JP2009191997A - Control device of transmission for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent an engaging shock of a start clutch in restarting from an idle stop, in a control device of a transmission for a vehicle comprising an oil pump connected to an engine having an idle stop control means for stopping and restarting the engine according to operating conditions, and driven by the engine, and the start clutch (an engaging element for starting) supplied with an operating oil pressure from the oil pump. <P>SOLUTION: When restarting the engine from the idle stop, the engagement processing of the start clutch is permitted after the engine speed NE reaches a threshold NESL or higher and further a reference time T has elapsed after the engine speed NE reached the threshold NESL or higher. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention is connected to an engine having an idle stop control means for stopping and restarting the engine in accordance with operating conditions, and an oil pump driven by the engine and an operating hydraulic pressure from the oil pump are The present invention relates to a control device for a vehicle transmission including a starting fastening element to be supplied.

In Patent Document 1, when the engine is restarted by the idle stop control means, a target engagement time and a target engagement torque of a starting engagement element (starting clutch) are set based on the accelerator opening, The engine torque is controlled based on the above.
JP 2006-219084 A

In the above-mentioned Patent Document 1, the target engagement time and the target engagement torque must be set assuming oil outflow from an oil passage or a clutch pack due to idle stop, and therefore, the characteristics of the outflow are tested. Therefore, it is necessary to obtain the optimum value of the target fastening time and the target fastening torque.
Also, there are various oil outflow states, and it is difficult to accurately estimate the rising state of the oil pressure, and there is a possibility that a shock may occur due to a sudden increase in the fastening pressure at the start due to an estimation error. .

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a control device for a vehicle transmission that can prevent occurrence of an engagement shock of a starting clutch when restarting from an idle stop with a small number of adaptation steps. And

  Therefore, in the present invention, when it is determined that the operating hydraulic pressure from the oil pump has reached a predetermined hydraulic pressure when the engine is restarted from the idle stop state, the fastening process of the fastening element for starting is started. I made it.

  According to the above invention, since the fastening process is prevented from being started in a state where the hydraulic pressure supply to the starting friction element is insufficient, the hydraulic pressure can be changed smoothly by the hydraulic control, and the starting shock can be changed. On the other hand, since only the determination as to whether or not the operating hydraulic pressure has reached a predetermined hydraulic pressure is performed and the fastening control is normally performed, it is possible to realize the control that can prevent the start shock with a small number of adaptation man-hours.

Embodiments of the present invention will be described below.
FIG. 1 shows a power system of a vehicle in the embodiment.
In FIG. 1, the output of the engine (internal combustion engine) 100 is transmitted to drive wheels 408 via a starting clutch (starting friction element) 200 and a continuously variable transmission 300.
Specifically, the crankshaft 101 of the engine 100 is connected to the input shaft 221 of the start clutch 200, and the input shaft 301 of the continuously variable transmission 300 is coupled to the output shaft 222 of the start clutch 200. Yes.

Further, the output shaft 302 of the continuously variable transmission 300 is connected to a wheel drive shaft 407 and a drive wheel 408 via a propeller shaft 404, a final gear 405, and a differential gear 406.
The starting clutch 200 is a wet multi-plate clutch, and includes an inner clutch plate 223 that connects and disconnects the input shaft 221 and the output shaft 222, and a planetary gear mechanism 224 that is interposed between the input shaft 221 and the output shaft 222. A support shaft of the intermediate gear 224a and an outer clutch plate 226 that connects and disconnects the clutch case (fixed body) 225 are provided.

The inner clutch plate 223 and the outer clutch plate 226 are each driven by a piston of a hydraulic cylinder to control the engagement state (fastening force).
When the vehicle moves forward, the forward driving force of the vehicle is increased by increasing the fastening force from the released state of the inner clutch plate (forward clutch) 223. When the vehicle moves backward, the outer clutch plate (reverse clutch) 226 is By increasing the fastening force from the released state, the reverse drive force of the vehicle is increased.

Further, a torsional damper 227 is provided on the input side of the starting clutch 200, and torsional vibration is suppressed by the torsional damper 227.
A system in which a torque converter is interposed between the starting clutch 200 and the engine 100 instead of the torsional damper 227 can be adopted.
The continuously variable transmission 300 is a belt-type continuously variable transmission that uses a pair of variable groove width pulleys and a metal belt wound around them.

The continuously variable transmission 300 includes a primary pulley 303 provided on the input shaft 301 side, a secondary pulley 304 provided on the output shaft 302 side, and hydraulic pressures for changing the groove widths (effective diameters) of the pulleys 303 and 304, respectively. Cylinders 305 and 306 and a metal belt 307 wound around the pulleys 303 and 304 are provided.
In the continuously variable transmission 300, the pulley ratio changes by controlling the hydraulic pressure of the hydraulic cylinders 305 and 306, and the gear ratio changes steplessly according to the change in the pulley ratio.

In addition, an oil pump 450 that is rotationally driven by the crankshaft 101 of the engine 100 is provided, and hydraulic pressure discharged from the oil pump 450 is supplied to the starting clutch 200 and the hydraulic cylinders 305 and 306. It has become.
The intake air amount, fuel injection amount, ignition timing, etc. in the engine 100 are controlled by an engine control module (hereinafter referred to as ECM) 500 having a microcomputer.

  Here, the ECM 500 automatically stops the operation of the engine 100 when the vehicle is stopped (vehicle speed = 0 km / h) and an idle stop condition such as a brake operation state by the driver is satisfied. The engine 100 is provided with a control function (idle stop control means) that automatically restarts the engine 100 when a restart condition such as a brake release operation by the driver or depression of an accelerator pedal is established.

In addition, the engagement / disengagement operation of the starting clutch 200 and the operation of the hydraulic cylinders 305 and 306 in the continuously variable transmission 3 are controlled by the supply of operating hydraulic pressure by a transmission control unit (hereinafter referred to as TCU) 600 incorporating a microcomputer. Be controlled.
The TCU 600 determines a target gear ratio from the driving state of the vehicle (vehicle speed, accelerator opening degree, etc.), and controls the oil pressure of the hydraulic cylinders 305 and 306 to bring the actual gear ratio closer to the target gear ratio. The start clutch engagement control (so-called ND selection control) is performed according to the selection of the shift range.

The ECM 500 and the TCU 600 are communicably connected to each other, and the ECM 500 is a signal of the engine rotational speed NE calculated based on the output from the rotation sensor 501 with respect to the TCU 600, whether or not it is in an idle stop state. , A signal of the opening degree TVO of the throttle valve 503 detected by the throttle sensor 502, and the like are output.
By the way, when the engine 100 is stopped, the oil pump 450 is stopped, the hydraulic pressure supplied to the start clutch 200 and the hydraulic cylinders 305 and 306 is released, and when the engine 100 is restarted from the idle stop state, the start clutch 200 is stopped. Is in a state where its engaged state has been released.

For this reason, when the engine 100 is restarted from the idle stop state and the vehicle is started, it is necessary to supply hydraulic pressure to the start clutch 200.
However, since the rise of the operating hydraulic pressure from the oil pump 450 is delayed with respect to the restart of the engine 100, and the discharge pressure is unstable immediately after the oil pump 450 is started, the start clutch 200 is synchronized with the engine restart. When the hydraulic pressure supply control (fastening process) is started, a fastening shock may occur due to a sudden increase in the fastening hydraulic pressure (see FIG. 3).

Therefore, the TCU 600 performs the engagement control of the start clutch 200 at the time of restart from the idle stop, as shown in the flowchart of FIG. 2, in order to engage the start clutch 200 while preventing the occurrence of the engagement shock. Do.
In the flowchart of FIG. 2, in step S1001, it is determined whether or not an idle stop is being performed.

When the engine is idling, the engine 100 is stopped and the oil pump 450, which is the supply source of the operating hydraulic pressure, is also stopped, so that the operating hydraulic pressure cannot be supplied to the starting clutch 200. .
On the other hand, if the engine is not idling stop, the process proceeds to step S1002, and it is determined whether or not it is determined that the hydraulic pressure (discharge pressure) in the hydraulic circuit from the oil pump 450 has reached the required pressure.

The determination that the required pressure has been reached is canceled during the idle stop, and the determination is set when the routine proceeds to step S1008 described later, and the engine 100 is restarted from the idle stop state. In the initial stage of switching to NO, a determination of NO (determination that the required pressure has not been reached) is made in step S1002.
If NO is determined in step S1002, the process proceeds to step S1003, and it is determined whether or not the engine speed NE at that time is equal to or higher than a threshold value NESL.

Since the oil pump 450 is rotationally driven by the engine 100, the engine rotational speed NE is proportional to the rotational speed of the oil pump 450 and correlates with the discharge amount of hydraulic oil from the oil pump 450.
As shown in FIG. 3, the threshold NESL is set to a rotational speed that is higher than the cranking speed and lower than the idle rotational speed, and that the engine rotational speed NE is equal to or higher than the threshold NESL. This indicates that the discharge amount exceeds the reference amount.

When the engine speed NE is less than the threshold NESL, in other words, when cranking for engine restart is being performed and the discharge amount of the oil pump 450 is small, the process proceeds to step S1004, and the engine speed is increased. The measured value of the elapsed time after NE reaches the threshold value NESL (after the first explosion) is reset to zero.
After step S1004, the process proceeds to step S1007, where the engagement control of the start clutch 200 is held in a stopped state, and the operation hydraulic pressure is not supplied to the start clutch 200 (engagement control).

On the other hand, if it is determined in step S1003 that the engine rotational speed NE has become equal to or higher than the threshold value NESL, the process proceeds to step S1005, and the elapsed time after the engine rotational speed NE is switched from the state below the threshold value NESL to the threshold value NESL or more is measured. .
In the next step S1006, it is determined whether or not the measurement result of the elapsed time has reached a reference time T.

The reference time T is determined from a standard time required until the hydraulic pressure (discharge pressure) in the hydraulic circuit from the oil pump 450 becomes a required pressure, and can be set as a fixed value stored in advance. It can be variably set according to the load.
The engine load can be represented by, for example, the opening degree TVO of the throttle valve 503. As shown in FIG. 4, the reference time T becomes longer as the engine load (the opening degree TVO of the throttle valve 503) is larger. Set to time.

  This is because the higher the engine load (TVO), the higher the tightening torque of the start clutch 200 is required. For this purpose, a higher operating hydraulic pressure needs to be supplied to the start clutch 200. The higher the (TVO), the longer the time (delay time) required to permit the engagement control of the starting clutch 200, and the engagement control is permitted after reaching a higher hydraulic pressure.

It should be noted that the load on engine 100 is not limited to the configuration in which the load on engine 100 is determined based on throttle opening TVO, and the load on engine 100 can be determined from the basic injection amount, boost pressure, intake air amount, and the like.
If the state where the engine speed NE is equal to or greater than the threshold NESL continues for the reference time T, it is estimated that the hydraulic pressure (discharge pressure) in the hydraulic circuit from the oil pump 450 has reached the required pressure, and the process proceeds to step S1008. It is determined that the discharge pressure from the oil pump 450 has reached the required pressure.

Steps S1002 to S1006 and S1008 described above correspond to the hydraulic pressure determination means.
Then, after step S1008, the process proceeds to step S1009 (engagement processing delay means) to permit the engagement control of the start clutch 200, and if the selected range at that time is a travel range (for example, D range), the start clutch 200 Execute fastening control.

That is, when the engine 100 is restarted from the idle stop state, the start of engagement of the start clutch 200 is delayed until it is determined that the hydraulic pressure in the hydraulic circuit from the oil pump 450 has reached the required pressure. The start clutch 200 is engaged after the hydraulic pressure reaches the required pressure (see FIG. 3).
Accordingly, when the starting clutch 200 from which oil has been released due to idle stop is engaged when the engine 100 is restarted, the engagement process is performed with the hydraulic pressure sufficiently high. It is possible to control the change in hydraulic pressure during the period, and to prevent the occurrence of shock due to a sudden increase in the fastening pressure (see FIG. 3).

Further, in the above-described embodiment, it is possible to realize the fastening control that can avoid the occurrence of shock only by adapting the threshold value NESL of the engine rotational speed NE and the reference time T, and it is possible to reduce the man-hours for conforming the control specifications.
The determination of the elapsed time can be omitted, and it can be set to permit the engagement control of the starting clutch 200 when the engine speed NE becomes equal to or higher than the threshold NESL.

  In the first embodiment shown in the flowchart of FIG. 2 above, the increase in hydraulic pressure (discharge pressure) in the hydraulic circuit is estimated based on the engine rotational speed NE proportional to the rotational speed of the oil pump 450, but a hydraulic sensor is used. The fastening control of the second embodiment that can directly detect the hydraulic pressure and uses the hydraulic pressure sensor will be described with reference to the system diagram of FIG. 5 and the flowchart of FIG.

As shown in FIG. 5, the second embodiment includes a hydraulic sensor 601 that generates an output correlated with the hydraulic pressure (discharge pressure) of the hydraulic circuit from the oil pump 450, and the output of the hydraulic sensor 601 is the TCU 600. To be input.
Since the system configuration other than the hydraulic sensor 601 is the same as that of FIG. 1 showing the system configuration of the first embodiment, detailed description thereof is omitted.

  In the flowchart of FIG. 6, steps S2001, S2002, S2004 to S2009 other than step S2003 perform the same processing as steps S1001, S1002, and S1004 to S1009 of the flowchart of FIG. This process will be mainly described, and detailed description of the other steps will be omitted.

In step S2003, the oil pressure (discharge pressure) in the oil pressure circuit from the oil pump 450 is detected from the output of the oil pressure sensor 601, and it is determined whether or not the oil pressure detection value is equal to or higher than a reference pressure.
If the hydraulic pressure detection value is less than the reference pressure, after resetting the measurement result of the elapsed time in step S2004, the process proceeds to step S2007, where the engagement control of the start clutch 200 is held in a stopped state, and the start clutch 200 is stopped. The hydraulic pressure is not supplied (engagement control).

On the other hand, when the hydraulic pressure detection value becomes equal to or higher than the reference pressure, the process proceeds to step S2005, and the elapsed time from the time when the hydraulic pressure detection value becomes equal to or higher than the reference pressure is measured.
If it is determined in the next step S2006 that the elapsed time has reached the reference time T, the process proceeds to step S2008, where it is determined that the discharge pressure from the oil pump 450 has reached the required pressure, and the next step In S2009, the engagement control of the start clutch 200 is permitted, and if the travel range (for example, the D range) is selected, the engagement process of the transmission clutch 200 is started.

In the case of the second embodiment as well, since the start clutch 200 is engaged after the oil pressure is sufficiently high, it can be controlled to the desired oil pressure by the oil pressure control signal, and a sudden increase in the engagement pressure can be achieved. Can prevent the occurrence of shocks and reduce the man-hours for conforming to the control specifications.
In the second embodiment, since the hydraulic pressure is not estimated but the discharge pressure of the oil pump 450 is directly detected by the hydraulic sensor 601, there are conditions such as the amount of oil leakage from the clutch pack and the hydraulic circuit. Even if they are different from each other, the engagement process of the starting clutch 200 can be delayed by a necessary minimum.

That is, when the discharge pressure of the oil pump 450 is estimated from the engine rotational speed NE as in the first embodiment, the start clutch 200 is estimated until it is estimated that the required pressure is obtained even when the oil leaks most. Unless the start of fastening is delayed, the occurrence of fastening shock cannot be avoided reliably.
On the other hand, if the hydraulic pressure is detected directly, the start of engagement of the start clutch 200 can be permitted in a shorter time if the hydraulic pressure is restored immediately with a small amount of leakage, and excessive start of engagement of the start clutch 200 is excessive. There is no delay.

In the second embodiment as well, the determination of the elapsed time can be omitted and the engagement control of the starting clutch 200 can be permitted when the hydraulic pressure detected by the hydraulic pressure sensor 601 becomes equal to or higher than the reference pressure. .
Further, instead of the hydraulic sensor 601, a hydraulic switch whose output is switched on and off at a set pressure can be used, and the third embodiment using the hydraulic switch is shown in the system diagram of FIG. 7 and FIG. As illustrated in FIG. 7 according to the flowchart, the third embodiment includes a hydraulic switch 602 that switches on and off the output depending on whether the hydraulic pressure in the hydraulic circuit from the oil pump 450 is higher or lower than the set pressure. The output (ON / OFF signal) of the hydraulic pressure sensor 601 is input to the TCU 600.

Since the system configuration other than the hydraulic switch 602 is the same as that of FIG. 1 showing the system configuration of the first embodiment, detailed description thereof is omitted.
In the flowchart of FIG. 8, steps S3001, S3002, and S3004 to S3009 other than step S3003 perform the same processing as steps S1001, S1002, and S1004 to S1009 of the flowchart of FIG. This process will be mainly described, and detailed description of the other steps will be omitted.

  In step S3003, it is determined whether the hydraulic switch 602 is on or off. If the hydraulic pressure (discharge pressure) in the hydraulic circuit is less than a set pressure and the hydraulic switch 602 is off, the elapsed time is measured in step S3004. After resetting the result, the process proceeds to step S3007, where the engagement control of the start clutch 200 is held in a stopped state, and the operation hydraulic pressure is not supplied to the start clutch 200 (engagement control).

On the other hand, if the hydraulic pressure in the hydraulic circuit is equal to or higher than the set pressure and the hydraulic switch 602 is on, the process proceeds to step S3005, and the elapsed time from when the hydraulic pressure becomes equal to or higher than the set pressure is measured.
When it is determined in the next step S3006 that the elapsed time has reached the reference time T, the process proceeds to step S3008, where it is determined that the discharge pressure from the oil pump 450 has reached the required pressure. In step S3009, the engagement control of the start clutch 200 is permitted, and if the travel range (for example, the D range) is selected, the engagement control of the start clutch 200 is started.

Also in the case of the third embodiment, since the start clutch 200 is engaged after the oil pressure is sufficiently high, it can be controlled to the desired oil pressure by the oil pressure control signal, and a sudden increase in the engagement pressure can be achieved. Can prevent the occurrence of shocks and reduce the man-hours for conforming to the control specifications.
Further, in the third embodiment, by using a hydraulic switch 602 that is generally less expensive than the hydraulic sensor 601, the start clutch 200 is permitted to be engaged according to the actual hydraulic state while reducing the system cost. , It is possible to avoid excessive delay in the fastening process.

Also in the third embodiment, the determination of the elapsed time is omitted, and the engagement control of the starting clutch 200 is permitted when the hydraulic switch 602 is turned on (when the hydraulic pressure becomes equal to or higher than the set pressure). Can be set as follows.
Further, the transmission is not limited to the continuously variable transmission 300 described above, and may be a power train that combines a stepped transmission using a planetary gear with an engine via a starting clutch (forward clutch).

FIG. 9 shows a power train of a vehicle using a stepped transmission.
The power train shown in FIG. 9 includes an engine 1, a torque converter 2, a stepped automatic transmission 3, an ECM 500, and a TCU 600.
The output shaft of the engine 1 is connected to the input shaft of the torque converter 2, and the output shaft of the torque converter 2 is connected to the input shaft of the automatic transmission 3.

The torque converter 2 includes a lock-up clutch 21 that mechanically connects the input shaft and the output shaft, a pump impeller 22 on the input shaft side, a turbine impeller 23 on the output shaft side, and a one-way clutch 25. And a stator 24 that exhibits a torque amplification function.
The automatic transmission 3 is a planetary gear type stepped transmission, and includes clutch elements (C1 to C4 in the figure) that are friction engagement elements, brake elements (B1 to B4), and one-way clutch elements (F0 to F3). ) Is determined by the combination of engagement and release.

  Of the clutch elements (C1 to C4), the clutch element C1 is an input clutch 31. The input clutch 31 is used when a vehicle other than the parking (P) position, the reverse travel (R) position, and the neutral (N) position is used. A clutch that is always used in an engaged state when configuring a shift stage to move forward. For example, when shifting from the N range to the D range, control is performed to engage the input clutch 31 that has been released. Is called.

In other words, the input clutch 31 is fastened in a forward travel range (D range, etc.) other than the P range, R range, and N range, and the input clutch 31 is also referred to as a forward clutch or a forward clutch. This corresponds to the starting clutch 200.
The configuration of the frictional engagement element in the automatic transmission 3 is not limited to that shown in FIG. 9 and is called an input clutch 31, a forward clutch, a forward clutch, etc., and is always in the forward travel position (D range, etc.). What is necessary is just a stepped transmission provided with the clutch (engagement element for starting) fastened.

  The TCU 600 includes a shift position signal SP from the inhibitor switch 51 that outputs a signal corresponding to the operation position of the shift lever operated by the driver, an accelerator opening from the accelerator opening sensor 52 that detects the amount of depression of the accelerator pedal. From the signal APS, the vehicle speed signal VSP from the vehicle speed sensor 53 that detects the vehicle speed from the output shaft rotation speed of the automatic transmission 3, and from the turbine rotation sensor 54 that detects the turbine rotation speed that is the input shaft rotation speed of the automatic transmission 3 The turbine rotation signal NT is input.

The ECM 500 has a function of controlling the intake air amount, fuel injection amount, ignition timing, and the like in the engine 1 by arithmetic processing based on signals from various sensors that detect the operating conditions of the engine 1.
The TCU 600 and the ECM 500 are configured to communicate with each other, and the TCU 600 includes an engine rotation signal NE and an idle stop signal from the engine rotation sensor 41 that detects the rotation speed of the engine 1 via the ECM 500. Etc. are entered.

Then, at the time of restart from idle stop, the TCU 600 performs the engagement control of the input clutch 31 in the same manner as the engagement control of the start clutch 200 shown in each of the above-described embodiments, thereby preventing a start shock.
The present invention has been described based on the embodiments. However, the specific configuration of the present invention is not limited to each embodiment, and even if there is a design change or the like without departing from the scope of the invention, Included in the invention.

The figure which shows the motive power system for vehicles in 1st Embodiment. The flowchart which shows the fastening process of the starting clutch after the idle stop in the said 1st Embodiment. The time chart which shows the change of the fastening pressure of the starting clutch in the said 1st Embodiment. The diagram which shows the correlation with the engine load (TVO) and the reference time T in the said 1st Embodiment. The figure which shows the motive power system for vehicles in 2nd Embodiment. The flowchart which shows the fastening process of the starting clutch after the idle stop in the said 2nd Embodiment. The figure which shows the motive power system for vehicles in 3rd Embodiment. The flowchart which shows the fastening process of the starting clutch after the idle stop in the said 3rd Embodiment. The system diagram which shows the power train of the vehicle comprised including a stepped transmission.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 100 ... Engine, 200 ... Starting clutch (fastening element for starting), 300 ... Continuously variable transmission, 450 ... Oil pump, 500 ... Engine control module (ECM), 501 ... Rotation sensor, 502 ... Throttle sensor, 503 ... Throttle Valve, 600 ... Transmission control unit (TCU), 601 ... Hydraulic sensor, 602 ... Hydraulic switch

Claims (6)

The engine is connected to an engine having an idle stop control means for stopping and restarting the engine according to operating conditions, and an oil pump driven by the engine and a start to which operating hydraulic pressure is supplied from the oil pump. A vehicular transmission control device comprising:
Oil pressure determination means for determining the operating oil pressure supplied to the starting fastening element;
When the engine is restarted by the idle stop control means, the fastening for starting the fastening processing of the starting fastening element after the hydraulic pressure judgment means determines that the operating hydraulic pressure has reached a predetermined hydraulic pressure Processing delay means;
A control device for a transmission for a vehicle, comprising:   2. The control apparatus for a vehicle transmission according to claim 1, wherein the hydraulic pressure determination unit estimates the operating hydraulic pressure based on a rotation speed of the engine.   2. The control apparatus for a vehicle transmission according to claim 1, wherein the hydraulic pressure determination means determines the operating hydraulic pressure based on a signal from a hydraulic pressure sensor.   2. The control apparatus for a vehicle transmission according to claim 1, wherein the hydraulic pressure determining means determines the operating hydraulic pressure based on a signal of a hydraulic switch.   When the fastening processing delay means has reached a reference time after the engine speed or the hydraulic pressure detected by the hydraulic sensor reaches a reference value, or when a reference time has elapsed since the hydraulic switch was turned on / off. The control device for a vehicle transmission according to any one of claims 2 to 4, wherein it is determined that the operating hydraulic pressure has reached a predetermined hydraulic pressure.   6. The control device for a vehicle transmission according to claim 5, wherein the fastening processing delay means variably sets the reference time according to a load of the engine.

Images