JP4376562B2 - Automatic transmission gear shifting hydraulic system - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a transmission hydraulic device for an automatic transmission, and more particularly to a vehicle control device including an idle stop control device that stops idling of an engine when the vehicle is stopped while traveling.
[0002]
[Prior art]
A technique is known in which the fastening pressure of the forward fastening element is reliably secured by rapidly filling the fastening pressure to the forward fastening element when the engine is restarted after idling stop (see Patent Document 1). In this technique, the turbine rotational speed is detected, and the rapid filling is finished at a timing that can be a predetermined time ΔT before the apex of the turbine rotational speed generated at the time of starting, and the control is switched to the fastening control at the time of normal starting.
[0003]
[Patent Document 1]
JP 2000-35122 A (see FIG. 7).
[0004]
[Problems to be solved by the invention]
However, the above-described prior art has the following problems. That is, when the engine speed rapidly increases as in the case where the driver fully depresses the accelerator pedal, the predetermined time ΔT is naturally reduced. Even if the influence of secular change or the like can be corrected by learning control or the like, the timing is not corrected in real time based on the driving intention of the driver because it is controlled based on a unique time of ΔT. was there.
[0005]
The present invention has been made paying attention to the above-described problems of the prior art, and in an automatic transmission shift hydraulic system using an oil pump driven by an engine as a hydraulic supply source, the engine is restarted after an idle stop. It is an object of the present invention to provide a transmission hydraulic device for an automatic transmission that can achieve a smooth start at the time of start according to a driver's intention to travel.
[0006]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, in the present invention, in a transmission hydraulic device for an automatic transmission having an idle stop control means, the forward movement is performed based on a map that includes oil temperature, throttle opening, or engine stop time as an element. Set the target engine speed at which the fastening pressure of the fastening element can be secured, and when the engine restarts after idling stop, the communication command between the forward fastening element and the bypass oil passage is output and set to the switching valve. When the target engine speed is reached, a communication command between the forward fastening element and the normal oil passage is output, The engine speed when the vehicle starts is detected, and it is determined whether or not the speed difference obtained by subtracting the target engine speed from the detected start engine speed is greater than a predetermined positive speed difference set in advance. When the engine speed is large, the target engine speed set in the map is corrected to be increased. When the engine speed is small, the detected throttle opening is decreased in the direction to decrease the target engine speed set in the map. Execute the correction only when the value is greater than or equal to the specified value It was decided to.
[0007]
[Action and effect of the invention]
In the transmission hydraulic device of the automatic transmission according to the present invention, the target engine speed at which the fastening pressure of the forward fastening pressure can be secured is set from a map that uses oil temperature, throttle opening, or engine stop time as an element. The switching valve is switched when the target engine speed is reached. That is, the engine speed is linearly related to the oil pump discharge amount at least at the time of starting, and has a great relationship with the timing of securing the fastening pressure of the forward fastening element. In addition, by switching based on the engine speed instead of the elapsed time, it becomes possible to set the switching timing of the switching valve according to the driver's intention to travel regardless of the increasing speed of the engine speed. Switching timing can be obtained. Moreover, unlike the prior art, it is not necessary to detect the turbine rotation speed, and the vehicle application range can be expanded.
[0008]
Also The engine speed when the vehicle starts is detected by restarting the engine after the idle stop. Then, based on the difference between the target engine speed set by the map and the detected start engine speed, the target engine speed set by the map Supplement I decided to correct it. As a result, since the switching valve is switched based on the actual start timing, the clutch plate becomes thinner due to aging (enlargement of the clutch clearance due to friction wear of the friction elements, deterioration of the oil pump), and it takes time to secure the engagement pressure. Even when a timing shift occurs due to a decrease in the friction coefficient or the like, the optimum switching timing can always be obtained by correcting the map value based on the actual engagement timing of the friction element.
[0009]
Further, since the viewpoint set from the map and the viewpoint set from the starting engine speed are used and the target engine speed set based on this different viewpoint is compared, the reliability can be improved.
[0010]
As a method of detecting the engine speed at the time of starting, the engine speed when the vehicle speed is generated may be detected. If the vehicle is equipped with a front and rear G sensor or the like, when the forward G occurs. The engine speed may be detected.
[0011]
Also The learning correction is executed only when the detected throttle opening is equal to or greater than a predetermined value. At a low throttle opening, the forward fastening element can absorb the start shock by shelf pressure control, and the fastening hydraulic pressure is low and the heat generation amount is small, so that it is not necessary to perform learning control. On the other hand, at a high throttle opening, the engine output torque is large and the fastening hydraulic pressure is also high, so that the start shock due to the shift of the switching timing is great, and the heat generation of the forward fastening element is greatly affected. Therefore, the calculation load can be reduced by performing learning control only in a necessary situation.
[0012]
Claim 2 In the invention described in (1), it is determined whether or not the detected start turbine speed is greater than a preset predetermined turbine speed, and if it is greater, the next idle stop control is prohibited. That is, even if the switching timing of the switching valve is corrected, there is a case where the deviation due to secular change or the like is so large that it cannot be handled only by timing correction. At this time, when the engine is restarted, the clutch plate generates a large amount of heat, and there is a risk that it will burn out beyond the heat capacity. Furthermore, it takes time to start, which may give the driver a feeling of strangeness. At this time, by prohibiting the idle stop control, it is possible to prevent the driver from feeling uncomfortable and to prevent the forward fastening element from being seized.
[0013]
In addition, as a turbine rotation speed value corresponding to the engine rotation speed at the start, for example, the turbine rotation speed is sensed, and the timing at which the turbine rotation speed once increases and then decreases again is detected as the turbine rotation speed at the start. That is, when the fastening pressure is secured after the turbine rotation speed is increased, a load is applied to the turbine by the vehicle inertia, and the turbine rotation speed is once reduced. Further, since the deviation of the turbine rotational speed has a linear relationship with the slip amount of the forward fastening element rather than the engine rotational speed, the switching timing can be obtained with higher accuracy.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a diagram illustrating a control system of an automatic transmission according to an embodiment.
[0015]
Reference numeral 10 denotes an engine, 20 denotes an automatic transmission, 30 denotes a torque converter, 50 denotes a control unit, and 60 denotes a starter generator.
The engine 10 is provided with a fuel supply device 11 and supplies fuel to the engine 10. Further, a chain sprocket 12 is provided, and is connected to the starter generator 60 by a chain 63 and a chain sprocket 62 provided via an electromagnetic clutch 61. When this starter generator 60 functions as a starter of the engine 10, a generator in a decelerating state, and a generator that generates electric power according to the storage state of the battery, the starter generator 60 is brought into an engaged state with the engine 10 by an electromagnetic clutch 61.
[0016]
Further, the automatic transmission 20 is provided with an oil pump 22 that is driven to rotate together with the engine 10, and supplies hydraulic pressure to the hydraulic servo 23.
[0017]
Signals from the idle stop switch 1, brake switch 2, steering angle sensor 3, oil temperature sensor 4, vehicle speed sensor 5, throttle opening sensor 6 and engine speed sensor 7 are input to the control unit 50, and the starter generator 60. And the operation of the fuel supply device 11 is controlled.
[0018]
In the first embodiment, the transmission mechanism unit 24 includes a gear type stepped transmission. FIG. 2 is a schematic diagram showing the configuration of the stepped transmission according to the first embodiment.
In FIG. 2, G1 and G2 are planetary gears, M1 and M2 are connecting members, R / C, H / C and L / C are clutches, B / B and L & R / B are brakes, L-OWC is a one-way clutch, IN Is an input shaft (input member), and OUT is an output shaft (output member).
[0019]
The first planetary gear G1 is a single pinion type planetary gear having a first sun gear S1, a first ring gear R1, and a first carrier PC1 that supports a pinion that meshes with both the gears S1 and R1.
The second planetary gear G2 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 the gears S2 and R2.
The third planetary gear G3 is a single pinion type planetary gear having a third sun gear S3, a third ring gear R3, and a third carrier PC3 that supports a pinion that meshes with both the gears S3 and R3.
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 a member that integrally connects the first ring gear R1 and the second carrier PC2.
[0020]
The reverse clutch R / C is engaged in the R range and connects the input shaft IN and the first sun gear S1.
The high clutch H / C is engaged at the third speed and the fourth speed, and connects the input shaft IN and the first carrier PC1.
The low clutch L / C is engaged when the first speed, second speed, and third speed gears, and connects the first carrier PC1 and the second ring gear R2.
The low & reverse brake L & R / B is engaged at the first speed and the R range, and fixes the rotation of the first carrier PC1.
The band brake B / B is engaged at the second speed and the fourth speed, and fixes the rotation of the first sun gear S1.
The low one-way clutch L-OWC operates at the first speed when the vehicle is accelerating, and fixes the rotation of the first carrier PC1. Does not work during deceleration.
[0021]
The input shaft IN is connected to the first ring gear R <b> 1 and inputs the engine rotational driving force via the torque converter 30. The output shaft OUT is connected to the second carrier PC2 and transmits the output rotational driving force to driving wheels via a final gear or the like not shown. Each clutch and brake is connected to a hydraulic servo 23 that generates an engagement pressure and a release pressure at each gear position.
[0022]
[Shifting action]
FIG. 3 is a diagram illustrating a fastening operation table in the transmission mechanism unit 24 of the first embodiment.
In FIG. 3, ◯ indicates a fastening state and × indicates a non-fastening state.
[0023]
FIG. 4 is a hydraulic circuit diagram showing a hydraulic circuit for supplying control hydraulic pressure from the hydraulic servo 23 to the transmission mechanism 24 in the first embodiment. An oil pump 22 driven by the engine 10, a pressure regulator valve 47 for adjusting the discharge pressure of the oil pump 22 as a line pressure, a first line pressure oil passage 39 for supplying the line pressure to the manual valve, and after passing through the manual valve A second line pressure oil passage 40 for supplying the line pressure is provided.
[0024]
Further, a first shift valve 41 and a second shift valve 42 for switching the hydraulic circuit, and pilot pressure oil passages 41b and 42b for supplying a pilot pressure for operating the shift valves 41 and 42 are provided. A low clutch pressure supply oil passage 101 that passes through the first shift valve 41 and supplies oil to the low clutch L / C is provided with a bypass oil passage 45 having a small passage resistance. The bypass oil passage 45 is provided immediately before the low clutch L / C, and a switching valve 44 for switching a communication state between the bypass oil passage 45 and the low clutch pressure supply oil passage 101 is provided.
[0025]
As shown in FIG. 3, the hydraulic pressure is originally supplied to the low clutch L / C at the first, second and third speeds, but the supply to the low clutch L / C must be stopped at the fourth speed. Interlocked. However, in the state where the first shift valve 41 is switched, the switching valve 44 sticks and the hydraulic pressure is not supplied even if the bypass oil passage 45 and the low clutch L / C remain in communication with each other. Can be prevented.
[0026]
Also, a pilot valve 48 that regulates the source pressure of the signal pressure, a line pressure duty solenoid 70 that outputs each signal pressure based on the pilot pressure supplied from the pilot valve 48, a lock-up solenoid 75, a first shift solenoid, A second shift solenoid or the like is provided. The signal pressure output from the line pressure duty solenoid 70 is supplied to the pressure modifier valve 80 and also to the low clutch accumulator control valve 90.
[0027]
The pressure modifier pressure adjusted by the pressure modifier valve 80 based on the signal pressure of the line pressure duty solenoid 70 acts on the pressure regulator valve 47 and changes the pressure adjustment level of the line pressure. Similarly, the signal pressure adjusted by the low clutch accumulator control valve 90 that operates based on the signal pressure of the line pressure duty solenoid 70 acts as the back pressure of the low clutch accumulator 300, and the piston stroke of the low clutch accumulator 300 is reduced. Control.
[0028]
The signal pressure output from the lockup solenoid 75 is supplied to the first shift valve 41 via the oil passage 76. The first shift valve 41 is connected to an oil passage 78 that communicates with a lockup control valve 74 that controls the engagement and release of the lockup clutch, and an oil passage 77 that communicates with the back pressure chamber of the switching valve 44. In the automatic transmission according to the present embodiment, the lockup clutch is not engaged at the first and second speeds. Therefore, when the first shift valve 41 is ON at the first and second speeds, the lock-up solenoid 75 and the switching valve 44 are communicated, and the first shift valve 41 at the third and fourth speeds is OFF. At this time, the lockup solenoid 75 and the lockup control valve 74 are communicated. Thus, the switching valve 44 can be switched by electronic control without increasing the number of components by using the lock-up solenoid 75 that is not normally used for the switching control of the switching valve 44.
[0029]
Here, if the full throttle start is performed immediately after the engine is restarted, the low clutch engagement torque is insufficient, and a large shock may occur. Moreover, since pressure loss occurs due to the pipe resistance of the low clutch oil passage, the actual low clutch hydraulic pressure may be lowered. Further, since this pressure loss is affected by the oil temperature, the controllability may be deteriorated.
[0030]
In view of the above-described problems, the set load of the spring provided in the switching valve 44 is used to ensure communication between the bypass oil passage 45 and the low clutch L / C until sufficient hydraulic pressure is secured from the pump. Think about making it higher. At this time, when sufficient hydraulic pressure is obtained from the pump, the communication between the bypass oil passage 45 and the low clutch L / C is switched after the pressure opposite to the spring is secured, thus solving the above-mentioned problems it can. However, during normal operation ND selection with sufficient pump oil pressure, the oil pressure is supplied from the shift valve to the low clutch L / C as usual. However, if the set load of the spring is too large, the bypass oil passage 45 and the low clutch L / C communicate with each other before that, and there is a possibility that a select shock or the like occurs. Therefore, by using the signal oil pressure of the lock-up solenoid 75, the oil pressure is smoothly supplied even if the full throttle starts immediately after the engine restart at the time of idling stop without increasing the set load of the spring more than necessary. In addition, a hydraulic circuit capable of preventing a select shock or the like in normal control is configured.
[0031]
FIG. 5 is an enlarged cross-sectional view of the switching valve 44. The switching valve 44 includes a spool valve 44f and a return spring 44g. The spool valve 44f is provided with a pressure receiving portion 44i that receives a hydraulic pressure opposed to the spring force of the return spring 44g.
[0032]
A normal low clutch pressure supply oil passage 101 having an orifice d1 is communicated with the port 44a, a low clutch L / C is communicated with the port 44b, and a bypass oil passage 45 having a small passage resistance is communicated with the port 44c. The pilot pressure oil passage 102 for switching is communicated with the port 44e, the low clutch accumulator oil passage 105 communicating with the low clutch accumulator chamber 300 is communicated with the port 44k, and the signal pressure of the lockup solenoid 75 is communicated with the port 44m. An oil passage 77 for supplying is communicated.
[0033]
Further, it is desirable to reduce the passage resistance of the bypass oil passage 45 as much as possible. That is, the other oil passages (particularly immediately before each fastening element) are provided with orifices for preventing surge pressure immediately after fastening, and further provided with an accumulator to adjust the rise characteristic of the line pressure. On the other hand, by setting the passage resistance of the bypass oil passage 45 to be small, a large amount of oil discharged from the oil pump can be supplied to the low clutch L / C.
[0034]
When the signal pressure from the lockup solenoid 75 is supplied, the switching valve 44 is urged upward in FIG. 5 by the lockup solenoid signal pressure and the spring force of the return spring 44g to bypass the low clutch L / C and the bypass. The oil passage 45 is communicated. When the signal pressure from the lockup solenoid 75 is not supplied, the switching valve 44 is urged downward in FIG. 5 to connect the low clutch L / C and the normal oil passage 101.
[0035]
FIG. 6 is a flowchart showing the control content of the idle stop control in the first embodiment.
[0036]
In step 101, it is determined whether the idle stop flag Fi is 1, the idle stop switch 1 is energized, the vehicle speed is 0, the brake switch is ON, the steering angle is 0, and a range other than the R range is selected. The process proceeds to step 102 only when the condition is satisfied, otherwise the idle stop control is ignored.
[0037]
In step 102, it is determined whether or not the oil temperature Toil is higher than the lower limit oil temperature Tlow and lower than the upper limit oil temperature Thi. If the condition is satisfied, the process proceeds to step 103. Otherwise, the idle stop control is terminated. .
[0038]
In step 103, the engine 10 is stopped.
[0039]
In step 104, it is determined whether the brake switch 2 is OFF or the idle stop switch 1 is energized. If the condition is satisfied, the process proceeds to step 500. Otherwise, the process proceeds to step 103.
[0040]
In step 500, engine restart control is executed.
[0041]
In step 107, engagement control of the low clutch L / C is executed.
[0042]
In step 108, it is determined whether or not the engine restart process and the engagement control process have been completed. If completed, the process proceeds to step 109. Otherwise, step 106 and step 107 are repeated.
[0043]
(Next idle stop permission judgment process)
In step 109, the detected peak speed Ne of the engine speed at the restart Ne _top Is the limit speed Ne _hi If it is larger, the process proceeds to step 111. Otherwise, the process proceeds to step 110.
In step 110, an idle stop flag Fi is set to 1.
In step 111, the idle stop flag Fi is set to zero.
[0044]
That is, the idle stop flag Fi is set to 1 (idle stop permission), the driver desires idle stop control, the vehicle is stopped, the brake is stepped on, the steering angle is 0, the R range If is not selected, the engine 10 is stopped. Here, the idle stop switch 1 conveys the intention of the driver to execute or cancel the idle stop. This switch is energized when the ignition key is turned. The reason why the rudder angle is 0 is that, for example, idle stop is prohibited when the vehicle is temporarily stopped during traveling such as when turning right.
[0045]
In addition, the idle stop control in the R range is prohibited because the amount of oil required for achieving the engagement completion state is much larger than that in the first-speed engagement state, so that a sufficient amount of oil may not be supplied. That is, as shown in the engagement table of FIG. 3, at the first speed, it is necessary to supply hydraulic pressure to the low clutch L / C. Therefore, it is only necessary to supply hydraulic pressure from the bypass oil passage 45 only to the low clutch L / C even when each shift valve is not switching the oil passage. However, in the R range, oil pressure must be supplied to the reverse clutch R / C and the low & reverse brake L & R / B, so it is difficult to supply the amount of oil required for engagement before the engine starts. .
[0046]
Next, it is determined whether the oil temperature Toil is higher than the lower limit oil temperature Tlow and lower than the upper limit oil temperature Thi. This is because if the oil temperature is not equal to or higher than the predetermined temperature, there is a possibility that the predetermined amount of oil cannot be filled before the engine complete explosion due to the viscous resistance of the oil. In addition, when the oil temperature is high, the volumetric efficiency of the oil pump 22 decreases due to a decrease in viscous resistance, and the amount of leakage at each part of the valve increases. This is because there is a possibility that cannot be filled.
[0047]
Next, when the brake is released, it is determined that the driver is willing to start the engine, and when the deactivation of the idle stop switch 1 is confirmed even when the brake is depressed. It is determined that the driver has an intention to start the engine. For example, when the engine 10 is stopped by an idle stop, a load is applied to the battery, and an air conditioner or the like cannot be used. That is, when the driver feels that the temperature in the passenger compartment is hot, the idle stop control can be canceled according to the driver's will, so that the control more in line with the driver's intention can be executed. . Thereby, engine restart control is executed.
[0048]
(Engine restart control process)
Next, the engine restart control process will be described. FIG. 7 is a flowchart showing the control contents of the engine restart control.
[0049]
In step 201, the starter generator 60 is operated.
[0050]
(Starter generator drive processing)
In step 202, the engine speed is read.
[0051]
In step 203, it is determined whether or not the engine has completely exploded. If the engine has completely exploded, the process proceeds to step 204. Otherwise, the process returns to step 201 and the starter generator 60 continues to operate.
[0052]
In step 204, the operation of the starter generator 60 is stopped.
[0053]
(Lock-up solenoid drive processing)
In Step 205, it is determined whether or not the current range is the D range.
[0054]
In step 206, the lockup solenoid 75 is turned on.
[0055]
In step 207, the throttle opening, oil temperature, engine stop time, and engine speed are read.
[0056]
In step 208, the target engine speed Nea is calculated from the three-dimensional map for each oil temperature shown in FIG.
[0057]
In Step 209, it is determined whether or not the engine speed Ne is equal to or higher than the target engine speed Nea. If the target engine speed Nea is equal to or higher than the target engine speed Nea, the process proceeds to Step 210. Otherwise, the process returns to Step 206. Supply from the bypass oil passage 45 is continued.
[0058]
In step 210, the lockup solenoid 75 is turned OFF.
[0059]
(Target engine speed correction process)
In step 211, it is determined whether or not the engine speed Ne exceeds a predetermined engine speed Nem. If it exceeds, the process proceeds to step 212, otherwise the engine speed is read again.
[0060]
In step 212, the engine speed Ne is read.
[0061]
In step 213, it is determined whether a vehicle speed has occurred or whether a start G has been detected. If not detected, the process proceeds to step 214. If detected, the process proceeds to step 215.
[0062]
In step 214, the engine speed Ne read in step 212 is updated as Ne1.
[0063]
In step 215, it is determined whether or not the throttle opening is equal to or greater than a predetermined value.
[0064]
In step 216, the absolute value of the value obtained by subtracting the predetermined rotational speed difference ΔN from the difference between the set engine rotational speed Ne1 and the target engine rotational speed Nea is set to a predetermined deviation ε. ₁ It is determined whether it is larger than (variation allowable range). If it is larger, the process proceeds to step 218. Otherwise, the process proceeds to step 217.
[0065]
In step 217, the target engine speed Nea at the time of engine restart after the next idle stop is used as a value read from the conventional map.
[0066]
In step 218, it is determined whether or not a value obtained by subtracting the target engine speed Nea from the set engine speed Ne1 at the time of starting is larger than a predetermined speed difference ΔN. If larger, the process proceeds to step 219. Proceed to step 220.
[0067]
In step 219, the target engine speed Nea at the time of engine restart after the next idle stop is changed to a higher value.
[0068]
In step 220, the target engine speed Nea at the time of engine restart after the next idle stop is changed to a low value.
[0069]
The engine restart control will be described based on the time chart of FIG.
When an engine restart command is output at time t1, the starter generator 60 starts to be driven and the lockup solenoid 75 is turned on. Here, the lock-up solenoid driving process and the starter generator driving process are performed in parallel.
(Starter generator drive processing)
In the flowchart of FIG. 7, the process proceeds from step 201 to step 202 to step 203. When the engine complete explosion determination is made at time t2, the starter generator 60 is turned off.
[0070]
(Lock-up solenoid drive processing)
It is assumed that the signal of the lockup solenoid 75 outputs a MAX value at time t1. As a result, the switching valve 44 is urged upward in FIG. 5 and the low clutch L / C and the bypass oil passage 45 communicate with each other, so that the low clutch L / C is quickly filled with hydraulic pressure. At this time, the throttle opening, oil temperature, engine stop time, and engine speed are read, and the target engine speed Nea is calculated from the three-dimensional map for each oil temperature shown in FIG. Here, the target engine rotational speed Nea is a rotational speed that represents the timing at which an OFF command is output to the lockup solenoid 75.
[0071]
[Target engine speed Nea]
Here, the target engine speed Nea will be described in more detail. Basically, when oil filling to the low clutch L / C is completed by rapid filling from the bypass oil passage 45, a fastening pressure is generated in the low clutch L / C. When the oil pump 22 can output a sufficient discharge pressure due to the complete explosion of the engine, thereafter, the low clutch engagement pressure is gradually increased by engagement control to avoid a start shock. That is, if the switching timing of the switching valve 44 is too early, a sufficient fastening force cannot be ensured, and the engine may blow up. On the other hand, if the switching timing is too late, a large pump discharge pressure is directly supplied to the low clutch L / C, which may cause a fastening shock. In view of this, the target engine speed Nea, which is the timing for switching the switching valve 44 at the optimal timing for completing the oil filling of the low clutch L / C, is calculated from a preset map (corresponding to claim 1). .
Basically, there is an appropriate predetermined speed difference ΔN between the engine speed Ne1 at the time of start and the target engine speed Nea corresponding to the switching timing, so correction is made by learning control to obtain the speed difference ΔN. Is running.
[0072]
Although the value calculated from the map is used as the target engine speed Nea, the engine speed Ne1 at the time of start is sensed, and when the engine speed reaches a predetermined engine speed lower than the engine speed, the switching valve 44 May be switched. Thereby, the switching valve 44 can be switched at an optimal timing similarly to the control from the map described above. Moreover, since it is not necessary to provide a map or the like, it is advantageous in terms of memory.
[0073]
When the engine speed Ne reaches the target engine speed Nea at time t3, the lockup solenoid 75 is turned off. Then, at time t4 after the hydraulic response delay time has elapsed, the switching valve 44 is switched, and the normal oil passage 101 and the low clutch L / C are communicated. In the flowchart of FIG. 7, the process proceeds from Step 206 → Step 207 → Step 208 → Step 209 → Step 210.
[0074]
When the lockup solenoid 75 is turned off, the engagement control is executed thereafter, the low clutch engagement pressure gradually increases, and the vehicle starts smoothly.
[0075]
(Target engine speed correction process)
During the engine restart process described above, the engine speed Ne1 at the time when the vehicle speed or the start G is detected is detected. When it is determined that the start of the throttle opening is greater than or equal to the predetermined value, since it is highly possible that a start shock will occur if the target engine speed Nea at the next control is not appropriate, the target engine speed Nea (Claims) 1 Corresponding).
[0076]
At this time, as shown in the enlarged view of FIG. 10, the absolute value of the difference between the detected difference between the starting engine speed Ne1 and the target engine speed Nea and the speed difference ΔN considering the hydraulic response delay is predetermined. Deviation ε ₁ To determine if it is greater than Predetermined deviation ε ₁ In the following, that is, if the target engine speed Nea exists in the hatched area in FIG. 10, the switching valve 44 is switched at the optimum timing, so that the target engine is also determined from the map when the engine is restarted after the next idle stop. Calculate the rotation speed Nea.
[0077]
On the other hand, when a difference larger than the predetermined deviation ε1 occurs, that is, when the target engine speed Nea exists outside the area indicated by hatching in FIG. 10, the detected start engine speed Ne1 and the target engine speed Nea are detected. It is optimal to change the target engine speed Nea to increase the target engine speed Nea if the difference is larger than the speed difference ΔN. Secure the right timing. As a result, the target engine speed can be corrected to the optimum timing including the driving situation and aging, and stable engine restart control can be achieved. 1 Corresponding).
[0078]
(Next idle stop permission judgment process)
Next, the next idle stop permission determination process will be described. During execution of each control process above, at the start of the turbine speed (vertex Nt _top Engine speed Ne) _top Is detected. Where Ne _top Is equivalent to the timing at which the engagement pressure of the low clutch L / C is secured. The engine speed increases as the engine starts. At this time, since the engagement pressure of the low clutch L / C is not sufficiently increased, the engine load is small and the engine rotation is increased. Thereafter, when the engagement pressure of the low clutch L / C is secured, the vehicle starts to start.
[0079]
FIG. 11 is a time chart showing the relationship between the engine speed and the start G generation timing.
(1) is a time chart when the clutch clearance of the low clutch L / C is appropriate (no deterioration of the clutch plate).
(2) is a time chart when the clutch clearance is enlarged (small) due to wear or when the oil pump is deteriorated (small).
(3) is a time chart when the clutch clearance increases due to wear (middle) or the oil pump deteriorates (middle).
(4) is a time chart when the clutch clearance is enlarged (large) or the oil pump is deteriorated (large) due to wear.
[0080]
Engine speed Ne at start _top The timing is delayed due to an increase in clutch clearance and a shortage of discharge due to pump deterioration. Since the timing is delayed, the generation of the engine load is delayed, and the engine speed when the start G is generated also increases. FIG. 12 is a diagram showing the relationship between the engine speed and the time lag. If the engine speed is less than Netop, an appropriate time lag is obtained, but if the engine speed is higher than that, an inappropriate time lag occurs.
[0081]
When the engine is restarted after the idling stop, the engine speed is sensed every time. If the engine speed is within the number of revolutions capable of obtaining an appropriate time lag, the idling stop flag Fi is set to 1 in order to permit the next idling stop control. On the other hand, the limit speed Ne _hi If you exceed, the time lag will be too long. As a result, the value of the engine speed when the start G occurs increases, and the speed difference when the low clutch L / C is engaged becomes too large. Therefore, the amount of heat generated by the clutch becomes large, and there is a concern that the clutch plate will be burned. Therefore, the idle stop flag Fi is set to 0, and the idle stop is prohibited from the next time.
[0082]
As described above, when the engine is restarted after idling stop, the engine speed Netop (corresponding to the top Nttop of the turbine speed) that senses the start G is sensed, and the engine speed limit value at which an appropriate time lag can be obtained. When Nehi is exceeded, seizing of the clutch plate can be prevented by determining that engine restart control cannot be executed at an appropriate timing due to secular change. 2 Corresponding).
[0083]
(Embodiment 2)
FIG. 13 is a schematic diagram showing a hydraulic circuit in the second embodiment. Since the basic configuration is the same as that of the first embodiment, only different points will be described. The hydraulic circuit which provided the low clutch bypass solenoid 100 only for the switching valve 44 is shown.
[0084]
FIG. 14 is an enlarged view of the switching valve 44. The switching valve 44 includes a spool valve 44f and a return spring 44g. The spool valve 44f is provided with a pressure receiving portion 44i that receives a hydraulic pressure opposed to the spring force of the return spring 44g. A pilot pressure is communicated with the pressure receiving portion 44i. A port 44m communicating with the oil passage 103 is provided in the storage chamber 44j in which the return spring 44g is stored. The oil passage 103 is connected to a low clutch bypass solenoid 100 having a pilot pressure as an original pressure, and can arbitrarily set a pressure based on a control signal. As a result, the pilot pressure is set to a pressure opposite to the spring 44g and the low clutch bypass solenoid pressure, and the switching valve 44 can be switched at an arbitrary timing.
[0085]
FIG. 15 is a flowchart showing the control contents of the idle stop control in the second embodiment. Since the basic control contents are the same as those in the first embodiment, only different steps will be described.
[0086]
In step 600, an engine restart control process based on the turbine speed is executed.
[0087]
(Next idle stop permission judgment process)
In step 601, it is determined whether or not the turbine speed Ntop2 at the top of the sensed turbine speed at restart is larger than the limit speed Nthi. If larger, the process proceeds to step 603. Otherwise, the process proceeds to step 602. move on.
In step 602, the idle stop flag Fi is set to 1.
In step 603, the idle stop flag Fi is set to zero.
[0088]
Hereinafter, the engine restart control in the second embodiment will be described based on the flowchart of FIG. Note that the description of the same steps as those in Embodiment 1 is omitted.
[0089]
(Lock-up solenoid drive processing)
In Step 205, it is determined whether or not the current range is the D range.
[0090]
In step 306, the low clutch bypass solenoid 100 is turned ON.
[0091]
In step 307, the throttle opening, oil temperature, engine stop time, and engine speed are read.
[0092]
In step 308, the target turbine speed Nta is calculated from the three-dimensional map for each oil temperature shown in FIG.
[0093]
In step 309, it is determined whether or not the turbine speed Nt is equal to or higher than the target turbine speed Nta. If the target turbine speed Nta is higher than the target turbine speed Nta, the process proceeds to step 310. Otherwise, the process returns to step 306. Supply from the bypass oil passage 45 is continued.
[0094]
In step 310, the low clutch bypass solenoid 100 is turned OFF.
[0095]
(Target turbine speed correction process)
In step 311, it is determined whether or not the turbine rotational speed Nt exceeds the predetermined turbine rotational speed Ntm. If it exceeds, the process proceeds to step 312. Otherwise, the turbine rotational speed is read again.
[0096]
In step 312, the turbine speed Nt is read.
[0097]
In step 313, the read turbine speed Nt and the apex Nt of the set turbine speed _top It is determined whether the difference from the (turbine speed detected in the previous control cycle) is negative. If it is negative, the turbine speed starts to decrease and the currently set Nt _top Is determined to be the apex, and the process proceeds to step 315. If the value is positive, the turbine speed has increased, and thus the process proceeds to step 314.
[0098]
In step 314, the turbine rotational speed Nt read in step 312 is changed to Nt. _top Update as.
[0099]
In step 315, the turbine speed Nt read in the previous control cycle is converted to the apex of the turbine speed (starting turbine speed) Nt. _top Set as.
[0100]
In step 316, it is determined whether or not the throttle opening is greater than or equal to a predetermined value. If the throttle opening is greater than or equal to the predetermined value, the process proceeds to step 317. Otherwise, the present control is terminated.
[0101]
In step 317, the set start turbine speed Nt _top And the absolute value of the difference between the target turbine speed Nta and the predetermined speed difference ΔNt is the predetermined deviation ε ₂ It is determined whether or not the difference is larger than (variation allowable range).
[0102]
In step 318, the target turbine speed Nta at the time of engine restart after the next idle stop is used as a value read from the conventional map.
[0103]
In step 319, the set start turbine speed Nt _top It is determined whether or not the value obtained by subtracting the target turbine rotational speed Nta from the predetermined rotational speed difference ΔNt is greater than the predetermined speed difference ΔNt.
[0104]
In step 320, the target turbine speed Nta at the time of engine restart after the next idle stop is changed to a higher value.
[0105]
In step 321, the target engine speed Nta at the time of engine restart after the next idle stop is changed to a lower value.
[0106]
The engine restart control will be described based on the time chart of FIG. Note that since time t1 to time t2 is the same as that of the first embodiment, description thereof is omitted.
[0107]
(Lock-up solenoid drive processing)
It is assumed that the signal of the low clutch bypass solenoid 100 outputs a MAX value at time t1. Accordingly, in FIG. 14, the switching valve 44 is urged upward, and the low clutch L / C and the bypass oil passage 45 communicate with each other, so that the low clutch L / C is rapidly filled with hydraulic pressure. At this time, the throttle opening, oil temperature, engine stop time, and engine speed are read, and the target engine speed Nta is calculated from the three-dimensional map for each oil temperature shown in FIG. Here, the target turbine rotational speed Nta is a rotational speed that represents the timing at which an OFF command is output to the low clutch bypass solenoid 100.
[0108]
[Target turbine speed Nta]
Here, the target turbine speed Nta will be described in more detail. Basically, it is the same logic as the target engine speed Nea described in the first embodiment, and the target turbine speed is the timing for switching the switching valve 44 at the optimal timing when the oil filling to the low clutch L / C is completed. The number Nta is calculated from a preset map.
[0109]
When the turbine speed Nt reaches the target turbine speed Nta at time t3, the low clutch bypass solenoid 100 is turned OFF. Then, at time t4 after the hydraulic response delay time has elapsed, the switching valve 44 is switched, and the normal oil passage 101 and the low clutch L / C are communicated.
[0110]
When the low clutch bypass solenoid 100 is turned off, the engagement control is executed thereafter, the low clutch engagement pressure gradually increases, and the vehicle starts smoothly.
[0111]
(Target turbine speed correction process)
During the engine restart process described above, the top of the turbine speed immediately before the turbine speed decreases (starting turbine speed) Nt _top Is detected. When the throttle opening is greater than or equal to a predetermined value, there is a high possibility that a start shock will occur, and therefore the target turbine speed Nta is corrected. At this time, the detected starting turbine speed Nt _top And the absolute value of the difference between the difference between the target turbine speed Nta and the predetermined speed difference ΔNt considering the hydraulic response delay is the predetermined deviation ε ₂ To determine if it is greater than Predetermined deviation ε ₂ If it is below, since the switching valve 44 is switched at an optimal timing, the target turbine speed Nta is calculated from the map even when the engine is restarted after the next idle stop.
[0112]
On the other hand, the predetermined deviation ε ₂ Is greater than the detected starting turbine speed Nt _top And the target turbine speed Nta is determined to be larger than the rotational speed difference ΔNt. When the difference is larger, the target turbine speed Nta is changed to a higher direction. When the difference is smaller, the target engine speed Nta is decreased. To ensure optimal timing. As a result, it is possible to correct the target turbine speed Nta at an optimal timing including traveling conditions and secular changes, and stable engine restart control can be achieved.
[0113]
(Next idle stop permission judgment process)
Next, the next idle stop permission determination process will be described. While the above control processes are being performed, sensing of the turbine speed is performed. And the starting turbine speed Nt at the start of the turbine speed _top Is detected. Here, the vertex at the start of the turbine rotation speed will be described. When the engine is started, the turbine speed increases via the torque converter 30. At this time, since the engagement pressure of the low clutch L / C is not sufficiently increased, the turbine speed increases in proportion to the engine speed. Thereafter, when the engagement pressure of the low clutch L / C is secured, the turbine speed is loaded, so the speed is once lowered and the vehicle starts to start. That is, the top Nt at the start of the turbine speed _top Is equivalent to the timing at which the engagement pressure of the low clutch L / C is secured.
[0114]
FIG. 19 is a time chart showing the relationship between the engine speed and the turbine speed.
(1) is a time chart when the clutch clearance of the low clutch L / C is appropriate (no deterioration of the clutch plate).
(2) is a time chart when the clutch clearance is enlarged (small) due to wear or when the oil pump is deteriorated (small).
(3) is a time chart when the clutch clearance increases due to wear (middle) or the oil pump deteriorates (middle).
(4) is a time chart when the clutch clearance is enlarged (large) or the oil pump is deteriorated (large) due to wear.
[0115]
Top Nt of starting turbine speed _top The timing is delayed due to an increase in clutch clearance and a shortage of discharge due to pump deterioration. As the timing is delayed, the turbine speed increases as the engine speed increases. _top The number of revolutions increases. FIG. 20 shows the top Nt of the turbine speed _top It is a figure showing the relationship between a time lag. Turbine speed is Nt _hi If it is below, an appropriate time lag is obtained, but an inappropriate time lag occurs at a higher rotational speed.
[0116]
The top Nt of this turbine speed when the engine is restarted after idling stop _top Each time is sensed, and when the rotational speed is within the rotation speed at which an appropriate time lag can be obtained, the idle stop flag Fi is set to 1 in order to permit the next idle stop control. On the other hand, limit speed Nt _hi If you exceed, the time lag will be too long. As a result, the top of the turbine speed Nt _top Increases, and the difference in rotational speed when the low clutch L / C is engaged becomes too large. Therefore, the amount of heat generated by the clutch becomes large, and there is a concern that the clutch plate will be burned. Therefore, the idle stop flag Fi is set to 0, and the idle stop is prohibited from the next time.
[0117]
Therefore, when the engine is restarted after idling stop, the top of the turbine speed Nt _top The limit value of the turbine speed Nt for sensing an appropriate time lag _hi When the value exceeds the value, it is determined that the engine restart control cannot be executed at an appropriate timing due to the secular change, and the seizure of the clutch plate or the like can be prevented.
[0118]
As described above, the first and second embodiments have been described. However, the present invention is not limited to the above-described configuration, and can be applied not only to the low clutch as long as it is a fastening element when the automatic transmission moves forward. Moreover, although the case where it applied to the forward fastening element of a stepped automatic transmission was shown in each above-mentioned embodiment, you may apply to the forward fastening element of a continuously variable transmission.
[Brief description of the drawings]
FIG. 1 is a diagram showing a configuration of a main unit of a vehicle provided with a transmission hydraulic device for an automatic transmission according to an embodiment.
FIG. 2 is a schematic diagram illustrating a configuration of a stepped transmission that is a speed change mechanism in the embodiment.
FIG. 3 is a fastening table of each fastening element of the stepped transmission according to the embodiment.
FIG. 4 is a circuit diagram showing a hydraulic circuit in the first embodiment.
5 is a cross-sectional view illustrating a configuration of a switching valve according to Embodiment 1. FIG.
FIG. 6 is a flowchart showing idle stop control in the first embodiment.
FIG. 7 is a flowchart showing engine restart control according to the first embodiment.
FIG. 8 is a map showing the relationship among the target engine speed, engine stop time, throttle opening, and oil temperature according to the first embodiment.
FIG. 9 is a time chart showing idle stop control in the first embodiment.
FIG. 10 is an enlarged time chart showing a relationship between a target engine speed and a starting engine speed in the first embodiment.
11 is a time chart showing the relationship between engine speed and start G when the engine is restarted in the first embodiment. FIG.
FIG. 12 is a diagram illustrating a relationship between an engine speed and a time lag at the time of starting in the first embodiment.
FIG. 13 is a circuit diagram illustrating a hydraulic circuit according to a second embodiment.
14 is a cross-sectional view illustrating a configuration of a switching valve according to Embodiment 2. FIG.
FIG. 15 is a flowchart showing idle stop control in the second embodiment.
FIG. 16 is a flowchart showing engine restart control in the second embodiment.
FIG. 17 is a map showing the relationship among the target turbine speed, engine stop time, throttle opening, and oil temperature in the second embodiment.
FIG. 18 is a time chart showing idle stop control in the second embodiment.
FIG. 19 is a time chart showing the relationship between the engine speed and the turbine speed when the engine is restarted in the second embodiment.
FIG. 20 is a diagram illustrating the relationship between the apex of turbine rotation speed at the time of start and a time lag in the second embodiment.
[Explanation of symbols]
1 Idle stop switch
2 Brake switch
3 Rudder angle sensor
4 Oil temperature sensor
5 Vehicle speed sensor
6 Throttle opening sensor
7 Engine speed sensor
8 Turbine speed sensor
10 engine
11 Fuel supply device
12 Chain sprocket
13 Third switching valve
13a port
13b port
13c port
13d port
13f Spool valve
13g return spring
15 Second switching valve
15a port
15f Spool valve
15g return spring
20 Automatic transmission
22 Oil pump
23 Hydraulic servo
24 Transmission mechanism
30 Torque converter
39 Line pressure oil passage
40 line pressure oil passage
41 Second shift valve
42 First shift valve
41b, 42b Pilot pressure oil passage
44. Switching valve (switching valve described in claims)
44a port
44b port
44c port
44d port
44e port
44d port
44f Spool valve
44g spool valve
44i pressure receiving part
45 Bypass oil passage
47 Pressure regulator valve
50 Control unit
60 Starter generator
61 Electromagnetic clutch
62 Chain sprocket
63 chain
70 Line pressure duty solenoid
74 Lock-up control valve
75 Lock-up solenoid
80 pressure modifier valve
80a output port
80b spring
81 Oilway
90 Accumulation control valve
101 Low clutch pressure supply oil passage
102 Pilot pressure supply oil passage
105 Accum oil passage
213 Manual valve
300 Low clutch accumulation room
301,302 Accumulation room
d1 orifice
G1 planetary gear
G2 planetary gear
H / C high clutch
B / B band brake
L / C low clutch (fastening element as described in claims)
R / C reverse clutch
IN input shaft
OUT output shaft

Claims (2)

In accordance with idling stop conditions set in advance, the engine has idle stop control means for outputting an idling operation and stop signal of the engine, and performs a shift control by a control valve unit using an oil pump driven by the engine as a hydraulic supply source,
In the control valve unit, a normal oil passage, a bypass oil passage having a passage resistance smaller than that of the normal oil passage by directly supplying a line pressure after passing through the shift valve or the manual valve, and a forward fastening element are in communication with each other. In a transmission hydraulic device of an automatic transmission having a switching valve that can be switched based on a command signal,
A target engine speed setting means for setting a target engine speed that can secure the fastening pressure of the forward fastening element based on a map that uses oil temperature, throttle opening, or engine stop time as an element;
When the engine restarts after idling stop with respect to the switching valve, a communication command between the forward fastening element and the bypass oil passage is output, and when the set target engine speed is reached, the forward fastening element And switching valve control means for outputting a communication command between the oil passage and the normal oil passage,
Detecting the engine speed when the vehicle starts, whether greater than a predetermined rotational speed difference of positive that the detected rotational speed difference the target engine rotational speed is subtracted from the starting engine speed with the preset Determining, when large, learning correction means for correcting in a direction to increase the target engine speed set in the map, and when small, learning correction means for correcting in a direction to decrease the target engine speed set in the map ;
Provided,
The automatic transmission transmission hydraulic device according to claim 1, wherein the learning correction means performs the correction only when the detected throttle opening is equal to or greater than a predetermined value. The transmission hydraulic device for an automatic transmission according to claim 1,
An idle stop prohibition judging means for judging whether or not the detected turbine speed at the time of starting is larger than a predetermined turbine speed set in advance and prohibiting the next idle stop control when it is larger is provided. Shifting hydraulic device for automatic transmission.

Images