JP6801220B2 - Hybrid vehicle - Google Patents

Description

The present invention relates to a hybrid vehicle powered by an engine and a motor.

Hybrid electric vehicles equipped with an engine and a motor as power sources for driving have been developed and are becoming widespread. Some of these hybrid electric vehicles are equipped with auto-cruise control that maintains 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, a patent). Reference 1).

Japanese Unexamined Patent Publication No. 2015-073347

In order to respond to the growing interest in environmental issues in recent years, improvement of fuel efficiency is also required for vehicle auto-cruise control. The same applies to a hybrid vehicle with relatively good fuel efficiency, and further improvement in fuel efficiency is required especially during auto-cruise, which does not require manual operation by the driver.

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 aspect of the present invention is a hybrid vehicle using an engine and a motor generator as driving forces. In this hybrid vehicle, a clutch that controls power transmission of the engine, a main transmission mechanism for decelerating the rotational drive of the engine transmitted via the clutch, and a gear ratio of the main transmission mechanism are adjusted. A transmission including an auxiliary transmission mechanism, a propeller shaft that transmits the power of the engine to the drive wheels via the auxiliary transmission mechanism, a control device that controls the operation of the hybrid vehicle in autocruise, and operation of the hybrid vehicle. It is provided with a shift lever for switching between the hand selecting the gear of the transmission and the control device automatically controlling the selection of the gear. Here, the motor generator is connected to the propeller shaft via a reduction mechanism, and the control device is (1) the clutch is connected, (2) the auxiliary transmission mechanism is in the non-neutral state, and (3) the control device. When the motor generator is in the regenerated state, the auxiliary transmission mechanism is put into the neutral state when the driver selects to have the control device 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 rotation speed of the engine while the auxiliary transmission mechanism is in the neutral state. You may.

According to the present invention, it is possible to provide a technique for achieving both improvement of fuel efficiency and response speed of acceleration / deceleration in auto cruising of a hybrid vehicle.

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 of the transmission which concerns on embodiment. It is a figure which shows the classification of the traveling mode which the HEV which concerns on embodiment can take. It is a figure which shows typically the functional structure of the hybrid vehicle which concerns on embodiment.

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

The details will be described later, but in the HEV auto cruise mode, an "engine driving mode" that uses only a diesel engine as a driving force, a "motor driving mode" that uses only a motor generator, and a diesel engine and a motor generator are used together. There are four driving modes: an "assisted driving mode" and a "coasting driving mode" in which the diesel engine and the motor generator are not used and the vehicle travels by inertial force. Implementation of the present invention relates mainly to the control performed on the diesel engine, the motor generator, and the transmission when one driving mode in the auto cruise mode transitions to another driving mode.

In the following, the outline of the HEV which is the premise of the embodiment of the present invention will be described first, and then the transmission mounted on the HEV will be described. After that, the control device responsible for controlling the diesel engine, the motor generator, and the transmission of the HEV will be described, and finally, the transition of the driving mode included in the HEV will be described.

<Overview of hybrid vehicle>
First, an outline of the hybrid vehicle according to the embodiment of the present invention will be described.
FIG. 1 is a diagram showing a configuration of HEV100 according to an 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 combinedly controlled by the control device 80 according to the operating state of the HEV 100.

The HEV 100 is also configured to execute the auto cruise mode under the control of the controller 80 when the auto cruise actuation 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 the control device 80 automatically controls the selection of the gear of the transmission 20. The shift lever 81 is also used when the driver of the HEV 100 manually gear shifts the transmission 20.

The diesel engine 10 rotationally drives the crankshaft 13 by the thermal energy generated by burning fuel in a plurality of (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 multi-plate not shown, a dry clutch, or the like.

For example, when the driver depresses the clutch pedal, the 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 the power transmission of the diesel engine 10. Hereinafter, in the present specification, a state in which the clutch 15 transmits the rotational power of the diesel engine 10 to the transmission 20 may be described as a “clutch connected state”, and a state in which the clutch 15 is not transmitted may be described as a “clutch disengaged state” or the like.

The transmission 20 is connected to the diesel engine 10 via the clutch 15. The transmission 20 employs an AMT (Automated Manual Transmission) in which the control device 80 automatically shifts to a preset target shift stage 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 in a plurality of stages for decelerating the rotational drive of the diesel engine 10 transmitted via the clutch 15, and an auxiliary transmission mechanism for adjusting the gear ratio of the main transmission mechanism 21. 22 and is included. The auxiliary transmission mechanism 22 further includes a first auxiliary transmission mechanism 22a capable of shifting the rotational power transmitted from the diesel engine 10 via the clutch 15 to two stages, a low speed stage and a high speed stage, and transmitting the rotational power to the main transmission mechanism 21. It is composed of a second auxiliary transmission mechanism 22b capable of shifting the rotational power transmitted from the main transmission mechanism 21 to two stages, a low speed stage and a high speed stage. The first auxiliary transmission mechanism 22a may be referred to as a "splitter", and the second auxiliary 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 shifted 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 each pair of driving wheels 27 composed of double tires.

The motor generator 33 is arranged on the opposite side of the diesel engine 10 with the transmission 20 in between. The motor generator 33 is connected to the propeller shaft 25 via a 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 hydrogen 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 for storing the electric 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 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. That is, in the reduction mechanism 30, the reduction ratio (Nm / Np), which is the ratio of the rotation speed Np of the propeller shaft 25 to the rotation speed Nm of the motor generator 33, is larger than 1.0. The reduction ratio may be set to either fixed or variable.

Of the gears included in the reduction mechanism 30, the gear connected to the rotating shaft 32 may be fixed and released by a sleeve (not shown), and the operation of this sleeve is such that the control device 80 operates an actuator (not shown). It may be controlled by making it. When the gear is released from the sleeve, the reduction mechanism 30 is in the neutral state, and the power transmission between the propeller shaft 25 and the rotating shaft 32 is stopped.

By providing the reduction mechanism 30 in the HEV 100, the regenerative braking torque of the motor generator 33 can be increased by the reduction mechanism 30 regardless of the gear stage of the transmission 20 during inertial running of the HEV 100 during high-speed traveling. Thereby, the regeneration efficiency can be improved. Further, when the charged state (State Of Charge; hereinafter referred to as “SOC”) of the battery 35 exceeds a predetermined threshold value (for example, 90%), the deceleration mechanism 30 is set to neutral, so that the battery 35 is overcharged. It can be suppressed.

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

The combination switch 95 is a switch operated by the driver to control the braking of the HEV 100. 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 for 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 HEV100 operates, and when the combination switch 95 is set to 2, the exhaust brake of the HEV100 and the compression release brake operate. Similarly, when the driver sets the combination switch 95 to 3, the exhaust brake, compression release brake, and retarder 28 of the HEV 100 are activated.

When the driver sets the combination switch 95 to any of 1 to 3, the valve 76 provided in the exhaust path 73 blocks the exhaust path. As a result, the friction of the diesel engine 10 increases, and the exhaust brake operates. 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 suppresses the rotation of the propeller shaft 25. Works.

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

The first auxiliary transmission mechanism 22a, also called a splitter, includes two gears, a low gear 221 and a high gear 222, and a first sleeve 223 for adjusting the gear ratio of the main transmission mechanism 21. The low gear 221 includes a first low gear 221a arranged 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 arranged 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.

Note that FIG. 2 shows a state in which 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 both the first low gear 221a and the first high gear 222a. Therefore, the rotational drive of the input shaft 29a is not transmitted to the counter shaft 29b. Hereinafter, in the present specification, a 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 a "neutral state of the auxiliary transmission mechanism 22" or a "neutral state of the splitter". May be described as.

When the splitter is in the neutral state, the power transmission path between the diesel engine 10 and the counter shaft 29b is cut off. This state has an effect corresponding to a state in which the clutch 15 is disengaged in the sense that the rotational power of the diesel engine 10 is not transmitted to the counter shaft 29b. Therefore, in the present specification, the "neutral state of the splitter" may be referred to as the "disengagement equivalent state of the clutch 15" and the like.

Generally, when the transition between the disengaged state and the connected state of the clutch 15 is repeated, parts such as the clutch release bearing constituting the clutch 15 are worn. Therefore, by substituting the disengaged state of the clutch 15 with the neutral state of the splitter, the wear 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 driven is often generated. In such a case, the clutch 15 is generally disengaged in order to reduce the friction loss caused by the diesel engine 10. By substituting this with the neutral state of the splitter, it is possible to reduce the wear of the clutch 15 during power running of the motor generator 33.

The main transmission mechanism 21 includes a first gear 211, a second gear 212, a third gear 213, a second sleeve 214, and a third sleeve 215. The first gear 211 includes a first gear 211a arranged on the output shaft 23 and a second gear 211b fixed to the counter shaft 29b. Similarly, the second gear 212 includes a first second gear 212a arranged on the output shaft 23 and a second second gear 212b fixed to the counter shaft 29b, and the third gear 213 is on the output shaft 23. It includes a first third gear 213a arranged and a second third gear 213b fixed to a 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. Further, the third sleeve 215 can be connected to the first third gear 213a, or the input shaft 29a and the output shaft 23 can be directly connected to each other.

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. It is also not possible to directly connect the 29a and the output shaft 23. The reverse is also true: when the third sleeve 215 is connected to the first third gear 213a or the input shaft 29a and the output shaft 23 are directly connected, the second sleeve 214 is the first first gear. It cannot be connected to either the 211a or the first second gear 212a.

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

The second auxiliary transmission mechanism 22b, also called a range, is provided on a drive transmission path that transmits the rotational drive of the output shaft 23 to the propeller shaft 25. The second auxiliary transmission mechanism 22b is a known planetary gear mechanism 224, and the reduction ratio can be switched between 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 driven under the control of the control device 80.

3 (a)-(r) are diagrams for explaining the operation of the transmission 20 according to the embodiment. In FIGS. 3A-(r), in order to avoid complication, a reference numeral indicating the same member is attached to only one place. Further, in FIGS. 3 (a)-(r), the thick line indicates the power transmission path. In particular, the gear shown by the thick line indicates a state in which the diesel engine 10 is rotated by the rotational drive.

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

FIG. 3 (g) shows a state in which the input shaft 29a and the output shaft 23 are directly connected, and the second auxiliary transmission mechanism 22b is in the low speed stage, and this state is the 7th speed of the transmission 20. Further, FIG. 3H shows a state in which the input of the output shaft 23 is the low gear 221 of the first auxiliary transmission mechanism 22a, and this state is the 8th speed of the transmission 20.
3 (i)-FIG. 3 (p) are the same as FIGS. 3 (a)-(h) except that the second auxiliary transmission mechanism 22b is a high-speed stage. For example, if the second auxiliary transmission mechanism 22b is switched to the high speed stage while the transmission 20 is in the 1st speed, the transmission 20 becomes the 9th speed. By configuring the transmission 20 in multiple stages in this way, it is possible to maintain an engine-efficient rotation range in the diesel engine 10, which contributes to improving the fuel efficiency of the HEV 100.

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

<HEV driving mode>
The traveling mode M that the HEV 100 can take will be described.
FIG. 4 is a diagram showing the classification of the traveling mode M that can be taken by the HEV 100 according to the embodiment. As shown in FIG. 4, the traveling mode M that the HEV 100 can take is roughly classified into a normal mode NM and an auto cruise mode AM.
The normal mode NM is a mode in which the driver of the HEV100 operates the accelerator pedal and the brake pedal to change the speed of the HEV100 while driving. The normal mode NM is mainly used when the HEV 100 travels while frequently repeating starting and stopping, such as in an urban area.

The normal mode NM is further divided into an auto shift mode ASM and a manual shift mode MSM. In the auto shift mode ASM, a predetermined map is based on at least 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. Based on the data, the control device 80 sets the gear of the main transmission mechanism 21 and the gear of the auxiliary transmission mechanism 22 in the traveling mode.

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 1st 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. That is, the manual shift mode MSM can be said to be a mode in which the driver selects the shift timing of the transmission 20.

When the driver of the HEV100 turns on the auto-cruise operation switch 811 provided on the shift lever 81, the HEV100 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 by 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 driving mode EDM, an assist driving mode ADM, a motor driving mode MDM, and an inertial driving mode IDM, and the control device 80 appropriately selects each driving mode. The vehicle speed V of the HEV100 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. The speed is set to 0 km / h or more and +10 km / h or less with respect to the speed va, 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 running mode EDM, the HEV 100 is driven 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 reduction mechanism 30 is set to the neutral state, and the motor generator 33 is cut off from the propeller shaft 25. Therefore, in the engine running mode EDM, the HEV 100 accelerates only by the driving force of the diesel engine 10, and the driving force of the motor generator 33 is not used. Further, 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 traveling mode MDM, the clutch 15 is in a state equivalent to disengagement, that is, the splitter is in a neutral state, and the HEV 100 is driven by the driving force Fm from the motor generator 33. In the motor running mode MDM, the driving force of the diesel engine 10 is not transmitted to the propeller shaft 25. Instead, in the motor running mode MDM, the motor generator 33 is forced to run when the HEV 100 is accelerated, and the motor generator 33 is regeneratively generated when the HEV 100 is decelerated.

The assist traveling mode ADM travels the HEV 100 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 reduction mechanism 30. In the assisted traveling 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.

The inertial traveling mode IDM travels the HEV 100 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 the inertial traveling mode IDM, the clutch 15 is equivalent to disengagement, and the deceleration mechanism 30 is in the neutral state. Therefore, both the diesel engine 10 and the motor generator 33 are cut off from the propeller shaft 25.

When the HEV 100 is in the motor running mode MDM or the coasting running mode IDM, the control device 80 puts the clutch 15 in the disengaged state or the state equivalent to the disengagement, stops the fuel injection, stops the diesel engine 10, and puts the idling stop state. It may be maintained, or the fuel may be injected in an amount that maintains the idling of the diesel engine 10.

When the HEV 100 is in the auto cruise mode AM, when the accelerator pedal depression is detected by the accelerator opening sensor 92, the HEV 100 can be accelerated by the driving force from the diesel engine 10. Further, when the brake pedal opening 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 HEV100 is auto-automatic. Cruise mode is canceled.

Subsequently, the functional configuration of the HEV 100 according to the embodiment will be described.
FIG. 5 is a diagram schematically showing 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. Note that FIG. 4 shows a configuration for explaining the HEV 100 according to the embodiment from the functional aspect, and other configurations are omitted.

The control device 80 controls the disconnection and connection of the diesel engine 10 and 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 in auto-cruise.
Specifically, the control device 80 supplies fuel to the cylinder 12 of the diesel engine 10 based on the engine speed Ne detected by the rotation speed sensor 86 and the depression amount of the accelerator pedal detected by the accelerator opening sensor 92. Adjust the injection amount and injection timing. Further, the control device 80 adjusts the frequency of the inverter 34 and the current value between the battery 35 and the motor generator 33 according to the SOC of the battery 35 and the like. The control device 80 controls the motor generator 33 when the HEV 100 starts or accelerates to assist at least a part of the driving force. On the other hand, the control device 80 causes the motor generator 33 to regenerative power generation during the inertial running or braking of the HEV 100, converts excess kinetic energy into electric power, and charges the battery 35.

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

[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 and 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 has not reached the target speed range, the HEV 100 shifts to the assist traveling mode ADM driven by both the driving force of the diesel engine 10 and the driving force of the motor generator 33.

[Transition from assisted driving mode to motor driving mode]
When the HEV 100 is in the assist traveling mode ADM, the control device 80 determines the fuel injection amount to 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 operation of the motor generator 33. By controlling the power running, the vehicle speed of the HEV100 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 km / h), the transmission 20 is at the highest speed. In the example shown in FIG. 2, when the HEV 100 transitions to the inertial traveling mode IDM, the gear of the transmission 20 is in 16th speed.

If the HEV 100 approaches, for example, an uphill during the assisted driving 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 sets (1) the clutch 15 to be disengaged or equivalent to disengagement, (2) the fuel injection amount to be supplied to the diesel engine 10 to a predetermined value (for example, 40 mm cubic meter per stroke of the piston) or less, and (3) Control to power the motor generator 33 is executed. As a result, the HEV 100 transitions from the assist traveling mode ADM to the motor traveling mode MDM. Although not limited, as an example, when the vehicle speed of the HEV 100 is 90 km / h, the control device 80 generates a torque of 50 Nm in terms of the propeller shaft 25 in the motor generator 33.

Generally, a large driving force is not required to restore the vehicle speed of the HEV 100, which is slightly below the target speed range, to the target speed range. Therefore, if this driving force is to be covered by the output of the diesel engine 10, the diesel engine 10 is used in a rotation range where the engine efficiency is low, which is inefficient. Therefore, in such a case, the fuel consumption can be reduced by using the driving force of the motor generator 33. Further, since the motor generator 33 has less filtering and the like 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 HEV100 can be realized in a short time.

Here, if the HEV 100 approaches, for example, a downhill during the assisted driving 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 controls (1) disengages or corresponds to disengagement of the clutch 15, (2) reduces the fuel injection amount supplied to the diesel engine 10 to a predetermined value or less, and (3) regenerates the motor generator 33. Execute. As a result, the HEV 100 transitions from the assist traveling mode ADM to the motor traveling mode MDM. Although not limited, as an example, when the vehicle speed of the HEV 100 is 90 km / h, the control device 80 regenerates the motor generator 33 with a torque of 100 Nm in terms of the propeller shaft 25.

As a result, the regeneration of the motor generator 33 can be frequently used for the speed control using the engine friction of the diesel engine 10, and the SOC of the battery 35 can be kept at a high value. As a result, the assist traveling mode ADM using the motor generator 33 can be frequently used, so that the frequency of using the transmission 20 in a higher gear stage increases, and the fuel consumption can be reduced.
Further, since the motor generator 33 has less filtering and the like 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 HEV100 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 electric power of the battery 35. Therefore, when the SOC of the battery 35 is low, it is preferable not to power the motor generator 33 in order to prevent the battery 35 from being over-discharged.
Therefore, when the SOC of the battery 35 is less than a predetermined threshold value (for example, 20%), the control device 80 connects (1) 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 released, (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) the control to regenerate the motor generator 33 is executed. As a result, the HEV 100 transitions from the motor running mode MDM to the engine running mode EDM.

In this way, the control device 80 drives the HEV 100 with the output of the diesel engine 10 and regenerates the motor generator 33 when the SOC of the battery 35 is low. 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 regenerates, the SOC of the battery 35 can be increased.

Further, the battery 35 is charged by the regeneration of the motor generator 33. Therefore, 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 value (for example, 90%), the control device 80 connects the clutch 15 or puts the splitter in the neutral state even when the vehicle speed of the HEV 100 exceeds the target speed range. Execute the control to release. The control device 80 may further set the speed reduction mechanism 30 to neutral. As a result, the amount of power generated by the regeneration of the motor generator 33 can be reduced, and the battery 35 can be prevented from being overcharged. As a result, the life of the battery 35 can be extended.

The control device 80 is a vehicle when the HEV 100 is requested to perform an exhaust brake, that is, when the combination switch 95 is set to any of 1 to 3, and the HEV 100 is traveling by auto cruise. Even if the speed is below the target speed range, the control for engaging the clutch 15 or releasing the neutral state of the splitter is executed. As a result, the exhaust brake acts on the HEV 100, and the HEV 100 can be decelerated.

[Transition from motor drive mode to assist drive mode]
When the HEV 100 is in the motor traveling mode MDM, the state is equivalent to the clutch disengagement except when the driver intentionally disengages 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 regenerates the motor generator 33 and decelerates the HEV 100 by the regenerative brake.

In such a situation, that is, in the case where (1) the clutch 15 is connected, (2) the splitter is in the neutral state, and (3) the motor generator 33 is in the regenerative state, control is performed when the driver requests the operation of the exhaust brake. The device 80 releases the neutral state of the splitter. As a result, the HEV 100 transitions from the motor traveling mode MDM to the assist traveling mode ADM. As a result, since the diesel engine 10 and the propeller shaft 25 are connected to each other, 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 options: to put the first auxiliary transmission mechanism 22a in the low gear 221 or in 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 rotation speed of the diesel engine 10 is equal to or lower than a predetermined rotation speed. The "predetermined rotation speed" is a permissible limit value of the rotation speed preset in the diesel engine 10, and is a so-called "rev limit". The specific value of the predetermined rotation speed may be determined by the manufacturer in consideration of the performance of the diesel engine 10. The control device 80 refers to the predetermined map data based on the vehicle speed of the HEV 100 and the gear of the main transmission mechanism 21, and when the first auxiliary transmission mechanism 22a is set to the low gear 221, the engine rotation of the diesel engine 10 It is determined whether or not the number Ne is below the rev limit.

When the first auxiliary transmission mechanism 22a is set to the low gear 221, the engine speed Ne of the diesel engine 10 is higher than when the first auxiliary transmission mechanism 22a is set to the high gear 222. Therefore, the braking torque of the HEV 100 becomes large, and a large braking force acts on the HEV 100. Therefore, it is possible to suppress the overspeeding of the HEV100 during the auto-cruise operation, and the vehicle can travel more safely. In addition, as 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. Therefore, it is possible to suppress the overspeeding of the HEV 100 when the auto cruise is operated, and it is possible to drive more safely.

By setting the first auxiliary transmission mechanism 22a to the low gear 221 and determining that the engine speed Ne of the diesel engine 10 exceeds the rev limit, control for switching the first auxiliary transmission mechanism 22a to the high gear 222 is executed. As a result, it is possible to prevent the engine speed Ne of the diesel engine 10 from exceeding the rev limit, and it is possible to prevent the diesel engine 10 from being adversely affected.

[Transition to coasting mode]
When the HEV100 is an engine driving mode EDM, an assisting driving mode ADM, or a motor driving mode MDM, the SOC of the battery 35 is within a predetermined range (for example, 30% or more and 80% or less), and the vehicle speed of the HEV100 is within the target speed range. After staying for a certain period of time, the traveling mode M of the HEV100 transitions to the coasting traveling mode IDM. As a result, the fuel consumption and the usage of the battery 35 can be reduced.

[Transition from auto cruise mode to normal mode]
Subsequently, the transition of the HEV 100 from the auto cruise mode AM to the normal mode NM will be described.
Consider, for example, when the HEV 100 is traveling on a gentle downhill during the motor drive mode MDM, which is one of the auto cruise mode AMs. At this time, the HEV 100 is a case where (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, it is considered that the driver may desire to use the engine brake of the diesel engine 10, although it is not enough to use the exhaust brake.

In such a case, the driver of the HEV 100 requests that the shift lever 81 be operated to shift down the transmission 20. The control device 80 releases the neutral state of the splitter when the driver requests a shift down of the transmission 20. More specifically, the control device 80 releases the neutral state of the splitter by driving the first actuator 201a 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 as to be a gear determined based on the operating state of the HEV 100 and the map data. As a result, the HEV 100 transitions from the motor traveling mode MDM to the manual shift mode MSM.

As a result, the braking force of the HEV 100 is increased, and the vehicle behavior close to the driver's request can be obtained. In particular, since a braking force close to the braking force required before the HEV 100 turns a curve on a downward slope can be obtained, the safety performance of the HEV 100 is further improved. Further, since the clutch 15 is in the connected state when the HEV 100 re-accelerates after turning a curve on a flat ground, the re-acceleration of the HEV 100 becomes quick. 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 HEV100 does not step on the brake pedal. When the driver of the HEV100 depresses the brake pedal, the auto-cruise mode AM of the HEV100 is canceled and the mode shifts to the auto-shift mode ASM which is the normal mode NM.

[Transition from manual shift mode to auto shift mode]
When the HEV100 is not accelerating in the manual shift mode MSM, (1) the clutch 15 is in the connected state, (2) the first auxiliary transmission mechanism 22a is in the non-neutral state, and (3) the motor generator 33 is in the regenerative state. There is. In such a case, when the driver sets the shift lever 81 to the drive range (not shown), the control device 80 shifts to the auto shift mode ASM that automatically controls the gear selection of the transmission 20. When the HEV100 is in autoshift mode ASM, the driver does not manually select the gear of the transmission 20.

Therefore, the control device 80 sets the operation equivalent to clutch disengagement, that is, the first auxiliary transmission mechanism 22a to the neutral state, triggered by the transition from the manual shift mode MSM to the auto shift mode ASM in a state where the HEV 100 is not accelerating. .. As a result, the energy obtained by the braking regeneration of the motor generator 33 can be increased.

The above transition is based on the assumption that the driver of HEV100 does not step on the brake pedal. When the driver of the HEV100 depresses the brake pedal, the manual shift mode MSM of the HEV100 is maintained.

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

Further, the control device 80 stops the diesel engine 10 or puts it in an idling state during the auto-cruise of the HEV 100, so that the exhaust gas 71 from the exhaust valve 70 can be reduced. Therefore, it is possible to suppress a decrease in the purification capacity of the exhaust gas purification device 75, which is arranged 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 to recover and regenerate the purification capacity of the exhaust gas purification device 75. There is. When the exhaust gas 71 from the exhaust valve 70 is reduced, the chance of recovering the purification capacity of the exhaust gas purification device 75 is also reduced, so that the fuel consumption required for its regeneration can also be reduced. The exhaust gas purifying device 75 is, for example, a collecting device that collects particulate matter in the exhaust gas 71, and while the HEV 100 is traveling by motor and coasting, the particulate matter is deposited on the collecting device. Since it is suppressed, the fuel consumption required for regenerating the collecting device can be suppressed.

In addition, the rotational power of the propeller shaft 25 is the rotation of the diesel engine 10 by setting the clutch 15 to be in a disengaged state or a state equivalent to disengagement during coasting and stopping the injection of fuel to stop the diesel engine 10. Since it is possible to avoid a decrease due to drag, it is possible to reduce energy loss during motor running and coasting running and further improve fuel efficiency.

Further, the control device 80 may put the clutch 15 into a disengaged state or a disengaged state while the motor is running, and control the fuel injection amount to stop or put the diesel engine 10 into an idling state. As a result, the fuel consumption during the running of the motor can be reduced, and the decrease in the purification capacity of the exhaust gas purification device 75 can be suppressed, so that the fuel consumption can be further improved.

Although the present invention has been described above using the embodiments, the technical scope of the present invention is not limited to the scope described in the above embodiments. It will be apparent to those skilled in the art that various changes or improvements can be made to the above embodiments. It is clear from the description of the claims that such modified or modified forms may also be included in the technical scope of the present invention.

10 ... Diesel engine 15 ... Clutch 20 ... Transmission 21 ... Main transmission mechanism 22 ... Auxiliary transmission mechanism 25 ... Propeller shaft 28 ... Retarder 30 ... Reduction 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 ... Auto cruise operation switch

Claims (2)

It is a hybrid vehicle that uses an engine and a motor generator as driving force.
The clutch that controls the power transmission of the engine and
A transmission including a main transmission mechanism for decelerating the rotational drive of the engine transmitted via the clutch and an auxiliary transmission mechanism for adjusting the gear ratio of the main transmission mechanism.
A propeller shaft that transmits the power of the engine to the drive wheels via the auxiliary transmission mechanism.
A control device that controls the operation of the hybrid vehicle in auto-cruise,
A shift lever for switching between the driver of the hybrid vehicle selecting the gear of the transmission and the control device automatically controlling the selection of the gear.
A brake pedal for the driver to decelerate the hybrid vehicle,
With
The motor generator is connected to the propeller shaft via a reduction mechanism.
The control device includes (1) the clutch is engaged, (2) the auxiliary transmission mechanism is in the non-neutral state , ( 3) the motor generator is in the regenerative state, and (4) the driver does not step on the brake pedal. The sub-transmission mechanism is put into the neutral state when the driver selects to have the control device automatically control the selection of the gear.
A hybrid vehicle that features that. The auxiliary transmission mechanism is provided on a drive transmission path that transmits the rotational drive of the engine transmitted via the clutch to the main transmission mechanism, and is a high gear for adjusting the gear ratio of the main transmission mechanism. Equipped with two gears with low gear,
When the control device receives a request to operate the exhaust brake when (1) the clutch is in the connected state, (2) the auxiliary transmission mechanism is in the neutral state, and (3) the motor generator is in the regenerative state. The hybrid vehicle according to claim 1, wherein the control for switching the auxiliary transmission mechanism to the low gear is executed on condition that the rotation speed of the engine becomes a predetermined rotation speed or less .

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