JPH0439459A - Line pressure control device for automatic transmission - Google Patents

Abstract

PURPOSE:To suppress a speed change shock by providing a means which corrects a value of line pressure, set by a line pressure setting part, in accordance with a car speed or an engine speed, detected by a car speed or engine speed detecting means, when a speed change operating part is detected to perform manual operation. CONSTITUTION:In the case of performing automatic speed change operation by a speed change mechanism provided in an automatic transmission, that is, speed change operation according to the preset normal speed change characteristic, a line pressure has a value based on a kind of speed change operation and a load condition of an engine, and a speed change shock is suppressed by selectively supplying an operating oil pressure in accordance with the line pressure to a plurality of friction engaging elements in the speed change mechanism from an operating oil pressure supply part. When manual operation of a speed change operating part is performed, accordingly when a speed change operational condition is taken, not in accordance with the normal speed change characteristic preset in the speed change mechanism following the manual operation, the value of the line pressure is corrected in accordance with a car speed.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention provides line pressure control for a working hydraulic pressure supply unit that selectively supplies working hydraulic pressure to a plurality of frictional engagement elements in a transmission mechanism provided in an automatic transmission. The present invention relates to a line pressure control device for an automatic transmission that controls the line pressure according to the shift operation state.

(Prior Art) As an automatic transmission installed in a vehicle, one configured with a combination of a torque converter and a multi-gear type transmission mechanism is commonly used. Such an automatic transmission is usually attached with a hydraulic control device whose main component is a hydraulic circuit section.

In the hydraulic circuit section of a hydraulic control device, there is generally a line pressure forming section consisting of a regulator valve, etc. that adjusts the hydraulic pressure from the oil pump to form line pressure, and a manual valve and line that are manually operated to switch the gear range. a plurality of shift valves that form working hydraulic pressure based on line pressure from the compression forming section and selectively supply the working hydraulic pressure to a plurality of hydraulically controlled friction engagement elements such as clutches and brakes in the transmission mechanism; , and an operating hydraulic pressure supply section comprising a plurality of solenoid valves and the like for switching the operating state of the shift valve. In the case of shift control in an automatic transmission, a control unit provided in a hydraulic control device performs
The engine load and vehicle speed are compared with the shift line in the shift characteristic diagram stored as a data map in the built-in memory, and it is determined whether the shift conditions are met, and it is determined that the shift conditions are met. In this case, a drive signal is supplied from the control unit to a predetermined solenoid valve provided in the hydraulic pressure supply section to switch the operating state of the shift valve, whereby one of the plurality of frictional engagement elements in the transmission mechanism is switched. The selected one is engaged or released, and the automatic transmission changes the gear position, that is, the gear change operation is performed.

In such an automatic transmission, the line pressure forming section is configured to change the line pressure according to the type of shift operation when a shift operation is performed in order to suppress the shift shock that occurs with the shift operation. For example, it has been proposed to do so as shown in Japanese Patent Publication No. 48021/1983. In an automatic transmission equipped with such a line pressure forming section, when a gear change operation is not performed, the line pressure corresponding to the engine load condition and the output shaft rotation speed of the torque converter increases the coefficient of friction in the transmission mechanism. The line pressure is set relatively high to prevent slippage of the mating element, and when a gear shift operation is performed, the line pressure is set according to the engine load state and the type of gear shift operation to suppress shift shock. The line pressure is set to be lower than the line pressure when no gear shifting operation is being performed.

(Problem to be Solved by the Invention) As described above, the engine load and vehicle speed are compared with the shift line in the predetermined shift characteristic diagram to determine whether or not the shift condition is satisfied. When it is determined that the condition has been established, a gear shift operation is performed, and when the gear shift operation is performed, the line pressure is set to be relatively low. In an automatic transmission, a manual valve that switches the gear range is operated. When the gear range is changed by manual operation of the shift lever for the forward range, or when the so-called halt switch is manually operated to fix the gear position in a predetermined forward range, the gear shift operation is performed without following the shift line in the shift characteristic diagram. However, even in such a case, the line pressure is adjusted so that it corresponds to the engine load state that would occur if the gear shift operation was performed according to the shift line in the shift characteristic diagram, but in reality, Since the shift operation is performed without following the shift line in the shift characteristic diagram, the actual vehicle speed is different from the vehicle speed that would be obtained if the shift operation was performed according to the shift line in the shift characteristic diagram. Since the line pressure after the shift operation does not correspond to the actual vehicle speed, there is a problem that shift shock cannot be effectively suppressed.

In view of this point, the present invention provides a method for presetting a line pressure for a working hydraulic pressure supply section that selectively supplies working hydraulic pressure to a plurality of frictional engagement elements in a transmission mechanism included in an automatic transmission. When a shift operation is performed according to the shift line in the shift characteristic diagram, it shall be done according to the load condition of the engine to which the automatic transmission is attached and the type of shift operation. By manually operating the gear shift operation part such as the shift lever,
Even when the shift operation in the transmission mechanism is performed without following the shift line in a preset shift characteristic diagram, it is possible to effectively suppress shift shock accompanying the shift operation. Another object of the present invention is to provide a line pressure control device for an automatic transmission.

(Means for Solving the Problem) In order to achieve the above-mentioned object, a line pressure control device for an automatic transmission according to the present invention is provided in an automatic transmission, as the basic configuration is shown in FIG. A line pressure forming section that adjusts the hydraulic pressure from the hydraulic pressure ordering section to form line pressure, and a working hydraulic pressure obtained by adjusting the line pressure from the line pressure forming section.
A hydraulic pressure supply section that selectively supplies a plurality of frictional engagement elements in a transmission mechanism provided in an automatic transmission; a line pressure setting section that sets a value of line pressure formed by a line pressure formation section; A shift operation determining means for determining the type of shift operation performed in the transmission mechanism; an engine load detection means for detecting the load condition of the engine to which the automatic transmission is attached; In addition to a line pressure control means for setting a line pressure value based on the type of speed change operation determined by the speed change operation determination means and the engine load state detected by the engine load detection means, the above-mentioned automatic Vehicle speed or rotational speed detection means for detecting the vehicle speed of a vehicle equipped with an engine equipped with a transmission, or the rotational speed of an output element in the engine or automatic transmission, and a speed change operation section provided in connection with the speed change mechanism. an operation detection means for detecting that a manual operation has been performed; and when the operation detection means detects that a manual operation of the gear shift operation section has been performed, the line pressure value set by the line pressure setting section is set to the vehicle speed or and line pressure correction means for correcting according to the vehicle speed or rotation speed detected by the rotation speed detection means.

(Function) In the line pressure control device for an automatic transmission according to the present invention configured as described above, an automatic gear change operation by a gear change mechanism provided in the automatic transmission, that is, a preset When a shift operation is performed according to normal shift characteristics, the line pressure has a value based on the type of shift operation and the engine load condition, and the hydraulic pressure according to the line pressure is It is selectively supplied from the supply section to a plurality of frictional engagement elements in the transmission mechanism to suppress transmission shock, and when the transmission operation section is manually operated,
Accordingly, when a shift operation state that does not follow the normal shift characteristics set in advance in the transmission mechanism is taken, the line pressure value obtained based on the type of shift operation and the engine load condition is Or, the working oil pressure corresponding to the line pressure that is corrected according to the rotation speed of the output element in the engine or automatic transmission and takes the corrected value is supplied from the working oil pressure supply section to the plurality of frictional engagement elements in the transmission mechanism. selectively supplied to As a result, even when the gear shift operation section is manually operated and the shift mechanism adopts a gear shift state that does not follow the preset normal gear shift characteristics, the shock associated with the gear shift operation can be effectively suppressed. Ru.

(Embodiment) FIG. 2 shows an example of a line pressure control device for an automatic transmission according to the present invention, together with a vehicular automatic transmission to which the device is applied.

In FIG. 2, the automatic transmission 10 includes a torque converter 14 and a transmission mechanism 20 with two multi-stage gears, and is further supplied with hydraulic pressure used to control their operations from a hydraulic circuit section 40.

The torque converter 14 includes a pump impeller 14a, a turbine runner 14b, a stator 14c, and a case 11.
An oil pump 15 is connected via a pump drive shaft 16 to an output shaft 12 of the engine to which a pump impeller 14a is connected. Turbine runner 14b
is connected to a transmission mechanism 20 via a hollow turbine shaft 17 and to an output shaft 12 via a lock-up clutch 19, and is connected to a stator 14c and a case 11.
A one-way clutch 18 is interposed between the stator 14c and the stator 14c, so that the stator 14c rotates in the same direction as the pump impeller 14a and the turbine runner 14b.

The transmission mechanism 20 includes a planetary gear unit 21 for obtaining four forward speeds and one reverse speed. The planetary gear unit 21 includes a small diameter sun gear 22, a large diameter sun gear 23. Long pinion gear 24. It has a short pinion gear 25 and a ring gear 26. A forward clutch 27 for forward running and a coasting clutch 2 are installed in parallel between the small diameter sun gear 22 and the turbine shaft 17.
A one-way clutch 29 is interposed between the two. A rehearsing gear 30 for backward travel is provided between the large diameter sun gear 23 and the turbine shaft 17, and
A 2-4 brake 31 is provided, and a 3-4 clutch 32 is provided between the long pinion gear 24 and the turbine shaft 17. The long-binion gear 24 is connected to a transmission case 35 via a carrier 33 and a one-way clutch 34.
is engaged and disengaged by a low reverse brake 36. The ring gear 26 is connected to an output gear 38 via an output shaft 37 of the automatic transmission IO, and the torque obtained from the output shaft 37 is transmitted to the drive wheels of the vehicle via a differential gear unit (not shown) or the like. is transmitted to the front wheels.

In the multi-gear type transmission mechanism 20 having such a configuration, the forward clutch 27, which is a frictional engagement element. Coasting Franch 2B, Reverse Clutch 30.2-
4 brakes 31. : The 3-4 clutch 32 and the low reverse brake 36 are selectively activated as appropriate by the hydraulic pressure from the hydraulic circuit section 40, so that the P range (parking range), R range (reverse range),
N range (neutral range), D range, S range (2 range), and L range (lunge) that constitute the forward range, and each gear stage from 1st to 4th speed in the forward range are obtained. It turns out. A control unit 50 is provided to control the operation of the hydraulic circuit section 40 that forms the hydraulic pressure for operating the clutches 27, 28, 30, and 32, and the brakes 31 and 36, respectively. .

The control unit 50 receives a detection output signal S obtained from a throttle opening sensor 51 that detects the opening of the throttle valve (throttle opening), which indicates the engine load condition.
t, the detection output signal Sr obtained from the turbine rotation speed sensor 52 that detects the rotation speed of the turbine runner 14b (turbine rotation speed), the detection output signal Sv obtained from the vehicle speed sensor 53 that detects the vehicle speed, and the shift lever 54. a detection output signal Ss obtained from the shift position sensor 55 that detects the operating position of the switch, and a hold switch that, for example, when operated in the D range driving state, issues a signal instructing the gear stage to be fixed at 3rd gear. The command signal sh obtained from 56 is supplied, and other signals Sx necessary for controlling the automatic transmission 10 are also supplied.

The control unit 50 performs shift control and lock-up control in the automatic transmission 10 based on the various signals described above.

When the control unit 50 performs shift control and lock-up control, the vertical axis represents the throttle opening TH, and the horizontal axis represents the vehicle speed ■, which is stored as data in the built-in memory of the control unit 50. In the shift characteristic diagram shown in FIG. 3 (the example of this shift characteristic diagram is for the D range), the shift line L
a, Lb Lc, Ld, Le, and Lf, the detection output signals St and Sv are checked against the actual throttle opening and vehicle speed, and it is determined whether the shift amplifier condition or the shift down condition is satisfied; Lock-up operating lines Lg and Li, and lock-up release lines Lh and L
The detected output signals St and Sv are compared with the actual throttle opening and vehicle speed, and it is determined whether the lock-up condition or the opening/aqua/2-brake release condition is satisfied. Note that the shift lines La, Lb, and LCl shown in FIG.
Le and Lf are related to downshifting from 2nd gear to 1st gear, from 3rd gear to 2nd gear, and from 4th gear to 3rd gear, respectively, and the mouth/knob actuation ILi and Lg are related to downshifting from 3rd gear to 2nd gear, and from 4th gear to 3rd gear, respectively. For lockup operation in 3rd and 4th gears, lockup release lines Lj and Lh relate to the release of the lock 7 knob in 3rd and 4th gears, respectively.

When it is determined that the shift-up condition or the shift-down condition is satisfied, the control unit 50 sends drive signals Ca, Cb, and Cc to the solenoid valves 41 to 43 provided in the hydraulic pressure supply section in the hydraulic circuit section 40. is selectively supplied.

As a result, the operating states of various shift valves and the like provided in the hydraulic pressure supply section are changed, and the supply and discharge of hydraulic pressure to each of the plurality of frictional engagement elements in the transmission mechanism 20 is controlled. is selectively brought into the engaged or released state, and an upshift or downshift operation is performed. Further, when it is determined that the lock-up activation condition is satisfied, the drive signal Cd is supplied from the control unit 50 to the solenoid valve 44 provided in the hydraulic pressure supply section, and on the other hand, it is determined that the lock-up release condition is satisfied. If so, the supply of the drive signal Cd to the solenoid valve 44 is stopped. As a result, the lock-up clutch 1 provided in the torque converter 14
9 is assumed to selectively assume a fastened state or a released state.

Further, when the hold switch 56 is manually operated, the command signal sh from the hold switch 56 is sent to the control unit 50.
, the throttle opening TH is plotted on the vertical axis, and the vehicle speed is plotted on the horizontal axis. In the characteristic diagram shown in the figure (the example of this characteristic diagram is for the D range), the shift line Hb,
He and Hf and the detection output signals St and Sv are compared against the throttle opening and vehicle speed, and it is determined whether the conditions for upshifting to 3rd speed or downshifting to 3rd speed are satisfied. Note that the shift line Hb shown in FIG. 4 relates to the shift amplifier from 2nd speed to 3rd speed, and the shift lines He and Hf relate to downshifts from 3rd speed to 2nd speed and from 4th speed to 3rd speed. When the condition for upshifting to the third speed or the condition for downshifting to the third speed is satisfied, the control unit 50 supplies the solenoid valves 41 to 41 provided in the hydraulic pressure supply section in the hydraulic circuit section 40.
Drive signals Ca, Cb, and CC are selectively supplied to the hydraulic pressure supply section; the operating states of various shift valves, etc. provided therein are changed, and the operation states of the plurality of frictional engagement elements in the transmission mechanism 20 are changed. Supply and discharge control of hydraulic pressure to each is performed, and they are selectively engaged or released, and a shift amplifier shift operation to 3rd gear or a downshift operation to 3rd gear is performed, and the gear position is changed. is fixed at 3rd gear.

Furthermore, in addition to the above-mentioned control, the control unit 50 supplies a drive signal Ce to the solenoid valve 45 provided in the line pressure forming section in the hydraulic circuit section 40, so that the operating pressure generated by the line pressure forming section is controlled by the control unit 50. Line pressure control is performed to adjust the line pressure that is supplied to the supply section and is the basis of the working hydraulic pressure obtained from the working hydraulic pressure supply section.

FIG. 5 shows a specific configuration example of a portion of the hydraulic circuit section 40 that includes a line pressure forming section. It has a regulator valve 72 and a reducing valve 73 connected to the oil pump 15 via the valve, and a normally closed solenoid valve 45 provided in the oil passage 62 that communicates the regulator valve 72 and the reducing valve 73. It is said that

In such a line pressure forming section 46, the hydraulic pressure discharged from the oil pump 15 is supplied to the reducing valve 73 through the oil path 61 and the boat a, and is reduced in pressure at the reducing valve 73 to take a constant value. After that, the pressure is supplied from boat B in the reducing valve 73 to boat C in the regulator valve 72 through the oil passage 62 as pyro nodal pressure. This regulator valve 72
The value of the pyro nodal pressure supplied to the boat C is adjusted by a solenoid valve 45 provided in the oil passage 62. The open state of the solenoid valve 45 is controlled by a drive signal Ce sent from the control unit 50, and the drive signal Ce is a pulse signal with a predetermined period, and corresponds to the response width of the solenoid valve 45. Solenoid valve 4
5 to take the open state. Therefore, the solenoid valve 45 has an open period corresponding to the pulse width of the drive signal Ce, and the pilot pressure, which takes a value that is changed according to the valve open period, is applied to the regulator valve 72 through the oil passage 62. will be supplied to boat c at

The regulator valve 72 has two spools 72a and 72
b and a spring 72c disposed between them,
In addition to the boat C, a port d connected to the oil passage 61, a port e connected to the oil passage 63, and a boat f connected to the oil passage 64 are provided. Such regulator valve 7
In 2, the effective opening areas of boats d and e are changed according to the pilot pressure supplied to boat c,
The available oil pressure is adjusted to form line pressure. Then, the line pressure is supplied to the manual valves 74 in the hydraulic pressure supply section 47 from ports d and e through oil passages 63 and branch oil passages from the ports d and e to the boats g and h.
Supplied through.

The manual valve 74 includes a spool 74a that is displaced by operating the shift lever 54. Depending on the position of the spool 74a, a state in which boat g and port j communicate with each other, a state in which port h and boat i communicate with each other, and a state in which port h and boat i communicate with each other are determined. )
The line pressure from port g or port h is transmitted to ports i, j, etc., and the resulting oil pressure is transferred to the oil line 65.
66 and 67, etc., it is supplied as hydraulic pressure to various shift valves that control the operations of the clutches 27, 28.3'0 and 32, and the brakes 3f and 36 in the transmission mechanism 20, respectively. For example, shift lever 54
5, the spool 74a of the manual valve 74 is placed in the position shown in FIG.
and port i and port are in communication with each other, and the hydraulic pressure obtained at port i and the hydraulic pressure obtained at boat k are transmitted to shift valve 1-2 and shift valve 2-3 through oil passages 65 and 67, respectively. Supplied to shift valves, etc.

Under such a configuration, the line pressure control performed by the control unit 50 is performed as steady state line pressure control when the automatic transmission 10 is in a steady state in which no gear shifting operation is performed in the transmission mechanism 20. I, also, automatic transmission 10
However, when the transmission mechanism 20 is in a normal shifting operation state in which gears are changed according to the normal shifting characteristics set in advance as shown in the shifting characteristic diagram in FIG. 3, the line pressure during normal shifting is This is carried out as a control, and furthermore, the automatic transmission 10 should fix the gear stage to 3rd gear by manually operating the shift lever 54 and switching the gear range, or by manually operating the hold switch 56. As a result of the command signal sh instructing the transmission, the transmission mechanism 20 changes gears that do not follow the preset normal transmission characteristics as shown in the transmission characteristic diagram of FIG. When in a specific shift operation state in which the gear stage is changed according to a special shift characteristic set in advance as shown in the characteristic diagram shown in FIG. 4, line pressure control is performed during the specific shift.

In steady-state line pressure control, the detected output signals St and Sr are applied to the throttle opening degree and turbine rotation speed, respectively, based on a line pressure characteristic map that is converted into data and stored in advance in the memory built into the control unit 50. The values are compared and a line pressure value based on the throttle opening and turbine rotational speed is set. The change in the line pressure value with respect to the throttle opening at a given turbine speed is:
Line pressure PL is plotted on the vertical axis, and throttle opening T is plotted on the horizontal axis.
The solid line Pa in the graph of FIG. 6 where H is taken
It is said to be like a hailstone. Then, the pulse occupancy rate that determines the pulse width of the drive signal Ce is calculated according to the line pressure value set as described above, and the drive signal Ce is set to have the calculated pulse occupancy rate. is formed and supplied to the solenoid valve 45.

As a result, the pilot pressure supplied to the port C of the regulator valve 72 is made to correspond to the pulse width of the drive signal Ce, and the line pressure obtained at the port d or the boat e of the regulator valve 72 is adjusted to the throttle opening. and a value based on the turbine rotation speed.

In line pressure control during normal gear shifting, the detection output signals St and Sv are compared with the actual throttle opening and vehicle speed, respectively, or with normal gear shifting characteristics as shown in the gear shifting characteristic diagram in FIG. When it is detected that the upshift condition is met, the upshift to be performed at that time is from 1st to 2nd, from ■ to 3rd, from 1st to 4th, or from 2nd to 2nd. It is determined whether the shift is to 3rd gear, from 2nd gear to 4th gear, or from 3rd gear to 4th gear, and the determined upshift mode and detection output signal St are used when the throttle is opened. The relationship between the upshift mode, the throttle opening and the line pressure, which is stored as data in advance in the memory built into the control unit 50, is compared with the line pressure setting map. The value of the line pressure is set according to the mode of the shift amplifier and the throttle opening at the time. Changes in the line pressure value set in this manner with respect to the throttle opening are, for example, as shown by the broken line Pb, -dotted chain line Pc, and two-dot chain line Pd in the graph of FIG. indicates that the upshift mode is from 1st to 2nd gear, and - dotted chain line Pc indicates that the upshift mode is from 1st to 3rd gear or 2nd gear.
The two-dot chain line Pd indicates that the upshift is from 1st to 4th gear, 2nd to 4th gear, or 3rd to 4th gear. This shows the case of upshifting.

Then, the pulse occupancy rate that determines the pulse width of the drive signal Ce is calculated according to the line pressure value set as described above, and the drive signal Ce is set to have the calculated pulse occupancy rate. is formed and solenoid valve 4
5. As a result, the pilot pressure supplied to the port C of the regulator valve 72 is made to correspond to the pulse width of the drive signal Ce, and the line pressure obtained at the boat d or boat e of the regulator valve 72 changes during upshift. It has a value based on the mode and throttle opening.

Furthermore, it is detected that the downshift condition has been met by comparing the detection output signals St and Sv with the actual throttle opening and vehicle speed, respectively, or the normal shift characteristics as shown in the shift characteristic diagram in FIG. When the downshift is performed, it is determined whether the downshift to be performed at that time is from 3rd gear to 2nd gear. As a result, if a downshift other than a downshift from 3rd gear to 2nd gear is detected, line pressure control similar to the steady state line pressure control described above is performed; When it is detected that the downshift is to a higher speed, the detected output signal Sr indicates that the turbine rotational speed is equal to the turbine rotational speed that is stored as data in advance in the memory built into the control unit 50. The relationship with the line pressure is checked against the existing line pressure setting map, and the line pressure value is set according to the turbine rotation speed at that time. The reason why the line pressure value at the time of downshifting from 3rd gear to 2nd gear is made to correspond to the turbine rotation speed is that when downshifting from 3rd gear to 2nd gear, the 3-4 clutch is activated in the transmission mechanism 20. 2-4 when 32 is released and the turbine rotational speed reaches an appropriate value.
The brake 31 is in the engaged state, but the mutual timing in this case is different depending on the turbine rotation speed, so if the line pressure value is set based only on the throttle opening, the shift shock will occur. This is because there is a possibility that the suppression will not be carried out effectively.

The line pressure value set in such a case is corrected by being multiplied by a correction coefficient according to the change in throttle opening, and the change in the correction coefficient in response to the change in throttle opening in such a case is corrected on the vertical axis. The coefficient Cr is plotted, and the change in throttle opening THv is plotted on the horizontal axis, as shown by the solid line C in the graph of FIG.

Then, the pulse occupancy rate that determines the pulse width of the drive signal Ce is calculated according to the line pressure value set as described above, and the drive signal Ce is set to have the calculated pulse occupancy rate. is formed and solenoid valve 4
5. As a result, the pilot pressure supplied to the port c of the regulator valve 72 is made to correspond to the pulse width of the drive signal Ce, and the line pressure obtained at the port d or port e of the regulator valve 72 is changed for downshifting. It has a value based on the mode and throttle opening.

Furthermore, in line pressure control during specific gear shifting, when manual operation of the shift lever 55 is detected based on the detection output signal Ss, or when the hold switch 5
6 is manually operated and the command signal sh is sent from the hold switch 56 (at this time, the shift lever 5
5), or a shift operation to 3rd speed based on the command signal Sh from the hold switch 56), the detection output signals St and Sv are detected as the throttle opening. The vehicle speed and vehicle speed are compared with special shift characteristics as shown in the shift characteristic diagram of FIG. 4, and the vehicle speed VN at the gear position after the shift operation is set according to the throttle opening and vehicle speed at that time. For example, as shown by point Ql on the shift characteristic diagram in FIG. 3, when the vehicle is in second gear, the vehicle speed is 1, and the throttle opening is THI, the hold switch 56 is manually operated. Taking the case where the command signal sh is sent from the hold switch 56 as a specific example, the command signal s
Since the shift up from 2nd speed to 3rd speed is performed based on h, the shift line Lb related to the shift amplifier from 2nd speed to 3rd speed
The vehicle speed v2 corresponding to the point Q2 above where the throttle opening is THI is set as the post-shift vehicle speed VN.

Next, the set vehicle speed VN after the gear shift operation is subtracted from the actual vehicle speed VM before the gear shift operation, for example, vehicle speed ■1 in the above specific example, and the vehicle speed difference ΔV (= VM - VN) is obtained.
is calculated and the absolute value of the calculated vehicle speed difference Δ■ is less than a predetermined value α], and when the absolute value of the vehicle speed difference Δ■ is greater than or equal to the predetermined value α, the vehicle speed difference Δ■ is A correction coefficient Kp that takes a value is set. The setting of such correction coefficient Kp is as follows:
For example, in FIG. 8, the correction coefficient Kp is plotted on the vertical axis and the vehicle speed difference ΔV is plotted on the horizontal axis, which is stored as data in advance in the memory built into the control unit node 50. This is done by comparing the vehicle speed difference Δ■ with the relationship expressed by the curve vAK in the characteristic diagram and finding the correction coefficient Kp corresponding to the vehicle speed difference Δ■. In such a case,
When the vehicle speed difference Δ■ takes a positive value greater than or equal to α, the correction coefficient Kp
is assumed to take a value greater than 1, and the vehicle speed difference △■
When Kp takes a negative value less than or equal to α, it is assumed that the correction coefficient Kp takes a value smaller than 1.

In addition, if the shift operation in such a case is an upshift, the shift-up condition is satisfied under the line pressure control during normal shift described above, and the shift-up in one of the plurality of M modes is performed. The line pressure value PUV for upshifting is set in the same way as in the case where upshifting is performed. On the other hand, when the shift operation is downshifting, the downshifting condition is set under the line pressure control during normal shifting described above. The line pressure value PDV for the downshift is set in the same manner as when the downshift is performed in one of a plurality of modes. Then, the line pressure value PUV for upshifting or the line pressure value PDV for downshifting is multiplied by the correction coefficient Kp set as described above.
UV or the line pressure value PDV is corrected, and the corrected line pressure value PUV' (-PUV・Kp),
Alternatively, the corrected line pressure value PDV' (=P
DV・Kp) is obtained.

After the corrected line pressure value PU■'' or PDV' is obtained in this way, the pulse occupancy rate that determines the pulse width of the drive signal Ce is changed to the corrected line pressure value PUV'
Alternatively, the drive signal C is calculated as corresponding to PDV' and has the calculated pulse occupancy rate.
e is formed and supplied to the solenoid valve 45. As a result, the pyro nodal pressure supplied to the boat C of the regulator valve 72 is made to correspond to the pulse width of the drive signal Ce, and the boat d or the boat e of the regulator valve 72 is
It is assumed that the line pressure obtained is a value obtained by correcting a value based on the mode of the speed change operation and the throttle opening based on the vehicle speed.

In addition, in the above-mentioned line pressure control during specific gear shifting, the correction coefficient Kp is the vehicle speed difference Δ■ obtained by subtracting the set vehicle speed VN after the gear shifting operation from the actual vehicle speed VM before the gear shifting operation.
However, instead of the vehicle speed difference Δ■, the correction coefficient Kp is calculated based on the engine speed or turbine speed corresponding to the actual vehicle speed VM before the speed change operation, and the vehicle speed after the set speed change operation. It may be set based on an engine rotation speed difference or a turbine rotation speed difference obtained by subtracting the engine rotation speed or turbine rotation speed corresponding to VN. That is, the correction coefficient Kp is set according to the vehicle speed, the engine speed, or the turbine speed difference.

In this manner, when line pressure control is performed during a specific shift, the line pressure generated in the line pressure forming section 46 in the hydraulic circuit section 40 and supplied to the working hydraulic pressure supply section 47 is controlled in the mode of the shift operation. and the value set based on the throttle opening is further corrected based on the vehicle speed, so the automatic transmission 1
0, the shift lever 54 was manually operated to switch the gear range, or the hold switch 56 was manually operated and a command signal sh was issued instructing that the gear should be fixed at 3rd gear. As a result, transmission mechanism 2
0, the change of the gear stage does not follow the preset normal shift characteristics as shown in the shift characteristic diagram of FIG. 3;
Alternatively, for example, even when a specific shift operation state in which gears are changed according to a preset special shift characteristic as shown in the characteristic diagram shown in FIG. 4, the shift shock is effective. will be suppressed.

The control unit 50 that performs the control operations as described above is configured using, for example, a microcomputer.
An example of a program executed by the microcomputer to control the line pressure in such a case will be described with reference to the flowchart of FIG. 9.

In the flowchart of FIG. 9, after the start, in step 80, various detection output signals St, Sr, Sv
, Ss and Sx are taken in, and in the subsequent step 81, if the detection output signals St and S are not present, the throttle opening and vehicle speed are converted into data and stored in the built-in memory, and the gear shift is performed as shown in FIG. It is checked against the characteristic diagram to determine whether the upshift condition is satisfied. As a result, if the shift-up condition is satisfied, the manner of the shift-up to be performed is detected in step 82, and in the subsequent step 83, the throttle opening detected by the detection output signal St and the throttle opening detected in step 82 are detected. The line pressure value is set based on the upshift mode.

Next, in step 84, the hold switch 56 is manually operated, and the command signal s is sent from the hold switch 56.
It is determined whether or not h has arrived, and if the command signal sh has not arrived, in step 85, it is determined whether or not the shift lever 54 has been manually operated based on the detection output signal Ss, and the shift lever 54 is If not manually operated, the process advances to step 86.

On the other hand, if it is determined in step 84 that the hold switch 56 has been manually operated, or
If it is determined in step 5 that the shift lever 54 has been manually operated, in step 87, after shifting up to 3rd speed based on the command signal sh from the hold switch 56, or changing the shift range by manual operation of the shift lever 54. Vehicle speed VN after upshift due to switching of
, and subtract the vehicle speed VN after the upshift from the actual vehicle speed VM before the upshift to find the vehicle speed difference ΔV (= VM
-VN). In the subsequent step 88, the calculated vehicle speed difference Δ■ is compared with the relationship expressed by the curve K in the characteristic diagram of FIG. Also, the vehicle speed difference Δ
When ■ takes a positive value less than or equal to α, it takes a value greater than 1, and when vehicle speed difference Δ■ takes a negative value less than or equal to α, it takes a value greater than 1.
Set a correction coefficient Kp that takes a smaller value, and step 8
In step 9, the line pressure value set in step 83 is corrected by multiplying it by the correction coefficient KP set in step 88, the corrected line pressure value is set, and the process proceeds to step 86.

In step 86, the pulse occupancy rate is calculated according to the line pressure value set in step 83 or the line pressure value set in step 89. Then, in the following step 90, a drive signal Ce having the set pulse occupancy rate is formed, and in step 91,
The drive signal Ce is sent to the solenoid valve 45, and then the process returns to step 80.

If it is determined in step 81 that the upshift condition is not satisfied, in step 92 the throttle opening and vehicle speed generated by the detection output signals St and Sv are converted into data in a built-in memory. It is determined whether or not the downshift condition is satisfied by comparing the shift characteristic diagram as shown in FIG. 4 stored in FIG. As a result, if the downshift condition is satisfied, in step 93, the mode of downshift to be performed is changed to 3.
It is determined whether or not it is a downshift from speed to second speed.

As a result, in the case of downshifting from 3rd gear to 2nd gear, in step 94, the value of the line pressure is set based on the turbine rotation speed generated by the detection output signal Sr, and in the following step 7 step 95 In step 94, the line pressure value set in step 94 is corrected using a correction coefficient Cr corresponding to the change in throttle opening detected by the detection output signal St, and the corrected line pressure value is set.

Subsequently, in step 96, it is determined whether the shift lever 54 has been manually operated based on the detection output signal Ss, and if the shift lever 54 has not been manually operated, the process proceeds to step 97. If it is determined that the shift lever 54 has been manually operated, then in step 98, the vehicle speed VN is set after downshifting from 3rd gear to 2nd gear, which is caused by changing the gear range by manual operation of the shift lever '54. , the vehicle speed VN after downshifting from 3rd gear to 2nd gear is subtracted from the actual vehicle speed VM before downshifting from 3rd gear to 2nd gear to calculate a vehicle speed difference ΔV (=VM−VN).

In the subsequent step 99, the calculated vehicle speed difference ΔV is checked against the relationship expressed by the curve K in the characteristic diagram of FIG. 8, and 1 is taken when the absolute value of the vehicle speed difference ΔV is less than a predetermined value α. , and a correction coefficient that takes a value greater than 1 when the vehicle speed difference ΔV takes a positive value equal to or greater than α, and further takes a value smaller than l when the vehicle speed difference ΔV takes a negative value equal to or less than 1α. Kp is set, and in step 100, the line pressure value set in step 95 is applied to it in step 99.
The line pressure is corrected by multiplying it by the correction coefficient Kp set in , and the corrected line pressure value is set, and the process proceeds to step 97.

In step 97, the pulse occupancy rate is calculated according to the line pressure value set in step 95 or the line pressure value set in step 100, and the process proceeds to step 90, and steps 9 and 91 are performed. Execute in the same manner as described above and return to step 80.

Further, if it is determined in step 92 that the downshift condition is not satisfied, or in step 93
If it is determined in step 101 that there is no downshift from 3rd gear to 2nd gear, the detection output signal St is determined based on the actual throttle opening degree and the detection output signal Sr is the actual turbine rotation speed. Set the pressure value.

Then, in step 102, the pulse occupancy rate is calculated according to the line pressure value set in step 101, and the process proceeds to step 90, where steps 90 and 91 are executed in the same manner as described above, and the process returns to step 80.

(Effects of the Invention) As is clear from the above description, according to the line pressure control device for an automatic transmission according to the present invention, automatic gear shifting operation by a gear changing mechanism provided in an automatic transmission, that is, a preset When a shift operation is performed according to the normal shift characteristics,
The line pressure has a value based on the type of shift operation and the load condition of the engine, and the hydraulic pressure corresponding to the line pressure is selectively applied from the hydraulic pressure supply section to the plurality of frictional engagement elements in the transmission mechanism. In addition, when a manual operation of a shift operation part such as a shift lever or a hold switch provided in connection with a transmission mechanism is performed, the transmission shock is suppressed. When a shift operation state that does not follow the set normal shift characteristics is taken, the line pressure value obtained based on the type of shift operation and the engine load condition may vary depending on the vehicle speed or the engine or automatic transmission. Since the working oil pressure corresponding to the line pressure that is corrected according to the rotation speed of the output element and takes the corrected value is selectively supplied from the working oil pressure supply section to the plurality of frictional engagement elements in the transmission mechanism,
It is possible to effectively suppress the shock associated with the gear shifting operation even when the gear shifting operation section is manually operated and the gear shifting mechanism takes a gear shifting state that does not follow the preset normal gear shifting characteristics. .

[Brief explanation of the drawing]

FIG. 1 is a basic configuration diagram showing a line pressure control device for an automatic transmission according to the present invention in accordance with the claims, and FIG. 2 is a main diagram of an example of the line pressure control device for an automatic transmission according to the present invention. 3 and 4 are characteristic diagrams used to explain the operation of the automatic transmission in the example shown in FIG. 2, and FIG. 2 is a schematic configuration diagram showing the hydraulic circuit part in the example shown in FIG. 2, FIGS. 6 to 8 are characteristic diagrams used to explain the operation of the example shown in FIG. 2 is a flowchart showing an example of a program executed by a microcomputer when the microcomputer is used in the control unit shown in FIG. In the figure, 10 is an automatic transmission, 15 is an oil pump, 20 is a transmission mechanism, 40 is a hydraulic circuit section, 41 to 45 are solenoid valves, 46 is a line pressure forming section, 47 is an operating hydraulic pressure supply section, 5
0 is a control unit, 51 is a throttle opening sensor, 52
53 is a turbine rotation speed sensor, 53 is a vehicle speed sensor, 54 is a shift lever 55 is a shift position sensor, 56 is a hold switch, 72 is a regulator valve, 73 is a reducing valve, and 74 is a manual valve. Patent applicant Mazda Motor Corporation Figure 1 Figure 3 (VM) (VN) Figure 4

Claims (1)

[Claims] 1. A line pressure forming section that adjusts hydraulic pressure from a hydraulic pressure generating section provided in an automatic transmission to form line pressure; and a line pressure generating section that adjusts the line pressure from the line pressure forming section. a working oil pressure supply unit that selectively supplies working oil pressure to a plurality of friction engagement elements in a transmission mechanism included in the automatic transmission; and a line pressure forming unit that sets a value of a line pressure formed by the line pressure forming unit. a line pressure setting section; a shift operation determining means for determining the type of shift operation performed in the transmission mechanism; an engine load detection means for detecting a load condition of an engine to which the automatic transmission is attached; When a shift operation is performed, a line pressure value is set in the line pressure setting section based on the type of shift operation determined by the shift operation determination means and the engine load state detected by the engine load detection means. line pressure control means for detecting the vehicle speed of a vehicle equipped with an engine to which the automatic transmission is attached, or vehicle speed or rotational speed detection means for detecting the rotational speed of an output element in the engine or the automatic transmission; an operation detection means for detecting manual operation of a speed change operation section provided in connection with the speed change mechanism; and when the operation detection means detects that the speed change operation section has been manually operated; Line pressure correction means for correcting the line pressure value set by the line pressure setting section according to the vehicle speed or rotation speed detected by the vehicle speed or rotation speed detection means; Pressure control device. 2. The line pressure correction means adjusts the line pressure to be set by the line pressure setting section based on a preset correction coefficient when the operation detection means detects that the shift operation section has been operated. 2. The line pressure control device for an automatic transmission according to claim 1, wherein the line pressure control device corrects the value of .