JP2003294123A - Parallel hybrid vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a parallel hybrid vehicle which obtains stable creep torque without generating booming noise or vibration, and generates power, even when a traveling range is selected, and the vehicle is stopped by brakes. <P>SOLUTION: This parallel hybrid vehicle is provided with a one-way clutch to allow one-way rotation direction only on a shaft connected to a transmission. It is provided with a range position detecting means to detect a range position of the transmission, a brake state detecting means to detect the brake state of drive wheels, and a distortion quantity reducing means to reduce distortion quantity of a drive shaft when the range position detecting means detects the traveling range, and the brake state detecting means detects the braking state. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention has a motor that also functions as a generator and an engine, and outputs the output torques of these to a transmission through a differential device.
The present invention relates to a parallel hybrid vehicle in which a traveling driving force is obtained by either or both of an engine and a motor.

[0001]

2. Description of the Related Art In recent years, there has been a demand for improving fuel efficiency of automobiles from the viewpoint of protecting the global environment and saving limited resources. A hybrid vehicle is considered as one means to meet the demand for improving fuel efficiency. In this hybrid vehicle, an engine and a motor are arranged in series or in parallel, the engine output is assisted, and the motor is made to act as a generator at the time of deceleration to convert the kinetic energy of the automobile into electric energy. It is configured to assist the output.

From such a point of view, for example, Japanese Patent Laid-Open No.
The device shown in FIG. 19 of Japanese Patent Publication No. 304513 is known. This device is a composite distribution mechanism that mechanically combines and distributes forces by including an engine, a motor generator that can act as an electric motor and a generator that operate by electric energy, and a single-pinion type planetary gear device. An electric torque converter and an automatic transmission are provided along the front-rear direction of the vehicle, and the driving force is transmitted from the output shaft to the drive wheels via a propeller shaft, a differential device, and the like.

The characteristic of this device is that it is equipped with a transmission input shaft and a one-way clutch that limits the rotation direction of the carrier of the planetary gear device that combines the composite distribution mechanism to the same direction as the engine rotation direction. The motor generator can be used as a starter at the time of starting.

[0004]

However, in the above hybrid vehicle, if the accelerator is not stepped on, the creep torque is controlled to be generated. However, the driver depresses the brake, If creep torque continues to be generated without stopping the engine even when the drive wheels are fixed, a large preload (load) is applied to the drive shaft and mount, and vibration cannot be absorbed, resulting in violent vibration and loud muffled noise. However, there is a problem in that it causes the passengers to feel uncomfortable.

In other words, in a situation where creep running and stopping are repeated, the engine is not stopped even if the brake is depressed in order to run smoothly, or the remaining charge of the battery is small and the power generation of the motor generator is small. If the engine is not stopped in an attempt to perform the operation, a carrier torque, which is a creep torque, will be generated in the carrier of the planetary gear mechanism connected to the transmission input shaft.

Here, as shown in a time chart of engine torque fluctuation and accumulated torsion torque in FIG. 16, the engine torque constantly fluctuates when the engine is not stopped even when the drive wheels are fixed. As a result, the carrier torque also constantly fluctuates. When this fluctuating carrier torque is positive, torsional displacement occurs due to elastic deformation of the drive shaft such as the drive shaft, and the carrier makes a slight rotation in the positive direction.When it is negative, the one-way clutch acts so that the carrier moves in the reverse direction. Does not rotate to. As a result, the carrier intermittently continues to rotate only in the positive direction, and the torsional deformation and the torsional torque in the positive direction are generated on the drive shaft until the torque accumulated on the drive shaft matches the positive peak value of the carrier torque. It will be accumulated. At this time, the mesh torque of the one-way clutch receives the torsion torque of the drive system, and the one-way clutch is locked. Torque and displacement are also stored in the engine block that receives the one-way clutch and the mount of the transmission case.

Usually, the vibration is absorbed by the elasticity of the drive shaft and is largely shut off. However, in the case where the one-way clutch of the transmission input shaft is provided, as described above, a large preload is applied to the drive shaft. Since (load) is applied, there is a problem in that vibration cannot be absorbed and the vibration is not blocked.

On the other hand, although the engine block and the transmission case are integrally formed by bolts or the like, the engine torque fluctuation normally acts, and in the above-mentioned situation, the one-way clutch is locked, so that the fluctuation of the carrier torque causes the fluctuation of the carrier torque. The torque fluctuation that is larger than usual acts on the case. Moreover, since the preload is added to the mount, the vibration isolation performance due to elasticity is reduced,
As a result, there is also a problem that more intense vibration than usual is transmitted from the mount to the vehicle body.

The present invention has been made in view of the above-mentioned problems, and in a parallel hybrid vehicle equipped with a one-way clutch that allows only one direction of rotation of a transmission input shaft, a traveling range is selected. In the state
An object of the present invention is to provide a parallel hybrid vehicle capable of generating electric power when stable creep torque can be obtained without generating muffled noise or vibration even when the vehicle is stopped by a brake.

[0010]

According to a first aspect of the present invention, torque is transmitted to a drive wheel via an engine, an electric rotary drive source having both functions of a generator and an electric motor, and a drive shaft. And a differential device in which an output shaft of the engine is connected to a first shaft, an output shaft of the electric rotary drive source is connected to a second shaft, and the transmission device is connected to a third shaft. A parallel hybrid vehicle including a one-way clutch that allows only one direction of rotation on the third shaft, and the parallel hybrid vehicle includes a range position detection unit that detects a range position of the transmission. Brake state detecting means for detecting the brake state of the drive wheels and the range position detecting means detect that the vehicle is in a traveling range, and the brake state detecting means detects the brake state. When I is characterized in that a, the torsion amount reducing means for reducing the torsional amount of the drive shaft.

According to a second aspect of the present invention, in the parallel hybrid vehicle according to the first aspect, the transmission has a friction element that is brought into a neutral state by being released, and the twist amount reducing means is provided in the parallel hybrid vehicle. It is characterized in that it is a means for reducing the engagement capacity for reducing the engagement capacity of the friction element.

According to a third aspect of the present invention, in the parallel hub vehicle according to the second aspect, the fastening capacity lowering means is provided with the friction element of the friction element after a lapse of a predetermined time after the input shaft rotation speed becomes a predetermined value or less. It is characterized by being a means for reducing the fastening capacity.

According to a fourth aspect of the present invention, in the parallel hybrid vehicle according to the second aspect, the engagement capacity reducing means is means for intermittently reducing the engagement capacity at every predetermined time. To do.

According to a fifth aspect of the present invention, in the parallel hybrid vehicle according to the second aspect, the engagement capacity reducing means is means for continuously reducing the engagement capacity.

According to a sixth aspect of the present invention, in the parallel hybrid vehicle according to the fourth or fifth aspect, the input shaft average torque calculating means calculates the average torque of the input shaft based on the current torque of the electric drive source. It is characterized in that the engaging capacity reducing means is means for decreasing the engaging capacity to substantially match the average torque of the input shaft based on the calculation result of the calculating means.

According to a seventh aspect of the present invention, in the parallel hybrid vehicle according to the first aspect, the twisting amount reducing means reduces the torque of the electric rotary driving source to a rotational drive lower than that in a normal state. It is characterized in that the source torque reducing means is used.

[0017]

In the parallel hybrid vehicle according to the first aspect of the present invention, the brake is stepped on while the traveling range is selected, and the drive shaft is fixed and the one-way clutch causes torsional displacement. Even if you do so, by reducing the amount of torsional displacement of the drive block and the mount of the transmission case that receives the drive shaft and the one-way clutch by the twist amount reduction means, the elasticity of the drive shaft and the mount is ensured, and The generated vibration and noise can be reduced.

In the parallel hybrid vehicle according to the second aspect of the present invention, by reducing the engagement capacity of the friction element in the engagement capacity reducing means, the accumulation of the torsional displacement is reduced or eliminated, so that the elasticity of the drive shaft is secured. It is possible to reduce vibration and noise generated in the engine.

In the parallel hybrid vehicle according to the third aspect of the invention, the engagement capacity reducing means reduces the engagement capacity of the friction element after a predetermined time elapses after the input shaft rotation speed becomes equal to or lower than a predetermined value. That is, the torsional displacement amount of the drive shaft is gradually accumulated after the brake is depressed and the input shaft rotation speed becomes 0, and the torsional displacement amount that causes vibration and muffled noise that make the driver feel uncomfortable. It will take more time to reach. Therefore, it is possible to suppress the occurrence of vibrations and muffled noise and reduce the possibility of impairing the starting acceleration by reducing the engagement capacity to a neutral state after a lapse of a predetermined time.

In the parallel hybrid vehicle according to the fourth aspect, the engaging capacity reducing means intermittently reduces the engaging capacity of the friction element, so that the engaging capacity of the friction element is secured for a certain period of time. By providing it for a long time,
Even if the accelerator is suddenly depressed, the risk of impairing the startability is reduced. Further, since the creep force is generated immediately when the brake is released, the creep force can be obtained without delaying the response.

In the parallel hybrid vehicle according to the fifth aspect of the present invention, the fastening capacity reducing means continuously reduces the fastening capacity, so that the accumulation of the torsional displacement amount can be reduced or eliminated. Therefore, elasticity of the drive shaft is ensured, and vibration and noise generated in the engine can be reduced.

In the parallel hybrid vehicle according to the sixth aspect, the average torque of the input shaft is calculated, and the hydraulic pressure is accurately lowered so that the engagement capacity of the friction element is slightly lower than the carrier average torque. Even when the vehicle is stopped in an uphill state (brake torque + creep torque = uphill direction component of vehicle weight), it is possible to prevent the vehicle from moving backward. Further, when the brake is released, the creep force is generated immediately, so that the response delay can be reduced.

In the parallel hybrid vehicle according to the seventh aspect of the invention, the torque of the electric rotary drive source is controlled by the rotary drive source torque reducing means while maintaining the engagement capacity of the engagement elements in the transmission. It is possible to reduce the response delay until the creep force is generated after the brake is released.

[0024]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. (Embodiment 1) FIG. 1 is a system diagram showing an overall configuration of a hybrid vehicle in the embodiment, in which a dotted arrow represents a hydraulic signal, a one-dot chain arrow represents an electric signal, and a two-dot chain arrow represents electric power. First, the configuration will be described.

Reference numeral 1 is an engine connected to a ring gear 31 by an engine output shaft 1a, 2 is a motor generator connected to a sun gear 33 for driving and regenerating, 3 is a planet gear, and D / C is a ring gear 31 and a pinion carrier. A direct clutch that engages between 32 and 5 is a transmission input shaft 6a
Is a one-way clutch that allows rotation in only one direction, 6 is a transmission mechanism that shifts the input rotation, and 6b is a differential 7 that rotates the output from the transmission output shaft OUT.
A drive shaft that is transmitted to the drive wheels 8 via a drive shaft 9 is a hydraulic control circuit that includes a solenoid valve and hydraulically controls the gear ratio of the transmission mechanism unit 6.

Reference numeral 10 denotes an engine control unit for electrically controlling engine driving (hereinafter, the control unit will be referred to as ECU), 11 denotes a motor generator ECU for controlling the operation of the motor generator 2, 11a.
Is an inverter that outputs the drive current of the motor generator 2 from the signal of the motor generator ECU 11, and 12 is a battery EC that monitors the temperature and charge amount of the battery 12a.
U and 13 are hybrid ECUs that control the hybrid drive device, and 14 is an ATE that controls the shift mechanism 6
CU.

As a sensor for detecting a signal input to the hybrid ECU 13, an accelerator sensor 21 for outputting a signal indicating an operation amount of an accelerator pedal, a shift position of a shift lever operated by a driver (for example, P, N, D range). Etc.), a shift position sensor 22 that outputs a signal that indicates the engine rotation speed, an engine rotation speed sensor 23 that outputs a signal that indicates the engine rotation speed, a throttle opening sensor 24 that outputs a signal that indicates the throttle opening, and a signal that indicates the motor rotation speed. A motor rotation speed sensor 25 that outputs, an output shaft rotation speed sensor 26 that outputs a signal that indicates the rotation speed of the transmission output shaft OUT, and an input shaft rotation speed sensor that outputs a signal that indicates the input shaft rotation speed of the transmission input shaft IN. 27, drive wheel 8
A brake oil pressure sensor 28 that outputs a signal representing the brake oil pressure is provided.

The hybrid ECU 13 has a CPU,
It has a RAM, a ROM, etc., and executes signal processing according to a program stored in advance in the ROM while utilizing the temporary storage function of the RAM. As a result, each ECU 10, 1
1 and 14 are controlled, and an electric signal is output to a solenoid valve or the like of the hydraulic control circuit 9 to control engagement / disengagement of the direct clutch D / C.

The ATCU 14 sends a signal to a solenoid in the hydraulic control circuit 9 to control the target shift stage, for example, based on a shift pattern using preset vehicle speed and throttle opening as parameters. Although the present embodiment is provided with a stepped automatic transmission, it may be provided with a continuously variable transmission.

FIG. 2 is a schematic diagram showing the structure of the stepped transmission according to the first embodiment. In FIG. 2, G1 is the first
Planetary gear, G2 is the second planetary gear, M1 and M2 are connecting members, R / C, H / C and L / C are clutches, 2-4 / B, L & R / B are brakes, L-owc is a low one-way clutch. Is.

The first planet gear G1 is a first sun gear S.
1 is a single pinion type planetary gear having a first ring gear R1, and a first carrier PC1 supporting a pinion meshing with both gears S1 and R1. The second planetary gear G
Reference numeral 2 is a single pinion type planetary gear having a second sun gear S2, a second ring gear R2, and a second carrier PC2 that supports a pinion that meshes with both gears S2, R2. The first connecting member M1 is a member that integrally connects the first carrier PC1 and the second ring gear R2 via the low clutch L / C. The second connecting member M2 is
It is a member that integrally connects the first ring gear R1 and the second carrier PC2.

The reverse clutch R / C is engaged in the R range to connect the input shaft IN and the first sun gear S1. The high clutch H / C is engaged in the 3rd and 4th speeds to connect the input shaft IN and the first carrier PC1. Low clutch L / C is 1st speed,
The second and third gears are engaged to connect the first carrier PC1 and the second ring gear R2. Low & reverse brake L &
The R / B is fastened at the 1st speed and the R range to fix the rotation of the first carrier PC1. The band brake 2-4 / B is engaged in the 2nd and 4th speeds to fix the rotation of the first sun gear S1. The low one-way clutch L-owc operates when the vehicle is accelerating at the 1st speed and locks the rotation of the first carrier PC1. It does not work during deceleration.

The transmission input shaft 4 is connected to the first ring gear R1 and inputs the rotational driving force of the engine and the motor generator 2. The transmission output shaft OUT is the second carrier
It is connected to the PC 2 and transmits the output rotational drive force to the drive wheels 8 via the differential 7.

[Shifting Action] FIG. 3 is a diagram showing a fastening operation table in the shifting mechanism portion 6 of the first embodiment. In FIG.
○ indicates the fastening state, and ○ on the dotted line indicates fastening only when traveling at the 1st speed.

[Hydraulic Circuit Configuration] FIG. 4 is a hydraulic circuit diagram showing a hydraulic circuit for supplying control hydraulic pressure from the hydraulic control circuit 9 to the speed change mechanism portion 6 in the first embodiment.

In the hydraulic control circuit 9, a manual valve 91 that switches a line pressure PL supplied from an oil pump between forward and reverse in conjunction with a shift lever (not shown) operated by a driver, and a transmission mechanism. A pilot valve 92 for adjusting the signal pressure supplied to each engagement element and the direct clutch D / C in the section 6 and pressure control valves 93 to 98 for controlling the engagement pressure of each engagement element are provided.

The line pressure PL is applied to each of the pressure control valves 93 to 98.
Is used as the source pressure, and the pilot pressure PPLT branched from the pilot valve 2 and the spool supply pressures PS-FWD and PS-RVS branched from the manual valve 91 are supplied, and these supply pressures are adjusted and output to each engagement element.

The reverse clutch pressure control valve 97
To each pressure control valve except the forward spool supply pressure PS-FWD branched by the manual valve 91, and the reverse clutch pressure control valve 97 is supplied to the reverse spool supply pressure PS.
-RVS supplied. In addition, each spool supply pressure PS-FWD, PS
-RVS is equal to line pressure PL.

FIG. 5 is a schematic view showing the structure of each pressure control valve 93-98. Solenoid valve 40 that creates spool pilot pressure PS-PLT from pilot pressure PPLT and spool supply pressure PS by this spool pilot pressure PS-PLT
-FWD, PS-RVS from each friction element supply pressure PL / C, PH / C, P2-4 /
Spool valve 50 that outputs B, PL & R / B, PR / C, PD / C
It has and. As is well known, the solenoid valve 40 has a plunger 42 depending on a value of a current supplied to the coil 41.
Of the pilot pressure PPLT side and the spool pilot pressure PS-PLT side, the flow path 44 is opened by the movement of the ball 43 that blocks the pilot pressure PPLT side and the spool pilot pressure PS-PLT side. -Communicate with the PLT side to increase the spool pilot pressure PS-PLT.

The value of the current supplied to the coil 41 of the solenoid valve 40 is controlled by the drive signal from the AT ECU 14. Here, duty ratio control for controlling the pulse width of the pulse voltage signal according to the duty ratio is used. ing. That is, the duty ratio is 0% to 100%
Then, for example, the ratio of the standing time of the pulse voltage signal corresponds to the duty ratio. Therefore, generally, the larger the duty ratio, the larger the supply current value, and in the first embodiment, the spool pilot pressure PS-PLT is simultaneously increased. This duty ratio pulse voltage signal is driven at a high frequency, which is called the drive frequency.

On the other hand, the spool valve 50 shuts off the spool supply pressure side and each friction element side, the spool 51 moves together with the increase of the spool pilot pressure PS-PLT to open the flow path, and the spool supply pressure PS-FWD. , PS-RVS increases the friction element supply pressure. Therefore, in the first embodiment, when the duty ratio of the pressure control valves 93 to 98 to the solenoid valve 40 is large, the spool pilot pressure PS-PLT and the friction element supply pressure are linearly increased.

[Drive System of Hybrid Drive Device] When the engine is started, the motor generator 2 is driven in reverse as a starter motor. The forward rotation / forward torque indicates the same rotation direction / torque direction as the engine 1, and the reverse rotation / reverse torque indicates the reverse rotation direction / torque. The pinion carrier 32 is stopped by the action of the one-way clutch 5, the ring gear 31 is normally rotated, and the engine 1 is started. It should be noted that when the speed change mechanism unit 6 is not transmitting a drive force such as neutral, the engine 1 can be started by driving the motor generator 2 in the normal direction while the direct clutch D / C is engaged. .

At the time of starting, the motor generator 2 starts by outputting an appropriate positive torque corresponding to the output torque of the engine 1 estimated from the current SOC (State Of Charge) of the battery 12 and the engine rotation speed.
While the vehicle is starting, the rotation speed of the pinion carrier 32 is smoothly increased, and the rotational speed difference between the engine 1 and the motor generator 2 is gradually reduced. When the speed difference becomes small enough, the direct clutch D / C is engaged and the start is completed.

After the start of the vehicle, the engine 1 is directly connected to the transmission input shaft 4 as in the lockup state in the conventional hydraulic torque converter with a lockup clutch. In the direct connection state, the motor generator 2 performs torque assist or power generation depending on the situation.

During deceleration, the motor generator 2 regeneratively brakes and recovers the kinetic energy of the vehicle as electric energy. The engine 1 may be stopped at the time of deceleration so that a larger amount of energy can be recovered.

FIG. 6 is a flowchart showing the control of the hybrid vehicle in the first embodiment.

In step 101, it is determined whether the signal from the shift position sensor 22 is in the traveling range. If the signal is in the traveling range, the process proceeds to step 102. Otherwise, the process proceeds to step 300 to perform other mode control.

In step 102, it is determined whether the vehicle speed detected by the output shaft rotation speed sensor 26 is less than or equal to a predetermined value, and if it is less than or equal to the predetermined value, the process proceeds to step 103. Otherwise, the process proceeds to step 300 to control other modes. I do.

In step 103, it is judged whether or not the throttle opening detected by the throttle opening sensor 24 is 0. When the throttle opening = 0, the routine proceeds to step 200, where creep mode control is performed and throttle opening ≠ 0. If so, the process proceeds to step 300 to perform other mode control.
Here, the other mode controls include, for example, a start mode, an engine running mode in which only the engine runs, a motor assist mode in which both the engine and the motor generator run, and a mode is selected according to the running state, and the direct clutch D Controls / C, motor generator 2 and engine 1.

The torque control of the motor generator 2 during the creep mode control in the first embodiment is estimated from the idle rotation speed of the engine 1 so that a preset creep torque is output from the transmission output shaft OUT. The torque determined from the engine torque and the SOC of the battery 12 is output.

FIG. 7 is a flow chart showing the creep mode control in the first embodiment.

In step 201, it is determined whether the brake pressure detected by the brake oil pressure sensor 28 is equal to or higher than a predetermined value. If it is equal to or higher than the predetermined value, the process proceeds to step 202, and if it is lower than the predetermined value, the process proceeds to step 212.

In step 202, it is judged whether or not the first timer count value T is larger than a predetermined timer value T1, and when it is larger, the process proceeds to step 204, and when it is T1 or less, the process proceeds to step 203.

In step 203, the first timer is counted up.

In step 204, it is determined whether or not the first hydraulic pressure down flag F1 = 1. If F1 = 1, the process proceeds to step 207, otherwise the process proceeds to step 205.

At step 205, the low clutch pressure is reduced to a preset initial value P0. This initial value
P0 is, for example, experimentally obtained a hydraulic pressure in which the transmission input shaft rotation speed Ni is in a target rotation speed region (N1 <Ni <N2),
It is set in advance.

In step 206, the first hydraulic pressure down flag is set to F1 = 1.

In step 207, the rotation speed Ni detected by the input shaft rotation speed sensor 27 is set to the preset rotation speed.
It is determined whether or not it is within the range of N1 and N2, and if it is within the range, proceed to step 208, and if it is out of the range, step 209
Go to.

At step 208, the low clutch pressure is maintained.

In step 209, it is determined whether the rotation speed Ni detected by the input rotation speed sensor 27 is N1 or less,
When it is less than N1, the process proceeds to step 210, and when it is greater than N1, the process proceeds to step 211.

At step 210, the low clutch pressure is reduced by a predetermined amount.

At step 211, the low clutch pressure is increased by a predetermined amount.

In step 212, the first timer count value T is set to 0.

In step 213, it is determined whether or not the first hydraulic pressure down flag F1 = 1. If F1 = 1, the process proceeds to step 214. If F1 ≠ 1, step 3 is performed.
Go to 01.

At step 214, the low clutch pressure is increased by a predetermined amount.

In step 215, it is determined whether or not the low clutch pressure is equal to or higher than a predetermined value, and if it is equal to or higher than the predetermined value, the process proceeds to step 216, and if it is lower than the predetermined value, this control ends.

In step 301, low clutch pressure normal pressure hydraulic control is performed. In this low clutch normal pressure hydraulic control, the line pressure determined based on the transmission input shaft torque is supplied as the low clutch pressure PL / C, so that the engagement capacity of the low clutch L / C with respect to the transmission input shaft torque. Is always controlled.

FIG. 8 is a time chart showing the creep mode control in the first embodiment. The above control will be described based on a time chart.

In the creep running state in which the D range which is the running range is detected and the driver does not step on the accelerator, the engine 1 continues the idle rotation speed and the creep mode control is performed. At this time, the low clutch L / C is under normal low clutch hydraulic control, and the line pressure is supplied to the low clutch L / C via the pressure control valve 93. The line pressure PL is determined based on the transmission input shaft torque, and is adjusted by a pressure adjusting valve (not shown), so the low clutch L / C does not slip.

The torque of the motor generator 2 is
The engine torque estimated from the idle rotation speed of the engine 1 and the charge amount SOC of the battery 12 so that a preset creep torque is output from the transmission output shaft OUT.
The torque determined from and is output.

After that, when the driver intends to stop and the brake is depressed, the drive wheels 8 are fixed and the transmission output shaft OUT
The rotation of the transmission input shaft 4 is also stopped via the low clutch L / C. Therefore, the transmission input shaft rotation speed becomes 0 between T11 and T12.

At this time, the first timer T is counted up in steps 202 to 203, and when the first timer count value T becomes equal to or greater than the predetermined value T1, the vehicle is continuously stopped and the one-way clutch 5 operates. Due to the action, torque may be accumulated on the drive shaft (causing displacement of the drive shaft). Therefore, the routine proceeds to step 204, where it is determined whether the first hydraulic pressure down flag F1 is 1. Since F1 ≠ 1, the routine proceeds to step 205, where the low clutch pressure PL / C is reduced to a preset initial value P0, and the first hydraulic pressure down flag F1 is set to 1.

When the first hydraulic pressure down flag F1 is set to 1, it is determined whether the transmission input shaft rotation speed Ni is between preset rotation speeds N1 and N2 (N1 <N2) (target). The rotation speed is, for example, about 100 rpm). At this time, since the transmission input shaft rotation speed Ni is 0, the process proceeds from step 209 to step 210, and the low clutch pressure PL / C
Is reduced by a predetermined amount. Then, step 210 is repeated until the transmission input shaft rotation speed Ni exceeds N1.

When the low clutch pressure PL / C gradually decreases,
Since the torque input to the transmission input shaft 4 (the sum of the torque according to the idle rotation speed of the engine and the torque output from the motor generator 2) is constant, the low clutch L / C begins to slip. Therefore, as shown in the collinear diagram of FIG. 9, the carrier 32, which is the transmission input shaft rotation speed Ni, gradually starts to rise, and the low clutch pressure PL is maintained so as to maintain the rotation speed between the set rotation speeds N1 and N2. / C is controlled.

When the brake is released, the first timer count value T is reset to 0, and the first hydraulic pressure down flag F1
Since the low clutch pressure PL / C decreases while = 1, the low clutch pressure is gradually increased by a predetermined amount, and when it becomes equal to or higher than a predetermined value, the first hydraulic pressure down flag F1 is reset to 0. , Low clutch pressure Normal hydraulic pressure control is performed so that the engagement capacity of the low clutch L / C is always secured with respect to the transmission input shaft torque.

As described above, in the control device for a hybrid vehicle of the first embodiment, the low clutch engagement pressure PL / C is reduced to the engagement pressure that secures the transmission input shaft rotational speed Ni, and the low clutch engagement pressure PL / C is reduced. Since the clutch L / C is always slid, torque is not accumulated in the drive device, and noise and vibration can be reduced. Further, since torque fluctuation does not occur, smooth creep mode control can be achieved.

(Second Embodiment) Next, a second embodiment will be described. Since the configuration of the hybrid drive device is the same, a description thereof will be omitted and only different control will be described.

FIG. 10 is a flow chart showing the creep mode control of the second embodiment.

In step 401, it is judged whether the brake pressure is a predetermined value or more. If it is the predetermined value or more, step 4
02, when it is less than the predetermined value, the routine proceeds to step 301, where the low clutch pressure normal time hydraulic control is performed.

In step 402, it is determined whether or not the second hydraulic pressure down flag F2 = 1. If F2 = 1, the process proceeds to step 408, and if F2 ≠ 1, the process proceeds to step 403.

In step 403, the routine proceeds to step 404 while performing the low clutch pressure normal hydraulic control.

In step 404, the second timer Tb is counted up.

In step 405, it is determined whether or not the second timer count value Tb is larger than the predetermined value β. If it is larger than the predetermined value β, the process proceeds to step 406. If it is smaller than β, the count-up is continued until it becomes larger than β. This predetermined value β
Is an experimentally obtained time that torque more than a predetermined value is accumulated in the drive shaft, and vibration or muffled noise that is uncomfortable for the driver is generated, and the value is set as a predetermined value β,
For example, it is set to 1 second.

In step 406, the second timer count value Tb is reset to 0.

In step 407, the second hydraulic pressure down flag F2 is set to 1.

In step 408, the average carrier torque is calculated from the current output torque of the motor generator 2, and the low clutch pressure PL and the hydraulic pressure Pu_ave are set so that the engagement capacity of the low clutch L / C is slightly lower than the average carrier torque.
Reduce / C.

At step 409, the low clutch pressure PL / C is set.
The third timer Ta, which represents the duration of the decrease of the, is counted up.

In step 410, it is determined whether or not the third timer count value Ta is larger than the predetermined value α. When it is larger, the process proceeds to step 411, and when it is smaller, the third timer Ta continues to count up until it becomes α or more. To do. This predetermined value α is a so-called stick slip in which the response delay of the actual hydraulic pressure to the hydraulic pressure command, the torque accumulated in the drive shaft are released, and the transmission input shaft rotation speed Ni slightly moves or stops. The time until the state starts to be obtained experimentally, and this time is set as a predetermined value α.

In step 411, the third timer count value Ta is reset to 0.

In step 412, the second hydraulic pressure down flag F2 is reset to 0.

FIG. 11 is a time chart showing the creep mode control in the second embodiment. The above control will be described based on a time chart. In the creep running state in which the D range which is the running range is detected and the driver does not step on the accelerator, the engine 1 continues the idle rotation speed and the creep mode control is performed. At this time, the low clutch L / C is under normal low clutch hydraulic control, and the line pressure is supplied to the low clutch L / C via the pressure control valve 93. The line pressure PL is determined based on the transmission input shaft torque, and is adjusted by a pressure adjusting valve (not shown), so the low clutch L / C does not slip.

The torque of the motor generator 2 is
The engine torque estimated from the idle rotation speed of the engine 1 and the charge amount SOC of the battery 12 so that a preset creep torque is output from the transmission output shaft OUT.
The torque determined from and is output.

At this time, when the driver intends to stop and the brake is depressed, the drive wheels 8 are fixed, and the transmission output shaft OU
As the rotation of T stops, the rotation of the transmission input shaft 4 also stops via the low clutch L / C. Therefore, the transmission input shaft rotation speed becomes 0 between T21 and T22.

Then, from this T1, steps 404 to 4 are performed.
At 05, the second timer Tb is counted up.
When the second timer count value Tb becomes larger than the predetermined value β, the vehicle is continuously stopped, the torque of the predetermined value or more is accumulated in the drive device by the action of the one-way clutch 5, and the vibration unpleasant to the driver is generated. A muffled sound may be generated. Therefore, the routine proceeds to step 406, where the second timer count value Tb is reset to 0 and the second hydraulic pressure down flag F2 is set to 1.

When the second hydraulic pressure down flag F2 is set to 1 in step 402, the process proceeds to step 408, the average carrier torque is calculated from the current torque of the motor generator 2, and the engagement capacity of the low clutch L / C is averaged. The hydraulic pressure Pu_ave is lowered to be slightly lower than the carrier torque. At this time, the hydraulic pressure is reduced to Pu_ave, and at the same time, the third timer Ta starts counting up.

Then, the low clutch pressure PL / C is reduced to Pu_ave until the so-called stick-slip state in which the transmission input shaft rotation speed Ni stops or moves,
During that time, the torque accumulated on the drive shaft and the like is released.

Here, the third timer Ta is reset to 0 and the second hydraulic pressure down flag F2 is reset to 0. Hereinafter, while the brake is being depressed, stick-slip control is intermittently performed to release the torque accumulated in the drive device. When the brake is released, the low clutch pressure normal pressure hydraulic control is performed.

As described above, in the hybrid vehicle control device according to the second embodiment, the low clutch engagement pressure is intermittently reduced, so that the engagement capacity of the clutch is surely secured for most of the time. Therefore, the startability is not impaired even if the accelerator is suddenly depressed.

Further, the carrier average torque is calculated on the basis of the motor generator torque, and the hydraulic pressure is accurately lowered so that the engagement capacity of the clutch is slightly lower than the carrier average torque. Even in the case (brake torque + creep torque = uphill component of vehicle weight), it is possible to prevent the vehicle from moving backward. Further, since the creep force is generated immediately after the creep mode control is released, the responsiveness can be secured.

(Third Embodiment) Next, a third embodiment will be described. Since the configuration of the hybrid drive device is the same, a description thereof will be omitted and only different control will be described.

FIG. 12 is a flow chart showing the creep mode control of the third embodiment.

In step 401, it is judged whether or not the brake pressure is a predetermined value or more, and if it is the predetermined value or more, step 5
01, when it is less than the predetermined value, the routine proceeds to step 301, where the low clutch pressure normal time hydraulic control is performed.

In step 501, the average carrier torque is calculated from the current output torque of the motor generator 2, and the low clutch pressure PL / ave is set so that the engagement capacity of the low clutch L / C becomes the hydraulic pressure P_ave which becomes the average carrier torque.
Lowers C.

FIG. 13 is a time chart showing the creep mode control in the third embodiment. The above control will be described based on a time chart.

In the creep running state in which the D range which is the running range is detected and the driver does not step on the accelerator, the engine 1 continues the idle rotation speed and the creep mode control is performed. At this time, the low clutch L / C is under normal low clutch hydraulic control, and the line pressure is supplied to the low clutch L / C via the pressure control valve 93. The line pressure PL is determined based on the transmission input shaft torque, and is adjusted by a pressure adjusting valve (not shown), so the low clutch L / C does not slip.

The torque of the motor generator 2 is
The engine torque estimated from the idle rotation speed of the engine 1 and the charge amount SOC of the battery 12 so that a preset creep torque is output from the transmission output shaft OUT.
The torque determined from and is output.

When the driver intends to stop and the brake is stepped on, the drive wheels 8 are fixed and the transmission input shaft 4 is passed through the low clutch L / C as the rotation of the transmission output shaft OUT is stopped.
Also stops rotating. Therefore, the transmission input shaft rotation speed is T
It becomes 0 between 31 and T32.

At this time, in step 501, the average carrier torque is calculated from the current torque of the motor generator 2, and the hydraulic pressure P_ave is reduced so that the engagement capacity of the low clutch L / C becomes the average carrier torque.

That is, in the transmission input rotation speed Ni, the carrier torque also fluctuates due to the fluctuation of the input torque from the engine. As a result, as shown in FIG. 16, slippage occurs due to insufficient engagement capacity of the low clutch L / C only when this carrier torque is equal to or greater than the average carrier torque, and the so-called input shaft rotation speed stops or moves. There will be a stick-slip condition and excessive torsional torque will not build up in the drive. After that, when the brake is released, the low clutch pressure normal hydraulic control is performed.

As described above, in the control device for a hybrid vehicle of the third embodiment, the carrier average torque is calculated based on the motor generator torque, and the clutch engagement capacity is reduced so that the carrier average torque is obtained. Then, by utilizing the characteristics of the torque fluctuation of the engine,
Only when the carrier torque is equal to or higher than the average carrier torque, slippage occurs due to insufficient engagement capacity of the low clutch L / C.

Further, for example, even when the vehicle is stopped in an uphill state (brake torque + creep torque = uphill direction component of vehicle weight), the backward movement of the vehicle can be prevented. Further, the response delay until the creep force is generated after the brake is released can be minimized.

(Fourth Embodiment) Next, a fourth embodiment will be described. Since the configuration of the hybrid drive device is the same, a description thereof will be omitted and only different control will be described.

FIG. 14 is a flow chart showing the creep mode control of the fourth embodiment.

In step 401, it is judged whether or not the brake pressure is a predetermined value or more. If it is the predetermined value or more, step 6
01, when it is less than the predetermined value, the routine proceeds to step 301, where the low clutch pressure normal time hydraulic control is performed.

In step 601, the motor generator torque and the engine torque are smaller than those when the brake oil pressure is less than the predetermined value so that the creep torque becomes smaller than the creep torque generated when the brake oil pressure is less than the predetermined value. Set to.

FIG. 15 is a time chart showing the creep mode control in the fourth embodiment, and the dotted line is a comparative example when the motor generator torque is not reduced.
The above control will be described based on a time chart.

In the creep running state in which the D range, which is the running range, is detected and the driver does not step on the accelerator, the engine 1 continues the idle rotation speed and the creep mode control is performed. At this time, the low clutch L / C is under normal low clutch hydraulic control, and the line pressure is supplied to the low clutch L / C via the pressure control valve 93. The line pressure PL is determined based on the transmission input shaft torque, and is adjusted by a pressure adjusting valve (not shown), so the low clutch L / C does not slip.

Further, the torque of the motor generator 2 is
The engine torque estimated from the idle rotation speed of the engine 1 and the charge amount SOC of the battery 12 so that a preset creep torque is output from the transmission output shaft OUT.
The torque determined from and is output.

When the driver intends to stop and depresses the brake, the drive wheels 8 are fixed, and as the rotation of the transmission output shaft OUT is stopped, the transmission input shaft 4 is passed through the low clutch L / C.
Also stops rotating. Therefore, the transmission input shaft rotation speed is T
It becomes 0 between 41 and T42.

Here, when the motor generator torque is set to a small torque, the predetermined brake oil pressure which is the control start condition is set to a value larger than the predetermined brake oil pressure set in the first to third embodiments. This is to reduce the motor generator torque only when the brake hydraulic pressure is strong enough that the driver does not intend to creep. That is, when the motor generator torque is reduced, the creep torque is also reduced, which prevents the driver from feeling uncomfortable because the vehicle cannot travel smoothly.

If it is obvious that the brake is surely depressed and the creep running is not intended, in step 601, the forward direction torque of the motor generator 2 is set as the forward direction of the vehicle. At the same time as the reduction, the average engine torque is reduced to (motor generator torque / tooth ratio).
That is, the engine 1 is constantly rotating at the idle rotation speed, and the steady engine torque and the idle rotation speed are input to the ring gear 31. Since the low clutch L / C is engaged and the drive wheel 8 is also fixed by the brake, the rotation speed of the carrier 32 is zero.

Therefore, from the alignment chart, the motor generator 2
The sun gear 33 connected to is rotating negatively. In the positive direction torque output state of the motor generator 2, since the positive direction torque is output by the rotation in the negative direction, the generator is in a regenerative operation state. Therefore, the reduction of the forward torque of the motor generator 2 means the reduction of the regeneration amount as the generator. At the same time, the average engine torque is reduced while maintaining the engine rotation speed so that the engine torque corresponds to the reduced motor generator torque.

The torque output to the carrier 32 is the sum of the engine torque and the motor generator torque. By reducing the motor generator torque and the average engine torque, the torque applied to the carrier 32 is reduced, and the carrier torque fluctuation amplitude is reduced. Therefore, the torque accumulated in the drive device can be reduced.

When the brake is released, the motor-generator torque and the engine torque are restored to normal torque, so that the creep force can be obtained.

As described above, in the hybrid vehicle control device according to the fourth embodiment, the torque accumulated in the drive device is reduced by reducing the motor generator torque and the average engine torque accordingly. Can be reduced, and noise and vibration can be reduced.

Further, it is possible to minimize the response delay until the creep force is generated after the creep mode control is released.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram showing an embodiment.

FIG. 2 is a skeleton diagram of a speed change mechanism unit according to the embodiment.

FIG. 3 is an engagement logic table of the speed change mechanism unit in the embodiment.

FIG. 4 is a schematic diagram showing a configuration of a hydraulic control circuit in the embodiment.

FIG. 5 is a sectional view showing a configuration of a pressure control valve.

FIG. 6 is a flowchart showing control of the hybrid vehicle in the embodiment.

FIG. 7 is a flowchart showing creep mode control in the first embodiment.

FIG. 8 is a time chart showing the creep mode control in the first embodiment.

FIG. 9 is an alignment chart of the planetary gear mechanism during creep mode control in the first embodiment.

FIG. 10 is a flowchart showing creep mode control in the second embodiment.

FIG. 11 is a time chart showing creep mode control in the second embodiment.

FIG. 12 is a flowchart showing creep mode control in the third embodiment.

FIG. 13 is a time chart showing creep mode control in the third embodiment.

FIG. 14 is a flowchart showing creep mode control in the fourth embodiment.

FIG. 15 is a time chart showing creep mode control in the fourth embodiment.

FIG. 16 is a time chart showing engine torque fluctuations and torque accumulated on a drive shaft in a conventional technique.

[Explanation of symbols]

1 engine 2 motor generator 3 Planetary gear mechanism 4 Transmission input shaft 5 one-way clutch 6 Transmission mechanism 7 differential 8 drive wheels 9 Hydraulic control circuit 10 engine ECU 11 Motor generator ECU 11a inverter 12 batteries 13 Hybrid ECU 14 AT ECU 21 Accelerator sensor 22 Shift position sensor 23 Engine speed sensor 24 Throttle opening sensor 25 Motor rotation speed sensor 26 Output shaft rotation speed sensor 27 Input shaft rotation speed sensor 28 Brake oil pressure sensor 41 solenoid 31 ring gear 32 carriers 33 Sun Gear 40 solenoid valve 41 coils 42 Plunger 43 balls 44 channel 50 spool valve 51 spool 91 Manual valve 92 Pilot valve 93,94,95,96,97,98 Pressure control valve

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) B60K 6/04 733 B60K 6/04 733 B60L 11/14 B60L 11/14 // F16H 59:08 F16H 59: 08 59:54 59:54 F Term (reference) 3J552 MA02 NA01 NB09 PA45 RC07 RC12 SA07 VA62W VA76W VD11W 5H115 PA01 PC06 PG04 PI16 PI21 PO06 PU08 PU22 PU23 PU28 PV09 QE10 QE11 QI04 QN03 RE03 SE04 TE02 TE03 TI02 TO04 TO21 TO21 TO04 TO21 TO21

Claims (7)

[Claims] 1. An engine, an electric rotary drive source having both functions of a generator and an electric motor, a transmission for transmitting torque to drive wheels via a drive shaft, and an output shaft of the engine for a first shaft. And a differential device in which an output shaft of the electric rotary drive source is connected to a second shaft and the transmission device is connected to a third shaft, respectively, and the third shaft is rotated in one direction. In a parallel hybrid vehicle having a one-way clutch that allows only direction, in the parallel hybrid vehicle, a range position detecting means for detecting a range position of the transmission, and a brake state detecting means for detecting a brake state of the drive wheels. When the range position detecting means detects that the vehicle is in the traveling range and the brake state detecting means detects the brake state, the twist amount of the drive shaft is reduced. Parallel hybrid vehicle, characterized by comprising the Gillet amount reduction means. 2. The parallel hybrid vehicle according to claim 1, wherein the transmission has a friction element that is brought into a neutral state by being released, and the twist amount reducing means reduces a fastening capacity of the friction element. A parallel hybrid vehicle characterized by being a means for reducing the engagement capacity. 3. The parallel hub vehicle according to claim 2, wherein the engagement capacity lowering means is means for lowering the engagement capacity of the friction element after a predetermined time elapses after the input shaft rotation speed becomes a predetermined value or less. A parallel hybrid vehicle characterized by the above. 4. The parallel hybrid vehicle according to claim 2, wherein the engagement capacity reducing means is means for intermittently reducing the engagement capacity every predetermined time. 5. The parallel hybrid vehicle according to claim 2, wherein the engagement capacity reducing means is means for continuously reducing the engagement capacity. 6. The parallel hybrid vehicle according to claim 4 or 5, further comprising an input shaft average torque calculating means for calculating an average torque of the input shaft based on a current torque of an electric drive source, wherein the engagement capacity is reduced. A parallel hybrid vehicle, wherein the means is means for reducing the engagement capacity to substantially match the average torque of the input shaft based on the calculation result of the calculation means. 7. The parallel hybrid vehicle according to claim 1, wherein the twist amount reducing means is a rotary drive source torque reducing means for reducing a torque of the electric rotary drive source as compared with a torque at a normal time. Is a parallel hybrid vehicle.