WO2017086468A1

WO2017086468A1 - Hybrid vehicle and method for controlling same

Info

Publication number: WO2017086468A1
Application number: PCT/JP2016/084331
Authority: WO
Inventors: 憲仁岩田
Original assignee: いすゞ自動車株式会社
Priority date: 2015-11-20
Filing date: 2016-11-18
Publication date: 2017-05-26
Also published as: JP2017094831A

Abstract

Provided is a hybrid vehicle provided with: a hybrid system 30 having a motor generator 31 connected to an output axis 13 which transmits power of an engine 10; a transmission 20 to which the power of the engine is transmitted via a clutch 14; and a control device 80, wherein the control device, when a preset idling stop control execution condition is fulfilled, controls the clutch to a disengaged state and sets a target number of revolutions of the motor generator to zero while executing an idling stop control that stops fuel injection of the engine.

Description

Hybrid vehicle and control method thereof

This disclosure relates to a hybrid vehicle and a control method thereof.

In recent years, a hybrid vehicle (hereinafter referred to as “HEV”) including a hybrid system having an engine and a motor generator that are controlled in combination according to the driving state of the vehicle has attracted attention from the viewpoint of improving fuel efficiency and environmental measures. . In this HEV, driving force is assisted by a motor generator when the vehicle is accelerated or started, while regenerative power generation is performed by the motor generator during inertia traveling or braking (see, for example, Patent Document 1).

In recent years, in order to improve fuel efficiency, HEVs that perform idle stop control for stopping engine fuel injection have also been developed (see, for example, Patent Document 2). However, immediately before the forward rotation of the engine stops due to the execution of the idle stop control, the engine reversely rotates due to compression repulsion and generates an unpleasant vibration called bull (hereinafter, this unpleasant vibration is referred to as “roll vibration”). ).

Japanese Unexamined Patent Publication No. 2002-238105 Japanese Unexamined Patent Publication No. 2001-54208

One aspect of the present disclosure has been made in view of the above, and an object of the present disclosure is a hybrid vehicle that can suppress the occurrence of engine roll vibration when idle stop control is executed, and a control method thereof. It is to provide.
Another object of the present disclosure is to provide a hybrid vehicle and a control method thereof that can shorten the time until the rotational speed becomes zero when the idle stop control is executed.

In order to achieve the above object, a hybrid vehicle according to an embodiment of the present disclosure includes a hybrid system having a motor generator connected to an output shaft that transmits engine power, and the engine power is transmitted via a clutch. And a control device that executes idle stop control that stops fuel injection of the engine when a preset idle stop control execution condition is satisfied. In addition, the clutch is controlled to be disengaged, and the target rotational speed of the motor generator is set to zero.

In addition, a hybrid vehicle control method according to an aspect of the present disclosure for achieving the above object includes a hybrid system having a motor generator connected to an output shaft that transmits engine power, and the engine power is a clutch. And a transmission transmitted through the vehicle, and executes an idle stop control for stopping fuel injection of the engine when a preset idle stop control execution condition is satisfied. In addition, the clutch is controlled to be disengaged, and the target rotational speed of the motor generator is set to zero.

According to the present disclosure, the idle stop control is executed to stop the fuel injection of the engine when the idle stop control execution condition is satisfied, the clutch is disengaged, and the rotational torque on the transmission side is transmitted to the engine side. In addition, since the target rotational speed of the motor generator is set to zero, it is possible to suppress the reverse rotation of the engine immediately before stopping the forward rotation and the occurrence of roll vibration. Thereby, the comfort of a hybrid vehicle can be improved.

Also, according to the present disclosure, the motor generator can generate a resistance torque against the rotation of the engine by setting the target rotation speed of the motor generator to zero. As a result, the time until the engine speed reaches zero can be shortened. As a result, it is possible to reduce the time required from when the engine is restarted (restart request) until the engine is restarted.

Further, according to the present disclosure, the motor generator is driven by the energy of the inertia (inertia) of the engine after the fuel injection of the engine is stopped by executing the idle stop control until the engine speed actually becomes zero. You can also. Thus, the energy can be recovered up to the inertia of the engine by the motor generator. As a result, fuel consumption can be improved.

Further, a hybrid vehicle according to another embodiment of the present disclosure includes a hybrid system having a motor generator connected to an output shaft that transmits engine power, a transmission in which the engine power is transmitted via a clutch, and a control device The control device executes idle stop control for stopping fuel injection of the engine when a preset idle stop control execution condition is satisfied, and the clutch is disengaged. The motor generator is driven while being controlled in a disconnected state.

Note that the idle stop control execution condition can be exemplified by a condition that the hybrid vehicle is decelerating.

According to the present disclosure, it is possible to suppress the occurrence of engine roll vibration when the idle stop control is executed.

FIG. 1 is a configuration diagram of a hybrid vehicle according to an embodiment of the present disclosure. FIG. 2 is a flowchart illustrating an example of control processing by the control device.

Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. FIG. 1 is a configuration diagram of a hybrid vehicle according to an embodiment of the present disclosure. This hybrid vehicle (hereinafter referred to as “HEV”) is a vehicle including not only a normal passenger car but also a bus, a truck, etc., and a hybrid having an engine 10 and a motor generator 31 that are controlled in combination according to the driving state of the vehicle. A system 30 is provided.

In the engine 10, the crankshaft 13 is rotationally driven by thermal energy generated by the combustion of fuel in a plurality (four in this example) of cylinders 12 formed in the engine body 11. The engine 10 is a diesel engine or a gasoline engine. The rotational power of the crankshaft 13 is transmitted to the transmission 20 via a clutch 14 (for example, a wet multi-plate clutch) connected to one end of the crankshaft 13.

The transmission 20 is not particularly limited by the type of manual transmission (MT) or automatic transmission (AT, AMT).

Rotational power changed by the transmission 20 is transmitted to the differential 23 through the propeller shaft 22 and distributed to the pair of driving wheels 24 as driving force.

The hybrid system 30 includes a motor generator 31, and an inverter 35, a high voltage battery 32, a DC / DC converter 33, and a low voltage battery 34 that are electrically connected to the motor generator 31 in this order.

Preferred examples of the high voltage battery 32 include a lithium ion battery and a nickel metal hydride battery. The low voltage battery 34 is a lead battery.

The DC / DC converter 33 has a function of controlling the charge / discharge direction and the output voltage between the high voltage battery 32 and the low voltage battery 34. The low voltage battery 34 supplies power to various vehicle electrical components 36.

Various parameters in the hybrid system 30, such as current value, voltage value, and SOC, are detected by the BMS 39 (battery management system).

The motor generator 31 is an endless shape wound around a first pulley 15 attached to the rotating shaft 37 and a second pulley 16 attached to the other end of the crankshaft 13 which is an output shaft of the engine body 11. Power is transmitted to and from the engine 10 via the belt-shaped member 17. Note that power can be transmitted using a gear box or the like instead of the first pulley 15, the second pulley 16 and the belt-like member 17. Further, the output shaft of the engine main body 11 connected to the motor generator 31 is not limited to the crankshaft 13, and may be, for example, a transmission shaft or the propeller shaft 22 between the engine main body 11 and the transmission 20.

The motor generator 31 has a function of performing cranking instead of a starter motor (not shown) that starts the engine body 11.

The hybrid system 30 described above is controlled by the control device 80. Specifically, the hybrid system 30 is controlled by the control device 80 to assist at least a part of the driving force by the motor generator 31 supplied with power from the high voltage battery 32 when the HEV starts or accelerates. On the other hand, during inertial running or braking, regenerative power generation is performed by the motor generator 31, and excess kinetic energy is converted into electric power to charge the high voltage battery 32.

Further, in addition to the hybrid system 30, the control device 80 controls the disengagement and connection of the clutch 14, and also controls the gear stage of the transmission 20 by controlling the speed change actuator 21.

The control device 80 executes idle stop control for stopping fuel injection of the engine 10 when a condition (idle stop control execution condition) for executing idle stop control set in advance is satisfied, and the clutch 14 is controlled to a disconnected state (a disconnected state), and the target rotational speed of the motor generator 31 is set to zero. The details of this control processing will be described with reference to a flowchart.

FIG. 2 is a flowchart showing an example of control processing by the control device 80. The control device 80 repeatedly executes the flowchart of FIG. 2 at a predetermined cycle. It is assumed that the idle stop control is not executed at the first start of FIG. 2, and the normal HEV travel control (referred to as normal control) is executed.

In step S10, the control device 80 determines whether or not the idle stop control execution condition is satisfied. Although the specific content of this idle stop control execution condition is not specifically limited, In this embodiment, the condition that HEV is at the time of deceleration is used as an example. That is, the control device 80 according to the present embodiment executes the idle stop control when the HEV is decelerated. Specifically, the control device 80 acquires the HEV vehicle speed based on the detection result of a vehicle speed sensor (not shown), and determines whether the HEV is in a deceleration state based on the acquired vehicle speed. To do. Then, the control device 80 determines that the idle stop control execution condition is satisfied when it is determined that the HEV is in a deceleration state. However, the content of step S10 mentioned above is only an example, and the specific content of step S10 is not limited to this.

When it is determined No in step S10 (when the idle stop control execution condition is not satisfied), the control device 80 ends the execution of the flowchart. On the other hand, when it is determined Yes in step S10, the control device 80 performs idle stop control for stopping the fuel injection of the engine 10 and controls the clutch 14 to the disengaged state, so that the transmission 20 side (that is, the drive wheel) (24 side) rotational torque is not transmitted to the engine 10 side, and the target rotational speed of the motor generator 31 (MG) is set to zero (step S20). After step S20, the control device 80 ends the execution of the flowchart.

The control device 80 according to the present embodiment is provided with a target rotational speed setting unit (which is realized by a CPU, for example) that sets the target rotational speed of the motor generator 31. Controls the motor generator 31 so that the rotational speed of the motor generator 31 becomes the rotational speed set in the target rotational speed setting unit. Therefore, when setting the target rotational speed to zero in step S20, specifically, the control device 80 sets the value of the target rotational speed set in the target rotational speed setting unit to zero. As a result, the motor generator 31 is controlled so that its rotational speed is actually zero.

In addition, when the idle stop control is executed in step S20, the engine 10 can rotate for a while due to the inertia (inertia) of the engine 10, but eventually the rotation speed becomes zero. Further, the target rotational speed of the motor generator 31 is set to zero in step S20, so that the rotational speed of the motor generator 31 is finally zero. However, in this case, the motor generator 31 is driven by the inertia (inertia) energy of the engine 10 until the rotational speed of the engine 10 actually becomes zero after the fuel injection of the engine 10 is stopped. The motor generator 31 can execute regenerative power generation.

In addition, the period (execution period) for executing the control process according to step S20 is not particularly limited, but in the present embodiment, as an example, the idle stop control execution condition is satisfied. That is, the control device 80 according to the present embodiment continuously executes the control process of step S20 while the idle stop control execution condition is satisfied. When the idle stop control execution condition is not satisfied because the HEV is not in the deceleration state, the control device 80 stops the control process in step S20 and returns to the normal control state.

According to the present embodiment described above, when the idle stop control execution condition is satisfied, the idle stop control for stopping the fuel injection of the engine 10 is performed, and the clutch 14 is disengaged, and the transmission 20 side , And the target rotational speed of the motor generator 31 is set to zero, so that the engine 10 reversely rotates immediately before stopping normal rotation to generate roll vibration. This can be suppressed. Thereby, the comfort of HEV can be improved.

Further, according to the present embodiment, the motor generator 31 can generate a resistance torque against the rotation of the engine 10 by setting the target rotational speed of the motor generator 31 to zero. Thereby, time until the rotation speed of the engine 10 becomes zero can also be shortened. As a result, it is also possible to reduce the time required from when the engine 10 is restarted (restart request) until the engine 10 is restarted.

Further, according to the present embodiment, the motor is driven by the inertia (inertia) energy of the engine 10 after the fuel injection of the engine 10 is stopped by the execution of the idle stop control until the rotational speed of the engine 10 actually becomes zero. The generator 31 can also be driven. Thereby, the energy can be recovered by the motor generator 31 up to the inertia of the engine 10. As a result, fuel consumption can be improved.

Although the preferred embodiments of the present disclosure have been described above, the present disclosure is not limited to such specific embodiments, and various modifications and changes can be made within the scope of the gist of the present disclosure described in the claims. Is possible.

This application is based on a Japanese patent application (Japanese Patent Application No. 2015-227563) filed on November 20, 2015, the contents of which are incorporated herein by reference.

The hybrid vehicle of the present disclosure is useful in that it can suppress the occurrence of engine roll vibration when the idle stop control is executed.

10 Engine 13 Crankshaft (output shaft)
14 Clutch 20 Transmission 30 Hybrid system 31 Motor generator 80 Control device

Claims

A hybrid system having a motor generator connected to an output shaft for transmitting engine power;
A transmission in which the power of the engine is transmitted via a clutch;
A control device;
A hybrid vehicle with
The control device executes idle stop control for stopping fuel injection of the engine when a preset idle stop control execution condition is satisfied, controls the clutch to a disengaged state, and the motor generator A hybrid vehicle characterized in that the target rotational speed of the vehicle is set to zero.
The hybrid vehicle according to claim 1, wherein the control device determines that the idle stop control execution condition is satisfied when the hybrid vehicle is decelerating.
A hybrid vehicle control method comprising: a hybrid system having a motor generator connected to an output shaft for transmitting engine power; and a transmission for transmitting the engine power via a clutch.
When a preset idle stop control execution condition is satisfied, idle stop control for stopping fuel injection of the engine is executed, the clutch is controlled to be disengaged, and the target rotational speed of the motor generator is set. A control method for a hybrid vehicle, characterized in that it is set to zero.
4. The hybrid vehicle control method according to claim 3, wherein when the hybrid vehicle is decelerated, it is determined that the idle stop control execution condition is satisfied.
A hybrid system having a motor generator connected to an output shaft for transmitting engine power;
A transmission in which the power of the engine is transmitted via a clutch;
A control device;
A hybrid vehicle with
The control device executes idle stop control for stopping fuel injection of the engine when a preset idle stop control execution condition is satisfied, controls the clutch to a disengaged state, and the motor generator A hybrid vehicle characterized by driving the vehicle.
The hybrid vehicle according to claim 1, wherein the control device determines that the idle stop control execution condition is satisfied when the hybrid vehicle is decelerating.