes it possible to use the regeneration of the motor generator 33 more frequently for speed control using the engine friction of the diesel engine 10, and to maintain the SOC of the battery 35 at a high value. As a result, the assist travel mode ADM using the motor generator 33 can be frequently used, so that the frequency of using the transmission 20 at a higher gear stage can be increased and the fuel consumption can be reduced.
Further, since the motor generator 33 has less annealing such as filter processing than the diesel engine 10, it can respond to the drive request of the control device 80 in a short time. As a result, the vehicle speed correction of the HEV 100 can be realized in a short time.

[Transition from motor drive mode to engine drive mode]
Here, the motor generator 33 is driven by the power of the battery 35. For this reason, when the SOC of the battery 35 is small, it is preferable not to power the motor generator 33 in order to prevent the battery 35 from being overdischarged.
Therefore, when the SOC of the battery 35 is less than a predetermined threshold (for example, 20%), the control device 80 (1) connects the clutch 15 even when the vehicle speed of the HEV 100 falls below the set target speed range. Alternatively, the neutral state of the splitter is canceled, (2) the fuel injection amount supplied to the diesel engine 10 is controlled so as to be within the target speed range of the HEV 100, and (3) control for regenerating the motor generator 33 is executed. As a result, the HEV 100 transitions from the motor travel mode MDM to the engine travel mode EDM.

  As described above, when the SOC of battery 35 is low, control device 80 drives HEV 100 with the output of diesel engine 10 and causes motor generator 33 to regenerate. As a result, the battery 35 is prevented from being over-discharged, and the life of the battery 35 can be extended. Further, since the motor generator 33 is regenerated, the SOC of the battery 35 can be increased.

The battery 35 is charged by regeneration of the motor generator 33. For this reason, when the SOC of the battery 35 is large, it is preferable not to regenerate the motor generator 33 in order to prevent the battery 35 from being overcharged.
Therefore, when the SOC of the battery 35 is equal to or higher than a predetermined threshold (for example, 90%), the control device 80 connects the clutch 15 or sets the neutral state of the splitter even when the vehicle speed of the HEV 100 exceeds the target speed range. Execute the control to cancel. The control device 80 may further make the speed reduction mechanism 30 neutral. As a result, the amount of power generated by regeneration of the motor generator 33 is reduced, and the battery 35 can be prevented from being overcharged. As a result, the life of the battery 35 can be extended.

  When the HEV 100 is requested to exhaust brake, that is, when the combination switch 95 is set to any one of 1 to 3, the control device 80 determines whether the HEV 100 is traveling by auto-cruising. Even if the speed falls below the target speed range, control is performed to connect the clutch 15 or release the neutral state of the splitter. Thereby, an exhaust brake acts on HEV100, and HEV100 can be decelerated.

[Transition from motor drive mode to assist drive mode]
When the HEV 100 is in the motor travel mode MDM, a state corresponding to clutch disconnection is obtained except when the driver intentionally disconnects the clutch 15. That is, the clutch 15 maintains the connected state, and the splitter is in the neutral state. In this case, for example, when the HEV 100 approaches a downhill, the control device 80 causes the motor generator 33 to regenerate and decelerate the HEV 100 by regenerative braking.

  In such a situation, that is, (1) the clutch 15 is in the engaged state, (2) the splitter is in the neutral state, and (3) the motor generator 33 is in the regenerative state, The device 80 releases the neutral state of the splitter. As a result, the HEV 100 transitions from the motor travel mode MDM to the assist travel mode ADM. Thereby, since the diesel engine 10 and the propeller shaft 25 are connected, it becomes possible to operate the exhaust brake using the friction of the diesel engine 10.

  Here, in order for the control device 80 to release the neutral state of the splitter, there are two selections of whether the first auxiliary transmission mechanism 22a is put into the low gear 221 or the high gear 222. The control device 80 executes control for switching the first auxiliary transmission mechanism 22a to the low gear 221 on condition that the rotational speed of the diesel engine 10 is equal to or lower than a predetermined rotational speed. The “predetermined number of revolutions” is an allowable limit value of the number of revolutions set in advance in the diesel engine 10 and is a so-called “rev limit”. The specific value of the predetermined rotational speed may be determined by the manufacturer in consideration of the performance of the diesel engine 10 and the like. The control device 80 refers to predetermined map data based on the vehicle speed of the HEV 100 and the gears of the main transmission mechanism 21, thereby setting the engine rotation of the diesel engine 10 when the first auxiliary transmission mechanism 22a is set to the low gear 221. It is determined whether the number Ne is below the rev limit.

  The engine speed Ne of the diesel engine 10 increases when the first auxiliary transmission mechanism 22a is set to the low gear 221 than when the first gear mechanism 22a is set to the high gear 222. For this reason, the braking torque of HEV100 becomes large and a big braking force acts on HEV100. Therefore, it is possible to suppress excessive speed during the auto cruise operation of the HEV 100, and it is possible to travel more safely. In addition, when the engine speed Ne of the diesel engine 10 increases, the braking torque of the exhaust brake and the compression release brake also increases, and the braking force increases. For this reason, the speed excess at the time of the auto cruise operation of HEV100 can be suppressed, and it becomes possible to drive | work more safely.

  When it is determined that the engine speed Ne of the diesel engine 10 exceeds the rev limit by setting the first auxiliary transmission mechanism 22a to the low gear 221, control for switching the first auxiliary transmission mechanism 22a to the high gear 222 is executed. Thereby, it can suppress that the engine speed Ne of the diesel engine 10 exceeds a rev limit, and can suppress having a bad influence on the diesel engine 10.

[Transition to coasting mode]
When HEV 100 is in engine travel mode EDM, assist travel mode ADM, or motor travel mode MDM, the SOC of battery 35 is within a predetermined range (for example, 30% to 80%), and the vehicle speed of HEV 100 is within the target speed range. When the vehicle stays for a certain period of time, the traveling mode M of the HEV 100 transitions to the inertial traveling mode IDM. Thereby, the fuel consumption and the usage amount of the battery 35 can be reduced.

[Transition from auto cruise mode to normal mode]
Next, the transition of the HEV 100 from the auto cruise mode AM to the normal mode NM will be described.
Consider a case where the HEV 100 is traveling on a gentle downhill, for example, during the motor travel mode MDM in which the HEV 100 is one of the auto-cruise modes AM. At this time, HEV 100 is (1) the clutch 15 is in the connected state, (2) the splitter is in the neutral state, and (3) the motor generator 33 is in the regenerative state. At this time, the driver may not want to use the exhaust brake, but may wish to use the engine brake of the diesel engine 10.

  In such a case, the driver of the HEV 100 requests to shift down the transmission 20 by operating the shift lever 81. The control device 80 cancels the neutral state of the splitter in response to a request for downshifting the transmission 20 by the driver. More specifically, the control device 80 releases the splitter neutral state by driving the first actuator 201 a and fixing the high gear 222 or the low gear 221 with the first sleeve 223. At the same time, the control device 80 shifts to the gear of the main transmission mechanism 21 so that the gear is determined based on the operation state of the HEV 100 and the map data. As a result, the HEV 100 transits from the motor travel mode MDM to the manual shift mode MSM.

  Thereby, the braking force of HEV100 increases and the vehicle behavior close | similar to a driver | operator's request | requirement can be obtained. In particular, since the braking force close to the braking force required before the HEV 100 bends the curve with a downward slope is obtained, the safety performance of the HEV 100 is further improved. Furthermore, since the clutch 15 is in the engaged state when the HEV 100 re-accelerates after bending a flat ground curve, the HEV 100 re-accelerates quickly. As a result, the driving feel given to the driver can be improved.

  The above transition is based on the assumption that the driver of the HEV 100 does not step on the brake pedal. When the driver of the HEV 100 depresses the brake pedal, the auto cruise mode AM of the HEV 100 is canceled, and the mode shifts to the auto shift mode ASM that is the normal mode NM.

[Transition from manual shift mode to auto shift mode]
When the HEV 100 is not accelerating in the manual shift mode MSM, (1) the clutch 15 is in a connected state, (2) the first auxiliary transmission mechanism 22a is in a non-neutral state, and (3) the motor generator 33 is in a regenerative state. Yes. In such a case, when the driver sets the shift lever 81 to a drive range (not shown), the control device 80 shifts to an automatic shift mode ASM that automatically controls the selection of the gear of the transmission 20. When the HEV 100 is in the automatic shift mode ASM, the driver does not manually select the gear of the transmission 20.

  Therefore, the control device 80 sets the operation corresponding to the clutch regenerative regeneration, that is, the first auxiliary transmission mechanism 22a to the neutral state when the HEV 100 is not accelerated and transits from the manual shift mode MSM to the auto shift mode ASM. . Thereby, the energy obtained by the brake regeneration of the motor generator 33 can be increased.

  The above transition is based on the assumption that the driver of the HEV 100 does not step on the brake pedal. When the driver of the HEV 100 depresses the brake pedal, the manual shift mode MSM of the HEV 100 is maintained.

  As described above, according to the hybrid vehicle according to the embodiment, the fuel efficiency in auto cruising of the hybrid vehicle can be improved. Further, it is possible to achieve both improvement in fuel efficiency and acceleration / deceleration response speed in auto cruising of a hybrid vehicle. Furthermore, safety in auto cruising of the hybrid vehicle can be improved.

  Further, the control device 80 can reduce the exhaust gas 71 exhaust from the exhaust valve 70 by stopping or idling the diesel engine 10 during the HEV 100 auto-cruise. For this reason, it is possible to suppress a reduction in the purification capability of the exhaust gas purification device 75 that is disposed in the exhaust path 73 and purifies the exhaust gas 71 that drives the turbine 74 from the exhaust valve 70 via the exhaust manifold 72.

  When the purification capacity of the exhaust gas purification device 75 is reduced, it is necessary to inject fuel that does not contribute to the driving force of the HEV 100 to raise the temperature of the exhaust gas 71 and to recover and regenerate the purification capacity of the exhaust gas purification device 75 There is. If the exhaust gas 71 emission from the exhaust valve 70 is reduced, the opportunity to recover the purification capability of the exhaust gas purification device 75 is also reduced, so that the fuel consumption required for the regeneration can also be reduced. The exhaust gas purification device 75 is, for example, a collection device that collects particulate matter in the exhaust gas 71. During the HEV 100 running on a motor and coasting, particulate matter is deposited on the collection device. Since it is suppressed, the fuel consumption required for regeneration of the collection device can be suppressed.

  In addition, during the inertia running, the clutch 15 is in a disconnected state or a state corresponding to the disconnected state, and the fuel injection is stopped to stop the diesel engine 10, so that the rotational power of the propeller shaft 25 is rotated by the rotation of the diesel engine 10. Since it is also possible to avoid a decrease due to drag, it is possible to reduce energy loss during motor traveling and coasting and to improve fuel efficiency.

  Further, the control device 80 may place the clutch 15 in the disconnected state or a state corresponding to the disconnected state while the motor is running, and control the fuel injection amount to stop the diesel engine 10 or in the idling state. As a result, the amount of fuel consumed while the motor is running can be reduced, and the reduction in the purification capacity of the exhaust gas purification device 75 can be suppressed, so that the fuel efficiency can be further improved.

  As mentioned above, although this invention was demonstrated using embodiment, the technical scope of this invention is not limited to the range as described in the said embodiment. It will be apparent to those skilled in the art that various modifications or improvements can be added to the above embodiment. It is apparent from the scope of the claims that the embodiments added with such changes or improvements can be included in the technical scope of the present invention.

DESCRIPTION OF SYMBOLS 10 ... Diesel engine 15 ... Clutch 20 ... Transmission 21 ... Main transmission mechanism 22 ... Sub transmission mechanism 25 ... Propeller shaft 28 ... Retarder 30 ... Deceleration mechanism 33 ... Motor generator 35 ... Battery 80 ... Control device 81 ... Shift lever 95 ... Combination switch 100 ... Hybrid vehicle 201 ... Actuator 214 ... Second sleeve 215 ... Third Sleeve 221... Low gear 222... High gear 223... First sleeve 811.

Claims (2)

A hybrid vehicle having an engine and a motor generator as driving forces,
A clutch for controlling power transmission of the engine;
A transmission including a main transmission mechanism for decelerating the rotational drive of the engine transmitted through the clutch, and a sub-transmission mechanism for adjusting a transmission ratio of the main transmission mechanism;
A propeller shaft that transmits the power of the engine to drive wheels via the auxiliary transmission mechanism;
A control device for controlling the operation of the hybrid vehicle in auto-cruising;
A shift lever for switching whether the driver of the hybrid vehicle selects a gear of the transmission or causes the control device to automatically control the selection of the gear;
With
The motor generator is connected to the propeller shaft via a speed reduction mechanism,
In the case where (1) the clutch is in a connected state, (2) the auxiliary transmission mechanism is in a non-neutral state, and (3) the motor generator is in a regenerative state, Taking the opportunity to automatically control the selection of the gear, the auxiliary transmission mechanism is set to the neutral state.
A hybrid vehicle characterized by that.   The control device sets the gear of the main transmission mechanism and the gear of the auxiliary transmission mechanism based on at least the vehicle speed of the hybrid vehicle and the rotational speed of the engine while the auxiliary transmission mechanism is in the neutral state. The hybrid vehicle according to claim 1, wherein:

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