JP2000002319A - Control device for automatic transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To control a shift stage by one solenoid valve, and also switch-control line pressure into a high pressure condition in the cases of first speed condition and start in second speed condition. SOLUTION: In a D range, three shift valves of a pressure modifier valve 30, connected to 1-2 and 2-3 shift valves 60 and 70, and a pressure regulator valve 40, are switch-controlled by three-stage oil pressure supplied from a solenoid valve 90, to be controlled into first, second, and third speeds. At the time of 2-range or 1-range, line pressure is supplied to the oil passage 52 of a manual valve 50 to change oil pressure, for causing the switch of the spool positions of the 2-3 shift valve 70 and the pressure modifier valve 30, and the oil pressure is controlled into three ways of high line pressure in first and second speeds, and normal line pressure in a third speed. The line pressure is made a normal condition in the second speed at normal travel, and can be controlled into a high pressure condition at the time of start in the second speed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for an automatic transmission for a vehicle.

[0002]

2. Description of the Related Art A conventional automatic transmission control device for a vehicle is disclosed in Japanese Utility Model Publication No. 5-38286. In this control device, the duty ratio controlled 1
An arrangement is shown in which two solenoid valves are used to control two valves. That is, the 2-3 shift valve is switched by a relatively low signal pressure obtained by the solenoid valve, and the 1-2 shift valve is switched by a relatively high signal pressure. As a result, two valves are controlled by one solenoid,
The shift speed is switched between the second speed, the second speed, and the third speed.

[0003]

However, in the conventional automatic transmission control device, since only the control method of the shift speed is described, when it is desired to increase the line pressure at the time of starting or the like, for example, for example, A separate line pressure control means such as a hydraulic control circuit for particularly increasing the line pressure only in the first speed state has to be provided, and there is a problem that the hydraulic control circuit becomes large and complicated.

[0004] In recent years, with the spread of outdoor orientation of vehicle users, the number of cases of traveling on off-roads such as coasts and traveling on snowy roads has increased, and it has become easier to start at places where slips are likely to occur. A vehicle having two ranges fixed to the second speed has been developed so that the vehicle can start in the second speed state. However, simply fixing the gear to the second speed may cause insufficient fastening force to the fastening element at the time of starting.
As in the case of the speed state, it is desirable to particularly increase the line pressure. The present invention has been made in view of such a conventional problem, and using one solenoid valve,
It is an object of the present invention to provide a control device for an automatic transmission capable of controlling a shift speed and switching control of a line pressure to a high pressure state when starting in a first speed state and when starting in a second speed state.

[0005]

Therefore, according to the present invention, at least three stages of a first hydraulic pressure P1, a second hydraulic pressure P2, and a third hydraulic pressure P3, which sequentially increase in hydraulic pressure value in response to a signal from the electronic control unit, are provided. A solenoid valve that outputs a solenoid pressure, and a first shift valve and a second shift valve that are connected to a hydraulic circuit of a fastening element in the power transmission mechanism and are respectively connected to the solenoid valves to be switched between a first position and a second position. A pressure that is connected to a solenoid valve and is switched between a first position and a second position, and the line pressure, which is the operating pressure for the fastening element, is higher than the normal pressure at the first position and is normal pressure at the second position. A hydraulic valve circuit comprising a modifier valve and a switching hydraulic circuit for supplying a switching signal pressure to each of the second shift valve and the pressure modifier valve; When both the first shift valve and the second shift valve are in the first position, the first gear ratio state is established. When the first shift valve is in the second position and the second shift valve is in the first position, the second gear ratio state is established. When the first shift valve and the second shift valve are both at the second position, the third shift ratio state is established, and the first shift valve is configured such that the solenoid pressure is equal to the second hydraulic pressure P2. When the switching signal pressure is switched between the third hydraulic pressure P3 and the switching signal pressure is off, the second shift valve switches the solenoid pressure between the first hydraulic pressure P1 and the second hydraulic pressure P2, and the pressure modifier valve switches the solenoid pressure. Switching between the second hydraulic pressure P2 and the third hydraulic pressure P3, and when the solenoid pressure is the first hydraulic pressure P1, the first shift valve, the second shift valve, and the pressure modifier valve are all in the second position. What: third gear ratio, the line pressure normal state, the solenoid pressure second pressure P
At the time of 2, the first shift valve and the pressure modifier valve are at the second position, and the second shift valve is at the first position. The second speed ratio, the line pressure normal state, and the solenoid pressure are At the time of the third hydraulic pressure P3, the first shift valve, the second shift valve, and the pressure modifier valve are all in the first position: the first speed ratio, the line pressure high state, and the switching signal pressure is reduced. When on, the second shift valve is fixed at the first position, and the pressure modifier valve switches the solenoid pressure between the first oil pressure P1 and the second oil pressure P2. When the solenoid pressure is the first oil pressure P1, The first shift valve and the pressure modifier valve are in the second position, and the second shift valve is in the first position. When the ratio, the line pressure is in the normal state, and the solenoid pressure is the second hydraulic pressure P2, the first shift valve is in the second position, and the second shift valve and the pressure modifier valve are in the first position. The gear ratio, the line pressure is high, and the solenoid pressure is the third hydraulic pressure P3
In this case, the first shift valve, the second shift valve, and the pressure modifier valve are all in the first position, and are in the first gear ratio and high line pressure state.

The solenoid valve is a duty cycle type solenoid valve that drives a valve body with a duty ratio controlled in accordance with a running state.
The first gear ratio is in a first gear state, the second gear ratio is in a second gear state, the third gear ratio is in a third gear state, and the first gear ratio is a first gear state.
Is preferably a 1-2 shift valve, and the second shift valve is a 2-3 shift valve.

Further, the automatic transmission has at least one speed, two speeds,
A drive range for changing gears between the first and third speeds,
1 range and 2 to change gears between 1st and 2nd speed
Has two ranges for fixing the shift speed to a high speed, the switching hydraulic circuit includes a manual valve connected to a shift lever,
When the drive range is selected by the shift lever, the switching signal pressure supplied from the switching hydraulic circuit is turned off, and the electronic control unit switches the first hydraulic pressure P1,
A signal for driving the solenoid valve is supplied so as to supply the second hydraulic pressure P2 or the third hydraulic pressure P3. When one range or two ranges is selected by the shift lever, the switching signal pressure is turned on, and one range is set. When selected, the electronic control unit outputs a signal for supplying the first hydraulic pressure P1 or the third hydraulic pressure P3 according to the traveling state, and when two ranges are selected, the electronic control unit outputs A signal for supplying the first oil pressure P1 or the second oil pressure P2 is output according to the state.

Further, the electronic control unit selects a solenoid pressure to be supplied based on a traveling vehicle speed, a throttle opening, and a shift position signal. In particular, when two ranges are selected by a shift lever, a normal range is selected. 2
When traveling at the second speed, a signal for supplying the first hydraulic pressure P1 is output to keep the line pressure in the normal state, and when starting at the second speed, the second pressure is output.
By outputting a signal for supplying the oil pressure P2, the line pressure can be maintained at a high pressure state.

[0009]

When the switching signal pressure supplied from the switching hydraulic circuit is off, when the solenoid pressure is the first hydraulic pressure P1, the line pressure is in the normal state at the third gear ratio, and when the solenoid pressure is the second hydraulic pressure P2, At the second speed ratio, the line pressure is in the normal state, and at the third hydraulic pressure P3, the line pressure is at the high speed at the first speed ratio. When the switching signal pressure is ON, when the solenoid pressure is the first oil pressure P1, the line pressure is in the normal state at the second gear ratio, and when the solenoid pressure is the second oil pressure P2, the line pressure is at the second gear ratio. In the high pressure state, the line pressure is high at the first speed ratio when the third hydraulic pressure is P3.

As described above, the combination of the gear ratio and the line pressure when the switching signal pressure is off and on is different from each other by three.
When the switching signal pressure is off, 3
A desired gear ratio can be selected from the two gear ratios. When the switching signal pressure is ON, the gear ratio is the same as the second gear ratio, and the line pressure is in the normal state and the line pressure is in the high state. It can be selected from three states in the case of the second gear ratio. For example, the first shift valve is a 1-2 shift valve, the second shift valve is a 2-3 shift valve,
Assuming that the first speed ratio is the first speed, the second speed ratio is the second speed, and the third speed ratio is the third speed, when the hydraulic pressure switching circuit is turned on, the first hydraulic pressure P1 or the second hydraulic pressure is set as the solenoid pressure. Hydraulic pressure P
By selecting No. 3, when the shift stage is the second speed, the line pressure can be selected from two types of a normal state and a high pressure state.

A drive range in which the gear position is changed between the first, second, and third speeds, and a drive range in which the gear position is changed between the first and second speeds and a two range in which the gear position is fixed to the second speed. When the drive range is selected by the shift lever in an automatic transmission having three types of ranges, the switching signal pressure is turned off, and one range or two
When the range is selected, the switching signal pressure is turned on. In particular, when the two ranges are selected, the line pressure is maintained in the normal state by supplying the first hydraulic pressure P1 during normal second speed running. If the second hydraulic pressure P2 is supplied at the start of the second speed, the line pressure can be maintained at a high pressure state.

Further, when the switching hydraulic circuit is on, the 2-3 shift valve is fixed at the first position, so that the third shift state is established even if the first hydraulic pressure P1 is output from the solenoid valve. The second speed is set by both the first oil pressure P1 and the second oil pressure P2, and the range of the solenoid pressure corresponding to the second speed is widened.
When the line pressure is selected between the normal state and the high pressure state, the solenoid valve is used even if the pressure modifier valve used varies between the first position and the second position. If it is between the first oil pressure P1 and the second oil pressure P2 output from the controller, the throttle pressure is switched.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below based on examples. First, a power transmission mechanism of a vehicle automatic transmission according to the present embodiment will be described. FIG.
FIG. 3 is a skeleton diagram of a power transmission mechanism of an automatic transmission of three forward speeds and one reverse speed to which the present embodiment is applied. This power transmission mechanism is connected to an engine output shaft 2 via a torque converter 1.
Is input to the input shaft 3 and transmitted from the output shaft 4 to the final drive device. The power transmission mechanism further
It has a first planetary gear set 5, a second planetary gear set 6, a front clutch 7, a rear clutch 8, a low and reverse brake 9, a second band brake 10, and a one-way clutch 11.

The first planetary gear set 5 includes a sun gear S1, an internal gear R1, and a carrier PC1 that supports a pinion gear P1 that meshes with both of these gears simultaneously. The second planetary gear set 6 includes a sun gear S
2, a carrier PC2 that supports an internal gear R2 and a pinion gear P2 that meshes simultaneously with both of these gears.
It is composed of

The internal gear R1 is connectable to the input shaft 3 via a rear clutch 8, and is connected to a sun gear S1.
And the sun gear S <b> 2 are always connected and can be connected to the input shaft 3 via the front clutch 7. The internal gear R2 and the carrier PC1 are always connected to the output shaft 4. The second band brake 10 can fix the sun gears S1 and S2, and the low and reverse brake 9 can fix the carrier PC2. One-way clutch 11 is a carrier PC
2 is arranged so as to allow forward rotation (rotation in the same direction as the output shaft 4) but not reverse rotation (rotation in the opposite direction to the normal rotation).

In the power transmission mechanism, the front clutch 7, rear clutch 8, one-way clutch 11, low-and-reverse brake 9, and second-band brake 10, which are fastening elements, are operated in a combination as shown in FIG. By changing the rotation state of each element of the first planetary gear set 5 and the second planetary gear set 6 and changing the rotation speed of the output shaft 4 with respect to the rotation speed of the input shaft 3, three forward speeds and one reverse speed can be obtained. .

The control circuit for the shift speed and the line pressure will be described. FIG. 3 shows a portion of the hydraulic control circuit directly related to the present invention. In this control circuit, a line pressure control for adjusting a line pressure, which is an operating pressure of the hydraulic circuit, is performed together with a shift speed control for switching a shift speed.

First, the configuration of the hydraulic circuit for controlling the shift speed will be briefly described. This hydraulic circuit is connected to the shift lever by a link mechanism (not shown), supplies line pressure to the oil passage 51 in the D range, and connects the oil passage 51 and the oil passage 5 in the two range.
2, the oil passage 51, the oil passage 52, and the oil passage 53 in one range.
Valve 50 that supplies line pressure to the first, second and third gear
1-2 shift valve 60 for switching between speeds, 2nd speed and 3rd speed
A 2-3 shift valve 70 for switching between speeds, and a 3-2 timing valve 80 for adjusting the timing of switching to second speed in accordance with the vehicle speed when switching from third speed to second speed
, 1-2 shift valve 60, 2-3 shift valve 7
It comprises a solenoid valve 90 for controlling switching of the 0, 3-2 timing valve and a pressure modifier valve 30, which will be described later, and an electronic control unit 91 for sending an electric signal to the solenoid valve 90.

When the line pressure is supplied to the oil passage 51, the hydraulic pressure is supplied to the rear clutch 8 to be engaged. When the line pressure is supplied to the oil passage 51 and connected to the oil passage 64, the line pressure is supplied to the servo apply chamber S / A of the second band brake 10, and the second band brake 10 operates.
The line pressure is supplied to the oil passage 51 and the oil passage 64 and the oil passage 74
Is connected, the line pressure is supplied to the servo release chamber S / R of the second band brake 10, and the second band brake 10 is released. When the oil pressure is supplied to the oil passage 53 and connected to the oil passage 65, the line pressure is supplied to the row and reverse brake 9, and the row and reverse brake 9 operates. The 3-2 timing valve 80 adjusts the engagement timing of the second band brake 10 by changing the hydraulic pressure release time of the servo release chamber S / R according to the vehicle speed when downshifting from third speed to second speed.

Next, the configuration of the hydraulic circuit for adjusting the line pressure will be briefly described. This circuit is a throttle pressure adjusting valve 20 that generates a throttle pressure inversely proportional to the accelerator opening.
A pressure modifier valve 30 for supplying a throttle pressure for controlling the line pressure to an oil passage 34, and a hydraulic pressure discharged from an oil pump by the throttle pressure to be supplied to a manual valve 50 via an oil passage 43 as a line pressure. A pressure regulator valve 40, a manual valve 50 for opening and closing a hydraulic pressure to an oil passage 52 that supplies a switching signal pressure to the pressure modifier valve 30, a solenoid valve 90 for switching the pressure modifier valve 30, and an electronic control unit 91. You.

In the operation of the clutch or brake, which is a fastening element, on the one hand, the shock at the time of fastening is reduced, and on the other hand, in order to prevent excessive wear due to slippage at the time of releasing the fastening,
It is necessary to set an appropriate line pressure in accordance with the operating state, particularly the magnitude of the torque applied as the operating oil pressure. In the present embodiment, the line pressure is controlled by the throttle pressure which is inversely proportional to the accelerator opening, and a higher line pressure can be obtained particularly at the time of starting which requires a large fastening pressure.

Next, the configuration of each hydraulic circuit element will be described. The throttle pressure adjusting valve 20 is a pressure adjusting valve that performs pressure adjustment by changing a spring force in the throttle pressure adjusting valve according to an accelerator opening, and generates a throttle pressure inversely proportional to the accelerator opening and supplies the throttle pressure to the oil passage 21. are doing.

The pressure modifier valve 30 is
A shift valve that includes a spool 31 and a spring 32 and opens and closes a hydraulic circuit. When the spool 31 is in the upper half position in the figure, the oil passage 33 and the oil passage 34 communicate with each other,
At the lower half position in the figure, the oil passage 34 is drained. Oilway 3
3, the throttle pressure is supplied from the throttle pressure adjusting valve 20 and supplied to the oil passage 34. As the force for pushing the spool 31 to the right, there are a force due to the oil pressure acting on the port 36 from the oil passage 35 and a force due to the oil pressure acting on the port 38 from the oil passage 37. It is determined by the sum of the forces and the balance of the leftward pushing force by the spring 32.

The oil passage 37 is switched and controlled. When the oil pressure of the oil passage 37 is on, the upper half of the drawing is in the state when the oil pressure of the oil passage 35 is approximately 75 kPa or less, and when the oil pressure of the oil passage 37 becomes larger than approximately 75 kPa. The state is in the middle and lower half, and the oil passage 37
Is off, the spring force is set so that when the oil pressure in the oil passage 35 is 275 kPa or less, the state is in the upper half in the figure, and when the oil pressure is greater than 275 kPa, the state is in the lower half in the figure. .

The pressure regulator valve 40 is a pressure regulating valve composed of spools 41a and 41b and a spring 42. The force for pushing the spool 41a to the right includes a force FL due to the line pressure acting from the oil passage 43 to the port 44 and a force FMS due to the throttle pressure acting from the oil passage 34 to the port 47. , Spring force FS1 and oil passage 4
5 to force FS due to throttle pressure acting on port 46
There is. The spool 41b contacts the spool 41a and exerts a force for pushing the spool 41a to the left.

Line force FL and throttle pressure FM
When the sum of S becomes FL + FMS> FS + FS1 (other than at the time of reverse), hydraulic pressure acts on the control piston of the oil pump via the oil passage 48, and the discharge pressure of the oil pump decreases. Therefore, the line pressure supplied to the oil passage 43 is adjusted such that the force FL due to the line pressure becomes FL = FS + FS1-FMS (other than at the time of reverse).

During normal running, the pressure regulator valve 40 is controlled by using the throttle pressure generated by the throttle pressure adjusting valve 20 as a signal pressure to obtain a line pressure according to the running state. When a high fastening pressure is required, the throttle pressure supplied to the oil passage 34 is cut by the pressure modifier valve 30 so that the throttle pressure is reduced by the pressure regulator valve 40.
, So that a large line pressure can be obtained. The hydraulic pressure is also supplied to the torque converter 1 via the oil passage 49.

The manual valve 50 distributes the line pressure supplied from the oil passage 43 to each hydraulic circuit according to the shift position selected by the shift lever. When the D (drive) range is selected, the line pressure is delivered to the oil passage 51. The oil passage 51 is connected to the 1-2 shift valve 60 and the rear clutch 8. When the two ranges are selected, the line pressure is delivered to the oil passage 51 and the oil passage 52.
The oil passage 52 is connected to the 2-3 shift valve 70 and the pressure modifier valve 30. When one range is selected, the line pressure is delivered to the oil passage 51, the oil passage 52, and the oil passage 53. The oil passage 53 is connected to the 1-2 shift valve 60. In the N (neutral) range, no line pressure is delivered to any oil line.

The 1-2 shift valve 60 includes a spool 61
And a spring 62, the spool 6
1 connects the oil passage 63 and the oil passage 64 at the upper half position in the drawing, and connects the oil passage 53 and the oil passage 65 at the lower half position in the drawing. The oil passage 64 is connected to the servo apply chamber S / A of the second band brake 10 and the shift valve 70. The oil passage 65 is connected to the low and reverse brake 9. The position of the spool 61 is determined by the balance between the force of the spring 62 and the force of the solenoid pressure generated by the solenoid valve 90 acting on the port 68 from the oil passage 67. The oil pressure of the oil passage 67 is 275
When the pressure is more than kPa, the lower half of the drawing is in the state of 275k
The spring force of the spring 62 is set so that when it is smaller than Pa, it is in the upper half state in the figure.

The 2-3 shift valve 70 includes a spool 71
And a spring 72.
1 connects the oil passage 73 and the oil passage 74 at the upper half position in the drawing, and drains the oil passage 74 at the lower half position in the drawing. The oil passage 74 is connected to a servo release chamber S / R of the second band brake 10 via an orifice 86. Further, it is connected to the front clutch 7 and the oil passage 87. The force for pushing the spool 71 to the right includes a force due to the solenoid pressure acting on the port 76 from the oil passage 75 and a force due to the hydraulic pressure acting on the port 78 from the oil passage 77. It is determined by the sum of the pushing force and the balance of the force by the spring 72. When the oil pressure of the oil passage 77 is on, the oil passage 77 is fixed at the lower half in the figure, and when the oil passage 77 is off, the oil passage 7 is fixed.
The spring force is set such that when the hydraulic pressure of No. 5 is approximately 75 kPa or more, the state is in the lower half in the figure, and when the hydraulic pressure is lower than about 75 kPa, the state is in the upper half in the figure.

The 3-2 timing valve 80 comprises a spool 81 and a spring 82. When the spool 81 is at the lower half position in the figure, the oil passage 83 and the oil passage 87 are not connected, and the upper half At the position, the oil passage 83 and the oil passage 87 are connected. The oil passage 83 is connected to the servo release chamber S / R of the second band brake 10. Spool 81
Is determined by the balance between the force by the solenoid pressure acting on the port 85 from the oil passage 84 and the force by the spring 82. The spring force is set such that when the oil pressure of the oil passage 84 is 165 kPa or less, the state is in the upper half in the figure, and when the oil pressure is larger than 165 kPa, the state is in the lower half in the figure. The orifice 86 does not affect the oil passage from the oil passage 74 to the servo release chamber S / R, but acts to narrow the oil passage from the servo release chamber S / R to the oil passage 74.

The solenoid valve 90 has an electronic control unit 91
A duty cycle type solenoid valve that drives the valve element in accordance with a signal from the
The solenoid pressure supplied to the oil passage 92 can be adjusted to a predetermined oil pressure commanded by the electronic control unit 91.

The electronic control unit 91 receives a traveling vehicle speed signal from a vehicle speed sensor (not shown) and a throttle opening signal from a throttle opening sensor. Further, a shift position signal is input from the shift lever. The electronic control unit 91 outputs a signal for adjusting the solenoid pressure of the oil passage 92 to four levels of 0 kPa, 120 kPa, 220 kPa, or 400 kPa based on these signals.

The set value of the solenoid pressure in the electronic control unit 91 will be described. First, in the D range, FIG.
As shown in (1), when the first speed is selected from the vehicle speed signal and the throttle opening signal, the solenoid pressure is set to 400 kPa. When the third speed is selected, it is set to 0 kPa. If the second speed is selected, the speed is set to 220 kPa in the case of an upshift. In the case of a downshift, the solenoid pressure set according to the immediately preceding traveling vehicle speed differs, and in the case of a downshift from a high vehicle speed, 220 k
Set to Pa and shift down from low vehicle speed,
Set to 120 kPa.

In the case of one range, as shown in FIG. 4B, when the first speed is selected, 400 kPa is set, and when the second speed is selected, 0 kPa is set. In the case of two ranges, the second speed is fixed, but the set value of the solenoid pressure differs depending on the vehicle speed immediately before the second range is selected.
When the range is switched to the two ranges during traveling, the solenoid pressure is set to 0 kPa. When switching is performed from a stop, the pressure is set to 220 kPa. By setting the hydraulic characteristics as described above, the gear position control and the line pressure control can be performed.

0 kPa supplied from the solenoid valve 90 is the first oil pressure P1 of the invention, 220 kPa is the second oil pressure P2, and 400 kPa is the third oil pressure P3. The 1-2 shift valve is a first shift valve of the invention, and the 2-3 shift valve is a second shift valve of the invention. The lower half position of each valve in the figure is the first position of the invention.
The upper half position in the figure is the second position. Further, the first speed is the first speed ratio of the invention, the second speed is the second speed ratio, and the third speed is the third speed ratio. Further, the manual valve 50, the oil passage 52, the oil passage 77, and the oil passage 30 constitute a switching hydraulic circuit of the present invention.

Next, the operation of the hydraulic circuit at each shift speed for each range will be described. First, the shift when the shift lever is set to the D range will be described. When the D range is selected, the line pressure is supplied to the oil passage 51 by the manual valve 50. Rear clutch 8
Is supplied with a line pressure via an oil passage 51, and the rear clutch 8 is engaged. Further, since no line pressure is supplied to the oil passage 52, that is, the oil pressures of the oil passage 77 and the oil passage 37 are also off, the position of the spool of each shift valve is switched by the switching pressure shown in FIG. .

When the first speed is selected by the electronic control unit 91, 400 kPa is supplied as a solenoid pressure to the oil passage 92 by the solenoid valve 90. The 1-2 shift valve 60 is in the lower half in the figure, and the oil passage 63 and the oil passage 64 are not in communication.
The rear clutch 8 is engaged regardless of the state of
It becomes a state of speed.

The 2-3 shift valve 70 is in the lower half in the figure, and is connected via the oil passage 92 and the oil passage 35 to the fourth shift valve 70.
A solenoid pressure of 00 kPa is supplied to port 36 of pressure modifier valve 30. The pressure modifier valve 30 is in the lower half in the figure, the oil passage 33 and the oil passage 34 are not connected, and the port 47 of the pressure regulator valve 40 is not supplied with the throttle pressure. Therefore, the pressure regulator valve 4
The line pressure regulated at 0 is in a high pressure state.

Next, when the second speed in upshifting is selected by the electronic control unit 91, the solenoid pressure is set to 220
kPa is supplied. The 1-2 shift valve 60 is in the upper half state in the figure, the oil passage 63 and the oil passage 64 are connected, the hydraulic pressure is supplied to the servo apply chamber S / A of the second band brake 10, and it is already engaged. Rear clutch 8
In addition, the second band brake 10 is engaged, and the automatic transmission is set to the second speed state.

The 2-3 shift valve 70 is in the lower half state in the figure, and no oil pressure is supplied to the oil passage 74. As in the case of the first speed, the solenoid pressure is also supplied to the port 36 of the pressure modifier valve 30 via the oil passage 92 and the oil passage 35, but since the solenoid pressure is 220 kPa, the pressure modifier valve 30 In the upper half of the figure, the oil passage 33 and the oil passage 34 are connected, the throttle pressure is supplied to the pressure regulator valve 40 via the pressure modifier valve 30, and the line pressure is maintained in the normal state. 3-2 Timing valve 8
0 indicates the upper half state in the figure, but does not affect the operation. The operation when the second speed is selected by downshifting will be described later.

Next, when the third speed is selected, 0 kPa is supplied as the solenoid pressure. 1-2 shift valve 60
Is in the upper half of the figure, the rear clutch 8 is engaged, and hydraulic pressure is supplied to the servo apply chamber S / A.
The -3 shift valve 70 is also in the upper half of the figure, the oil passage 73 and the oil passage 74 are connected, hydraulic pressure is supplied to the servo release chamber S / R, the second band brake 10 is released, and the front clutch 7 Is engaged, and a third speed state is established.

At this time, the solenoid pressure is 0 kP
Due to a, the pressure modifier valve 30 is in the upper half state in the figure, the throttle pressure is supplied to the port 47 of the pressure regulator valve 40, and the line pressure is maintained in the normal state.

Next, the operation when the second speed is selected by downshifting will be described. In this case, if the immediately preceding vehicle speed is different, the solenoid pressure set by the electronic control unit 91 is different. First, if the vehicle speed immediately before is low, a solenoid pressure of 120 kPa is supplied. The 1-2 shift valve 60 is in the upper half state in the figure, and the oil passage 63 and the oil passage 64
Is connected, and the hydraulic pressure supplied to the servo apply chamber S / A of the second band brake 10 is maintained. 2-3
The port 76 of the shift valve 70 is also connected to the
Since the solenoid pressure of 20 kPa is supplied, the state becomes the lower half in the drawing, and the oil pressure in the oil passage 74 is drained.

At this time, since the solenoid pressure 120 kPa is also supplied to the port 85 of the 3-2 timing valve 80, the upper half state in the figure is established, and the oil passage 83 and the oil passage 87 are connected, and the servo release chamber S / Since the hydraulic pressure supplied to the R is drained through the orifice 86 and the oil passage 83, the oil passage 87 and the oil passage 74, the operating pressure of the servo release chamber S / R is quickly released, and the second band brake 10 Will be concluded. At the same time, the engagement of the front clutch 7 is released. As in the case of the second speed at the time of upshifting, the throttle pressure is not supplied to the pressure regulator valve 40 via the pressure modifier valve 30, and the line pressure is maintained in a normal state.

If the vehicle speed immediately before is high, the electronic control unit 91 controls the solenoid valve 90 to output 220 kPa as the solenoid pressure when the vehicle is shifted down to the second speed. The 1-2 shift valve 60 is in the upper half in the figure, the oil passage 63 and the oil passage 64 are connected, and the hydraulic pressure supplied to the servo apply chamber S / A of the second band brake 10 is maintained. 2-3 shift valve 7
Since the solenoid pressure of 220 kPa is also supplied to the port 76 of 0 through the oil passage 75, the lower half state in the drawing is established, and the oil pressure of the oil passage 74 is drained.

At this time, since the solenoid pressure 220 kPa is supplied to the port 85 of the 3-2 timing valve 80, the state becomes the lower half state in FIG.
Is not connected. Therefore, the hydraulic pressure supplied to the servo release chamber S / R is gradually drained through the orifice 86 and the oil passage 74, so that the servo release chamber S / R
The time during which the operating pressure / R is released becomes longer, and a time during which the rotation of the engine rises can be secured, and a smooth shift can be performed.

The solenoid pressure is also supplied to the port 36 of the pressure modifier valve 30, but since the solenoid pressure is 220 kPa, the pressure modifier valve 30 is in the upper half in the drawing, and the oil passage 33 and the oil passage 34 Is connected, the throttle pressure is supplied to the port 47 of the pressure regulator valve 40, and the line pressure is maintained in a normal state.

Next, a description will be given of a shift operation when the shift lever is set to two ranges. When two ranges are selected, the manual valve 50 controls the oil passage 51.
Then, the line pressure is supplied to the oil passage 52, the oil passage 77 and the oil passage 37 are turned on, the 2-3 shift valve 70 is fixed to the lower half in the figure, and each valve is shown in FIG. The spool position is switched by the switching pressure. Electronic control unit 91
The solenoid pressure to be set differs depending on the vehicle speed immediately before the two ranges are selected.

First, when two ranges are selected during traveling, 0 kPa is supplied as a solenoid pressure to the oil passage 92 by the solenoid valve 90. The 1-2 shift valve 60 is in the upper half in the figure, and the oil passage 63 and the oil passage 6
4 is connected, hydraulic pressure is supplied to the servo apply chamber S / A of the second band brake 10, the second band brake 10 is engaged in addition to the rear clutch 8, and the automatic transmission enters the second speed state.

The 2-3 shift valve 70 is fixed in the lower half state in the figure, and no oil pressure is supplied to the oil passage 74. The solenoid pressure is also supplied to the port 36 of the pressure modifier valve 30 via the oil passage 92 and the oil passage 35, but since the solenoid pressure is 0 kPa, the pressure modifier valve 30 is in the upper half in the drawing. The oil passage 33 and the oil passage 34 are connected, and the throttle pressure is supplied to the port 47 of the pressure regulator valve 40,
The line pressure is kept at a normal state. The 3-2 timing valve 80 is in the upper half state in the figure, but does not participate in the operation.

Next, when the two ranges are selected during the stop, that is, when the vehicle starts in the second speed, the solenoid valve 9 is selected.
0, the oil pressure in the oil passage 92 is 220 kP
a is supplied. The 1-2 shift valve 60 is in the upper half state in the figure, the oil passage 63 and the oil passage 64 are connected, and hydraulic pressure is supplied to the servo apply chamber S / A of the second band brake 10 so that the oil is applied to the rear clutch 8. Then, the second band brake 10 is engaged, and the automatic transmission is in the second speed state.

The 2-3 shift valve 70 is fixed in the lower half state in the figure, and no oil pressure is supplied to the oil passage 74. The solenoid pressure is also supplied to the port 36 of the pressure modifier valve 30 via the oil passage 92 and the oil passage 35, and the solenoid pressure is 220 kPa. Since the line 33 and the oil line 34 are not connected and the throttle pressure is not supplied to the port 47 of the pressure regulator valve 40, the line pressure is set to a high pressure state. The 3-2 timing valve 80 is in the lower half state in the figure, but does not participate in the operation.

Next, a description will be given of a shift operation when the shift lever is set to one range. When one range is selected, the oil passage 5 is controlled by the manual valve 50.
1. Line pressure is supplied to the oil passages 52 and 53,
As in the case where the range is selected, the oil passage 77 and the oil passage 37 are turned on, the 2-3 shift valve 70 is fixed to the lower half in the figure, and each valve is switched as shown in FIG. The pressure switches the position of the spool. In addition, the line pressure is supplied to the row and reverse brake 9 via the oil passage 53 and is engaged. When the 2nd speed is selected by the electronic control unit 91, 0 kPa is supplied as the solenoid pressure as in the case other than the start of the 2 range, and the operation is the same.

When the first speed is selected, 400 kPa is supplied as the solenoid pressure. 1-2 shift valve 6
0 indicates the state of the lower half in the figure, and the 2-3 shift valve 7
Since 0 is fixed to the lower half state in the figure, the rear clutch 8 and the row and reverse brake 9 are engaged, and the first speed state is established. Further, a solenoid pressure of 400 kPa is supplied to the port 36 of the pressure modifier valve 30 via the oil passage 92 and the oil passage 35, and the pressure modifier valve 30 is in a lower half state in the drawing.
The oil passage 33 and the oil passage 34 are not connected, and the port 47 of the pressure regulator valve 40 is
No throttle pressure is supplied. For this reason, the line pressure regulated by the pressure regulator valve 40 is in a high pressure state.

As described above, in the present embodiment, the oil passage 77 and the oil passage 3 that are switched by the manual valve 50 are controlled.
In the D range where 7 is off, if the hydraulic pressure supplied from the solenoid valve 90 is 0 kPa, the gear stage is in the third speed and the line pressure is in a normal state, and if 220 kPa is set, the line pressure is in the second speed. Is in the normal state, 400k
When Pa is set, the opening / closing state of the valve is controlled so that the line pressure becomes high at the first speed.

When one or two ranges are selected,
The line pressure is supplied to the oil passage 52, and the oil passage 77 and the oil passage 3
7 is turned on, and if the hydraulic pressure supplied from the solenoid valve 90 is 0 kPa, the gear stage is in the second speed and the line pressure is in a normal state. If 220 kPa is set, 2
The opening and closing state of the valve is controlled so that the line pressure becomes a high pressure state at the first speed when 400 kPa is set. As a result, the shift speed can be controlled by using one solenoid valve 90, and the line pressure can be switched to the high pressure state in the case of starting in the first speed state and in the case of starting in the second speed state.

When two ranges are selected, two
-3 shift valve 70 is fixed in the lower half state in the figure, and the shift speed becomes the second speed when the solenoid pressure is in the range of 0 kPa to 220 kPa, and the pressure modification is performed when the normal state is selected as the line pressure and when the high pressure state is switched. The switching pressure at which the spool position of the valve 30 is switched is approximately 75k.
0 kPa and 22 kPa even if the switching pressure of the pressure modifier valve 30 used varies.
There is no risk of deviating from 0 kPa, the switching operation is performed reliably, and the reliability of the control device is improved. Further, since the 1-2 shift valve 60, the 2-3 shift valve 70 and the 3-2 timing valve 80 for switching the shift stage are all controlled by the solenoid valve 90 whose duty ratio is controlled, the shift ratio is controlled based on an arbitrary shift line. The shift speed can be switched, and the degree of freedom in designing the control device is improved.

[0059]

As described above, in the control apparatus for an automatic transmission according to the present invention, when the switching signal pressure supplied from the switching hydraulic circuit is off, the solenoid pressure is increased to the first hydraulic pressure P.
At the time of 1, the line pressure is in the normal state at the third speed ratio, at the second hydraulic pressure P2, at the line pressure normal state at the second speed ratio, and at the third hydraulic pressure P3, the line pressure is at the first speed ratio. It will be in a high pressure state. When the switching signal pressure is ON, when the solenoid pressure is the first oil pressure P1, the line pressure is in the normal state at the second gear ratio, and when the solenoid pressure is the second oil pressure P2, the line pressure is at the second gear ratio. In the high pressure state, the line pressure is high at the first speed ratio when the third hydraulic pressure is P3. As described above, the combination of the speed ratio and the line pressure in the case where the switching signal pressure is off and in the case where the switching signal pressure is on is set to three different combinations, so that when the switching signal pressure is off, the three speed ratios are desirable. When the gear ratio can be selected and the switching hydraulic circuit is on, the gear ratio is the same as the second gear ratio, and when the line pressure is normal, when the line pressure is high, and when the first gear ratio Can be selected from three states.

For example, the first shift valve is a 1-2 shift valve, the second shift valve is a 2-3 shift valve, and the first speed ratio is the first speed, the second speed ratio is the second speed, and the third speed ratio is the third speed. Assuming that the gear ratio is 3rd speed, when the hydraulic pressure switching circuit is turned on, the first hydraulic pressure P1 or the second hydraulic pressure P3 is selected as the solenoid pressure, so that when the shift speed is 2nd speed, the line pressure is normally The state can be selected from two types, a state and a high pressure state.

A drive range in which the gear position is changed between the first, second, and third speeds, and a drive range in which the gear position is changed between the first and second speeds, and two ranges in which the gear position is fixed to the second speed, are set. In an automatic transmission having three types of ranges, when a drive range is selected by a shift lever, the switching hydraulic circuit is turned off. When one or two ranges are selected by the shift lever, the switching is performed. When the hydraulic circuit is turned on, and particularly when the two ranges are selected, the line pressure can be maintained in the normal state by supplying the first hydraulic pressure P1 at the time of traveling at the normal second speed. If the second hydraulic pressure P2 is supplied at the time of starting, the line pressure can be maintained at a high pressure state. As a result, the shift speed can be controlled using one solenoid valve, and the line pressure can be switched to the high pressure state when starting in the first speed state and when starting in the second speed state.

When the switching hydraulic circuit is in the on state, the 2-3 shift valve is fixed at the second position, so that even if the first hydraulic pressure P1 is output from the solenoid valve, the third shift state is established. The second speed is set by both the first oil pressure P1 and the second oil pressure P2, and the range of the solenoid pressure corresponding to the second speed is widened. Therefore, the two ranges are selected, and the line pressure is in the normal state. When selecting either the high pressure state or the low pressure state, even if the pressure modifier valve used switches from the first position to the second position, the first hydraulic pressure output from the solenoid valve varies. If the throttle pressure is between P1 and the second hydraulic pressure P2, the switching of the throttle pressure is performed, so that the switching operation is performed reliably, and the reliability of the control device is improved. Further, since the 1-2 shift valve, the 2-3 shift valve, the 3-2 timing valve, and the like for switching the gears are all controlled by solenoid valves whose duty ratio is controlled, the gears are switched based on an arbitrary shift line. It is possible, and the degree of freedom in designing the control device is improved.

[Brief description of the drawings]

FIG. 1 is a skeleton diagram showing a power transmission mechanism of an automatic transmission.

FIG. 2 is a view showing an operation combination of a fastening element for shifting.

FIG. 3 is a diagram illustrating a configuration of an embodiment.

FIG. 4 is a diagram showing a solenoid pressure and a valve switching pressure.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Torque converter 2 Engine output shaft 3 Input shaft 4 Output shaft 5 First planetary gear set 6 Second planetary gear set 7 Front clutch 8 Rear clutch 9 Low and reverse brake 10 Second band brake 11 One-way clutch 20 Throttle pressure adjusting valve 30 Pressure modifier valve 40 Pressure regulator valve 50 Manual valve 60 1-2 shift valve 70 2-3 shift valve 80 3-2 Timing valve 86 Orifice 90 Solenoid valve 91 Electronic control unit

 ────────────────────────────────────────────────── ─── Continued on the front page F term (reference) 3J052 AA18 AA19 CA07 CA31 CB01 FB01 FB03 FB04 FB05 FB06 FB27 FB31 FB35 GC13 GC23 GC46 GC72 GD07 HA02 LA01

Claims (4)

[Claims] 1. A solenoid valve for outputting at least three-stage solenoid pressures of a first hydraulic pressure P1, a second hydraulic pressure P2, and a third hydraulic pressure P3 whose hydraulic pressure values sequentially increase in response to a signal from an electronic control unit, and power transmission. A first shift valve and a second shift valve connected to a hydraulic circuit of a fastening element in the mechanism and respectively connected to a solenoid valve to be switched between a first position and a second position; and a first position connected to a solenoid valve. A pressure modifier valve that sets the line pressure, which is the operating pressure to the fastening element, higher than the normal pressure at the first position and sets the normal pressure at the second position, and a second shift valve. A switching hydraulic circuit for supplying a switching signal pressure to each of the pressure modifier valves, wherein a hydraulic circuit of the fastening element includes a first shift valve and a second shift valve; When both lubs are in the first position, the first
When the first shift valve is in the second position and the second shift valve is in the first position, the state is in the second gear ratio state, and both the first shift valve and the second shift valve are in the second position. , The third shift ratio state is established, and the first shift valve operates when the solenoid pressure is equal to the second hydraulic pressure P2.
And the third hydraulic pressure P3, and when the switching signal pressure is off, the second shift valve operates with the solenoid pressure of the first hydraulic pressure P1.
And the second hydraulic pressure P2, and the pressure of the pressure modifier valve is changed to the second hydraulic pressure P2 and the third hydraulic pressure P2.
3, when the solenoid pressure is the first oil pressure P1, the first shift valve, the second shift valve, and the pressure modifier valve are all in the second position: the third speed ratio, the line Normal pressure state When the solenoid pressure is the second hydraulic pressure P2, the first shift valve and the pressure modifier valve are in the second position, and the second shift valve is in the first position. When the solenoid pressure is the third hydraulic pressure P3, the first shift valve, the second shift valve, and the pressure modifier valve are all in the first position, and the first shift ratio, the line pressure When the switching signal pressure is ON, the second shift valve is fixed at the first position, and the pressure modifier valve is When the solenoid pressure is switched between the first oil pressure P1 and the second oil pressure P2, and when the solenoid pressure is the first oil pressure P1, the first shift valve and the pressure modifier valve are in the second position and the second shift valve is in operation. Is the first position: the second gear ratio, the line pressure normal state When the solenoid pressure is the second hydraulic pressure P2, the first shift valve is in the second position, and the second shift valve and the pressure modifier valve are Is the first position,: second gear ratio, high line pressure state When the solenoid pressure is the third oil pressure P3, the first shift valve, the second shift valve and the pressure modifier valve are all in the first position. , A first transmission ratio and a high line pressure state. 2. The solenoid valve is a duty cycle type solenoid valve that drives a valve body with a duty ratio controlled in accordance with a running state, wherein the automatic transmission has a forward third speed. The first gear ratio is the first gear, the second gear ratio is the second gear, the third gear ratio is the third gear, the first shift valve is a 1-2 shift valve, and the second shift valve is 2. The control device for an automatic transmission according to claim 1, wherein the control device is a 2-3 shift valve. 3. The automatic transmission according to claim 1, wherein the automatic transmission is at least one speed, two speeds,
A drive range for changing gears between the first and third speeds,
1 range and 2 to change gears between 1st and 2nd speed
The switching hydraulic circuit includes a manual valve connected to a shift lever, and is provided from the switching hydraulic circuit when a drive range is selected by the shift lever. The switching signal pressure is turned off, and the electronic control unit outputs a signal for driving the solenoid valve so as to supply the first oil pressure P1, the second oil pressure P2, or the third oil pressure P3 according to the traveling state. When one range or two ranges is selected, the switching signal pressure is turned on, and when one range is selected, the electronic control unit is controlled according to a traveling state.
A signal for supplying the first hydraulic pressure P1 or the third hydraulic pressure P3 is output, and when the two ranges are selected, the electronic control unit determines whether the first hydraulic pressure P1 or the second hydraulic pressure P2
3. A control device for an automatic transmission according to claim 2, wherein the control device outputs a signal for supplying the following. 4. The electronic control unit selects a solenoid pressure to be supplied based on a traveling vehicle speed, a throttle opening, and a shift position signal. In particular, when two ranges are selected by a shift lever, a normal solenoid control is performed. When traveling in the second speed, a signal for supplying the first hydraulic pressure P1 is output to keep the line pressure in a normal state, and when starting in the second speed, the second hydraulic pressure P1 is output.
4. A control device for an automatic transmission according to claim 3, wherein a signal for supplying a second pressure is output to maintain the line pressure in a high pressure state.