JP2000039059A - Automatic transmission control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an automatic transmission control device to variably control a liquid pressure, applied on a friction element, according to engaging torque at which a friction element is engaged, high-precisely control a liquid pressure applied on the friction element in the wide control range of a solenoid valve, and control a liquid pressure, exerted on the friction element, to a given pressure regardless of a fluctuation in an engaging primary pressure. SOLUTION: A duty solenoid valve 44 performs control in a duty ratio of a modulate pressure governed to a constant pressure by a pressure reduction control valve 45 according to engine output torque and outputs the modulate pressure as a throttle pressure to a communication passage 115. A throttle pressure is an oil pressure not fluctuated by a line pressure and fluctuated according to output torque of an engine. A duty solenoid valve 12 performs control in a duty ratio of a throttle pressure and applied it as a command pressure on the left end of a control valve 10. By balancing a force, exerted on the control valve 10 from a command pressure, with the energizing force of a spring 11, an oil pressure applied on OD. C2 is controlled to an optimum value according to the fluctuation of engine output torque.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an automatic transmission control device for controlling a pressure applied to a friction element or a lock-up clutch.

[0002]

2. Description of the Related Art Conventionally, as disclosed in JP-A-63-210443 and JP-A-8-326902, hydraulic pressure applied to a plurality of friction elements as an auxiliary transmission is directly controlled by an electromagnetic valve. A hydraulic control device for an automatic transmission is known. In such a hydraulic control device, the hydraulic pressure applied to the friction element is controlled by the solenoid valve, which eliminates the need for an accumulator and simplifies the circuit configuration, and improves the responsiveness when controlling the friction element because it does not involve an accumulator. I do.

[0003] In a hydraulic control device that directly controls the hydraulic pressure applied to a friction element by a solenoid valve, a fixed line pressure may be used as a base pressure of the solenoid valve. In addition, the shift shock is reduced. In some cases, the line pressure input as the engagement source pressure of the friction element is changed between the low speed stage and the high speed stage of the forward range, and is used as the fixed pressure in each case.

In a lock-up clutch which avoids a fluid transmission device such as a torque converter and transmits at least a part of the engine output to an auxiliary transmission, for example, a lock-up pressure generated for lock-up from a line pressure is controlled by an electromagnetic valve. In some cases, the engagement hydraulic pressure is generated by controlling the lock-up pressure with an electromagnetic valve in a duty ratio control. Also, a constant control source pressure is generated from the line pressure, this control source pressure is input as the source pressure of the solenoid valve, the duty ratio of the control source pressure is controlled by the solenoid valve, and the command pressure is applied to the pressure regulating valve as a command pressure. In some cases, the lock-up pressure is adjusted by a pressure valve to generate the engagement hydraulic pressure of the lock-up clutch.

[0005]

When the throttle opening is small, the output torque of the engine is small. Therefore, even if the hydraulic pressure applied to the friction element and the lock-up clutch is low, the friction element and the lock-up clutch will not Output torque can be transmitted. However, as described above, even if the pressure is changed between the low speed stage and the high speed stage in the forward range, if the fixed line pressure is input to the solenoid valve as the engagement source pressure, the output torque of the fluctuating engine can be reliably reduced. In order to engage the friction element and the lock-up clutch with each other, the line pressure used as the engagement source pressure must be set to a high pressure.

When the throttle opening is small, in order to control the high-pressure line pressure input as the engagement source pressure and to apply low-pressure hydraulic oil to the friction element and the lock-up clutch,
It is necessary to use only a limited low pressure range in the pressure control range of the solenoid valve from low pressure to high pressure. In order to control the hydraulic pressure applied to the friction element and the lockup clutch with high accuracy using only a limited low pressure range, an expensive solenoid valve with high pressure resolution that controls oil pressure with high accuracy in a limited control range is required. Since it needs to be used, there is a problem that the cost increases.

Generally, the line pressure is set to a certain value by discharging the hydraulic oil discharged from the hydraulic pump to the drain side by the line pressure control valve. However, for example, when the hydraulic oil to be added to the friction element is rapidly filled in order to enhance the engagement response of the friction element, it is not possible to cope with the rapid filling of the hydraulic oil due to a response delay of the line pressure control valve, and the line pressure is temporarily reduced. May drop. When the line pressure decreases, the hydraulic pressure applied to the friction element and the lock-up clutch also decreases, and it may not be possible to properly perform the shift control of the friction element and the engagement control of the lock-up clutch.

Here, the line pressure is adjusted in accordance with the output torque of the engine, and the line pressure is controlled by a solenoid valve directly or by a pressure regulating valve according to the command pressure of the solenoid valve, so that the friction can be controlled in a wide hydraulic control range of the solenoid valve. It is possible to control the hydraulic pressure applied to the elements and the lock-up clutch. However, it is not possible to cope with the fluctuation of the line pressure accompanying the rapid filling control.

The control source pressure set to a constant pressure is used as the source pressure of the solenoid valve, the control source pressure controlled by the duty ratio is applied as a command pressure to the pressure regulating valve, and the hydraulic pressure applied to the lock-up clutch is adjusted by the pressure regulating valve. When pressurizing, the control source pressure is constant regardless of the fluctuation of the line pressure, and therefore cannot cope with the fluctuation of the line pressure accompanying the rapid filling control. Further, there is a problem that the hydraulic pressure applied to the friction element and the lock-up clutch cannot be controlled according to the fluctuation of the output torque of the engine.

An object of the present invention is to variably control a hydraulic pressure applied to a friction element in accordance with an engagement torque at which the friction element is engaged, and to precisely control a hydraulic pressure applied to the friction element in a wide control range of a solenoid valve. It is an object of the present invention to provide an automatic transmission control device for controlling a hydraulic pressure applied to a friction element to a predetermined pressure irrespective of a variation in an engagement source pressure.

Another object of the present invention is to variably control the hydraulic pressure applied to the lock-up clutch in accordance with the engagement torque at which the lock-up clutch is engaged, and to control the hydraulic pressure applied to the lock-up clutch to a wide range of the solenoid valve. It is an object of the present invention to provide an automatic transmission control device that controls the hydraulic pressure applied to the lock-up clutch to a predetermined pressure irrespective of the variation of the engagement source pressure by performing high-precision control within a range.

[0012]

According to the first aspect of the present invention, the command pressure control means generates the first command pressure by variably adjusting the hydraulic pressure of the working fluid at a constant pressure. Then, according to the second command pressure generated by the command pressure control valve using the first command pressure as the source pressure, the pressure regulator regulates the hydraulic pressure applied to the friction element regardless of the pressure of the engagement source pressure. Therefore, the hydraulic pressure applied to the friction element can be adjusted according to the torque at which the friction element is engaged.

Further, since the command pressure control valve uses the first command pressure variably generated by the command pressure control means as the base pressure, the hydraulic pressure applied to the friction element over a wide control range of the command pressure control valve can be accurately determined. Can be controlled.

Further, the second command pressure is generated irrespective of the variation of the engagement source pressure, and the pressure regulating valve regulates the hydraulic pressure applied to the friction element based on the second command pressure regardless of the engagement source pressure. Desired hydraulic pressure can be applied to the friction element even if the source pressure fluctuates.

According to the automatic transmission control device of the second aspect of the present invention, the first command pressure fluctuates according to the output torque of the engine, so that the torque for engaging the friction element is changed according to the output torque of the engine. It can be controlled optimally.

According to the automatic transmission control device of the third aspect of the present invention, the command pressure control valve is a duty solenoid valve. Therefore, by controlling the duty ratio, the friction can be easily adjusted with high accuracy over a wide control range. The hydraulic pressure applied to the element can be controlled.

According to the automatic transmission control device of the fourth aspect of the present invention, the command pressure control means generates the first command pressure by variably adjusting the hydraulic pressure of the working fluid at a constant pressure, and generates the first command pressure. The pressure regulating valve regulates the hydraulic pressure applied to the lock-up clutch regardless of the pressure of the engagement source pressure according to the second command pressure generated by the command pressure control valve using the pressure as the base pressure. Therefore, the hydraulic pressure applied to the lock-up clutch can be adjusted according to the torque at which the lock-up clutch is engaged.

Further, since the command pressure control valve uses the first command pressure variably generated by the command pressure control means as the original pressure, the hydraulic pressure applied to the lock-up clutch can be controlled with high precision over a wide control range of the command pressure control valve. Can be controlled.

Further, the second command pressure is generated irrespective of the variation of the engagement source pressure, and the pressure regulating valve regulates the hydraulic pressure applied to the lock-up clutch based on the second command pressure regardless of the engagement source pressure. Desired hydraulic pressure can be applied to the lock-up clutch even if the engagement source pressure fluctuates.

According to the automatic transmission control device of the fifth aspect of the present invention, the first command pressure fluctuates in accordance with the output torque of the engine. Therefore, the torque for engaging the lock-up clutch depends on the output torque of the engine. And can be optimally controlled.

According to the automatic transmission control device of the present invention, since the command pressure control valve is a duty solenoid valve, by controlling the duty ratio, it can be locked with high precision and easily in a wide control range. The hydraulic pressure applied to the up clutch can be controlled.

[0022]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing an embodiment of the present invention. FIG. 3 shows a hydraulic circuit according to an embodiment in which the automatic transmission control device of the present invention is applied to a hydraulic control device for an automatic transmission of five forward speeds. Reverse clutch (R / C) 1, Overdrive clutch (OD /
C) 2, 2-5 brake (2-5 / B) 3, underdrive clutch (UD / C) 4, low reverse brake (LR / B) 5, reduction brake (Red / B)
6 and a direct clutch (D / C) 7 are friction elements that are engaged or released by hydraulic pressure, and constitute an auxiliary transmission.

FIG. 4 shows engagement or disengagement of each friction element at each shift speed. ○ indicates the engaged state,
No mark indicates a released state. In FIG. 4, the speed indicated by R corresponds to the R (reverse) range, and the speed indicated by N corresponds to the P (parking) range and the N (neutral) range.
The shift speeds indicated by 1st, 2nd, 3rd, 4th, and 5th are D,
The corresponding range differs depending on the range of 4, 3, 2, 1 (forward range). In first gear, LR / B5 is engaged or released according to the range of the shift lever selected by the driver. For example, the clutch is engaged at the first speed in the first range, and is released at the first speed in the D range.

In FIG. 3, the control valve 10 and the duty solenoid valve 12, the control valve 16 and the duty solenoid valve 18, the control valve 20 and the duty solenoid valve 22, the control valve 26 and the duty solenoid valve 28, the control valve 32 and the duty solenoid valve. Reference numeral 34 denotes friction element control means for controlling the pressure applied to each friction element other than R / C1. Each duty solenoid valve constitutes a command pressure control valve, and each control valve constitutes a pressure regulating valve. Each control valve is constituted by a spool valve having two lands having different diameters, and the land diameter on the right side is larger than the land diameter on the left side. Duty solenoid valves 12, 18, 2
By applying the first command pressure, which is the output pressure of 2, 28, 34, to the right ends of the control valves 10, 16, 20, 26, 32 in FIG. 3, the output pressure of each control valve is controlled. Only when the driver selects R of the shift lever, the line pressure as a source pressure for hydraulically controlling each friction element is directly applied to the R / C1 via the manual valve 38.

The fail-safe valves 14, 24, 30 are valves for preventing double engagement of the friction elements. When the pressure applied to OD / C2 and UD / C4 are both line pressures, fail-safe valve 14 moves to the left in FIG. 3 regardless of the pressure applied to 2-5 / B3, and communicates with communication passage 174 and drain passage 190. And communicate with. Thus, when a line pressure is applied to OD / C2 and UD / C4, 2-5 / B3 becomes a drain pressure.

The failsafe valve 24 includes a communication passage 183,
Only when the drain pressure is at 185 and the communication passage 187 is at the line pressure, it moves to the right in FIG. At this time, the communication passage 189 communicates with the communication passage 188, and the communication passage 191 communicates with the drain passage 192.

The failsafe valve 30 moves to the left in FIG. 3 only when the communication path 127 is at line pressure and the communication path 161 is at drain pressure. At this time, the communication paths 130 and 191
And the communication passage 130 and the drain passage 131 communicate with each other at other times.

The high pressure selection valve 29 is a valve for selecting the pressure on the high pressure side. Either the communication passage 200 as the R / C1 pressure or the communication passage 189 as the output pressure of the fail-safe valve 24 is selected on the high pressure side and the pressure is applied to the LR / B5.

The first speed determination valve 36 is a valve for determining whether or not the shift speed is the first forward speed. When both the communication passage 180 at 2-5 / B pressure and the communication passage 181 at OD / C pressure are at drain pressure, the spring 37 moves to the right in FIG. The gear position where both the 2-5 / B pressure and the OD / C pressure become the drain pressure is at the first forward speed, N, and R from FIG. At this time, the communication passages 182, 183, 184 have a drain pressure. Further, even if one of the communication passages 180 and 181 becomes a line pressure and the first speed determination valve 36 moves to the left,
When the P, R, and N ranges are selected, the communication path 18
2, 183 and 184 are drain pressures. That is, the communication passages 182, 183, and 184, which are the output pressures of the first speed determination valve 36,
Are the drain pressure when the first forward speed, N, and R are set.

The manual valve 38 is connected to the shift lever via a link, and the range P (parking), R (reverse), N (neutral), D, 1, 2, 3 of the shift lever selected by the driver. , 4 (forward), the manual valve 38 switches. The manual valve 38 switches between the line pressure communication passage 120 and the drain passage 121 branched from the communication passage 100 depending on the position thereof, and controls whether the pressure of the communication passage 122 and the communication passage 123 becomes the line pressure or the drain pressure. . The switching position of the manual valve 38 corresponds to “P, R, N, D,
There are eight positions of "4, 3, 2, 1". "P, N",
“D, 4, 3, 2, 1” are the same communication patterns. Further, as shown in FIG. 4, a combination of engagement or disengagement of each friction element is predetermined in accordance with each shift speed, and an ECU (Elec not shown) is shown in accordance with the combination.
A gear change command is output from the tric control unit).

A hydraulic pump 40 as a hydraulic pressure source sucks hydraulic oil from a suction port 41 of an oil pan and supplies the hydraulic oil to each friction element and the lock-up clutch 51. The line pressure control valve 42 generates the operating pressure of each friction element and the lock-up clutch 51 together with the secondary valve 43 based on the command pressure of the duty solenoid valve 44. The pressure reduction control valve 45 is a valve that reduces the line pressure generated by the line pressure control valve 42. The duty solenoid valve 44 and the pressure reduction control valve 45 constitute command pressure control means. The oil cooler 46 is provided for cooling the working oil and exchanging heat.

The lock-up clutch 51 engages or disengages the output shaft of the engine and the input shaft of the automatic transmission. When engaged, the lock-up clutch 51 bypasses the torque converter 50 and supplies power from the engine to the auxiliary transmission. introduce. The lock-up on / off solenoid valve 53 controls a command pressure for switching the lock-up relay valve 52. The lockup control valve 54 as a pressure regulating valve is constituted by a spool valve having two lands having different diameters, and the land diameter on the right side is larger than the land diameter on the left side. The lock-up control valve 54 controls the pressure applied to the lock-up clutch 51 based on the second command pressure generated by the duty solenoid valve 55 as a command pressure control valve. The lock-up control valve 54 and the duty solenoid valve 55 constitute lock-up control means.

Next, the hydraulic pressure for controlling the hydraulic circuit of this embodiment will be described. As shown in FIG. 1, hydraulic oil is sucked from a suction port 41 of an oil pan by a hydraulic pump 40, and is discharged to the communication paths 100, 101, and 102 at high pressure. The line pressure control valve 42 controls the line pressure by discharging a part of the hydraulic oil sent from the communication passage 101 to the communication passages 103 and 104.

A pressure reducing control valve 45 is provided on a path branched from the communication path 100 to the communication path 110. Pressure reducing control valve 4
5 is output from the communication passage 111 to the throttle 1 in the communication passage 112.
1 and is fed back to the right side of the pressure reducing control valve 45 in FIG. Due to the balance between the force received by the pressure reducing control valve 45 from this output pressure and the urging force of the spring 45a, the pressure in the communication passage 111 does not exceed the line pressure, for example, about 0.4 MPa when the line pressure is 1.6 MPa at maximum. Controlled. This pressure is called the modulation pressure. The modulation pressure is adjusted to a constant pressure regardless of the level of the line pressure in the communication passage 100.

The modulated pressure regulated to a constant pressure by the pressure reducing control valve 45 is guided to the duty solenoid valve 44 via the throttle 114. The duty solenoid valve 44 generally controls a duty ratio by an output signal from an ECU (not shown) so as to set an appropriate line pressure in accordance with a vehicle operating state such as a throttle opening, an engine output torque and a turbine torque. Then, the command pressure is output to the communication passage 115. This command pressure is called a throttle pressure. The throttle pressure is a hydraulic pressure that does not vary according to the line pressure, but varies according to the operating state of the vehicle, such as the throttle opening, the engine output torque, and the turbine torque. The communication passage 115 is connected to the left end of the line pressure control valve 42 in FIG. FIG.
The line pressure is introduced into the right-side different diameter portion of the line pressure control valve 42 via the communication passage 105 branched from the communication passage 102 which is the line pressure passage, and is balanced with the throttle pressure which is the command pressure of the duty solenoid valve 44. The line pressure is feedback controlled. Therefore, the line pressure, which is the pressure in the communication passage 100, also varies according to the operating state of the vehicle, such as the throttle opening, the engine output torque, and the turbine torque, similarly to the throttle pressure.

The secondary valve 43 discharges a part of the hydraulic oil of the line pressure control valve discharged to the communication passage 103 to the drain passage 107 to thereby apply the pressure of the communication passage 106 to the lock-up mechanism at the original pressure. Set to a certain secondary pressure. By introducing and feeding back the pressure of the communication passage 106 to the right-hand different-diameter portion of the secondary valve 43 via the communication passage 108, the pressure of the communication passage 106, that is, the secondary pressure becomes a constant pressure set by the spring 43a.
As shown in FIG. 2, the communication paths 210 and 211 are
6, the hydraulic oil of the secondary pressure is introduced into the lock-up relay valve 52 and the lock-up control valve 54.

The lock-up relay valve 52 is connected to the communication passage 18.
2 is switched from the position shown in FIG. 2 only when the pressure of the communication passage 215 is the drain pressure.
16 and the communication path 217, and the communication path 213 and the communication path 2
10 communicates. Then, the secondary pressure is applied to the communication path 213, and the pressure of the communication path 217 regulated by the lock-up control valve 54 to the communication path 216.

The high pressure in the communication passage 184 is caused by OD / C2
And 2-5 / B3 when the pressures are both high, and when forward 2nd to 5th speed. When the power to the on / off solenoid valve 53 is turned on, the on / off solenoid valve 53 is switched from the position shown in FIG. 2, and the communication path 215 becomes drain pressure.

The duty solenoid valve 55 introduces a throttle pressure hydraulic oil from the communication passage 145 as a base pressure. The pressure in the communication passage 146 is varied by the duty solenoid valve 55 in accordance with the throttle opening, the engine output torque or the turbine torque. The lock-up control valve 54 has a set of lands having different diameters, and regulates the pressure in the communication path 217 regardless of the secondary pressure by the balance between the force received from the communication path 146 and the urging force of the spring 54a.

As shown in FIG. 3, the communication path 143 branches from the communication path 115 which is a throttle pressure, and the communication path 144
145 branches off from the communication passage 143 and is connected to the duty solenoid valves 34 and 55, respectively. Communication paths 150, 15
1, 152 and 153 are branched from the communication path 144,
Duty solenoid valves 12, 18, 22, 28 are connected. Therefore, the duty solenoid valves 12, 18, 22,
Throttle pressure is introduced at 28,34,55. The command pressures of the duty solenoid valves 12, 18, 22, 28, 34, 55 are respectively transmitted through the communication passages in FIG.
0, 16, 20, 26, 32, 54 are introduced on the right side. Communication passages 124, 125, 126, 14 for applying an engagement source pressure to control valves 10, 16, 20, 26, 32, 54
If the operating oil is supplied to 1, 140, and 211, the output pressure of each control valve is determined by the biasing force of the spring applied to each control valve and the force received by each control valve from the command pressure of each duty solenoid valve. Specified by balance.

The hydraulic pressure applied to each friction element except R / C1 and the lock-up clutch 51 is based on a throttle pressure that varies according to the operating state of the vehicle, such as the throttle opening, engine output torque and turbine torque. The duty ratio is controlled by a duty solenoid valve.

The operating principle of the hydraulic circuit of each friction element except for R / C1 is basically the same except for the presence or absence of the fail-safe valve, so the hydraulic circuit for OD / C2 is taken as an example, and its operation will be described next. explain.

As shown in FIG. 1, the throttle pressure in the communication passage 143 is introduced into the duty solenoid valve 12 from the communication passage 150, and a command pressure controlled by a duty ratio in accordance with a command from the ECU is applied to the duty solenoid valve 12 from the duty solenoid valve 12. In the control valve 1
0 is introduced at the right end. As described above, the control valve 10-2
The three lands have different diameters, and the land diameter on the right side in FIG. 3 is larger than that on the left side. Therefore, the communication passage 17
Due to the pressure of 5, a rightward pressing force is generated in the control valve 10. This hydraulic force is supplied to the communication passage 124 by the balance between the pressing force, the force received by the control valve 10 from the command pressure of the duty solenoid valve 12, and the urging force of the spring 11. The pressure in the communication path 175 is controlled according to the command pressure regardless of the pressure in the communication path 124.

Next, the operation of the hydraulic control device in each range selected by the shift lever will be described. (1) In the P and N ranges, the communication passages 122 and 123 communicate with the drain passage 121, and the communication passages 124, 125 and 126 branched from the communication passage 123 also have a drain pressure. Therefore, the R / C1, OD / C2, and R / C1, which are directly or indirectly connected to the communication paths 122, 124, 125, and 126, respectively.
-5 / B3 and UD / C4 are released and are not engaged by any control command from the ECU.

Since both the communication paths 180 and 181 are at the drain pressure, the communication path 183 having the output pressure of the first speed determination valve 36 is at the drain pressure. Further, the communication paths 185, 1
Since 87 is the drain pressure, the fail-safe valve 24
Moves to the left side in FIG. 3 by the urging force of the spring 25,
The communication passage 189 and the drain passage 192 communicate with each other. Therefore, LR / B5 is released.

Since the communication passage 140 branched from the communication passage 100 does not pass through the manual valve 38 but is connected to the control valve 32 which is a control means of the Red / B6, a line is connected to the control valve 32 irrespective of the selected range. Pressure has been introduced. Therefore, the communication passage 161 is set to the line pressure by the electromagnetic valve 34 whose duty ratio is controlled based on a command from the ECU,
Red / B6 is engaged.

The communication passage 127 is branched from the communication passage 140, and the pressure is always the line pressure regardless of the position of the manual valve 38. Further, since the pressure in the communication passage 161 is a line pressure, the fail-safe valve 30 moves to the right in FIG. 3 by the urging force of the spring 31, and the communication passage 130 and the drain passage 131 communicate with each other. The pressure becomes the drain pressure, and D / C 7 is released.

(2) Next, the forward range "D, 4, 3, 2,
"1" will be described using the D range as an example. 4, 3,
The operation of each shift speed in the 2nd and 1st ranges is the same as the corresponding shift speed in the D range, and thus the description is omitted.

In the D range, the communication passage 122 has a drain pressure, and the communication passage 123 has a line pressure. Since the R / C1 is connected to the communication passage 122, the R / C1 is released at all the shift speeds in the D range. The communication paths 124, 125, 126 branched from the communication path 123
6 and 20 are connected. Further, since the communication path 140 connected to the control valve 32 has a line pressure as described above,
OD / C2, 2-5 / B3, UD / C4 and Red /
B6 is engageable. Further, the communication path 130 and the communication path 191 can communicate with each other depending on the level of the pressure applied to Red / B6. Further, the communication path 189 and the communication path 188 can communicate with each other by switching the fail-safe valve 24. Therefore, LR / B5 and D / C7 can be engaged.

Next, the operation of each shift speed in the D range will be described. (i) UD / C at 1st speed based on the combination of FIG.
4. The duty solenoid valves 22 and 34 are controlled to set Red / B6 to a high pressure, and OD / C2 and 2-5 / B
3 is set to a low pressure so that the duty solenoid valves 12, 18
Control. Therefore, the communication passages 176 and 161 have a high pressure, and the communication passages 175 and 173 have a low pressure.

In FIG. 3, the line pressure is introduced to the left end of the fail-safe valve 14 through the communication passage 170, the OD / C pressure through the communication passage 171 at the right end, and the UD / C pressure through the communication passage 172. Has been introduced. The OD / C pressure is low and the UD / C pressure is high. Since the pressure receiving area of the fail-safe valve 14 that receives the UD / C pressure is smaller than the left end that receives the line pressure, the balance of the force causes the fail-safe valve 14 to move to the right in FIG.
Communicates with the communication passage 173. Since the pressure in the communication passage 173 is low, 2-5 / B3 is released.

In the case of the first speed, since the pressures in the communication passages 180 and 181 are both low, the first speed determination valve 36 moves rightward by the urging force of the spring 37, and the communication passage 182 becomes drain pressure. As a result, the communication passages 183 and 184 also have a drain pressure. Further, since the communication path 122 is at the drain pressure, the communication path 185 is also at the drain pressure. Therefore, the pressure on the right side of the fail-safe valve 24 in FIG. 3 is the drain pressure. Since the communication passage 187 has a line pressure, the left side of the failsafe valve 24 has a high pressure. Therefore, the fail-safe valve 24 moves to the right in FIG.
Communicates with the communication passage 189. Here, when the first speed in one range is selected, the command pressure of the duty solenoid valve 28 is increased to make the communication passage 188 high and the LR / B5 is engaged. The movement of the fail-safe valve 24 to the right in FIG. 3 is only at the first forward speed. Therefore, the communication passage 189 is always at the drain pressure except for the first forward speed.

Since the communication passage 127 and the communication passage 161 are at line pressure, the fail-safe valve 30
It moves to the right by the urging force of 1. Therefore, the communication passage 130 is at the drain pressure, and the D / C 7 is released.

(Ii) As shown in FIG. 4, when shifting from the first speed to the second speed, 2-5 / B3 is engaged and LR / B5 is released. When the command pressure of the duty solenoid valve 18 is gradually set to a high pressure, the basic operation of the control valve 16 causes
The pressure at 73 and 174 also increases and 2-5 / B3 engages.

By increasing the pressure of the communication path 174, the communication path 180 is increased.
Therefore, the first speed determination valve 36 moves to the left in FIG. Then, the communication passage 182 becomes a line pressure, and the fail-safe valve 24 moves to the left accordingly.
The communication passage 189 has a drain pressure. Since the pressure in the communication passage 200 is the drain pressure except in the R range, the LR / B5 is released. By switching the fail-safe valve 24, 2-5
/ B3 and LR / B5 are prevented from being double-engaged due to simultaneous engagement.

(Iii) As shown in FIG. 4, when shifting from the second speed to the third speed, 2-5 / B3 is released and OD / C2 is engaged. As the speed change control, the command pressure of the duty solenoid valve 18 is decreased while the command pressure of the duty solenoid valve 12 is increased, thereby performing the switching control of the friction element. Then, when the pressure of OD / C2 rises to a pressure equal to the line pressure and the sum of the forces received from the pressure applied to the right side of the fail-safe valve 14 exceeds the sum of the forces received from the pressure applied to the left side of the fail-safe valve 14, Moves to the left to communicate the communication passage 174 with the drain passage 190, releasing 2-5 / B3. As a result, a double engagement prevention measure is taken in the event of erroneous control of the duty solenoid valve 18.

(Iv) Since the fail-safe valve 24 moves to the left in the state of the third speed, the communication path 188
It communicates with 1. In 1st, 2nd and 3rd speed, Red /
Since the pressure of B6 is the line pressure, the fail-safe valve 3
0 is moving to the right. Therefore, since the communication path 130 and the drain path 131 communicate with each other, the D / C 7 is released. As shown in FIG. 4, when shifting from the third speed to the fourth speed, Red / B6 is released and D / C 7 is engaged.

Here, the duty ratio of the duty solenoid valve 34 is controlled, and the output pressure of the control valve 32 is slightly reduced within a range where the torque of Red / B6 does not fall below the transmission torque.
Then, the pressure of the communication passage 161 which is the output pressure of the control valve 32 also decreases, and the fail-safe valve 30 moves to the left. Then, the communication passage 191 communicates with the communication passage 130, and the pressure applied to the D / C 7 can be controlled by the duty solenoid valve 28. Therefore, the pressure applied to the D / C 7 is increased, and Red is increased.
The gear shift control is performed by lowering the pressure of / B6 to shift to the fourth speed.

(V) As shown in FIG. 4, when shifting from the fourth speed to the fifth speed, UD / C4 is released and 2-5 / B3 is engaged. When the duty ratio of the duty solenoid valve 22 is controlled and the output pressure of the control valve 20 is slightly reduced within a range where the torque of UD / C4 does not fall below the transmission torque, the fail-safe valve 14 moves to the right. Then, the communication passage 173 is communicated with the communication passage 174, and the duty solenoid valve 18 controls 2-5 / B
Since the pressure of No. 3 can be controlled, the pressure of 2-5 / B is increased, and the pressure of UD / C4 is decreased to shift to the fifth speed.

The basic shifting method in the D range has been described above, but the same shifting control is performed in the 4, 3, 2, and 1 ranges.

(3) Next, the R range will be described. When the manual valve 38 is set to the position of the R range, the communication passage 120 communicates with the communication passage 122, and the communication passage 123 communicates with the drain passage 121.
Communicate with When the communication path 122 becomes high pressure, R
The pressure of / C1 becomes high and R / C1 is engaged. The communication passage 185 branched from the communication passage 122 also has a high pressure, and the pressure applied to the LR / B5 via the high-pressure selection valve 29 increases due to the pressure of the communication passage 200 branched therefrom.
B5 is engaged. Since the communication passage 127 has a drain pressure,
The failsafe valve 30 has moved to the right in FIG. Therefore, D / C 7 is released. The shift range in the R range is achieved by increasing the pressure of Red / B6 by the duty solenoid valve 34.

Next, lock-up control will be described with reference to FIG. At the second to fifth forward speeds, the pressure in the communication passage 184 becomes the line pressure. At this time, when the power supply to the on / off solenoid valve 53 is turned on, the communication path 215 becomes drain pressure.
The lock-up relay valve 52 is switched from the position shown in FIG. 2, and the communication passages 216 and 217 and the communication passage 2
The communication path 13 communicates with the communication path 210. Therefore, the hydraulic oil at the secondary pressure is supplied to the torque converter 50, and the hydraulic oil adjusted by the lock-up control valve 54 is supplied to the communication path 216. Duty solenoid valve 55 according to throttle opening, engine output torque or turbine torque
By controlling the pressure in the communication passage 217, the engagement, slip and release of the lock-up clutch 51 can be controlled.

When the gear position is the first forward speed, R, N, the communication path 1
84 becomes the drain pressure. At this time, the lock-up relay valve 52 is at the position shown in FIG.
10, and the communication path 213 and the communication path 214 communicate with each other. Then, hydraulic oil is supplied to the left of the lock-up clutch 51 through the communication passage 216, and the torque converter 50
Is passed through the communication passage 213, the lock-up relay valve 52, the communication passage 214, and the oil cooler 46 to discharge the hydraulic oil. This is the lock-up off state, and the lock-up clutch 51 is released.

As described above, in the above embodiment showing the embodiment of the present invention, the control valves 10, 16, 20, 26,
32 and 54 are constituted by spool valves having two lands of different diameters, and the duty solenoid valve 1 is used as a command pressure for each control valve.
2, 18, 22, 28, 34, 54 output pressures are used. The source pressure of each duty solenoid valve is a throttle pressure that fluctuates according to the throttle opening, engine output torque or turbine torque. Therefore, the throttle opening,
The engagement pressure applied to each friction element and the lock-up clutch 51 can be optimally controlled according to the fluctuation of the engine output torque or the turbine torque. Since the throttle pressure fluctuates according to the throttle opening, the engine output torque or the turbine torque, the engagement hydraulic pressure can be controlled with high accuracy over a wide control range of each duty solenoid valve using the throttle pressure as the control source pressure. In addition, the spool valve composed of lands of different diameters regulates the output pressure by balancing the command pressure of each duty solenoid valve and the biasing force of each spring, and the throttle pressure is a constant pressure that is not related to line pressure fluctuation. Since the pressure is generated from the modulated pressure, rapid charging control is performed to quickly engage the friction elements, and even if the line pressure fluctuates, the output pressure of each control valve is adjusted only according to the throttle pressure which is the command pressure. Pressed.

In the above embodiment, a line pressure that fluctuates according to, for example, the output torque of the engine is introduced as the engagement source pressure into the control valve that controls the engagement oil pressure applied to the friction element. However, since the output pressure of each control valve is defined by the biasing force of the spring of each control valve and the command pressure of the duty solenoid valve, a constant line pressure may be introduced as the engagement source pressure.

[Brief description of the drawings]

FIG. 1 is an OD / C control circuit diagram showing a part of an automatic transmission control device according to an embodiment of the present invention.

FIG. 2 is a lock-up control circuit diagram showing a part of the automatic transmission control device according to the embodiment.

FIG. 3 is a hydraulic circuit diagram showing the automatic transmission control device according to the embodiment.

FIG. 4 is an explanatory diagram showing engagement or disengagement of a friction element at each shift speed of the embodiment.

[Explanation of symbols]

Reference Signs List 1 R / C (friction element) 2 OD / C (friction element) 3 2-5 / B (friction element) 4 UD / C (friction element) 5 LR / B (friction element) 6 Red / B (friction element) 7 D / C (friction element) 10, 16, 20, 26, 32 Control valve (pressure regulating valve,
Friction element control means) 12, 18, 22, 28, 34 Duty solenoid valve (command pressure control valve, friction element control means) 44 Duty solenoid valve (command pressure control means) 45 Pressure reduction control valve (command pressure control means) 51 Lock Up clutch 54 Lock-up control valve (pressure regulating valve, lock-up control means) 55 Duty solenoid valve (command pressure control valve, lock-up control means)

Continued on the front page (72) Inventor Masashi Honda 1-1-1, Showa-cho, Kariya-shi, Aichi F-term in Denso Corporation (reference) 3J052 AA01 CA07 CA31 FB05 FB08 FB35 GC11 HA02 KA01 3J053 CA02 CB11 CB19 DA01 EA05 FA04

Claims (6)

[Claims] An automatic transmission control device that controls engagement and disengagement of a plurality of friction elements by a hydraulic pressure of a working fluid and switches a gear position, wherein the automatic transmission control device generates a constant pressure working fluid, Command pressure control means for variably adjusting a working fluid to generate a first command pressure; and friction element control means for controlling engagement and release of at least one of the plurality of friction elements, wherein the first command A command pressure control valve for generating a second command pressure using the pressure as a source pressure;
A friction element control means having a pressure regulating valve capable of regulating an output pressure to a predetermined pressure according to the second command pressure. 2. The automatic transmission control device according to claim 1, wherein the first command pressure fluctuates according to an output torque of an engine. 3. The automatic transmission control device according to claim 1, wherein the command pressure control valve is a duty solenoid valve. 4. A fluid transmission, an auxiliary transmission connected to an output side of the fluid transmission, and a lock capable of avoiding the fluid transmission and transmitting at least a part of engine output to the auxiliary transmission. An automatic transmission control device for controlling an automatic transmission having an up clutch with a hydraulic pressure of a working fluid, comprising: generating a constant-pressure working fluid; variably adjusting the constant-pressure working fluid; Command pressure control means for generating pressure, and lock-up control means for controlling engagement and disengagement of the lock-up clutch, the command pressure control valve generating a second command pressure using the first command pressure as a source pressure An automatic transmission control device comprising: a lock-up control unit having a pressure regulating valve capable of regulating an output pressure to a predetermined pressure according to the second command pressure. 5. The automatic transmission control device according to claim 4, wherein the first command pressure is adjusted according to an output torque of the engine. 6. The automatic transmission control device according to claim 4, wherein the command pressure control valve is a duty solenoid valve.