JP2013095165A - Method for detecting torque transmission characteristic in hybrid vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a relatively exact torque transmission characteristic without starting a vehicle and giving a damage to a clutch.SOLUTION: A method for detecting torque transmission characteristic is a method in a hybrid vehicle 10 in which a transmission 14 is connected to an internal combustion engine 11 via the clutch 12 and a motor generator 13 in the order. The torque transmission characteristic is obtained by sequentially repeating a synchronizing rotation process of connecting the clutch while getting the transmission to neutral, and of synchronizing and rotating the internal combustion engine and the motor generator, a predetermined torque generating process of generating a predetermined torque in the direction reverse to the rotation direction of the internal combustion engine by the motor generator and a stroke value detection process of moving the clutch in a declutching direction and of detecting a position clutch stroke in which a difference in rotation between the internal combustion engine and the motor generator is produced. It is preferable that the succeeding predetermined torque is made smaller than the preceding predetermined torque.

Description

  The present invention relates to a hybrid vehicle in which a transmission is connected to an internal combustion engine through a clutch and a motor generator in this order. More particularly, the present invention relates to a method for detecting torque transmission characteristics in a hybrid vehicle that detects torque transmission characteristics including the relationship between clutch transmission torque and clutch stroke in such a hybrid vehicle.

  Conventionally, a motor generator is coupled to the output shaft of the internal combustion engine via a clutch, and the rotational driving force of the motor generator is transmitted to the transmission as a drive output, and the drive output of the transmission is transferred from the differential gear to the drive axle. A hybrid vehicle having a transmission structure is known. Such a hybrid vehicle travels by the rotational driving force of one or both of the internal combustion engine and the motor generator, and at the time of deceleration, the motor generator acts as a generator that recovers the kinetic energy of the vehicle as electric energy. Therefore, such a hybrid vehicle can take a parallel traveling mode in which both the internal combustion engine and the motor generator drive the vehicle and a traveling charging mode in which the vehicle is traveling while charging the power storage means. By cutting, the kinetic energy at the time of deceleration does not rotate the internal combustion engine, so that all of the kinetic energy at the time of deceleration can be recovered as electric energy by the motor generator.

  On the other hand, for large vehicles such as trucks and buses, a mechanical automatic transmission is employed that can start and change gears mechanically with a shift unit (eg, motor type, hydraulic type, pneumatic type). Some vehicles adopt this type of mechanical automatic transmission, and a clutch connecting / disconnecting operation accompanying a starting operation or a shifting operation is automatically executed.

  That is, a large vehicle such as a truck or a bus has a clutch actuator controlled by an electric signal from an automatic clutch control device, and a clutch booster that swings a clutch lever by retracting a retracting shaft according to a hydraulic pressure controlled by the clutch actuator. Is provided. The automatic clutch control device that generates an electric signal to the clutch actuator is a device constituted by an electronic circuit and software installed therein, and calculates a target transmission torque from information on the accelerator opening that is input, and transmits this to the transmission torque. A target clutch stroke is obtained based on a torque transmission characteristic consisting of the relationship between the clutch stroke and the clutch actuator, and an electric signal for achieving the target clutch stroke is sent to the clutch actuator. For this reason, the torque transmission characteristic consisting of the relationship between the transmission torque and the clutch stroke is important data for automatically executing the clutch engagement / disengagement operation. Conventionally, this torque transmission characteristic is calculated by calculation. (For example, refer to Patent Document 1).

  That is, in the conventional torque transmission characteristic detection method, the vehicle is stopped by applying a parking brake or a foot brake, the clutch is disconnected in this state, the gear in the transmission is engaged while the internal combustion engine is rotating, and the clutch is gradually released. The torque generated by the internal combustion engine is transmitted to the clutch side by being connected. At this time, it calculates from the generated torque of the internal combustion engine, monitors the increase in the estimated clutch transmission torque, and calculates the clutch stroke at the estimated clutch transmission torque from the change in the rotational speed of the internal combustion engine when the torque reaches a certain specified torque. doing.

JP 2008-275036 A (paragraph number “0007”)

  However, in the conventional torque transmission characteristic detection method, since the vehicle is stopped with the parking brake or foot brake applied, if the parking brake or foot brake is forgotten, the clutch is gradually connected. The vehicle may start unexpectedly. Further, since the clutch is gradually connected from the state where the vehicle is stopped while the vehicle is stopped, thereby causing the clutch disk to slip, there is also a problem that the clutch disk is damaged. Further, since the transmission torque at a certain clutch stroke is calculated from the estimated value of the clutch transmission estimated torque calculated from the torque generated by the internal combustion engine, the characteristic itself includes an error and the accuracy cannot be improved yet. Issues to be addressed remained.

  An object of the present invention is to provide a method for detecting torque transmission characteristics in a hybrid vehicle that obtains a relatively accurate torque transmission characteristic without starting the vehicle and damaging the clutch.

  The present invention is a method for detecting a torque transmission characteristic comprising a relationship between a clutch transmission torque and a clutch stroke in a hybrid vehicle in which a transmission is connected to an internal combustion engine through a clutch and a motor generator in this order.

  Its characteristic features are a synchronous rotation process in which the clutch is connected with the transmission as neutral and the internal combustion engine and the motor generator are rotated synchronously, and the motor generator generates a predetermined torque in a direction opposite to the rotation direction of the internal combustion engine. And a stroke value detecting step of detecting a position where a difference in rotation between the internal combustion engine and the motor generator is detected as a clutch stroke capable of transmitting a predetermined torque by sequentially moving the clutch in the disconnecting direction. By the way.

  In this method of detecting torque transmission characteristics in a hybrid vehicle, the predetermined torque generated by the motor generator in the subsequent predetermined torque generation step is made smaller than the predetermined torque generated by the motor generator in the previous predetermined torque generation step. It is preferable.

  In the torque transmission characteristic detection method of the present invention, since the transmission is neutral in which power is not transmitted, the vehicle does not start unexpectedly. In addition, the clutch is moved from the connected state in the disconnection direction, and the position when the clutch slips and the difference between the rotation of the internal combustion engine and the motor generator is detected as the clutch stroke. short. For this reason, the damage given to the clutch can be remarkably reduced as compared with the conventional case in which the disconnected clutch is moved in the connecting direction to cause the clutch to slip for a relatively long time. Further, since the motor generator is controlled with high accuracy, the torque generated by the motor generator becomes a relatively accurate value. For this reason, if the predetermined torque generated by the motor generator is the transmission torque, the clutch stroke at the stage where the clutch slips and the difference in rotation between the internal combustion engine and the motor generator occurs is the clutch that generates the transmission torque. Match the stroke. For this reason, the torque transmission characteristic consisting of the relationship between the obtained transmission torque and the clutch stroke is made up of actually measured values, and in the present invention, an accurate torque transmission characteristic can be obtained as compared with the conventional method obtained by calculation.

1 is a block configuration diagram of a hybrid vehicle according to an embodiment of the present invention. It is the block diagram of the automatic clutch control device. It is a figure which shows the torque transmission characteristic used for the automatic clutch control apparatus. It is a figure which shows the flow which obtains the torque transmission characteristic in the vehicle.

  Next, the best mode for carrying out the present invention will be described with reference to the drawings.

  FIG. 1 shows a block diagram of a hybrid vehicle 10 to which the present invention is applied. In this hybrid vehicle 10, a transmission 14 is connected to an output shaft of the internal combustion engine 11 through a clutch 12 and a motor generator 13 in this order. The clutch 12 is mechanically controlled by the clutch booster 17 in accordance with the hydraulic pressure controlled by the clutch actuator 16. The clutch actuator 16 is controlled by an electric signal from the automatic clutch control device 18. The amount of operation of the accelerator pedal 19 operated by the driver is detected by the accelerator sensor 21 and taken into the engine control device 22. The motor generator 13 is connected to the control output of the generator control device 24. The generator control device 24, the engine control device 22, and the automatic clutch control device 18 together with other control devices not described in this specification are connected to the communication network 23. And the control output from the engine control device 22 is connected to the fuel injection device 11a in the internal combustion engine 11.

  The clutch 12 is coupled to the drive output shaft of the internal combustion engine 11 on the left side of the drawing, and rotates with the output shaft. The clutch 12 is disposed so as to face the flywheel 12a and is integrated with the rotation shaft of the motor generator 13. A clutch disk 12b that rotates in a rotating manner. The clutch 12 is configured to change the rotational transmission between the flywheel 12a and the clutch disk 12b by changing the pressure-bonding load of the clutch disk 12b to the flywheel 12a. The torque that can be transmitted between the clutch disks 12b is referred to as “transmission torque”.

  Further, the clutch 12 is provided with a clutch lever 12c for changing the pressure-bonding load of the clutch disk 12b to the flywheel 12a, and the clutch booster 17 can be tilted with respect to the clutch lever 12c. In other words, the clutch booster 17 is configured to move the clutch lever 12c by moving (retracting) the rod 17a forward or backward in response to a command from the clutch actuator 16. In the figure, when the rod 17a is moved (advanced) forward and the clutch lever 12c is pushed to the left in FIG. 1 by the rod 17a, the pressure load of the clutch disc 12b against the flywheel 12a is reduced. On the contrary, the case where the pressure load of the clutch disc 12b against the flywheel 12a is increased when the rod 17a is moved backward (retracted) and the clutch lever 12c is returned will be exemplified.

  Here, the relationship between the movement position of the rod 17a and the torque transmitted by the clutch 12 will be described. When the rod 17a is moved (advanced) forward, finally, there is almost no crimping load of the clutch disk 12b on the flywheel 12a. At this time, the flywheel 12a and the clutch disc 12b are disconnected, and the rotation transmission between the flywheel 12a and the clutch disc 12b is lost. The state where the rotation transmission is lost is referred to as a disconnected state of the clutch 12. The position of the rod 17a at this time is referred to as a standby position. The amount of movement of the rod 17a corresponding to the position of the rod 17a is the “clutch stroke” as the control amount.

  On the other hand, when the rod 17a is moved backward (retreated) from the standby position, the pressure-bonding load of the clutch disk 12b to the flywheel 12a increases in accordance with the amount of movement. At this time, rotation transmission between the flywheel 12a and the clutch disc 12b is performed with a difference in the number of rotations (slip amount) corresponding to the crimping load. In particular, the flywheel 12a and the clutch disk 12b rotate synchronously when the difference in rotational speed (slip amount) becomes substantially zero due to an increase in the pressure-bonding load due to the movement (retraction) of the rod 17a. This state of synchronous rotation is referred to as the clutch 12 connected state. And the position of the rod 17a at this time is called a connection position. Therefore, the slip amount between the flywheel 12a and the clutch disk 12b is controlled by controlling the movement amount (clutch stroke) of the rod 17a from the standby position to the connection position at the time of synchronization by the clutch actuator 16. .

  The movement amount (clutch stroke) of the rod 17a is in the range from the standby position to the connection position, and the state in which the flywheel 12a and the clutch disk 12b slip is set to the half-clutch state. The internal combustion engine 11 is provided with an internal combustion engine rotation sensor 26 that detects the rotational speed of the internal combustion engine 11, and the detection output of the internal combustion engine rotation sensor 26 is connected to the engine control device 22. Further, a clutch rotation sensor 27 for detecting the number of rotations of the clutch disk 12b necessary for executing the shift control is provided, and the detection output of the clutch rotation sensor 27 is connected to the generator control device 24. The clutch booster 17 is provided with a stroke sensor 28 that detects a clutch stroke, which is the moving position of the rod 17a. The detection output of the stroke sensor 28 is connected to the automatic clutch control device 18. The clutch stroke is used for determining the state of rotation transmission by the friction clutch 12.

  FIG. 2 shows a detailed configuration of the automatic clutch control device 18 that issues a control signal to the clutch actuator 16. The automatic clutch control device 18 is a device constituted by an electronic circuit and software installed therein, and the automatic clutch control device 18 transmits a target transmission from information on the accelerator opening input via the communication network 23. Torque is calculated and converted into a target clutch stoke using a torque transmission characteristic 29 comprising a relationship between transmission torque and clutch stroke. Then, a control signal is sent to the clutch actuator 16 to physically match the amount of movement of the rod 17a of the clutch booster 17 with the target clutch stroke.

  The torque transmission characteristic 29 comprising the relationship between the transmission torque and the clutch stroke indicates the transmission torque with respect to the clutch stroke, which is the amount of movement of the rod 17a, and is therefore important for automatically executing the connecting / disconnecting operation of the clutch 12. Data. The present invention is a method for obtaining the torque transmission characteristic 29 comprising the relationship between the transmission torque and the clutch stroke. The torque transmission characteristic 29 generally increases as the clutch stroke increases. Have a relationship that That is, as shown in FIG. 3, the transmission torque is zero at the stroke S0, and the internal combustion engine 11 continues to rotate even in the idle state. The torque t1 is transmitted through the clutch 12 at the stroke S1, the larger torque t2 is transmitted at the stroke S2, and the larger torque t3 is transmitted at the stroke S3.

  The method for detecting torque transmission characteristics in the present invention includes a synchronous rotation process in which the transmission 14 is neutral and the clutch 12 is connected to rotate the internal combustion engine 11 and the motor generator 13 synchronously, and the motor generator 13 A predetermined torque generating step for generating a predetermined torque in a direction opposite to the rotation direction, and a predetermined torque is transmitted to a position where a difference in rotation between the internal combustion engine 11 and the motor generator 13 is generated by moving the clutch 12 in the disconnection direction. A stroke value detecting step of detecting as a clutch stroke to be obtained is sequentially repeated. The flow for obtaining this torque transmission characteristic is shown in FIG. 4 and each step will be described in detail below.

  In the synchronous rotation process, the clutch 14 is connected with the transmission 14 as neutral, and the internal combustion engine 11 and the motor generator 13 are rotated in synchronization. The reason why the transmission 14 is neutral is that the transmission 14 in the neutral state is in a state where the power is not transmitted without meshing the gear, so that the power is transmitted and the vehicle starts unexpectedly. This is to avoid it. The clutch 12 is connected by the automatic clutch control device 18, and the automatic clutch control device 18 controls the clutch actuator 16 so that the rod 17a of the clutch booster 17 is moved backward (retracted) to reach the connection position. Is done. Then, the internal combustion engine 11 is driven, the drive output shaft in the internal combustion engine 11 is rotated, and the rotation shaft of the motor generator 13 connected to the drive output shaft via the clutch 12 is integrated with the drive output shaft. Rotate synchronously. At this time, the motor generator 13 does not generate torque from itself.

  In the next predetermined torque generating step, the motor generator 13 is controlled by the generator control device 24, and the motor generator 13 generates a predetermined torque in the direction opposite to the rotation direction of the internal combustion engine 11. That is, the generator control device 24 applies a load to the motor generator 13 to generate power, thereby generating a predetermined torque in the direction opposite to the rotation direction of the drive output shaft in the internal combustion engine 11 at the rotation shaft of the motor generator 13. .

  In the next stroke value detection step, a clutch that can transmit a predetermined torque generated by the motor generator 22 at a position where a difference in rotation between the internal combustion engine 11 and the motor generator 13 is caused by moving the clutch 12 in the cutting direction. Detect as a stroke. The clutch 12 is moved in the disengagement direction by the automatic clutch control device 18, and a control signal is transmitted to the clutch actuator 16 so as to move (advance) the rod 17a in the clutch booster 17 to the flywheel 12a. The pressure-bonding load of the clutch disk 12b is gradually reduced. Then, the flywheel 12a and the clutch disk 12b are gradually separated, and a slip occurs between the flywheel 12a and the clutch disk 12b in a certain amount of movement of the rod 17a, that is, a certain clutch stroke, and the drive output shaft of the internal combustion engine 11 There is a difference between the rotation and the rotation of the motor generator 13. The rotation in the internal combustion engine 11 is detected by the internal combustion engine rotation sensor 27, and the rotation speed of the clutch disk 12 b is detected by the clutch rotation sensor 27. The clutch stroke, which is the movement position of the rod 17a of the actuator 23, is detected by the stroke sensor 28, and the clutch stroke in which there is a difference in rotation between the internal combustion engine 11 and the motor generator 13 is automatically set as a clutch stroke for transmitting a predetermined torque. The clutch control device 18 stores it.

  In the present invention, the torque transmission characteristic 29 between the clutch stroke and the predetermined torque generated by the motor generator 13 is obtained by sequentially repeating the synchronous rotation step, the predetermined torque generation step, and the stroke value detection step. That is, after a clutch stroke for a certain predetermined torque is obtained, the process returns to the synchronous rotation process again, and the internal combustion engine 11 and the motor generator 13 are rotated again in synchronism with each other. A different predetermined torque is generated in the direction opposite to the rotation direction of the internal combustion engine 11. Then, the stroke in which the clutch 12 is moved again in the disengagement direction and the difference in rotation between the internal combustion engine 11 and the motor generator 13 is stored as a clutch stroke at a predetermined torque newly generated by the motor generator 13 this time. .

  Here, when each step is repeated, the predetermined torque generated by the motor generator 13 in the subsequent predetermined torque generation step is smaller than the predetermined torque generated by the motor generator 13 in the previous predetermined torque generation step. It is preferable to do. In this way, by reducing the predetermined torque generated by the motor generator 13 in the subsequent predetermined torque generation step, even the clutch stroke detected in the previous stroke value detection step is generated by the motor generator 13. The internal combustion engine 11 and the motor generator 13 rotate in synchronization again at the stage where the predetermined torque is reduced. For this reason, in the subsequent predetermined torque generating step, it is not necessary to move the clutch 12 in the connecting direction in order to rotate the internal combustion engine 11 and the motor generator 13 again in synchronism with each other. It is preferable. In this way, the clutch strokes for a plurality of predetermined torques are obtained, and the torque transmission characteristic 29 as shown in FIG. 3 consisting of these relations is stored in the memory, and this torque transmission characteristic 29 is stored in the automatic clutch control device 18. Used for control (FIG. 2).

  The motor generator 13 is controlled with high accuracy by the generator control device 24, and the torque generated by the motor generator 13 is a relatively accurate value. For this reason, if the torque generated by the motor generator 13 is the transmission torque, the clutch stroke at the stage where the clutch 12 slips and the difference between the rotations of the internal combustion engine 11 and the motor generator 13 causes the transmission torque. This is the same as the clutch stroke to be performed. For this reason, the torque transmission characteristic 29 consisting of the relationship between the obtained transmission torque and the clutch stroke is composed of measured values, and it is possible to obtain a significantly more accurate torque transmission characteristic 29 compared to the conventional one obtained by calculation. it can. Then, the clutch 12 is controlled by the clutch actuator 16 based on the torque transmission characteristic 29 based on such actual measurement values, so that more accurate, for example, smooth startability of the vehicle and accurate acceleration of the vehicle can be obtained. Can do.

  In the present invention, the clutch stroke is moved from the connected state to the disconnection direction, and the clutch stroke at the stage when the clutch 12 slips and the difference between the rotations of the internal combustion engine 11 and the motor generator 13 is detected. Therefore, the time that the clutch disk 12 slides in the clutch 12 is extremely short. For this reason, the damage given to the clutch 12 can be remarkably reduced as compared with the conventional case in which the disconnected clutch is moved in the connecting direction to cause the clutch to slip for a relatively long time.

  On the other hand, when the connection / disconnection of one clutch 12 is repeated, the clutch disk 12b is worn, whereby the clutch stroke changes little by little. That is, the characteristics at the time of shipment shown by the solid line in FIG. 3 gradually change as shown by the broken line due to the change of the years such as wear of the clutch disk 12b. Accordingly, the detection method of the present invention is performed every predetermined time, and the torque transmission characteristic 29 composed of the relationship between the transmission torque and the clutch stroke stored in the automatic clutch control device 18 is rewritten as needed so that accurate control is always achieved. Will be.

  In the above-described embodiment, the case where the clutch booster 17 is provided and the clutch 12 is controlled by hydraulic pressure has been described, but the connection / disconnection control of the clutch 12 is performed using air pressure or a motor without using the clutch booster 17. You may do it.

DESCRIPTION OF SYMBOLS 10 Hybrid vehicle 11 Internal combustion engine 12 Clutch 13 Motor generator 14 Transmission 29 Torque transmission characteristic

Claims (2)

The transmission torque and clutch stroke of the clutch (12) in the hybrid vehicle (10) in which the transmission (14) is connected to the internal combustion engine (11) through the clutch (12) and the motor generator (13) in this order. In a method for detecting a torque transmission characteristic comprising a relationship,
A synchronous rotation step of rotating the internal combustion engine (11) and the motor generator (13) synchronously by connecting the clutch (12) with the transmission (14) as neutral;
A predetermined torque generating step of generating a predetermined torque in a direction opposite to the rotational direction of the internal combustion engine (11) by the motor generator (13);
A stroke value for detecting a position where a difference in rotation between the internal combustion engine (11) and the motor generator (13) is caused by moving the clutch (12) in the disconnecting direction as a clutch stroke capable of transmitting the predetermined torque. A method for detecting torque transmission characteristics in a hybrid vehicle, characterized by sequentially repeating the detection step.   The predetermined torque generated by the motor generator (13) in the subsequent predetermined torque generation step is made smaller than the predetermined torque generated by the motor generator (13) in the previous predetermined torque generation step. A method for detecting torque transmission characteristics in a hybrid vehicle.

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