JP3753671B2 - Vehicle hybrid system - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a vehicle hybrid system including an engine and a rotating electrical machine (motor generator) as a power source of the vehicle.
[0002]
[Prior art]
As a vehicle hybrid system, a clutch that connects and disconnects the output shaft of the engine and the input shaft of the transmission, a rotating electric machine that serves both as an electric motor and a generator, and a power transmission mechanism that connects the input / output shaft of the rotating electric machine and the input shaft of the transmission And a storage element that stores electric power supplied from the rotating electrical machine (see Japanese Patent Application No. 2000-315757).
[0003]
[Problems to be solved by the invention]
In such a hybrid system, in order to ensure quick start of the vehicle, control is performed so that the engine is in an operating state and the transmission is kept in a gear set or the clutch is stopped. When the vehicle is stopped under such conditions, power generation control of the rotating electrical machine is required, and when a clutch connection request is generated, the clutch is connected after the neutral setting of the transmission. At that time, since the rotating electrical machine is in a stopped state and has a considerable inertial mass together with the power transmission mechanism, a large shock (such as vehicle vibration) may be generated in the clutch connection.
[0004]
The object of the present invention is to provide an effective solution to cope with such problems.
[0005]
[Means for Solving the Problems]
A first invention is a clutch that connects and disconnects an output shaft of an engine and an input shaft of a transmission, a rotating electric machine that also serves as an electric motor and a generator, a power transmission mechanism that connects an input / output shaft of the rotating electric machine and an input shaft of the transmission And a power storage device connected to the rotating electrical machine, the power storage device needs to be charged, and when a clutch connection request is generated when the engine is stopped, the transmission neutral set Until the clutch is connected, the means for controlling the rotational speed of the rotating electrical machine with the engine rotational speed as a target value and the clutch connection when the rotational difference between the target value and the rotational speed of the rotating electrical machine converges within a predetermined range. Means for controlling.
[0007]
【The invention's effect】
In the first aspect of the invention, when a clutch connection request is generated when the engine is in a stopped state, the rotational speed of the rotating electrical machine is controlled with the rotational speed of the engine as a target value by the neutral set of the transmission. When the rotational difference between the speed and the rotational speed of the engine converges within a predetermined range, the clutch is controlled to be engaged. Therefore, it is possible to prevent a large shock from occurring in the clutch connection.
[0008]
When the connection of the clutch is completed , the power storage device can be charged by the power generation control of the rotating electrical machine when the transmission is in the neutral stop state, and the start of the vehicle based only on the output of the rotating electrical machine can be secured.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
In FIG. 1, 1 is an engine, 2 is a gear-type transmission, and a friction clutch 3 is interposed between them. The engine 1 is a diesel engine (or a CNG engine using compressed natural gas as fuel). Reference numeral 4 denotes a rotating electrical machine (motor generator), and an input / output shaft thereof is connected to an input shaft of the transmission 2 via a power transmission mechanism 5 (gear box).
[0010]
The transmission 2 is provided with a control unit 6 (FCT-ECU) for controlling the gear shift. The control unit 6 is connected to the hybrid control unit 10 (hybrid ECU), and controls gear shift according to a command of the hybrid ECU 10 based on a shift request from the change lever device 7 in the cab.
[0011]
The clutch 3 is provided with a clutch actuator 8 (clutch booster) for connecting and disconnecting the clutch 3. The clutch actuator 8 intermittently transmits power from the engine 1 to the transmission 2 and the gear box 5 in response to a driver's pedal operation or a request from the hybrid ECU 10.
[0012]
The rotating electrical machine 4 uses a permanent magnet type synchronous motor (IPM synchronous motor) from the viewpoint of high efficiency and small size and light weight, and is connected to a power storage device (not shown) via an inverter. In the power storage device, an electric double layer capacitor is used that easily regenerates brake energy in a short time with high efficiency without waste, so that it is easy to ensure a required output density with respect to the allowable battery mass of the vehicle.
[0013]
The inverter controls the rotating electrical machine 4 to the electric mode or the power generation mode according to the request of the hybrid ECU 10. In the electric mode, the charging power (DC power) of the power storage device is converted to AC power to drive the rotating electrical machine 4, while in the power generation mode, the generated power (AC power) of the rotating electrical machine 4 is converted to DC power. To charge the power storage device.
[0014]
The hybrid ECU 10 determines the accelerator opening (required driving force) from the amount of depression of the accelerator pedal 12, the clutch stroke sensor 14 that detects the stroke of the clutch 3, the engine rotation sensor 16 that detects the rotation speed (crankshaft rotation speed) of the engine. The accelerator opening sensor 13 to detect, the pedal switches 14a and 14b to detect the release (initial position) and the depression (operating position) of the clutch pedal 23, and the output side rotational speed (propeller shaft rotational speed) of the transmission 2 are detected. A PS rotation sensor 18 (vehicle speed sensor), a CP rotation sensor 19 that detects a rotation speed (counter shaft rotation speed) on the input side of the transmission 2, and the like are provided.
[0015]
Based on these detection signals and various information (obtained from the inverter of the rotating electrical machine 4, the control unit 6 of the transmission 2, etc.) including the SOC (State Of Chage) of the power storage device, the hybrid ECU 10 supplies the fuel for the engine. Control device, brake device for each wheel (not shown), clutch actuator 8 and inverter of rotating electrical machine 4, while commanding control unit 6 of transmission 2 (target gear signal, gear release timing signal, gear Send timing signal, etc.).
[0016]
FIG. 2 is a control map for setting a sharing ratio between the output of the rotating electrical machine 4 and the output of the engine 1 using the SOC of the power storage device as a parameter, and is stored in the hybrid ECU 10. The hybrid ECU 10 obtains an output sharing ratio according to the SOC information of the power storage device from the control map, and controls the output of the rotating electrical machine 4 and the output of the engine 1 based on the sharing ratio and the required driving force (accelerator operation amount). . That is, the inverter is controlled so that the rotating electrical machine 4 generates a shared output, while the fuel supply device is controlled so that the engine 1 generates a shared output.
[0017]
When the output sharing ratio of the rotating electrical machine = 1 (output sharing ratio of the engine 1 = 0), the inverter is controlled so that an output corresponding to the accelerator operation amount can be obtained from the rotating electrical machine 4 with the clutch 3 disconnected. . When the output sharing ratio of the rotating electrical machine 4 <1 (output sharing ratio of the engine 1> 0), the sharing output of the rotating electrical machine 4 decreases as the SOC of the power storage device decreases in the state where the clutch 3 is connected. Accordingly, the fuel supply device and the inverter of the engine 1 are controlled so that the shared output of the engine 1 is increased. When the output sharing ratio of the engine 1 is 1 (the output sharing ratio of the rotating electrical machine = 0), the fuel supply amount of the engine 1 is controlled so that an output corresponding to the accelerator operation amount can be obtained from the engine 1.
[0018]
The hybrid ECU 10 determines the rear wheel distributed braking force (required braking force × braking force distribution) in a state in which the clutch 3 is disengaged as long as the power storage device can be charged based on the depression amount (required braking force) of the brake pedal. When the inverter is controlled so that the regenerative braking force corresponding to the ratio) is obtained from the rotating electrical machine 4, the distributed braking force of the rear wheels cannot be covered by the regenerative braking force in addition to generating the distributed braking force of the front wheels. Then, the brake device of each wheel is controlled so that the insufficient braking force is generated in the rear wheel. Further, when the necessity of power generation is determined from the SOC information of the power storage device, the inverter is controlled so that the power storage device is charged by the power generation of the rotating electrical machine 4 when the output of the engine 1 has a margin in the clutch 3 connected state. To do.
[0019]
In FIG. 1, reference numeral 20 denotes a relay cylinder, in which two pistons 20a and 20b slidable in the axial direction are housed, and a hydraulic chamber A partitioned by these pressure-receiving surfaces facing each other; A fluid pressure chamber B partitioned by a pressure receiving surface opposite to the fluid pressure chamber A and a fluid pressure chamber C partitioned by a pressure receiving surface opposite to the fluid pressure chamber A of the piston are provided.
[0020]
The automatic control circuit 21 supplies and discharges the hydraulic pressure in the hydraulic chamber A, and the clutch booster 8 (clutch actuator) connects and disconnects the clutch using the hydraulic pressure in the hydraulic chamber B as a driving force. A manual control circuit 25 including a cylinder 24 is connected to the hydraulic chamber C.
[0021]
In the automatic control circuit 21, between the reservoir 26 and the hydraulic chamber A, a hydraulic pump 27 for clutch disconnection, an electromagnetic valve 28 for loose clutch connection, and an electromagnetic valve 29 for quick clutch connection are arranged in parallel. Intervened. When the hydraulic pump 27 is driven while the solenoid valves 28 and 29 are closed, the oil in the reservoir 26 is pressurized and fed into the hydraulic chamber A. The hydraulic pressure from the hydraulic pump 27 to the hydraulic chamber A is contained by stopping the hydraulic pump 27. When the electromagnetic valve 28 or 29 is opened while the pump is stopped, the hydraulic pressure in the hydraulic chamber A is released (discharged) to the reservoir 26 side via the electromagnetic valve 28 or 29.
[0022]
When the relay cylinder 20 is supplied with hydraulic pressure from the hydraulic pump 27 to the hydraulic chamber A in the illustrated state, the hydraulic chamber B is contracted by the forward movement of the piston 20a, and the hydraulic pressure is supplied to the clutch booster 8. . When the hydraulic pressure in the hydraulic pressure chamber A is released via the solenoid valve 28 or 29 in the stop state of the hydraulic pump 27, the hydraulic pressure chamber B expands while receiving the hydraulic pressure from the clutch booster 8 by the return movement of the piston 20a. To do.
[0023]
When the clutch 3 needs to be disconnected, the hybrid ECU 10 drives the hydraulic pump 27 with the solenoid valves 28 and 29 closed. When the clutch 3 is disconnected due to the extension of the clutch booster 8, the hydraulic pump 27 is stopped so as to keep the clutch 3 in a disconnected state. On the other hand, when the clutch 3 needs to be connected, the opening of the electromagnetic valves 28 and 29 is selectively controlled according to the required clutch stroke characteristics while maintaining the hydraulic pump 27 in a stopped state. When the clutch 3 needs to be suddenly connected, the solenoid valve 28 is opened, while when the clutch 3 needs to be loosely connected, the solenoid valve 29 is opened. When the clutch 3 is connected due to the contraction of the clutch booster 8, the electromagnetic valve 28 or 29 is switched to the closed state.
[0024]
When the clutch pedal 23 is depressed in the connected state of the clutch 3, the hydraulic pressure is supplied from the master cylinder 24 to the hydraulic pressure chamber C. In the illustrated state, the relay cylinder 20 contracts the hydraulic chamber B by the forward movement of the pistons 20 b and 20 a, and supplies hydraulic pressure to the clutch booster 8. When the clutch pedal 23 is returned, the corresponding hydraulic pressure is returned from the hydraulic chamber C to the master cylinder 23, and the hydraulic chamber B expands while receiving the hydraulic pressure from the clutch booster 8 by the return movement of the pistons 20a and 20b. . That is, the manual control circuit 25 can perform the engagement / disengagement of the clutch 3 in accordance with the depression amount of the clutch pedal 23.
[0025]
In the disengaged state of the clutch 3 based on the function of the automatic control circuit 21, the hydraulic pressure is confined in the hydraulic chamber A of the relay cylinder 20, and the clutch pedal 23 cannot be depressed. Therefore, when the pedal switch 14a is turned off in the hybrid ECU 10, a function (clutch release) for holding the electromagnetic valve 29 of the automatic control circuit 21 in an open state is set until it is turned on again. A play is provided between the initial position of the clutch pedal 23 and the initial position of the master cylinder 24, and the pedal switch 14a is turned on at the initial position of the clutch pedal 23, and is turned off when the clutch pedal 23 is stepped on from the initial position. Are arranged as follows.
[0026]
FIG. 3 shows a block configuration related to connection control of the clutch 3 when the engine is stopped in an operating state. When the vehicle is stopped, the engine 1 is controlled to be idle, the transmission 2 is set to a gear set, and the clutch 3 is disconnected to ensure quick start of the vehicle.
[0027]
The hybrid ECU 10 includes a rotation control means 10a (motor rotation control means) of the rotating electrical machine 4, a clutch connection means 10b that controls the electromagnetic valve 28 (or electromagnetic valve 29), a clutch connection condition determination means 10c, and a rotating electrical machine. 4, a means 10 d (target motor rotation calculating means) for calculating the target rotation 4, a rotation speed (rotational difference) determining means 10 f, and a means (not shown) for detecting the rotational speed of the rotating electrical machine 4.
[0028]
The clutch connection condition determining means 10c includes a detection signal (clutch stroke signal) of the clutch stroke sensor 14, a clutch close request signal based on the SOC of the power storage device, a detection signal (gear position signal) of the shift position sensor, and a PS rotation sensor. When the vehicle is stopped when the clutch 3 is disconnected, the transmission 2 is neutral, and the engine 1 is in operation (idle control) from the detection signal (vehicle speed signal) of the engine and the detection signal (engine speed signal) of the engine rotation sensor When the close request signal is generated, it is determined whether the clutch connection condition is satisfied.
[0029]
The target motor calculation means 10d obtains the target rotation speed of the rotating electrical machine 4 from the engine rotation speed detection signal and the gear ratio of the gear box 5 when the clutch connection condition is satisfied, and the motor rotation control means 10a rotates to the target rotation speed. The rotational speed of the electric machine 4 is controlled.
[0030]
Based on the rotational speed (detection signal) of the engine 1 and the rotational speed (detection signal) of the rotating electrical machine 4, the rotational speed determination means 10 f, when these rotational differences converge within a predetermined range, (A control command for switching the rotation control of the rotating electrical machine 4 to normal torque control) is output.
[0031]
When receiving the clutch 3 connection command, the clutch connecting means 10b controls the electromagnetic valve 28 (or electromagnetic valve 29) so that the clutch 3 is connected with a predetermined stroke characteristic. When receiving the reset signal, the motor rotation control means 10a stops the rotation control of the rotating electrical machine 4.
[0032]
FIG. 4 is a flowchart for explaining the connection control of the clutch 3 when the engine 1 is stopped. In S1, the engine 1 is idled from the detection signal of the engine rotation sensor 16 and the detection signal of the PS rotation sensor 18. It is determined whether or not the control is stopped. In S2, it is determined whether it is a clutch close request (that is, power generation control of the rotating electrical machine 4 is required from the SOC of the power storage device). In S3, it is determined from the detection signal of the clutch stroke sensor 14 whether the clutch stroke is not less than the reference stroke value for clutch connection determination. In S4, it is determined from the detection signal of the shift position sensor whether the transmission 2 is neutral.
[0033]
If the determination of S1 is yes, the determination of S2 is yes, the determination of S3 is yes, and the determination of S4 is yes, the process proceeds to S5, while if at least one of the determinations of S1 to S4 is no, the process returns to RETURN Exit.
[0034]
In S5, the establishment of the clutch engagement condition based on automatic control is confirmed. In S6, the target rotational speed of the rotating electrical machine 4 (which corresponds to the engine idle rotation equivalent value) is obtained, and the rotation control of the rotating electrical machine 4 is started. In S7, it is determined whether or not the detected rotation of the rotating electrical machine 4 is equal to the target rotation speed (idle rotation equivalent value). When the determination of S7 is yes, the process proceeds to S8, and when the determination of S7 is no, the process returns to RETURN. In S8, the connection of the clutch 3 is controlled.
[0035]
As a result of such control, when the engine 1 is in idle control, the clutch 3 is disengaged, and the transmission is in a gear set (for example, third gear) as shown in FIG. Then, the transmission 2 is set to neutral (gear disengagement), and the rotational speed of the rotating electrical machine 4 is controlled to the rotational speed of the engine 1 at the target rotational speed from the completion thereof. When the rotational speed of the rotating electrical machine 4 rises to the target rotational speed and the rotational difference from the rotational speed of the engine 1 converges to a predetermined range (in FIG. 4, the rotational speed of the rotating electrical machine 4 = the value corresponding to the idle rotation of the engine 1) The clutch 3 is controlled to be connected.
[0036]
Since the clutch 3 is connected with almost no rotational difference between the front and rear, it is possible to prevent the occurrence of a shock accompanying the connection. In addition, the clutch 3 can be suddenly connected by the operation of the electromagnetic valve 28. After the clutch 3 is connected, the rotation control of the rotating electrical machine 4 is stopped, and the rotating electrical machine 4 is subjected to a power generation operation based on normal torque control.
[Brief description of the drawings]
FIG. 1 is a system outline diagram showing an embodiment of the present invention.
FIG. 2 is a characteristic diagram for explaining the control content.
FIG. 3 is a block diagram showing a part of the control system.
FIG. 4 is a flowchart for explaining the control contents of the hybrid ECU.
FIG. 5 is a timing chart for explaining the control contents of the hybrid ECU.
[Explanation of symbols]
1 Engine 2 Transmission 3 Clutch 4 Rotating electrical machine 5 Gear box 6 Transmission control unit 7 Change lever device 8 Clutch actuator 10 Hybrid ECU
10a Motor rotation control means 10b Clutch connection means 10c Clutch connection condition determination means 10d Target motor rotation calculation means 10f Rotational speed determination means 13 Accelerator opening sensor 14 Clutch stroke sensors 14a, 14b Pedal switch 16 Engine rotation sensor 18 PS rotation sensor (vehicle speed) Sensor)
19 CS rotation sensor

Claims (1)

Connected to the rotating electrical machine, a clutch that connects / disconnects the output shaft of the engine and the input shaft of the transmission, a rotating electrical machine that serves both as an electric motor and a generator, a power transmission mechanism that connects the input / output shaft of the rotating electrical machine and the input shaft of the transmission In a vehicle hybrid system comprising a power storage device , the power storage device needs to be charged, and when a clutch connection request is generated when the engine is stopped while the engine is in a running state, from the neutral set of the transmission until the clutch is connected between, and means for controlling the rotational speed of the rotary electric machine rotational speed of the engine to a target value, when the rotational difference between the rotational speed of the target value rotary electric machine converges to a predetermined range and means for controlling the connection of the clutch, the A hybrid system for a vehicle, comprising:

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