JP2000219063A - Hybrid type vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To dissolve abnormal change of a vehicle speed or acceleration efficiently and in good responsiveness by compensating output torque in the shift period of a frictional engagement element by output toque of a motor directly coupled with a transmission shaft. SOLUTION: This parallel type hybrid vehicle is loaded with an engine 1 and a motorgenerator 10 as driving power sources, the output shaft 2 of the engine 1 is connected to an output shift device 20 through a damper device 3 and a rotary shaft 12, the rotary shaft 13 of the motorgeneator 10 is outerly fitted to the rotary shaft 12 and also connected to the output shift device 20. Accordingly, output torque can be easily increased or decreased by motor output, and at the same time by controlling the motor torque, the output torque can be adjusted. When displacement is generated in the changeover timing, what is called an interlock phnomenon is generated to suddenly lower the output torque, and abnormal change of vehicle speed or acceleration is prevented from generating.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hybrid vehicle, and more particularly, to an output control technique at the time of forward / reverse switching and speed change of a parallel hybrid vehicle.

[0002]

[Related Background Art] In recent years, an internal combustion engine (engine) has been mounted together with an electric motor (motor) as a driving force source of a vehicle.
2. Description of the Related Art A parallel hybrid vehicle capable of traveling by combining the output of an electric motor and the output of an internal combustion engine has been developed and is known. In such a parallel hybrid vehicle,
It is general to reverse the rotation of the electric motor when moving backward. However, in consideration of the case where the storage capacity of the battery is small, a hybrid drive device capable of moving backward even with the output of the internal combustion engine is disclosed in Japanese Patent Application Laid-Open No. 9-233606.

[0003]

By the way, in the hybrid drive disclosed in the above publication, the rotation of the transmission shaft (output shaft) is reversed by grasping the hydraulic friction engagement element (hydraulic clutch, hydraulic brake). Therefore, for example, if the release of the hydraulic friction engagement element on the release side is poor and the release timing is late, the engagement of the hydraulic friction engagement element on the release side is substantially maintained in the engaged state. As in the case of A / T (automatic transmission), there is a problem that a so-called interlock phenomenon occurs to give a feeling of strangeness and deceleration shock to the occupant of the vehicle, as in the case of A / T (automatic transmission).

In such a case, in the case of A / T, the degree of engagement of the hydraulic friction engagement element on the engagement side, that is, the hydraulic pressure may be feedback-controlled while monitoring the rotation fluctuation of the output shaft, for example. In general, hydraulic pressure control has a large response delay, which makes it difficult to reduce discomfort and deceleration shock. SUMMARY OF THE INVENTION The present invention has been made to solve such a problem, and an object of the present invention is to make effective use of an electric motor when performing forward / reverse switching or gear shifting by gripping a friction engagement element. An object of the present invention is to provide a hybrid vehicle that can reduce the uncomfortable feeling and deceleration shock given to an occupant without complicating the control.

[0005]

In order to achieve the above object, according to the first aspect of the present invention, in a parallel hybrid vehicle, the rotation of an internal combustion engine is switched by switching a friction engagement element to be engaged and transmitted. While providing a rotation switching means capable of transmitting to the shaft between the internal combustion engine and the transmission shaft,
Vehicle state detecting means for detecting the speed or acceleration of the vehicle, and a target change pattern of the speed or acceleration of the vehicle during a period in which the friction engagement element is switched by the rotation switching means is changed by the change pattern setting means. If it is set in advance, the speed or acceleration of the vehicle detected by the vehicle state detection means changes along the target change pattern set by the change pattern setting means during the switching operation of the friction engagement element. The output of the motor is controlled by the control means.

Therefore, during the period in which the frictional engagement element is switched, the frictional engagement element is switched when the release-side frictional engagement element is released slowly or when the engagement-side frictional engagement element is engaged early, for example. When a shift occurs in the switching timing of the engagement element, usually, a so-called interlock phenomenon occurs, and the output torque suddenly decreases to cause an abnormal change in the vehicle speed or the acceleration. Depending on the output torque of
The output torque is compensated efficiently and responsively with a simple configuration by changing the vehicle speed and acceleration according to the target change pattern, so that abnormal changes in vehicle speed and acceleration are eliminated, and the occupant of the vehicle is eliminated. Is suitably prevented from feeling uncomfortable or decelerating shock.

[0007]

Embodiments of the present invention will be described below with reference to the accompanying drawings. Referring to FIG. 1, a schematic configuration diagram of a parallel hybrid vehicle is shown.
The configuration of the hybrid vehicle according to the present invention will be described with reference to FIG. As shown in the figure, a parallel hybrid vehicle is equipped with an engine (internal combustion engine) 1 and a motor generator (electric motor) 10 as a driving force source (power plant). In the parallel hybrid vehicle of the present invention, the output shaft 2 of the engine 1 is connected to an output switching device (rotation switching means) 20 via a damper device 3 and a rotating shaft 12, and the rotation of the motor generator 10 is controlled. The shaft (transmission shaft) 13 is fitted around the rotating shaft 12 and is also connected to the output switching device 20. Further, the output switching device 20
Is an output shaft (transmission shaft) 21, an automatic transmission (T / M) 30
Is connected to the drive shaft 32 through the
Is connected to an axle 36 via a differential gear 34. A pair of wheels 38, 38 are connected to both ends of the axle 36 as drive wheels.

The engine 1 is, for example, a water-cooled gasoline engine, and has a maximum output sufficient to drive the wheels 38 and 38 to run the vehicle. The motor generator 10 is an electric motor that functions as both a motor and a generator, that is, a generator.
A stator coil (excitation coil) 16 is configured to surround a rotor coil 14 integrated with the rotating shaft 12. In other words, the motor generator 10 functions as a motor that rotates the rotating shaft 13 by energizing the stator coil 16 to form a magnetic field and also energizing the rotor coil 14 to generate a magnetic field. The magnetic field is generated by rotating the rotor coil 14 integrated with the rotating shaft 13 by the external force from the wheels 38 and 38 transmitted through the output shaft 21 or the output of the engine 1 to generate the magnetic field. Coil 1
4 functions as a generator for generating a current.

Then, the motor generator 10
When functioning as a motor, the output torque can be changed by changing the amount of current supplied to the rotor coil 14, while
When functioning as a generator, the stator coil 16
It is possible to adjust the amount of power generation by changing the amount of electricity to the power supply. Motor generator 10 is not limited to the above-described type, but may be of any type as long as it can freely control the torque.
For example, a motor having no coil in the rotor may be used.

The automatic transmission (T / M) 30 includes a rotating shaft 12
The rotation speed of the motor generator 1
The output torque generated on the 0 side is changed so that the wheels 38, 38
Side, where, for example, a continuously variable automatic transmission is used. In addition, the continuously variable automatic transmission is known, and the description thereof is omitted here. The output switching device 20 is a device that switches between the output of the motor generator 10 and the output of the engine 1 by connecting and disconnecting the clutch, and also switches between forward and reverse of the vehicle. As shown in a schematic configuration diagram in FIG. The switching device 20 mainly includes a hydraulic clutch (friction engagement element) 22, a planetary gear 24 of a double planet gear type, and a hydraulic brake (friction engagement element) 28.
It is composed of

More specifically, the structures of the hydraulic clutch 22 and the hydraulic brake 28 are the same, and when a hydraulic pressure is supplied from a hydraulic pressure supply unit (not shown), a friction engagement plate (clutch plate) is engaged. This is a generally well-known configuration in which the connection is made, and when the pressure is released, the friction engagement plate is released, that is, cut. The planetary gear 24 includes a first planet gear 26 a and a second planet gear 26 b (dual planet gears) rotatably fixed to a carrier 26 around a sun gear 25.
And a planetary gear device configured to revolve along a ring gear 27, wherein a first planet gear 26 a meshes with a sun gear 25 and a second planet gear 26
b, the second planet gear 26b meshes with the first planet gear 26a and the ring gear 27
Is engaged.

In other words, when the carrier 26 is fixed and the sun gear 25 is rotated, the ring gear 27 is connected to the sun gear 25 at a predetermined gear ratio via the first planet gear 26a and the second planet gear 26b.
It is configured to rotate in the same direction as. And
In the hybrid vehicle, the rotating shaft 12 is connected to the output shaft 21 via the hydraulic clutch 22, and the sun gear 25 is connected to the rotating shaft 12.
Is directly connected to the output shaft 21 and the rotating shaft 13
Is connected to the carrier 26. In addition, ring gear 2
7 is connected to a housing 29 via a hydraulic brake 28.

That is, according to the hybrid vehicle,
In a state in which both the hydraulic clutch 22 and the hydraulic brake 28 are released, the vehicle can travel forward and backward by the motor output from the motor generator 10, and in a state in which the hydraulic clutch 22 is engaged and the hydraulic brake 28 is released,
The vehicle can travel forward with the engine output from the engine 1 or the output obtained by adding the engine output to the motor output,
Further, the hydraulic clutch 22 is released and the hydraulic brake 28
When the vehicle is engaged, the vehicle can travel backward by using the engine output or the output obtained by adding the engine output to the motor output.

Electronic control unit (ECU) 50
Is a main control device which is composed of a central processing unit (CPU) and controls various operations of the hybrid vehicle. An input side of the main control device is connected to an accelerator pedal 52, and the operation amount of the accelerator pedal 52, Accelerator position sensor (APS) 54 for detecting accelerator opening degree θacc, which is an output required by the user, vehicle speed sensor (vehicle state detecting means) 60 for detecting vehicle speed V, longitudinal G sensor (vehicle) for detecting longitudinal acceleration G of the vehicle (State detecting means) 62 and a forward / reverse switch 64 for inputting a command for switching between forward and backward travel of the vehicle. The detection of the longitudinal acceleration G is based on the longitudinal G
Instead of using the sensor 62, for example, a method of calculating the amount of change per unit time of the vehicle speed sensor 60 may be used.

Further, the ECU 50 includes
A battery (secondary battery) 70 for operating various drive units is connected. The battery 70 is connected so that when the motor generator 10 functions as a generator, the generated power according to the amount of electricity supplied to the stator coil 16 is charged and stored. On the other hand, the output side of the ECU 50 is connected to the above-described rotor coil 14 and the stator coil 16 of the motor generator 10, the electromagnetic switching valve of the hydraulic supply unit provided in the output switching device 20, and the like.

Therefore, in the hybrid vehicle configured as described above, when the accelerator opening information θacc, that is, the required output amount, is input from the APS 54 to the ECU 50, the motor generator 10 and the engine 1
, That is, acceleration / deceleration control of the vehicle. In addition, engagement control and release control of the hydraulic clutch 22 and the hydraulic brake 28 are performed in response to a command from the forward / reverse switch 64, whereby reverse traveling by engine output can be realized.

However, when the vehicle is switched from forward running to reverse running or from reverse running to forward running, that is, when the hydraulic clutch 22 and the hydraulic brake 28 are gripped, the hydraulic clutch 2 is used as described above.
If the hydraulic release of the frictional engagement element on either release side of the hydraulic brake 2 or the hydraulic brake 28 is slow, or if the engagement of the frictional engagement element on either engagement side is early, a so-called interlock phenomenon may occur. For this reason, in the hybrid vehicle of the present invention, the problem caused by the interlock phenomenon is eliminated by operating the motor generator 10 to generate the motor torque at the time of the grip change.

Hereinafter, the motor torque control according to the present invention of the motor generator 10 when the hydraulic clutch 22 and the hydraulic brake 28 are re-engaged in order to switch the vehicle forward or backward, that is, the operation of the hybrid vehicle of the present invention. explain. Here, when the driver of the vehicle stops the operation of the accelerator pedal 52 and then switches the forward / reverse switch 64 from the forward side to the reverse side, that is, the hydraulic clutch 22
Is released and the hydraulic brake 28 is engaged.

Referring to FIG. 3, the forward / reverse selector switch 6
Output torque T when the hydraulic clutch 22 and the hydraulic brake 28 are gripped based on a command from
(A), a time chart showing the time change of the longitudinal acceleration information G (b) of the vehicle from the longitudinal G sensor 62, and the vehicle speed information V (c) from the vehicle speed sensor 60 is shown. Hereinafter, the control content of the motor torque control according to the present invention will be described.

In order to prevent the interlock phenomenon when the hydraulic clutch 22 and the hydraulic brake 28 are re-engaged, it is necessary to completely release the hydraulic pressure from the hydraulic clutch 22 before starting the engagement of the hydraulic brake 28. is there. However, in general, even when the hydraulic pressure is released from the hydraulic clutch 22, the hydraulic pressure does not come off immediately, and the transmission torque, that is, the torque T1 in FIG. 2, does not suddenly become zero but gradually decreases.
Further, even if the hydraulic pressure is supplied to the hydraulic brake 28, the hydraulic pressure does not rise immediately, and the torque T2 in FIG. 2 also gradually increases.

That is, referring to FIG. 4, when the hydraulic clutch 22 is disengaged and the hydraulic brake 28 is engaged, the respective torque amounts in the sun gear 25 (S) and the ring gear 27 (R), and the torque in the carrier 26 (C). The amount, that is, the output torque T is equal to the sun gear 25 (S) and the carrier 26 (C).
The gear ratio between the hydraulic clutches 22 is schematically shown as ρ, the state before the switching in which the hydraulic clutch 22 is engaged and the hydraulic brake 28 is released is indicated by a broken line, and the hydraulic clutch 22 is completely released and the hydraulic brake 28 is completely , The state in which the output shaft 21 is rotated around the ring gear 27 (R) in the reverse direction is indicated by a dashed line, and the state in which the hydraulic clutch 22 is released and the hydraulic brake 28 is engaged is indicated by a solid line. However, in this way, before switching, it is equal to the engine torque Te (T =
T1 = Te) The output torque T in the state (shown by a broken line)
Is the torque T1 that decreases when the hydraulic clutch 22 is released.
And then gradually decreases (T = T1), and then further decreases gradually with the torque T2 (negative sign) that increases due to the engagement of the hydraulic brake 28 (from the balance of torque, T
= T2 ・ (ρ-1) / ρ) (both are indicated by solid lines), and finally the hydraulic clutch 22 is completely released and the hydraulic brake 2
8 is completely engaged, the value obtained by multiplying the engine torque Te by a predetermined gear ratio (negative sign) (from the balance of the torque,
T = (ρ−1) · Te).

Therefore, here, first, the speed at which the hydraulic pressure is released from the hydraulic clutch 22 at normal temperature and the hydraulic brake 2
8 is measured in advance, and the standard change patterns of the torque T1 and the torque T2 are shown in FIG.
(A) Determined as indicated by the middle broken line. That is, a standard change pattern of the output torque T is determined as shown by a two-dot chain line in FIG. That is, based on the change pattern, when the torque T1 decreases to the value 0 and the output torque T reaches the value 0, the supply of the hydraulic pressure to the hydraulic brake 28 is started to supply the torque in the reverse direction to the output shaft 21. To

Actually, however, the speed at which the hydraulic pressure is released and the speed at which the hydraulic pressure rises change due to a change in viscosity due to the oil temperature. For example, when the viscosity increases, the hydraulic clutch 2
2, the speed of oil pressure drop is reduced, and as shown by the solid line in FIG. 3 (a), the torque T 1, ie, the output torque T, increases from the above-mentioned change pattern (two-dot chain line) to the larger side. It will decrease with a delay. And as it is,
As shown in FIG. 5, when the supply of the hydraulic pressure to the hydraulic brake 28 is started and the torque T2 starts to increase, the torque T1 still remains, so that a so-called interlock phenomenon occurs, and the output Torque T is torque T2
As the vehicle occupant experiences an uncomfortable feeling and a deceleration shock as described above.

In order to eliminate such inconvenience,
In the hybrid vehicle according to the present invention, when output torque T deviates from a preset change pattern, motor generator 10 is operated to correct output torque T such that output torque T follows the change pattern. Like that. That is, in the case of the hybrid vehicle, as shown in FIG. 2, the rotating shaft 13 of the motor generator 10 is directly connected to the output shaft 21, and the output torque T can be easily increased or decreased by the motor output. Therefore, the output torque T is adjusted by performing the motor torque control at the same time.

Although it is not easy to actually detect the output torque T, the output torque T has a correlation with the longitudinal acceleration G and the vehicle speed V of the vehicle. Accordingly, here, as shown by the two-dot chain line in FIG. 3B or 3C, the standard change pattern of the longitudinal acceleration G corresponding to the standard change pattern of the output torque T, A standard change pattern of the vehicle speed V is set in advance (change pattern setting means), and the longitudinal acceleration G detected by the longitudinal G sensor 62 or the vehicle speed V detected by the vehicle speed sensor 60 corresponds to the change pattern (two points). The motor generator 10 is operated such that the longitudinal acceleration G and the vehicle speed V follow the change pattern in the case where the vehicle generator 10 deviates from the dashed line) (control means).

More specifically, when it is determined that the longitudinal acceleration G and the vehicle speed V deviate from the change pattern, the motor generator 10 is operated (in this case, in the reverse direction), and as shown by a white arrow in FIG. The output torque T is corrected by the motor torque Tm by a torque corresponding to the deviation amount. In other words, the torque T for the change pattern
The motor torque control is performed in the reverse rotation direction so as to cancel the torque corresponding to the deviation amount of 1. At this time, the longitudinal acceleration G and the vehicle speed V are actually detected by the longitudinal G sensor 62 and the vehicle speed sensor 60.
While performing the feedback control, feedback control is performed toward a change pattern (two-dot chain line).

Thus, when the hydraulic clutch 22 and the hydraulic brake 28 are gripped, the output torque can be reduced even if the release of the oil from the release-side hydraulic clutch 22 is poor and the release speed of the hydraulic pressure is low. T changes satisfactorily according to a predetermined standard change pattern, and when the engagement of the hydraulic brake 28 on the engagement side is started, the torque T1 still remains but the value 0 is surely maintained.
Thus, the occurrence of discomfort or deceleration shock due to the so-called interlock phenomenon is prevented.

That is, as described above, the output torque T does not suddenly decrease as the torque T2 increases, and the longitudinal acceleration G and the vehicle speed V suddenly decrease as shown by solid lines in FIGS. 3 (b) and 3 (c). Will not change,
Therefore, the occupant of the vehicle is preferably prevented from feeling uncomfortable or decelerating shock. In the above embodiment, the case where the hydraulic clutch 22 is released and the hydraulic brake 28 is engaged has been described as an example. However, the reverse case, that is, the case where the hydraulic brake 28 is released and the hydraulic clutch 22 is engaged, is used. The present invention is similarly applicable to the present invention.

In the above embodiment, the case where the interlock phenomenon occurs due to the slow release of the hydraulic pressure from the release hydraulic clutch 22 has been described. However, the present invention is not limited to this. The present invention can be suitably applied even when the interlock phenomenon occurs due to the start of supply of the hydraulic pressure to the oil pressure 28 being too early. In this case, although not shown, since the output torque T changes earlier than the preset change pattern, the output torque T is corrected so as to cancel the torque corresponding to the deviation amount of the torque T2 from the change pattern. Motor torque control is performed in the direction of rotation.

Further, in the above-described embodiment, the case where the forward / reverse switching is performed has been described. However, the present invention can be applied to the speed change in the same direction as long as the switching of the hydraulic clutch or the hydraulic brake is performed. Is also possible. In the above embodiment, the vehicle speed sensor 60 is used as the vehicle state detecting means.
Although the vehicle speed V and the longitudinal acceleration G are directly obtained as the vehicle state by using the vehicle speed V and the longitudinal G sensor 62, the vehicle state detecting unit detects the vehicle speed V and the longitudinal acceleration G such as the output shaft rotation speed of the rotation switching unit. It is also possible to obtain a correlated state quantity.

[0031]

As described above in detail, according to the hybrid vehicle of the first aspect of the present invention, the vehicle speed and the acceleration change along the target change pattern during the switching operation of the friction engagement element. The output torque is compensated by the output torque of the electric motor directly connected to the transmission shaft so that abnormal changes in vehicle speed and acceleration can be eliminated efficiently and responsively with a simple configuration, and the occupants of the vehicle feel uncomfortable and decelerate. It is possible to preferably prevent a shock from being felt.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a hybrid vehicle according to the present invention.

FIG. 2 is a detailed view showing an output switching device in FIG.

FIG. 3 shows output torque T (a) when the hydraulic clutch is released and the hydraulic brake is engaged, longitudinal acceleration G (b) of the vehicle,
FIG. 4 is a time chart showing a time change of a vehicle speed V (c), and is a diagram illustrating motor torque control according to the present invention.

FIG. 4 shows the amount of torque in the sun gear (S) and the ring gear (R) and the output torque T in the carrier (C) when the hydraulic clutch is released and the hydraulic brake is engaged, and the engagement state of the hydraulic clutch and the hydraulic brake. It is the schematic diagram shown for every.

FIG. 5 is a schematic diagram showing torque amounts in a sun gear (S) and a ring gear (R), an output torque T in a carrier (C), and a motor torque Tm when the release of the hydraulic pressure of a hydraulic clutch is slow.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Engine (internal combustion engine) 10 Motor generator (electric motor) 12 Rotary shaft 13 Rotary shaft (transmission shaft) 20 Output switching device (rotation switching means) 22 Hydraulic clutch (friction engagement element) 24 Planetary gear 28 Hydraulic brake (friction engagement element) 50) Electronic control unit (ECU) 60 Vehicle speed sensor (vehicle state detecting means) 62 Front / rear G sensor (vehicle state detecting means) 64 Forward / backward changeover switch

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (Reference) F02D 29/00 B60K 9/00 Z F16H 61/04 (72) Inventor Yuichi Gota 33-3-8 Shiba 5-chome, Minato-ku, Tokyo No. Mitsubishi Motors Corporation F-term (reference) 3D041 AA33 AA53 AA68 AB01 AC11 AC15 AC19 AC30 AD10 AD33 AD36 AD51 AE02 AE16 AF09 3G093 AA06 AA16 BA03 BA15 CB07 CB08 DA06 DB05 DB11 EB08 EC01 FA07 FB01 A05A03A03A03A FB33 GC13 GC23 GC46 GC51 GC72 HA02 KA01 LA20 5H115 PA01 PG04 PI16 PU01 PU22 PU23 PU25 QI07 QN02 QN06 RB08 RE03 SE04 SE05 SE08 SJ12 TB01 TO02 TO21

Claims (1)

[Claims] 1. An internal combustion engine and an electric motor provided for driving a vehicle, a transmission shaft for transmitting an output of the electric motor to a driving wheel side, and provided and engaged between the internal combustion engine and the transmission shaft. Rotation switching means capable of switching the rotation of the internal combustion engine to transmit to the transmission shaft by switching the friction engagement element, vehicle state detection means for detecting the speed or acceleration of the vehicle, and the friction engagement by the rotation switching means Change pattern setting means for setting a target change pattern of the speed or acceleration of the vehicle during a period in which the element is operated to be switched; and a change state detecting means which is detected by the vehicle state detecting means during a period in which the friction engagement element is operated to be switched. Control means for controlling the output of the motor so that the speed or acceleration of the vehicle changes along the target change pattern set by the change pattern setting means. A hybrid vehicle.