JP2000225871A - Hybrid vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent damage of a clutch means and instability of a traveling state when the clutch means is connected, in a parallel type hybrid vehicle with the clutch means interposed between an engine and a drive wheel. SOLUTION: A motor for traveling 2 and an output shaft 12 are directly connected with drive wheels 9, 10. An engine 1 is connected with an output shaft 12 via a torque converter 5 and an automatic transmission 7. A multiple disc clutch of the automatic transmission 7 is used as also a clutch means, is switched to an N range and a gear shift range and intermits driving force of the engine. When a switching from the N range to the gear shift range is performed during traveling in the motor for traveling 2, the switching is performed after an input side engine speed and an output side engine speed of the automatic transmission 7 are preliminarily made to coincide each other. At the time, load is applied to the engine 1 by a generator motor 4, engine speed is controlled by an adjustment of this load, and the input side and output side engine speed of the automatic transmission 7 are made to coincide each other.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hybrid vehicle that runs using both an engine and a motor.

[0002]

2. Description of the Related Art Hitherto, a so-called series system has been known as a hybrid vehicle (see, for example, JP-A-6-165309). In this device, a generator is driven by an engine to generate electric power, and the electric power is stored in a battery. Then, electric power is supplied from a battery to the motor, and a driving force for traveling is obtained by the motor.

[0003] On the other hand, what is called a parallel system is known as a hybrid vehicle. In this case, the vehicle is configured to run using both an electric motor and an engine. In other words, the point that the battery is charged by driving the generator by the engine is the same as the above-mentioned series system, but different from the series system, not only the traveling by the motor driven by the electric power of the battery but also the traveling by the engine alone or the engine. It is configured to be able to run by both the motor and the motor. When the vehicle is started, the vehicle is driven by a motor. When the vehicle speed increases and the engine can be driven with efficient rotation, the driving source is switched from the motor to the engine and the vehicle is driven. When a large driving force is required such as sudden start or sudden acceleration, the vehicle is driven by both the motor and the engine.

[0004] In the above-mentioned parallel type hybrid vehicle, there has been proposed a hybrid vehicle in which a motor is directly connected to driving wheels, while an engine is connected to the driving wheels via a clutch. In this type of hybrid vehicle, the clutch is disengaged when the vehicle runs only by the motor, and the clutch is engaged when the vehicle runs only on the engine or both the engine and the motor.

[0005]

As described above, in the hybrid vehicle of the parallel system, the torque of the engine is transmitted to the driving wheels from the middle while the motor is running. That is, the clutch is engaged during traveling. Therefore,
If the clutch is engaged in a state where the rotation difference between the drive wheel side and the engine side of the clutch is large, there is a problem that the clutch is damaged. Even if the clutch is not damaged, for example, if the clutch is engaged while the engine speed is low, a shock will be generated due to deceleration of the vehicle body, the running state will be unstable, and the driver will feel uncomfortable. There was a problem that would give.

[0006] On the other hand, it is conceivable that the rotational speed of the engine is adjusted by controlling the throttle when the clutch is engaged to reduce the rotational speed difference between the drive wheel side and the engine side in the clutch. However, since the responsiveness of the engine speed to the change in the throttle opening is low, the speeds on both sides of the clutch cannot be matched well, and the above-mentioned problem cannot be solved.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a parallel type hybrid vehicle having a clutch means for connecting and disconnecting between an engine and a drive wheel. An object of the present invention is to improve the reliability and the running performance by preventing damage to the clutch means and instability of the running state during the operation.

[0008]

According to the present invention, an engine speed is controlled by a generator motor.

More specifically, a first solution of the present invention is to provide an engine, an output shaft connected to the engine via clutch means, a generator motor connected to the engine, The present invention is directed to a hybrid vehicle including a power storage unit for storing electric power generated by an electric motor, a traveling motor driven by the electric power of the power storage unit, and driving wheels connected to the traveling motor and an output shaft. Then, the detection means for detecting the input-side rotation speed on the engine side and the output-side rotation speed on the output shaft side of the clutch means, and the input-side rotation number and the output-side rotation number of the clutch means detected by the detection means match. And a control means for engaging the clutch means after performing a rotation synchronous operation for adjusting the number of revolutions of the engine by the generator motor.

[0010] The second solution taken by the present invention is:
In the first solution, there is provided an automatic transmission which is interposed between an engine and an output shaft and switches between a neutral state in which an input side and an output side are disconnected and a shift state in which an input side and an output side are connected. The clutch means is an automatic transmission clutch means for switching the automatic transmission between a neutral state and a shift state.

Further, a third solution taken by the present invention is:
In the first or second solution, the control means is configured to perform the rotation synchronous operation by adjusting the control amount of the generator motor while maintaining the output of the engine constant during the rotation synchronous operation. It is.

A fourth solution taken by the present invention is:
In the third solution, the control means is configured to control the input side rotation speed of the clutch means by applying a load to the output of the engine by the generator motor.

Further, a fifth solution taken by the present invention is:
In the third solution, the control means is configured to control the input-side rotation speed of the clutch means by applying power to the output of the engine by the generator motor.

[0014] A sixth solution taken by the present invention is:
In the third solution, the control means applies power to the output of the engine by the generator motor during the acceleration running, and applies a load to the output of the engine by the generator motor during the steady running, thereby enabling the clutch means to operate. It is configured to control the input-side rotational speed.

Further, a seventh solution taken by the present invention is:
In any one of the fourth to sixth solving means, the control means is configured to keep the control state of the traveling motor constant during the rotation synchronization operation.

An eighth solution taken by the present invention is:
In the fourth solving means, the control means calculates a target torque of the engine during engine running corresponding to the rotation speed of the output shaft, and the engine generates an output torque obtained by adding a predetermined additional torque to the target torque. Thus, while maintaining the control state of the engine, the magnitude of the added torque is changed according to the rate of change of the rotation speed of the output shaft.

A ninth solution means adopted by the present invention is:
In the fourth solving means, the control means calculates a target torque of the engine during engine running corresponding to the rotation speed of the output shaft, and the engine generates an output torque obtained by adding a predetermined additional torque to the target torque. Thus, while maintaining the control state of the engine, the magnitude of the added torque is changed according to the operation amount of the accelerator or the rate of change of the operation amount.

According to a tenth aspect of the present invention, in the first or the second aspect, the control means determines that a difference between an input rotation speed and an output rotation speed of the clutch means is a predetermined value. When the rotation speed falls within the allowable rotation range, the clutch means is engaged as a match between the two rotation speeds, and the rotation allowable range is changed according to the running state of the vehicle.

According to an eleventh aspect of the present invention, in the tenth aspect, a torque converter is provided between the engine and the clutch means, and the control means controls the torque converter to lock up. In the state, the rotation allowable range is narrowed.

According to a twelfth aspect of the present invention, in the fourth aspect, the control means controls the output of the engine by the generator motor for a predetermined time continuously after the engagement of the clutch means. It is configured to apply a load.

According to a thirteenth aspect of the present invention, in the sixth aspect, the control means operates the generator motor continuously for a predetermined time even after the clutch means is engaged during acceleration running. Add power to the engine output,
During steady running, the generator motor continuously applies a load to the output of the engine for a predetermined time even after the clutch means is engaged.

According to a fourteenth aspect of the present invention, in the first or the second aspect, the control means is arranged such that the control means comprises a transmission gear ratio of an automatic transmission interposed between the engine and the output shaft. Is selected in accordance with the traveling state, and at least until the clutch means is started until the clutch means is completed, the change of the selected gear ratio is prohibited.

According to a fifteenth aspect of the present invention, in the first aspect, an automatic transmission is interposed between the engine and the output shaft, and the control means controls the output side of the clutch means. The speed ratio of the automatic transmission in which the engine is in the most efficient operating state is selected based on the speed, and the input side speed of the clutch means is adjusted to the speed corresponding to the speed ratio to perform the rotation synchronization operation. It is configured as follows.

According to a sixteenth aspect of the present invention, in the third aspect, after the control means completes the engagement of the clutch means, the control state of the engine corresponds to the operation amount of the accelerator. It is configured to be in a control state.

-Operation- In the first solving means, the output of the traveling motor is transmitted to the driving wheels, while the output of the engine is also transmitted to the driving wheels when the clutch means is engaged. Then, the vehicle travels by transmitting one or both outputs of the traveling motor and the engine to the drive wheels. The generator motor is driven by the engine to generate electric power, and the generated electric power is stored in a power storage unit and used for driving a traveling motor or the like.

In the case of a hybrid vehicle, an on-off operation of the clutch means is performed while the vehicle is running in order to switch the drive source. In particular, when engaging the clutch means, the control means performs the rotation synchronization operation and then engages the clutch means.
That is, the control means controls the rotation speed of the engine by the generator motor, and engages the clutch means after matching the input rotation speed and the output rotation speed of the clutch means.
During the rotation synchronizing operation, the engine may be started and rotated by itself, or may be rotated only by the output of the generator motor before starting.

In the second solution, the clutch for the automatic transmission constituting the automatic transmission also functions as a clutch for intermittently connecting the engine and the output shaft.

In the third solution, the engine is maintained so that its output is constant. For example, the throttle opening and the like are kept constant so as to exhibit a predetermined output. On the other hand, the control amount given to the engine by the generator motor is adjusted to control the rotation speed of the engine, so that the input rotation speed and the output rotation speed of the clutch means are matched.

In the fourth solution, a load is applied to the output of the engine by the generator motor. That is, the generator motor is driven by the output of the engine. Then, the number of revolutions of the engine is suppressed by the generator motor, thereby performing the rotation synchronization operation. Therefore, the generator motor operates as a generator during the rotation synchronous operation.

Further, in the fifth solution, the output of the engine is powered by the generator motor. That is, the generator motor receives power from the power storage means to generate power,
This power drives the engine to rotate. The engine is not only rotated by itself but also driven by a generator motor, thereby performing a rotation synchronous operation. Therefore, the generator motor operates as a motor during the rotation synchronous operation.

Further, in the sixth solution, during acceleration running, power is applied to the output of the engine by the generator motor, and the engine is rotated by the power of the generator motor to perform rotation synchronous operation. On the other hand, during steady running, a load is applied to the output of the engine by the generator motor, and the rotation of the engine is suppressed by the load of the generator motor to perform the rotation synchronous operation.

In the seventh solution, the control state of the traveling motor, for example, the generated torque and the like is kept constant, and the output rotation speed of the clutch means or the rate of change of the rotation speed is kept constant. . Then, the output-side rotation speed and the input-side rotation speed of the clutch unit are matched with each other, and the clutch unit is engaged.

In the eighth or ninth solution means,
It is adjusted to a control state in which the engine generates an output torque, for example, a predetermined throttle opening. That is, the engine is controlled so as not to generate the target torque which is the minimum required for running only by the engine, but to generate an output torque larger by the added torque than the target torque. And the eighth
In the means for solving the problem, the added torque is changed depending on the rate of change of the rotation speed of the output shaft, that is, whether or not the vehicle is accelerating.
On the other hand, in the ninth solving means, the added torque is changed according to the operation amount of the accelerator or the rate of change of the operation amount, that is, whether or not the driver requests acceleration.

In the tenth solution, the clutch is engaged when the difference between the input-side rotation speed and the output-side rotation speed of the clutch is within the rotation allowable range. At this time, the rotation allowable range is changed according to the running state of the vehicle. For example, depending on the traveling state, there are a state in which the clutch means can be engaged while the difference between the input-side rotational speed and the output-side rotational speed remains to some extent, and a state in which the clutch means cannot be engaged unless the two rotational speeds substantially match. The rotation allowable range is changed according to such a difference in the running state.

In the eleventh solution, the allowable rotation range is changed depending on whether the torque converter is in a lockup state or a lockup release state. That is, in the lock-up state, the permissible rotation range is narrowed, and the clutch means is engaged after sufficiently matching the input-side rotation speed and the output-side rotation speed of the clutch means.

In the twelfth solving means, the generator motor is driven by the engine for a predetermined time to generate electric power even after the clutch means is engaged.

Further, in the thirteenth solution means, during acceleration running, that is, when performing rotation synchronous operation by applying power to the engine by the generator motor, the generator motor is driven even after the clutch means is engaged. To rotate the engine. On the other hand, during steady running, that is, when performing a rotation synchronous operation by applying a load to the engine with the generator motor, the generator motor is driven by the engine to generate power even after the clutch means is engaged.

In the fourteenth solving means, a predetermined gear ratio is usually selected by the control means, and the automatic transmission is shifted to the selected gear ratio. On the other hand, in the predetermined period, even if the traveling state changes and the corresponding gear ratio changes, the change of the gear ratio once selected is prohibited. Here, when the speed ratio of the automatic transmission changes, the engine speed changes in a state where the input side speed and the output side speed of the clutch means coincide with each other. Therefore, for example, even if the engine speed is adjusted to the speed ratio corresponding to the first speed in order to match the two speeds of the clutch means, when the clutch means is engaged, the selected speed ratio is changed to the second speed. If the ratio is changed, the clutch means will be engaged in a state where both rotational speeds of the clutch means are greatly different. Therefore, in order to avoid such a situation, the change of the selected gear ratio is prohibited until the engagement of the clutch means is completed.

In the fifteenth solving means, the speed ratio of the automatic transmission is selected so that the engine is in a high efficiency state. As a specific example, the engine is 2000 to 30
When the engine is operated most efficiently at 00 rpm, the engine speed is 2,000 to 300 at the vehicle speed at that time.
The gear ratio is selected so as to be 0 rpm. Then, the rotation speed of the engine is adjusted to a rotation speed corresponding to the selected gear ratio, so that the input-side rotation speed and the output-side rotation speed of the clutch unit are matched.

In the sixteenth aspect, after the clutch means is engaged, the control state of the engine, for example, the throttle opening and the like is set to a state corresponding to the operation amount of the accelerator.

[0041]

According to each of the above means, since the engine speed is controlled using the generator motor having excellent controllability and responsiveness, the engine speed can be quickly controlled. . Further, the use of the generator motor facilitates the detection of the engine speed. Therefore, as compared with the case where the engine itself is controlled by adjusting the throttle opening or the like, the input-side rotational speed of the clutch means can be controlled more reliably and quickly by using the generator motor. For this reason, the input-side rotational speed and the output-side rotational speed of the clutch device are reliably matched, and damage to the clutch device when the clutch device is engaged can be prevented, and the running state of the vehicle at that time can be stabilized. Can be maintained. As a result,
It is possible to improve the reliability and the traveling performance.

In particular, in the second solution, the clutch for the automatic transmission constituting the automatic transmission also serves as the clutch for intermittently connecting the engine and the output shaft. Here, the clutch means for the automatic transmission has a lower clutch capacity than a dedicated clutch for intermittently transmitting and receiving large power. Therefore, switching from the neutral state to the shift state in a state where the rotational speed difference between the input side and the output side is large is not assumed, and if the switching is performed in such a state, it is easily damaged. On the other hand, in this solution,
Since the control means performs the rotation synchronization operation, even if the automatic transmission clutch means of the automatic transmission also functions as the clutch means, it is possible to reliably prevent the automatic transmission from being damaged. it can. When an automatic transmission is provided between the engine and the output shaft, it is not necessary to provide an independent clutch between the engine and the output shaft, and the configuration can be simplified.

According to the third solution, after the engine is started, the engine speed is adjusted by both the control of the engine and the control of the generator motor, whereby the input side speed of the clutch means is reduced. The output side rotational speed can be matched. Further, since the output of the engine is kept constant, fluctuations in the input-side rotational speed can be suppressed. For this reason, it is possible to surely and quickly match the two rotational speeds of the clutch means. As a result, while protecting the clutch means, the clutch means can be quickly engaged, and the output of the engine can be transmitted to the drive wheels to improve the running performance.

Further, according to the fourth solution, since the engine speed is suppressed by the load of the generator motor, the input speed of the clutch means is stabilized, and the rotation synchronizing operation is facilitated. .

In the fifth solution, the engine speed is increased to match the input speed and the output speed of the clutch means. The engine is driven to rotate by the power of the generator motor together with the generated power, and the engine rotation increases. Therefore, the input-side rotational speed and the output-side rotational speed of the clutch means are matched in a shorter time than when the generator motor absorbs the engine output after waiting for the engine to generate a certain amount of output. be able to.

Further, according to the sixth solution, the rotation synchronous operation by the power of the generator motor and the rotation synchronous operation by the load can be properly used according to the running state. That is, during acceleration traveling, the rotation synchronous operation is performed by the power of the generator motor, whereby the fastening operation can be transmitted to the drive wheels as quickly as possible. On the other hand, during steady running, the rotation synchronous operation is performed with the load of the generator motor, and the accuracy of matching between the input side rotation speed and the output side rotation speed of the clutch means can be increased to stably maintain the running state.

According to the seventh aspect of the present invention, the output-side rotational speed of the clutch means or the rate of change of the rotational speed can be kept constant to suppress the fluctuation of the output-side rotational speed.
As a result, it is possible to more reliably and easily match the input-side rotational speed with the output-side rotational speed.

In the eighth or ninth means,
After the engine generates an output torque that is greater than the required minimum target torque by the added torque, the engine torque is absorbed by the generator motor to perform rotation synchronous operation. For this reason, the fluctuation of the input-side rotational speed can be suppressed, and the clutch means can be stably engaged. In addition, by making the value of the added torque according to the traveling state of the vehicle or the driver's request, the conflicting request between the fastening time and the shock accompanying the engagement can be matched with the traveling state or the driver's request. Can be. That is, for example, when acceleration is required, some shocks are allowed, the clutch means is quickly engaged to transmit the output of the engine to the drive wheels, while the clutch means is gradually engaged during steady running, and Shock can be minimized.

Further, according to the tenth solution means, it is possible to perform the rotation synchronization operation according to the running state. For example, when accelerating, it is desirable to transmit the output of the engine to the drive wheels as quickly as possible. In such a case, the clutch should be fastened while allowing some shock by widening the allowable rotation range. Can be. During steady running, it is desirable to suppress the shock at the time of engagement as much as possible to maintain the running state stably. In such a case, by narrowing the allowable range of rotation, the input side rotation speed and output side rotation of the clutch means are reduced. It is possible to prevent the occurrence of a shock at the time of fastening by increasing the accuracy of matching with the number.

Further, in the eleventh solution means, when the torque converter is in the lock-up state, the allowable rotation range is narrowed. In the lock-up state of the torque converter, the engine and the clutch means are directly connected. If the difference between the input-side rotation speed and the output-side rotation speed of the clutch means is large, a shock occurs at the time of engagement and damages the clutch means. There is a risk. On the other hand, in the present solution, since the allowable rotation range is narrowed, shock can be prevented even in the lock-up state, the running state can be stably maintained, and damage to the clutch means can be prevented.

Further, according to the twelfth solution means, the load by the generator motor is continuously applied before and after the engagement of the clutch means, so that the running state can be stably maintained. In other words, a slight change in the vehicle speed during steady-state running gives the driver an uncomfortable feeling. However, according to the present solution, the change in the vehicle speed can be prevented and the running state can be stably maintained. In addition, since the power of the power storage means is consumed by traveling by the traveling motor or the like, power generation by the generator motor can be performed as long as possible to recover the charge amount of the power storage means.

Further, according to the thirteenth solution means, since the state is maintained before and after the engagement of the clutch means, it is possible to stably maintain the running state as in the case of the twelfth solution means. Can be. Further, during acceleration traveling requiring a larger driving force, the output of the generator motor can be transmitted to the driving wheels, and an Uno harbor shape having an accelerating property can be achieved. On the other hand, at the time of steady running, power generation can be continued and the charge amount of the power storage means can be secured, as in the case of the twelfth solution means.

According to the fourteenth aspect, the control target of the input-side rotational speed can be prevented from being changed during the rotation synchronizing operation by prohibiting the change of the gear ratio. Can be shortened. In addition, the input rotation speed and the output rotation speed of the clutch device can be reliably matched, and the reliability and running performance can be improved by reliably protecting the clutch device and stabilizing the running. it can.

Further, according to the fifteenth solution, the engine can be operated with the highest fuel efficiency after the clutch means is engaged, and the fuel efficiency can be improved.

Further, according to the sixteenth solution, the control of the engine can be performed accurately and the control of the vehicle can be performed reliably.

[0056]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a block diagram showing the mechanical configuration of the hybrid vehicle according to the present embodiment.

As shown in FIG. 1, the hybrid vehicle according to the present embodiment includes, as a power unit for generating a driving force, a traveling motor 2 driven by electric power supplied from a battery 3 serving as power storage means, a gasoline or the like. Travels using the engine 1 driven by the explosive force of the liquid fuel of the vehicle, and travels only by the travel motor 2, travels only by the engine 1, or travels with the travel motor 2 according to the travel state of the vehicle described later Running by both of the engines 1 is realized.

The engine 1 is connected to driving wheels 9 and 10 via a torque converter 5 and an automatic transmission 7.
The driving force of the engine 1 is transmitted from the output shaft 12 directly connected to the output side of the automatic transmission 7 to the driving wheels 9 and 10 via the gear train 11 and the differential mechanism 8. Further, the engine 1 has a generator motor 4 for charging the battery 3.
Drive.

Although not shown, the torque converter 5 has a lock-up clutch which is a lock-up mechanism, and is configured so that when the lock-up clutch is engaged, the lock-up is performed, and when the lock-up clutch is disengaged, the lock-up is released. ing.

Although not shown, the automatic transmission 7 is a four-speed transmission composed of components such as a planetary gear mechanism, a multi-plate clutch, a brake, and a one-way clutch. The automatic transmission 7 is provided with a neutral range (hereinafter, referred to as a “neutral range”) in which the input side and the output side are disconnected due to intermittent operation of a multi-plate clutch.
N range) and 1 where the input side and the output side are connected.
It is configured to switch to each speed range from the first speed to the fourth speed. The automatic transmission 7 functions as a transmission, and switches between the N range and the shift range to perform intermittent connection between the engine 1 and the drive wheels 9 and 10. An automatic transmission clutch means such as a multi-plate clutch for switching the automatic transmission 7 between the N range and the shift range constitutes a clutch means for intermittently connecting the engine 1 and the output shaft 12.

The traveling motor 2 is driven by electric power supplied from the battery 3, and transmits a driving force to driving wheels 9, 10 via a gear train 11. The traveling motor 2 is driven by the driving wheels 9 and 10 when the vehicle decelerates, and converts the kinetic energy of the vehicle into electric power and supplies it to the battery 3.

The generator motor 4 is driven by the engine 1 to generate electric power, and supplies electric power to the battery 3. The generator motor 4 receives electric power from the battery 3 when the engine 1 starts, and causes the engine 1 to crank.

The engine 1 is mounted, for example, of a type that delays the closing timing of a fuel-efficient valve. The traveling motor 2 is, for example, an IPM synchronous motor having a maximum output of 20 kW, and the generator motor 4 is, for example. Maximum output 1
A battery of 0 KW is used, and a nickel hydrogen battery having a maximum output of 30 KW is mounted as the battery 3, for example.

The overall control ECU 100 includes a CPU, an RO,
M, RAM, an interface circuit, an inverter circuit, etc., control the ignition timing and fuel injection amount of the engine 1, etc., control the output and rotation speed of the traveling motor 2 and the generator motor 4, and lock the torque converter 5. The control unit controls the up control, the control of the automatic transmission 7, the charging and discharging of the battery 3, and the like.

The general control ECU 100 receives the number of revolutions of the crankshaft of the engine 1 and the number of revolutions of the traveling motor 2. Then, the overall control ECU 100 determines the input-side and output-side shaft rotation speeds of the automatic transmission 7 based on the input both rotation speeds, taking into account the speed ratio of the automatic transmission 7 and the gear ratio of the gear train 11. It is configured to calculate. That is, the overall control ECU 100
The detection means for detecting the input-side rotation speed and the output-side rotation speed of the automatic transmission 7 is configured.

Further, the overall control ECU 100 is configured to shift the speed of the automatic transmission 7 according to a shift schedule as shown in FIG. This shift schedule is represented by the relationship between the vehicle speed and the accelerator pedal depression amount, and three shift lines are defined corresponding to the 4-speed automatic transmission 7. Then, when the vehicle crosses the speed change line, the speed of the automatic transmission 7 is changed. This shift schedule
The rotation speed of the engine 1 is determined so as to be in the range of the rotation speed with the highest efficiency of the engine 1 in relation to the vehicle speed.

As shown by hatching in FIG. 2, a predetermined lock-up region is defined, and the torque converter 5 is locked up in this lock-up region. That is, while the lock-up region is limited to a region where no shift is performed in a vehicle with only the engine 1, the lock-up region is expanded to a region where a shift is performed in the present hybrid vehicle. This is because, in the present hybrid vehicle, the change in the driving force of the engine 1 due to the shift can be absorbed by the driving force of the traveling motor 2, and the shift can be performed without causing the shift shock even in the locked-up state of the torque converter 5. It is.

-Driving Operation-Next, referring to Table 1 below, the engine 1, the generator motor 4, the traveling motor 2, and the battery 3 under the main conditions will be described.
Will be described. In Table 1, "power running" means a state in which a driving torque is being output.

[0070]

[Table 1]

[Stopping] As shown in Table 1, when the vehicle is stopped, the engine 1, the generator motor 4 and the traveling motor 2 are stopped. However, the engine 1 is operated when the engine is cold and when the charged amount of the battery is low, and the generator motor 4 is driven to generate power during the operation of the engine and charges the battery 3.

[Slow Start] As shown in Table 1, during slow start, the engine 1 and the generator motor 4 are stopped, and the traveling motor 2 outputs a driving torque.

[Emergency Start] As shown in Table 1, at the time of sudden start, the traveling motor 2 outputs driving torque, and the engine 1 is operated at a high output after starting. The battery 3 discharges to the traveling motor 2. Although the generator motor 4 is stopped after the engine 1 is started here, the generator motor 4 may continuously output the driving torque.

[At the time of engine start] As shown in Table 1, at the time of engine start, the generator motor 4 outputs driving torque to crank the engine 1 and the engine 1 is started. Battery 3 discharges to generator motor 4.

[During steady low-load running] As shown in Table 1,
During steady low-load traveling, the engine 1 and the generator motor 4 are stopped, and the traveling motor 2 outputs driving torque. The battery 3 discharges to the traveling motor 2. However, the engine 1 is operated when the engine is cold and when the charged amount of the battery is low, and the generator motor 4 is driven to generate power during the operation of the engine and charges the battery 3. In the present embodiment, the state of steady low-load running is limited to the case where the vehicle speed is 20 km / h or less. Therefore, when the vehicle speed exceeds 20 km / h during steady running, the operation shifts from low load operation to medium load operation.

[During Steady Medium Load Running] As shown in Table 1,
During normal medium-load running, the traveling motor 2 is set to no output, the engine 1 is operated in a high-efficiency region, the battery 3 does not discharge to the traveling motor 2, and the generator motor 4 charges the battery 3. .

[During Steady High Load Running] As shown in Table 1,
At the time of steady high load running, the engine 1 is operated at high output,
The generator motor 4 and the traveling motor 2 output driving torque. The battery 3 discharges to the generator motor 4 and the traveling motor 2. However, the generator motor 4 charges the battery 3 when the battery charge is low.

[During Rapid Acceleration] As shown in Table 1, during rapid acceleration, the engine 1 is operated at high output, and the generator motor 4 and the traveling motor 2 output driving torque for traveling.
The battery 3 discharges to the generator motor 4 and the traveling motor 2.

At the time of deceleration (at the time of regenerative braking), as shown in Table 1, at the time of deceleration, the engine 1 and the generator motor 4 are stopped, and the traveling motor 2 regenerates electric power as a generator to discharge the battery 3. Charge.

-Operation when Engine is Connected- In the hybrid vehicle of this embodiment, the traveling motor 2
In some cases, the torque of the engine 1 may be transmitted to the driving wheels 9 and 10 from the middle while the vehicle is running only with the driving torque of. Specifically, this corresponds to the above-described sudden start or a transition from steady low-load running to steady medium-load running, steady high-load running, or sudden acceleration. In this case, the general control ECU 1
00 performs predetermined engine engagement control. In addition, as part of the engine engagement control, the overall control ECU 100 controls the generator motor 4 of the engine 1 so that the input-side rotation speed on the engine side and the output-side rotation speed on the output shaft side of the automatic transmission 7 match. A rotation synchronization operation for adjusting the rotation speed is performed.

First, the outline of the engine engagement control will be described with reference to the time chart of FIG. FIG. 3 shows a state in which the vehicle starts from the stop state, accelerates slowly, and shifts from steady low load running to steady medium load running. At time t1, the vehicle starts slowly and enters the steady low-load running state described above. Then, only the traveling motor 2 generates a driving force, and the vehicle speed gradually increases.

Thereafter, at time t2, the vehicle speed becomes 20
When the engine speed exceeds km, the engine 1 is driven by the generator motor 4 in order to shift from steady low load running to steady medium load running.
To crank. When the engine 1 starts, at time t3
, The feedback control for the generator motor 4 is started. Thereafter, until the time t4, the throttle opening is maintained at the predetermined opening to generate a predetermined torque in the engine 1, while the generator motor 4 acts as a generator to apply a load to the engine 1 and control this load. To control the engine speed.

When the engine speed matches the target engine speed at time t4, the automatic transmission 7 is switched from the N range to the first speed range. In this state, the engine 1
Is transmitted to the drive wheels 9 and 10. For this reason, at time t4, the automatic transmission 7 is switched and the driving force of the traveling motor 2 is reduced, so that the driving force transmitted to the driving wheels 9 and 10 is kept constant. After that, the traveling is continued only by the driving force of the engine 1.

Next, details of the engine engagement control will be described with reference to the flowcharts of FIGS.

At step ST1, the vehicle speed, the accelerator depression amount, the rotation speed of the traveling motor 2 and the rotation speed of the engine 1 are read. Then, the rotation speed of the output shaft 12 is calculated by multiplying the rotation speed of the traveling motor 2 by the gear ratio of the gear train 11, and the process proceeds to step ST2.

In step ST2, it is determined whether or not the engine 1 needs to be started based on the vehicle speed, the accelerator depression amount, and the rate of change of the accelerator depression amount. That is, if the vehicle speed is 2
When the vehicle shifts to the above-mentioned steady medium load running after exceeding 0 km, or when the accelerator is suddenly depressed and sudden acceleration or sudden start is required, it is determined that the engine 1 needs to be started, and step ST3 is performed. Move on to On the other hand, if the start of the engine 1 is unnecessary, the control returns to the normal control.

In step ST3, the speed range of the automatic transmission 7 is selected based on the shift schedule, and the target engine speed is calculated by multiplying the output shaft speed by the speed ratio of the speed range. When the rotation speed of the engine 1 reaches the target engine rotation speed, the input rotation speed and the output rotation speed of the automatic transmission 7 match. This step ST3
Thereafter, the change of the once-selected shift range is prohibited until the shift of the automatic transmission 7 is completed.

In the following step ST4, it is determined whether or not there is a request for sudden start. That is, when the accelerator is suddenly depressed while the vehicle is stopped, it is determined that sudden start is required, and the process proceeds to step ST15. On the other hand, when it is determined that the sudden start is not requested, the process proceeds to step ST5. The presence or absence of a request for sudden start may be determined based on the rate of change in the output shaft speed. That is, if the rate of increase in the output shaft rotation speed is large, it may be determined that there is a request for sudden start, and if the rate of increase in harm is small, it may be determined that there is no request for sudden start.

When a sudden start is requested, first, at step ST
At 15, control for releasing the lockup of the torque converter 5 is performed. The reason for releasing the lock-up is to transmit a larger driving force to the driving wheels 9 and 10 by utilizing the torque amplifying action of the torque converter 5.

In the following step ST16, the generator motor 4
Power is supplied from the battery 3 to the engine 1 and the engine 1 is cranked by the generator motor 4 to start the engine 1. When the engine speed reaches 1000 rpm, the process proceeds to step ST17.

In step ST17, fuel injection and ignition are performed on the engine 1 to try to start the engine 1. Then, it is confirmed whether or not the engine 1 has been started, and if it has been started, the process proceeds to step ST18. On the other hand, if the engine 1 has not been started, the process proceeds to engine start control and the engine 1
Try to start more. This engine start control will be described later. Note that whether or not the engine 1 has started is determined based on the current supplied to the generator motor 4. That is, if the current to the generator motor 4 has decreased, it is determined that the engine 1 has started, and if not, it is determined that the engine 1 has not started.

In step ST18, the throttle is fully opened in order to maximize the torque of the engine 1, and the rotation synchronous operation is performed with the torque generated by the generator motor 4 being maximized. That is, in the sudden start state, the torque of the traveling motor 2 is maximized and the vehicle has already started to move,
Even if the throttle is opened, the engine speed does not rise immediately. Therefore, the engine 1 is driven with the torque of the generator motor 4 being maximized, and the input and output speeds of the automatic transmission 7 are matched.

Here, if only a short time has passed since the driver issued a request for a sudden start, the vehicle speed has not yet increased so much.
And if the generator motor 4 is set to the maximum output, the automatic transmission 7
It can be considered that there is almost no difference in the number of rotations between the input side and the output side. Further, a slight difference in the number of rotations can be absorbed by the torque converter 5. Therefore, in step ST18, after the throttle is fully opened and the torque of the generator motor 4 is maximized, the automatic transmission 7 is quickly shifted from the N range to the first speed range without leaving time. After the shift is completed, the engine 1
And the driving wheels 9 and 10 are driven by the traveling motor 2,
The generator motor 4 is stopped. It should be noted that the torque of the generator motor 4 is also applied to the drive wheels 9 and 10 without stopping the generator motor 4.
, And in this case, a larger driving force can be transmitted to the driving wheels 9 and 10.

If there is no request for sudden start in step ST4, it is determined in step ST5 whether there is a request for sudden acceleration. That is, when the accelerator is suddenly depressed while the vehicle is running, it is determined that rapid acceleration is required, and the process proceeds to step ST6. On the other hand, if it is determined that rapid acceleration has not been requested, the process proceeds to step ST20. The presence or absence of a request for rapid acceleration may be determined based on the rate of change in the output shaft speed. That is, if the rate of increase in the output shaft rotation speed is large, it may be determined that there is a request for rapid acceleration, and if the rate of increase is small, it may be determined that there is no request for rapid acceleration.

When there is a request for rapid acceleration, first, in step ST
At 6, control for releasing the lockup of the torque converter 5 is performed. The lock-up is released in order to obtain the torque amplifying action of the torque converter 5 as in the case of step ST15.

In the following step ST7, the above-mentioned step ST1 is executed.
The engine 1 is cranked by the generator motor 4 corresponding to step 6, and when the engine speed reaches 1000 rpm, the process proceeds to step ST8.

In step ST8, an operation of starting the engine 1 is performed in response to step ST17. If the engine has been started, the process proceeds to step ST9. If not, the process proceeds to engine start control.

In step ST9, the output torque is calculated by adding the additional torque α2 to the target torque. This target torque is a torque that must be generated by the engine 1 in order to run only on the engine 1 at the vehicle speed read in step ST1 and the gear ratio of the shift range of the automatic transmission 7 selected in step ST3. On the other hand, the additional torque α2
Is set in advance according to the running state. Then, control is performed to generate an output torque for the engine 1. Specifically, the throttle is set to a predetermined opening, and the throttle opening is kept constant.

In the following step ST10, the traveling motor 2
Is controlled to keep the generated torque constant, and this state is maintained until the shift of the automatic transmission 7 is completed. In other words, until the shift is completed, the accelerator pedal depression amount,
That is, the torque of the traveling motor 2 is kept constant irrespective of the driver's intention. The reason for this is to keep the output shaft rotation speed or the rate of change of the rotation speed constant, and to surely adjust the engine rotation speed corresponding to the output shaft rotation speed.

In the following step ST11, a rotation synchronization operation is performed. Specifically, the generator motor 4 operates as a generator to apply a load to the engine 1, and the amount of the load is set to the engine speed such that the engine speed reaches the target engine speed calculated in step ST <b> 3. Feedback control is performed. This control is performed for a predetermined time, and step ST1
Move to 2.

In step ST12, the operation of switching the automatic transmission 7 from the N range to the shift range is started. At this time, if the rotation synchronization operation is performed for a certain period of time, the rotation speed difference between the actual engine rotation speed and the target engine rotation speed is sufficiently small, and the lock-up of the torque converter 5 is released in step ST6. As a result, even if there is a certain difference in the number of revolutions, the torque converter 5 can absorb the difference, so that the automatic transmission 7 performs the shifting operation.

In the following step ST13, it is confirmed that the shift to the shift range has been completed, and then the process proceeds to step ST14. Therefore, at the time of moving to step ST14, the driving force of the engine 1 has been transmitted to the driving wheels 9, 10.

In step ST14, the load applied to the engine 1 by the generator motor 4 is set to zero, and the throttle opening of the engine 1 is controlled in accordance with the amount of depression of the accelerator. Then, the engine 1 and the traveling motor 2
Is transmitted to the driving wheels 9 and 10 to perform rapid acceleration.

If there is no request for rapid acceleration in step ST5, the process proceeds to step ST20 shown in FIG. This step ST
At 20, the engine 1 is cranked by the generator motor 4 corresponding to the step ST16, and the engine speed becomes 1
When it reaches 000 rpm, the process moves to step ST21.

At step ST21, at step ST17
An operation for starting the engine 1 is performed in response to (1). If the engine has been started, the process proceeds to step ST22, and if not, the process proceeds to engine start control.

In step ST22, it is determined whether or not the charged amount of the battery 3 is small.
The process moves to ST23, and if less than the predetermined value, moves to step ST24.

In step ST23, the output torque is calculated by adding the additional torque α to the target torque corresponding to step ST9. This additional torque α is set to a value smaller than the additional torque α2 in step ST9. Then, the predetermined throttle opening is maintained so that the engine 1 generates the calculated output torque, and the process proceeds to step ST25.

On the other hand, in step ST24,
The output torque is calculated by adding the added torque α1 to the target torque corresponding to ST9. This additional torque α1 is calculated in steps
It is smaller than the added torque α2 of ST9, and step ST2
3 is larger than the added torque α. And
The predetermined throttle opening is maintained so that the engine 1 generates the calculated output torque, and the process proceeds to step ST25.

That is, while the addition torque α and the addition torque α1 are selectively used depending on the amount of charge of the battery 3 (see steps ST23 and ST24), the addition torque α2 and the addition torque α, α1 are selectively used depending on whether or not a rapid acceleration is requested. (See steps ST9, ST23, ST24).

At step ST25, torque converter 5
Is in a lockup state. If the lock-up state has been reached, the process proceeds to step ST26, while if the lock-up has been released, the process proceeds to step ST29.

If the torque converter 5 is in the lock-up state, in steps ST26 to ST28, the engine 1
The rotation synchronizing operation is performed until it can be considered that the actual engine speed and the target engine speed calculated in step ST3 almost completely match. This is because the engine 1 and the input side of the automatic transmission 7 are directly connected in the lock-up state of the torque converter 5, and unless the actual engine speed of the engine 1 substantially matches the target engine speed, the automatic Transmission 7
This is because there is a risk that a shock will be generated when the range is changed from the N range to the shift range, and that the automatic transmission 7 will be damaged.

In step ST26, the generator motor 4 operates as a generator to apply a load to the engine 1, and the amount of the load is adjusted so that the rotation speed of the engine 1 becomes the target engine rotation speed calculated in step ST3. Feedback control is performed on the rotation speed. On the other hand, in step ST27, the driving force of the traveling motor 2 is controlled so that the acceleration of the vehicle body becomes constant. Specifically, control is performed so that the rate of change of the output shaft speed is constant. And step ST2
In step ST2, until it can be considered that the actual rotation speed of the engine 1 substantially matches the target engine rotation speed, the process proceeds to step ST2.
6, the state of ST27 is held, and if it is considered that both rotation speeds match, the process proceeds to step ST30.

If the torque converter 5 is not in the lock-up state, the process proceeds to step ST29 where the above-mentioned step ST11 is performed.
Perform the rotation synchronization operation corresponding to. Specifically, the amount of load applied to the engine 1 by the generator motor 4 is feedback-controlled so that the number of revolutions of the engine 1 becomes the target number of engine revolutions in step ST3.

That is, in steps ST25 to ST29, whether or not the torque converter 5 is in the lock-up state is determined.
The degree to which the actual engine speed of the engine 1 matches the target engine speed is changed.

In step ST30, corresponding to step ST12, a shift operation for switching the automatic transmission 7 from the N range to the shift range selected in step ST3 is started.
Then, when it is confirmed in the subsequent step ST31 that the switching to the shift range has been completed, the process proceeds to step ST32. In addition, during the above-described shifting operation, the driving force transmitted from the engine 1 to the driving wheels 9 and 10 increases. However, the driving force of the traveling motor 2 is reduced accordingly, and the driving wheels 9 and 10 are driven. The driving force to 10 is kept constant.

In step ST32, the load applied to the engine 1 by the generator motor 4 and the driving force of the traveling motor 2 are set to zero, and the throttle opening of the engine 1 is controlled in accordance with the amount of depression of the accelerator. Do. Note that the load on the engine 1 by the generator motor 4 may not be set to zero, and the output of the engine 1 may be controlled to be relatively large to continue the power generation by the generator motor 4.

-Operation for Starting Engine- At the time of the above-described engine engagement control, the above-mentioned steps ST8 and ST1
7. If the engine 1 could not be started in ST21,
The engine start control shown in the flowchart of FIG. 6 is performed.

In step ST40, the power supplied from the battery 3 to the generator motor 4 is increased to increase the engine speed. And the engine speed is 1500 rpm
Is reached, the process moves to step ST41.

In step ST41, fuel injection and ignition are performed on the engine 1 to try to start the engine 1. Then, it is confirmed whether or not the engine 1 has been started. If the engine has been started, the process proceeds to step ST47, and returns to the original control flow, and proceeds to the next step from steps ST8, ST17, and ST21. On the other hand, if the engine 1 has not been started, the process proceeds to step ST42.

In step ST42, the current supplied from the battery 3 to the traveling motor 2 is reduced. This is because the current that can be discharged from the battery 3 has an upper limit, so that the current to the traction motor 2 is reduced and the current to the generator motor 4 that cranks the engine 1 is secured.

At the following step ST43, at step ST41
Attempt to start the engine 1 in the same manner as described above. Then, if the engine 1 is started, the process proceeds to step ST47 and returns to the original control flow, while if the engine 1 is not started, the process proceeds to step ST44.

In step ST44, the rotational speed of the engine 1 is matched with the target engine rotational speed in step ST3 only by the driving force of the generator motor 4, and then the automatic transmission 7 is shifted from the N range to the second speed range. And switch. Then, the engine 1 is rotated not only by the driving force of the generator motor 4 but also by the driving force of the traveling motor 2 and the inertial force of the vehicle body,
At the next step ST45, an attempt is made to start the engine 1. That is, in steps ST44 and ST45, a so-called “push-off” is attempted.

At that time, the driving force of the traveling motor 2 is increased with the switching of the automatic transmission 7 from the N range to the second speed range, and control is performed to keep the traveling state constant.
Here, if the driving force of the traveling motor 2 remains constant, the vehicle will decelerate if the engine 1 is directly connected to the driving wheels 9 and 10. On the other hand, the state of the vehicle is kept constant by increasing the driving force of the traveling motor 2 so that the driver does not feel uncomfortable.

In step ST45, if the engine 1 is started, the process proceeds to step ST47 and returns to the original control flow, while if the engine 1 is not started, the process proceeds to step ST47.
Move to 46.

In step ST46, the driver is informed of the fact that the engine 1 could not be started by a warning lamp or the like, and control is performed to emphasize the regeneration by the traveling motor 2 in order to secure the charge amount of the battery 3.

-Effects of Embodiment- In this embodiment, since the rotation speed of the engine 1 is controlled using the generator motor 4 having excellent controllability and responsiveness, it is possible to control the engine rotation speed quickly. Becomes Further, the use of the generator motor 4 facilitates detection of the engine speed. Therefore, the rotation speed of the engine 1 can be more reliably controlled by the generator motor 4 as compared with the case where the engine 1 itself is controlled by adjusting the throttle opening and the like. For this reason, the input-side rotation speed and the output-side rotation speed of the automatic transmission 7 are reliably matched. Thus, it is possible to reliably prevent the automatic transmission 7 from being damaged due to a difference in the number of revolutions between the input side and the output side. Also, preventing the vehicle from being decelerated due to the difference in rotation speed,
The running state can be stably maintained even when the range is switched. As a result, reliability and traveling performance can be improved.

In this embodiment, the multi-plate clutch or the like constituting the automatic transmission 7 also serves as a clutch means for intermittently connecting the engine 1 and the output shaft 12. Here, the above-mentioned multi-plate clutch or the like has a lower clutch capacity than a dedicated clutch for the purpose of intermittent transmission of large power. Therefore, if the range is changed from the N range to the shift range in a state where the rotational speed difference between the input side and the output side is large, it is easily damaged. On the other hand, according to the present embodiment, it is possible to reliably match the input-side rotational speed and the output-side rotational speed of the automatic transmission 7.
For this reason, even if the multi-plate clutch or the like of the automatic transmission 7 also functions as the clutch means, damage to the automatic transmission 7 can be avoided, and the configuration can be simplified while maintaining reliability.

After the engine 1 is started, the engine speed is adjusted by both the control of the engine 1 and the control of the generator motor 4. Further, since the output torque of the engine 1 is kept constant, fluctuations in the input-side rotation speed of the automatic transmission 7 can be suppressed. Therefore, it is possible to surely and quickly match the rotational speeds on both sides of the automatic transmission 7. As a result, while protecting the automatic transmission 7,
The automatic transmission 7 can be quickly switched from the N range to the shift range, and the output of the engine 1 can be transmitted to the drive wheels 9 and 10 to improve running performance.

Whether the rotation synchronous operation is performed by the load of the generator motor 4 or by the driving force is selectively used depending on whether or not the vehicle is accelerating (see steps ST18, ST26 and ST29).
Specifically, in the case of sudden start, the engine 1 is also rotated by the driving force of the generator motor 4. Therefore, the shift of the automatic transmission 7 can be completed within a shorter time, and the driving force of the engine 1 can be transmitted to the driving wheels 9 and 10. On the other hand, when neither sudden start nor rapid acceleration is performed, a load is applied to the engine 1 by the generator motor 4 so that the engine 1
Is set as the target engine speed.
Therefore, the control of the rotation speed of the engine 1 can be performed stably, and the switching from the N range to the shift range can be performed without damaging the automatic transmission 7 or giving a shock to the vehicle. Can be.

In this embodiment, the rotation synchronous operation is performed with the load of the generator motor 4 even during rapid acceleration (see step ST11). This means that during rapid acceleration, the vehicle speed is high to some extent and the rotation speed of the output shaft 12 is high, and even during acceleration, the protection of the automatic transmission 7 is prioritized with the rotation speed of the engine 1 as the target engine rotation speed. It is necessary.

Further, the added torque α and the added torque α1 are selectively used depending on the amount of charge of the battery 3 (step S1).
ST23, ST24). Specifically, when the charged amount of the battery 3 is small, the output torque of the engine 1 is increased. Therefore, the surplus torque of the engine 1 absorbed by the generator motor 4 can be increased, and the amount of power generated by the generator motor 4 can be increased.

Further, the addition torque α2 and the addition torque α, α1 are selectively used depending on the presence or absence of a request for rapid acceleration (see steps ST9, ST23, ST24). Specifically, when rapid acceleration is required, the output torque of the engine 1 is set to be relatively large. That is, a relatively large torque is generated in the engine 1 in advance, and the torque of the engine 1 is absorbed by the generator motor 4. For this reason, after the automatic transmission 7 is switched to the predetermined shift range, the torque transmitted from the engine 1 to the drive wheels 9 and 10 is quickly increased by reducing the load on the generator motor 4. I can do it. As a result, the traveling performance at the time of sudden acceleration can be improved.

When the torque converter 5 is in the lock-up state, the rotation synchronizing operation is performed until the input-side rotation speed and the output-side rotation speed of the automatic transmission 7 substantially coincide with each other. To the shift range. Therefore, it is possible to reliably prevent the multiple disc clutch and the like of the automatic transmission 7 from being damaged, and to improve reliability. Further, a shock when the automatic transmission 7 is set to the shift range can be suppressed, and the running can be stably maintained.

[0134]

Other Embodiments of the Invention-First Modification-In the above embodiment, a clutch means for connecting and disconnecting between the engine 1 and the output shaft 12 is provided by an automatic transmission 7 such as a multi-plate clutch. Although the transmission clutch means is used, an independent clutch may be provided between the engine 1 and the output shaft 12.

-Second Modification- In the above embodiment, when calculating the target engine speed in the engine engagement control, the output shaft speed is multiplied by the speed ratio of the automatic transmission 7 (see step ST3). . However, in the state where the lock-up of the torque converter 5 is released, the slippage of the torque converter 5 causes the input speed of the automatic transmission 7 and the output speed of the automatic transmission 7 even if the engine speed matches the target engine speed. It does not always match the rotation speed. Therefore, when the torque converter 5 is in the non-lockup state, a value that takes into account the slippage of the torque converter 5 is added to the value obtained by multiplying the output shaft speed by the above-mentioned speed ratio, and the value after this correction is used as the target engine speed. Good.

-Third Modification- In the above embodiment, in the rotation synchronization operation in the engine engagement control, a load is applied to the engine 1 by the generator motor 4, and the load is controlled to control the engine speed. (Steps ST11, ST26, ST29)
reference). On the other hand, even after the engine 1 is started, the engine 1 may be rotationally driven by the generator motor 4 and the driving force of the generator motor 4 may be controlled to control the engine speed.

The outline of the engine engagement control in this case will be described with reference to the time chart of FIG. 7, FIG. 7 shows a time period from a steady start to a slow acceleration to a transition from a steady low load running to a steady middle load running, similarly to the time chart of FIG.

When the vehicle starts at time t1, the vehicle gradually accelerates and the vehicle speed exceeds 20 km / h at time t2. Time t
In 2, the engine 1 is cranked by the generator motor 4 in order to shift from the steady low load running to the steady medium load running. When the engine 1 starts, the feedback control for the generator motor 4 starts at time t3. Thereafter, until time t4, the generator motor 4 continuously drives the engine 1 to rotate and controls the driving force of the generator motor 4 to control the engine speed.

When the engine speed matches the target engine speed at time t4, the automatic transmission 7 is switched from the N range to the first speed range. In this state, the engine 1
Is transmitted to the drive wheels 9 and 10. For this reason, at time t4, the automatic transmission 7 is switched and the driving force of the traveling motor 2 is reduced, so that the driving force transmitted to the driving wheels 9 and 10 is kept constant. After that, the traveling is continued only by the driving force of the engine 1.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a hybrid vehicle.

FIG. 2 is a diagram showing a relationship between a vehicle speed and an accelerator pedal depression amount, showing a shift schedule of an automatic transmission and a lock-up region of a torque converter.

FIG. 3 is a time chart showing an operation in engine engagement control.

FIG. 4 is a flowchart showing an operation in engine engagement control.

FIG. 5 is a flowchart showing an operation in engine engagement control.

FIG. 6 is a flowchart showing an operation in engine start control.

FIG. 7 is a diagram corresponding to FIG. 3 in another embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Engine 2 Running motor 3 Battery (power storage means) 4 Generator motor 5 Torque converter 7 Automatic transmission 12 Output shaft

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (Reference) F02D 29/06 B60K 9/00 Z F16H 61/02 // F16H 59:40 59:42 (72) Inventor Naoyuki Hikita Hiroshima Hiroshima 3-1, Fushin-machi, Shinchi, Aki-gun, Mazda Co., Ltd. (72) Inventor Michihiro Imada 3-1, Shinchi, Fuchu-cho, Aki-gun, Hiroshima F-term (reference) 3D039 AA01 AA02 AA03 AA04 AA07 AB27 AC03 AC06 AC21 AC36 AC39 AD06 AD23 AD53 3D041 AA04 AA31 AB01 AC01 AC08 AC15 AC18 AD02 AD10 AD11 AD31 AD51 AE00 AE01 AE03 AE04 AE30 AE31 AE32 AE33 3G093 AA05 AA07 BA03 BA17 CB00 CB05 DA00 DA01 DA06 DB05 EB00 DB01 EB00 AA01 AA04 AA17 CA04 CA11 CB01 EA02 EA04 EA10 FA01 FB33 GB01 GC13 GC43 GC44 GC46 HA02 HA17 LA20 5H115 PG04 PI16 PI22 PI29 PO17 PU01 PU22 PU24 PU25 PU29 QE01 QE08 QE10 QH02 QH03 QI04 QN12 SE08 RE05 RE01 RE05 RE08 RE05

Claims (16)

[Claims] 1. An engine, an output shaft connected to the engine via clutch means, a generator motor connected to the engine, power storage means for storing electric power generated by the generator motor, and A driving motor driven by electric power of the means, a driving wheel connected to the driving motor and an output shaft, and detecting an input-side rotation speed on an engine side and an output-side rotation speed on an output shaft side of the clutch means. Detecting means, and performing a rotation synchronization operation of adjusting the engine speed by the generator motor so that the input-side speed and the output-side speed of the clutch means detected by the detecting means coincide with each other. And a control means for engaging the means. 2. The hybrid vehicle according to claim 1, wherein a neutral state is interposed between the engine and the output shaft and the input side and the output side are disconnected, and a shift state in which the input side and the output side are connected. A hybrid vehicle that is an automatic transmission clutch that switches the automatic transmission between a neutral state and a shift state. 3. The hybrid vehicle according to claim 1, wherein the control means keeps the output of the engine constant during the rotation synchronization operation, and performs the rotation synchronization operation by adjusting the control amount of the generator motor. Hybrid vehicle that is configured as follows. 4. The hybrid vehicle according to claim 3, wherein the control means is configured to control the input side rotation speed of the clutch means by applying a load to the output of the engine by the generator motor. . 5. The hybrid vehicle according to claim 3, wherein the control means controls the input side rotation speed of the clutch means by applying power to the output of the engine by the generator motor. . 6. The hybrid vehicle according to claim 3, wherein the control means applies power to the output of the engine by the generator motor during acceleration running, and applies a load to the output of the engine by the generator motor during steady running. A hybrid vehicle configured to control the input-side rotational speed of the clutch means by providing the clutch means. 7. The hybrid vehicle according to claim 4, wherein the control unit is configured to keep a control state of the traveling motor constant during the rotation synchronization operation. 8. The hybrid vehicle according to claim 4, wherein the control means calculates a target torque of the engine during engine running corresponding to the rotation speed of the output shaft, and the engine adds a predetermined additional torque to the target torque. A hybrid vehicle configured to maintain the control state of the engine so as to generate the output torque, and to change the magnitude of the added torque in accordance with the rate of change in the rotation speed of the output shaft. 9. The hybrid vehicle according to claim 4, wherein the control means calculates a target torque of the engine during engine running corresponding to the rotation speed of the output shaft, and the engine adds a predetermined additional torque to the target torque. A hybrid vehicle configured to maintain the control state of the engine so as to generate the output torque, and to change the magnitude of the added torque according to the operation amount of the accelerator or the rate of change of the operation amount. 10. The hybrid vehicle according to claim 1, wherein the control means determines that the two rotation speeds match when a difference between the input rotation speed and the output rotation speed of the clutch device falls within a predetermined rotation allowable range. A hybrid vehicle in which the clutch means is engaged and the rotation allowable range is changed according to a running state of the vehicle. 11. The hybrid vehicle according to claim 10, wherein a torque converter is interposed between the engine and the clutch means, and the control means reduces a rotation allowable range when the torque converter is in a lockup state. A hybrid vehicle that is configured for. 12. The hybrid vehicle according to claim 4, wherein the control means is configured to apply a load to the output of the engine by the generator motor for a predetermined time continuously after the engagement of the clutch means. vehicle. 13. The hybrid vehicle according to claim 6, wherein the control means continuously applies power to the output of the engine by the generator motor for a predetermined time even after the clutch means is engaged during the acceleration running, so that the steady running is performed. A hybrid vehicle in which a load is applied to the output of the engine by the generator motor continuously for a predetermined time even after the engagement of the clutch means. 14. The hybrid vehicle according to claim 1, wherein the control means selects a gear ratio of the automatic transmission interposed between the engine and the output shaft in accordance with a traveling state, and A hybrid vehicle configured to prohibit a change in a selected gear ratio at least from the start of engagement of the clutch means to the completion thereof. 15. The hybrid vehicle according to claim 1, wherein an automatic transmission is interposed between the engine and the output shaft, and the control means controls the engine to be most efficient based on the output side rotation speed of the clutch means. A hybrid vehicle configured to perform a rotation synchronization operation by selecting a speed ratio of an automatic transmission in an operating state and adjusting an input-side speed of a clutch means to a speed corresponding to the speed ratio. 16. The hybrid vehicle according to claim 3, wherein the control means sets the control state of the engine to a control state corresponding to the operation amount of the accelerator after the engagement of the clutch means is completed. vehicle.