JP2002276784A - Hydraulic control device for automatic transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To sufficiently enhance control accuracy by reducing the increasing/ decreasing gradient of an output hydraulic pressure of a control valve obtained by the current control of a solenoid valve during a gear change. SOLUTION: This hydraulic control device for an automatic transmission comprises the solenoid valve for outputting a variable control hydraulic pressure in response to a current to the control valve and an ON-OFF solenoid valve for outputting a constant control hydraulic pressure in response to a current to the control valve. With the functional operation of the variable control hydraulic pressure output from the solenoid valve on the control valve, the pressure regulating function of the control valve is made effective and the hydraulic pressure supplied to a friction engagement element (the output hydraulic pressure of the control valve) is made into a variable regulated pressure. With the functional operation of the constant control hydraulic pressure output from the ON-OFF solenoid valve on the control valve, the pressure regulating function of the control valve is made ineffective and the hydraulic pressure supplied to the friction engagement element is made into a constant stall pressure.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydraulic control apparatus for an automatic transmission, which controls a supply / discharge of a hydraulic pressure to a plurality of frictional engagement elements to switch a shift speed.

[0002]

2. Description of the Related Art As a hydraulic control device for an automatic transmission of this kind, a plurality of frictional engagement elements capable of switching a gear position of the automatic transmission by changing an engagement state in accordance with a supplied oil pressure, and a line pressure. A control valve that controls the hydraulic pressure supplied to the friction engagement element by adjusting and controlling the hydraulic pressure according to the control hydraulic pressure, a solenoid valve that outputs a variable control hydraulic pressure according to the energization of the control valve, and various signals. A control unit for controlling the energization of the solenoid valve in response to a variable adjustment pressure (relatively low oil pressure) required during shifting as a hydraulic pressure supplied to the friction engagement element and a control unit required during non-shifting. There is a configuration in which a constant stall pressure (relatively high hydraulic pressure, for example, line pressure) is obtained.

In a conventional hydraulic control apparatus, the output hydraulic pressure of a control valve changes as shown by a virtual line in FIG. 6 according to a variable control hydraulic pressure obtained by controlling energization of a solenoid valve. Thus, a variable adjustment pressure required at the time of shifting and a constant stall pressure required at the time of non-shifting can be obtained.

[0004]

In the above-described conventional configuration, the control valve is controlled only by a variable control oil pressure (an oil pressure that changes between the minimum pressure Po and the maximum pressure Pm as shown in FIG. 6) by the energization control of the solenoid valve. The operation of the solenoid valve is controlled, and the output oil pressure of the control valve changes as shown by the imaginary line in FIG. 6, and the control oil pressure is controlled to the maximum pressure Pm by the energization control of the solenoid valve. Thus, the output oil pressure of the control valve is set to the stall pressure. For this reason, the control range (Po to Pc) of the solenoid valve used to obtain a variable adjustment pressure required during gear shifting
) Becomes a part of the entire control region (the region from Po to Pm), the gradient of increase / decrease of the adjustment pressure required during shifting (the gradient from Po to Pc) increases, and the control obtained by the energization control of the solenoid valve is performed. There is a problem that the control accuracy of the output hydraulic pressure of the valve cannot be sufficiently increased.

[0005]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention is directed to a plurality of friction engagement elements capable of switching a gear position of an automatic transmission by changing an engagement state according to a supply oil pressure. A control valve that controls the oil pressure supplied to the friction engagement element by adjusting and controlling the line pressure according to the control oil pressure, and a solenoid valve that outputs a variable control oil pressure according to the energization of the control valve. A control unit for controlling the energization of the solenoid valve in accordance with various signals, a variable adjustment pressure required during shifting as a hydraulic pressure supplied to the friction engagement element and a constant stall required during non-shifting. In a hydraulic control device for an automatic transmission capable of obtaining a pressure, a constant control oil pressure (either a line pressure or a modulator pressure) is output according to energization of the control valve.
An N-OFF solenoid valve is provided, and a variable control oil pressure output from the solenoid valve functionally acts on the control valve, so that the pressure regulating function of the control valve is enabled, and the friction engagement is performed. The oil pressure supplied to the element is a variable adjustment pressure, and a constant control oil pressure output from the ON-OFF solenoid valve functionally acts on the control valve, thereby disabling the pressure adjustment function of the control valve. The invention is characterized in that the oil pressure supplied to the friction engagement element is set to a constant stall pressure (the invention according to claim 1).

In this case, the control valve and the solenoid valve are plural and the ON-OFF solenoid valve is one, and the control oil pressure output from the ON-OFF solenoid valve is selectively applied to each of the control valves. (Invention according to claim 2), and in this case, each of the control valves has a valve body having a plurality of ports and a plurality of lands, and the valve body has a shaft. A valve spool movably mounted in the direction, wherein the valve body comprises:
A first port to which a control oil pressure output from the solenoid valve is supplied, and an output from the ON-OFF solenoid valve only when the control oil pressure is supplied to the first port and the valve spool is operating. It is desirable to have a second port to which the control hydraulic pressure is supplied (the invention according to claim 3).

[0007]

In the hydraulic pressure control apparatus for an automatic transmission according to the present invention (the invention according to claim 1), the variable control hydraulic pressure output from the solenoid valve functionally acts on the control valve. The pressure adjusting function of the control valve is enabled, the hydraulic pressure supplied to the friction engagement element is changed to a variable adjusting pressure, and a constant control oil pressure output from the ON-OFF solenoid valve functionally acts on the control valve. By doing so, the pressure regulating function of the control valve is invalidated, and the hydraulic pressure supplied to the friction engagement element is set to a constant stall pressure.

Therefore, as shown by the solid line in FIG. 6, the entire control range (Po to Pm) of the solenoid valve can be used to obtain a variable adjustment pressure required at the time of shifting, and It is possible to set the output oil pressure of the control valve to the maximum pressure of the variable adjustment pressure required at the time of gear shifting at the maximum pressure (Pm) of the control oil pressure by the energization control. For this reason, the increasing / decreasing gradient (gradient of Po to Pm) of the adjustment pressure required at the time of shifting can be reduced, and the control accuracy of the output oil pressure of the control valve obtained by the energization control of the solenoid valve can be sufficiently increased. .

Further, when a constant control oil pressure output from the ON-OFF solenoid valve acts on the control valve functionally, the pressure adjusting function of the control valve is invalidated, and the stall pressure is applied to the friction engagement element. Because it was supplied,
It is possible to invalidate the pressure regulating function of the control valve at the time of non-shifting, and to eliminate unnecessary pressure oil consumption (energy loss) accompanying unnecessary pressure regulating operation of the control valve.

In the hydraulic control apparatus for an automatic transmission according to the present invention (the invention according to claim 2), the ON-OFF
Since the control oil pressure output from the solenoid valve can be selectively supplied to a plurality of control valves, one ON-
The OFF solenoid valve can be shared by a plurality of control valves, and a hydraulic control device for an automatic transmission that requires a plurality of control valves can be configured compactly and inexpensively.

Further, in the hydraulic control apparatus for an automatic transmission according to the present invention (the invention according to claim 3), each control valve has a valve body having a plurality of ports and a valve body having a plurality of lands. A valve spool provided so as to be movable in the axial direction, the valve body having a first port to which a control oil pressure output from a solenoid valve is supplied; and a valve spool to which the control oil pressure is supplied to the first port. Has a second port to which the control hydraulic pressure output from the ON-OFF solenoid valve is supplied only when the is operated, and the control valve itself has a configuration in which the output from the ON-OFF solenoid valve is provided. Control hydraulic pressure can be selectively supplied to each control valve, so that one ON-OFF solenoid valve can be shared by a plurality of control valves. Another member upon (for example, switching valves, etc.) is not required, it is possible to constitute the hydraulic control device compact and inexpensive.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. FIG. 1 schematically shows an entire configuration of a power transmission device for a vehicle including an automatic transmission 10, FIG. 2 schematically shows a skeleton of a gear train of the automatic transmission 10, and FIG. The part 300 is shown.

The power transmission device for a vehicle shown in FIG. 1 includes an automatic transmission 10 connected to an output shaft (not shown) of an engine 500 and an automatic transmission 10 shown in a skeleton diagram of FIG.
The hydraulic control unit 300 shown in the hydraulic circuit diagram of FIG. 3 for controlling the supply and discharge of the hydraulic pressure to the five hydraulically driven friction engagement elements incorporated in the hydraulic control unit, and a plurality of solenoid valves in the hydraulic control unit 300 And an electronic control unit 400 as a control unit for controlling energization of the power supply. In the present embodiment, the hydraulic control unit 300 and the electronic control unit 400 constitute a hydraulic control device of the automatic transmission 10.

The automatic transmission 10 includes a torque converter 2
An input shaft 11, which is an output shaft of the first shaft, an output shaft 12 connected to the axle via a differential device (not shown), a single-row single pinion planetary gear G1 having a ring gear R1 connected to the input shaft 11, and a second shaft. A single pinion planetary gear G2 in a row and a single pinion planetary gear G3 in a third row are provided.

The automatic transmission 10 includes a first friction clutch C1, a second friction clutch C2, a third friction clutch C3, a first friction brake B1, a second friction brake B2, and the like. The five friction engagement elements of
By switching the supply / discharge of the hydraulic pressure to the five friction engagement elements (engagement / non-engagement of the friction engagement elements) by the hydraulic control unit 300 and the electronic control unit 400, the first to fourth speeds are under-driven, The fifth speed and the sixth speed are configured to achieve the overdrive of six forward speeds and one reverse speed. FIG. 4 shows the relationship between the engagement / disengagement of each friction engagement element and the gear position.

Next, the main configuration of the hydraulic control unit 300 will be described with reference to the hydraulic circuit diagram of FIG. Hydraulic control unit 3
Reference numeral 00 denotes an oil pump 20, a regulator valve 30 for generating a line pressure, a modulator valve 40 for reducing a line pressure to generate a modulator pressure, and a manual valve 50 for manually switching a travel range.
And three linear solenoid valves 60, 70, 80 for outputting a variable control oil pressure according to the energizing current by using a modulator pressure supplied from the oil pump 20 via the modulator valve 40, and according to the energizing current. And one ON-OFF solenoid valve 90 that outputs a constant control oil pressure.

The hydraulic control unit 300 introduces the control oil pressure output from the linear solenoid valves 60, 70, 80 and the control oil pressure output from the ON-OFF solenoid valve 90, and introduces the line pressure to the same line. Control valve 1 that regulates and outputs the pressure according to the control oil pressure
00, 110, 120, and each control valve 100, 11
Three fail valves 13 for introducing the hydraulic pressure output from 0, 120 to prevent double engagement of the friction engagement elements
0, 140, 150 and fail valves 130, 14
0, 150 via control valves 100, 110, 120
Shift valves 160, 170, 180, 190, and 20 that switch the supply of the hydraulic pressure to each friction engagement element according to the supplied hydraulic pressure while introducing the hydraulic pressure output from
0 and each shift valve 160, 17
Three Os for switching the positions of 0, 180, 190, 200
N-OFF solenoid valves 210, 220, and 230 are provided.

In this embodiment, when the linear solenoid valves 60, 70, and 80 are not energized, the variable control oil pressure becomes maximum, and in the energized state, the control oil pressure decreases as the energizing current increases, and the energizing current decreases. The control oil pressure is not supplied (does not act) to the control valves 90, 100, and 110 at the maximum value of. That is, when the linear solenoid valves 60, 70, 80 are not energized, the hydraulic pressure output from the control valves 100, 110, 120 is maximum, and when energized, the energizing current to the linear solenoid valves 60, 70, 80 is small. The output oil pressure becomes smaller as it becomes larger, and the output oil pressure is not generated (substantially zero) at the maximum value of the energizing current.

Also, an ON-OFF solenoid valve 90
In the non-energized state, a constant control oil pressure (line pressure) is applied via the shift valve 91 to the control valves 100, 110, and 120.
The ON-OFF solenoid valve 210 is a normally-open valve that is configured so that the hydraulic pressure is not supplied to the control valves 100, 110, and 120 via the shift valve 91 in the energized state. A line pressure is supplied to the shift valves 160 and 200, and no hydraulic pressure is supplied to the shift valves 160 and 200 in the energized state. On the other hand, the ON-OFF solenoid valves 220 and 230 always supply hydraulic pressure (line pressure) to the shift valves 180 and 190 when energized, and do not supply hydraulic pressure to the shift valves 180 and 190 when not energized. The valve is closed. A linear solenoid valve 240 is provided in addition to the three linear solenoid valves 60, 70, and 80.
0 generates an adjustment pressure to the lock-up control valve 250 for controlling the lock-up of the torque converter 2.

The electronic control unit 400 includes a microcomputer, and as shown in FIG.
, An engine speed sensor (Ne sensor) 41 for detecting the speed Ne of the output shaft, and an input shaft speed sensor (Nt sensor) for detecting the speed Nt of the input shaft 11 of the automatic transmission 10.
42, an output shaft rotation speed sensor (No sensor) 43 for detecting the rotation speed (corresponding to the vehicle speed of the vehicle) No of the output shaft 12 of the automatic transmission 10, the throttle opening of the engine 500 (corresponding to the engine load) The throttle opening sensor (θ sensor) 44 for detecting θ and the position sensor 45 for detecting the position (operating position) of the shift lever operated by the driver are connected to each other. Each linear solenoid 60, 70, 80, 240 and ON-OF
The power supply to the F solenoids 90, 210, 220 and 230 is controlled.

The electronic control unit 400 is turned on and off.
Without switching the energized state of the solenoid valves 210, 220, 230, the linear solenoid valves 60, 70,
A plurality of shift patterns for achieving a predetermined shift speed by controlling the hydraulic pressure supplied to the friction engagement element only by the energization control of 80 are set. In the present embodiment, as shown in FIG. 5, each of the ON-OFF solenoid valves 210, 22
Seven shift patterns from shift pattern 1 to shift pattern 7 are set by a combination of energization and non-energization of 0 and 230.

In FIG. 5, the column of ON-OFF S / V shows the energization state to the ON-OFF solenoid valves 210, 220, 230 in each shift pattern, and the column of frictional engagement element in each shift pattern. The friction engagement elements capable of supplying the output hydraulic pressure from each of the control valves 100, 110, and 120 are shown. In the column of the outputable gear, the gear that can output in each shift pattern (the gear at the time of steady running, (Gear stages that can be shifted during gear shifting). The shift speed at the time of steady running in each shift pattern is set on the higher speed side of the shift speed that can be output from the viewpoint of responsiveness at the time of downshift.

In the present embodiment configured as described above, in the shift pattern 1, each control valve 100, 1
When the output hydraulic pressures of the transmissions 10 and 120 are all substantially zero, all the friction engagement elements are disengaged, and the gear position of the automatic transmission 10 is set to the neutral N. Further, when the output oil pressure of the control valve 110 is set to the line pressure in the shift pattern 2, the friction engagement elements C1 and B2 are engaged, and
When the shift speed of the automatic transmission 10 is set to the first speed and the output oil pressure of the control valve 100 is set to the line pressure in the shift pattern 2, the friction engagement elements C1 and B1 are engaged, and
The speed of the automatic transmission 10 is set to the second speed. Further, when the output oil pressure of the control valve 110 is set to the line pressure in the shift pattern 3, the friction engagement elements C1 and C3 are engaged, and the shift speed of the automatic transmission 10 is set to the third speed.

When the output oil pressure of the control valves 100 and 120 is set to the line pressure in the shift pattern 5, the frictional engagement elements C1 and C2 are engaged, and the automatic transmission 10 shifts to the fourth gear. When the output oil pressure of the control valves 110 and 120 is set to the line pressure in the shift pattern 5, the friction engagement elements C2 and C3 are engaged, and the shift speed of the automatic transmission 10 is set to the fifth speed. You. When the output oil pressure of the control valve 120 is set to the line pressure in the shift pattern 7, the friction engagement elements C2 and B1 are engaged, and the automatic transmission 10 is set to the sixth speed.

In this embodiment, when the gear position of the automatic transmission 10 is switched from the first speed to the sixth speed, one frictional engagement element is changed from the engaged state to the disengaged state, and Is changed from the non-engaged state to the engaged state. For example, when shifting from the second speed state of the shift pattern 2 to the third speed state of the shift pattern 3, ON-O
By the pressure reducing operation of the linear solenoid valve 60 following the pressure reducing operation (ON operation) of the FF solenoid valve 90, the output oil pressure of the control valve 100 is reduced from the stall pressure (line pressure) as shown in FIG. ON-OFF following pressure increase operation of linear solenoid valve 70
The output hydraulic pressure of the control valve 110 is controlled to increase to the stall pressure by the pressure increasing operation (OFF operation) of the solenoid valve 90 as shown in FIG. 6B, and the first friction brake B1 in the engaged state is released. The non-engaged state is established, and the third friction clutch C3 in the non-engaged state is brought into the engaged state.

In the present embodiment, the linear solenoid valves 60, 70, 80 are provided corresponding to the control valves 100, 110, 120, respectively.
For these, an ON-OFF solenoid valve 90 is provided, and in a state where the hydraulic pressure is not supplied from the ON-OFF solenoid valve 90, the variable control hydraulic pressure output from each of the linear solenoid valves 60, 70, 80 controls each control. By functionally acting on the top oil chambers of the valves 100, 110, 120, each control valve 100, 110, 120
Is effective.

For this reason, as shown in FIGS. 6A and 6B, the hydraulic pressure supplied to the frictional engagement element, which is changed from the engaged state to the disengaged state or vice versa, is a variable adjustment pressure. And
In this state, the ON-OFF solenoid valve 90
When a constant control oil pressure (line pressure) output from the valve acts on the upper oil chamber of each control valve 100, 110, 120, the pressure adjusting function of the control valve is invalidated.
The oil pressure supplied to the friction engagement element is a constant stall pressure.

Therefore, in this embodiment, FIG.
As shown by the solid lines in (a) and (b), the entire control range (Po to Pm) of the linear solenoid valves 60, 70, and 80 is used to obtain a variable adjustment pressure required at the time of shifting. The linear solenoid valves 60, 7
The output hydraulic pressure of the control valves 100, 110, and 120 can be set so as to be the maximum variable pressure required for shifting at the maximum pressure (Pm) of the control hydraulic pressure by the energization control of 0 and 80. For this reason, the increasing / decreasing gradient (gradient of Po to Pm) of the adjustment pressure required at the time of shifting can be reduced,
The control accuracy of the output hydraulic pressure of the control valves 100, 110, 120 obtained by controlling the energization of the linear solenoid valves 60, 70, 80 can be sufficiently increased.

In this embodiment, the ON-OF
A constant control oil pressure output from a shift valve 91 that operates in conjunction with the operation of the F solenoid valve 90 acts on the upper oil chambers of the control valves 100, 110, and 120 to control the control valves 100, 110, and 120. The pressure regulating function is invalidated, and the stall pressure is supplied to the friction engagement element.
0, 120, the control valve 10 is disabled.
It is possible to eliminate unnecessary pressure oil consumption (energy loss) associated with unnecessary pressure control operations of 0, 110, and 120.

In the present embodiment, each of the control valves 100, 110, and 120 has a plurality of ports 101a to 101a as shown in FIG.
1g of the valve body 101 and a plurality of lands 10
The valve body 101 includes a valve spool 102 having 2a to 102c so as to be movable in the axial direction to the valve body 101, and a spring 103 for urging the valve spool 102 toward the top oil chamber. , A port 101a to which a control oil pressure output from the linear solenoid valve 60 is supplied, and a control oil pressure to be supplied to the port 101a so that the valve spool 102
The configuration has a port 101c to which a control oil pressure output from the ON-OFF solenoid valve 90 is supplied only in a state in which the valve is operated against the control valve 03.

For this reason, each control valve 100, 110,
120 itself, the ON-OFF solenoid valve 9
The control oil pressure output from the control valves 100, 11
0, 120 can be selectively supplied, and when one ON-OFF solenoid valve 90 is shared by a plurality of control valves 100, 110, 120, another member (for example, a switching valve or the like) is unnecessary, The hydraulic control device can be made compact and inexpensive.

In the above embodiment, the modulator pressure is controlled by the ON-OFF solenoid valve 90, the line pressure is controlled by the shift valve 91, and the output from the shift valve 91 is activated by the operation of the ON-OFF solenoid valve 90. The line pressure of each control valve 100, 110,
120, but the ON-OF
It is also possible to configure so that the line pressure is controlled by the F solenoid valve, and the line pressure output from the ON-OFF solenoid valve is supplied to each of the control valves 100, 110, and 120. . Further, in the above embodiment, the solenoid valves 60, 70, 8
Although 0 was implemented as a linear solenoid valve that outputs a variable control oil pressure according to the energizing current, it may be implemented using a duty solenoid valve that outputs a variable control oil pressure according to the energizing voltage, in addition to the linear solenoid valve. It is possible.

[Brief description of the drawings]

FIG. 1 is a diagram schematically showing an overall configuration of a vehicle power transmission device including an automatic transmission.

FIG. 2 is a skeleton diagram schematically showing a gear train of the automatic transmission shown in FIG.

FIG. 3 is a hydraulic circuit diagram showing a hydraulic control unit of the automatic transmission shown in FIG.

FIG. 4 is a diagram showing a relationship between engagement / disengagement of each friction engagement element and a shift speed.

FIG. 5 is a diagram illustrating a relationship between engagement / disengagement of each friction engagement element and a shift speed in each shift pattern.

FIG. 6 is a characteristic diagram showing an output oil pressure of a control valve whose operation is controlled by a linear solenoid valve and an ON-OFF solenoid valve.

FIG. 7 is an enlarged view of the control valve shown in FIG. 3;

[Explanation of symbols]

10 ... automatic transmission, 20 ... oil pump, 60, 70,
80: Linear solenoid valve, 90: ON-OFF solenoid valve, 100, 110, 120: Control valve, 130, 140, 150: Fail valve, 16
0, 170, 180, 190, 200 ... shift valve,
210, 220, 230: ON-OFF solenoid valve, 300: hydraulic control unit, 400: electronic control unit (control unit), C1, C2, C3, B1, B2: friction engagement element.

 ──────────────────────────────────────────────────続 き Continued on front page F term (reference) 3J552 MA02 MA12 MA26 NA01 NB01 PA54 PA65 QA13A QA26A QB03 QB04 QB05 RA02 SA07 SA51 SA52

Claims (3)

[Claims] A plurality of frictional engagement elements capable of switching a gear position of an automatic transmission by changing an engagement state in accordance with a supply hydraulic pressure, and adjusting and controlling a line pressure in accordance with a control hydraulic pressure. A control valve for controlling the oil pressure supplied to the friction engagement element, a solenoid valve for outputting a variable control oil pressure according to the energization of the control valve, and a control for controlling the energization of the solenoid valve according to various signals A hydraulic control device for an automatic transmission, wherein a hydraulic pressure supplied to the friction engagement element includes a variable adjustment pressure required during shifting and a constant stall pressure required during non-shifting. The control valve is provided with an ON-OFF solenoid valve that outputs a constant control oil pressure in accordance with energization, and a variable control oil pressure output from the solenoid valve functions as the control valve. The pressure regulating function of the control valve is enabled by the action, and the hydraulic pressure supplied to the friction engagement element is changed to a variable adjustment pressure, and a constant pressure output from the ON-OFF solenoid valve is provided. When the control oil pressure functionally acts on the control valve, the pressure adjusting function of the control valve is invalidated, and the oil pressure supplied to the friction engagement element is set to a constant stall pressure. A hydraulic control device for an automatic transmission, characterized in that: 2. The hydraulic control apparatus for an automatic transmission according to claim 1, wherein said control valve and said solenoid valve are plural, said ON-OFF solenoid valve is one, and said ON-OFF solenoid valve is A hydraulic control device for an automatic transmission, wherein the output control hydraulic pressure can be selectively supplied to each of the control valves. 3. The hydraulic control device for an automatic transmission according to claim 2, wherein each of the control valves has a valve body having a plurality of ports and a plurality of lands and moves in the axial direction to the valve body. A valve spool, the valve body being provided with a control hydraulic pressure output from the solenoid valve; and a control hydraulic pressure being supplied to the first port, whereby the valve spool is provided. A hydraulic control device for an automatic transmission, comprising: a second port to which a control hydraulic pressure output from the ON-OFF solenoid valve is supplied only in an operating state.