JPH07224927A - Hydraulic controller for automatic transmission and hydraulic pressure control method of automatic transmission - Google Patents

Abstract

PURPOSE:To prevent delay in shifting caused by moving time in a hydraulic valve from occuring so as to cancel time lag upon downshift by setting a mode to change over the valve after oil pressure change for directly control is made at the time of downshift of an automatic transmission. CONSTITUTION:A main part of hydraulic controller 400 is composed of an integrated type valve system 60 and a plurality of engagement oil pressure control valves 61, 62. To a plurality of ports in the valve 60 a hydraulic pump in a transmission 300 and 8 frictional engagement means are connected via a line pressure control valve 64 and the valves 61, 62. A connection part 11 is connected to a select lever 500 mechanically while a step motor 12 is connected to an ECU 70 for an automatic transmission. The valve 60 is connected to a torque converter 200 through a lockup hydraulic control valve 65. Upon downshift of automatic transmission high pump oil pressure is controlled by means of the valves 61, 62, and then the valve 60 is driven.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydraulic control device for hydraulically controlling a speed change mechanism of an automatic transmission and a control method thereof, and more particularly to a hydraulic control device for an automatic transmission and a hydraulic control method for a vehicle.

[0002]

2. Description of the Related Art Conventionally, as disclosed in Japanese Patent Laid-Open No. 4-77183, a control valve, an accumulator, etc. of a hydraulic control device for controlling an automatic transmission (automatic transmission, hereinafter referred to as AT) for a vehicle are provided. There is a proposal to integrate and directly control the clutch pressure. FIG. 10 shown in this document is an operation explanation example of the rotary valve which is the integrated hydraulic control valve shown in the embodiment, and shows changes in the control current and the hydraulic pressure during the shift transition. It is a thing. Although FIG. 10 shows an example of shifting from N (neutral) to D1 (first speed range), the same operation is performed for other shifts as well, for upshifting and downshifting.
The term "shift" refers to an operation for switching the shift speed of the automatic transmission. When performing this shift,
The AT is controlled by rotating the rotary valve to switch the oil passage. At this time, the AT is set to communicate with the engagement start pressure Ps which is a transitional position. This is because the torque suddenly changes at the start of gear shift and a sensation called gear shift shock occurs, and the hydraulic output is temporarily reduced for the purpose of control to prevent it.

[0003]

The gear shift in the AT is
In this way, the hydraulic pressure is switched by the operation of the hydraulic valve to switch the engagement of gears with different gear ratios.However, at the time of this gear shift instruction, the operating time of the rotary valve is added to the operating time of the hydraulic control valve to The time (the time from the start of the shift process to the end of the shift) is slightly longer. here,
Considering the case of upshifting for the AT shift, the shiftup instruction is usually a shift control device incorporated in an ECU (engine control unit), so a signal is automatically issued as the vehicle speed increases, The operator does not care about the length of the shift time.

However, in downshifting,
There are the following recognitions. That is, when the operator performs an operation that expects a shift, such as depressing the accelerator pedal or operating the shift lever, the start time of the shift is known from the operator's own action, so the time until the end of the shift is changed. Perceived by the person. Therefore, the long shift time in the downshift operation at the AT means that the shift mechanism is defective.
Alternatively, there is a problem that the performance is low. Normally, the downshift is performed by the operator with the expectation of acceleration by obtaining stronger driving force (for example, overtaking, start of uphill, etc.), so the time lag of gear shift reaction that does not suit the operator's will is minimized. There must be.

Therefore, an object of the present invention was devised in view of the above points, and it is an object of the present invention to provide a hydraulic control device for an automatic transmission, which realizes a shorter shift time at the time of downshifting.

[0006]

SUMMARY OF THE INVENTION The structure of the present invention for solving the above-mentioned problems includes a plurality of friction engaging devices for selectively connecting a plurality of rotating elements, and switching control of connection of the friction engaging devices. An automatic transmission including a hydraulic circuit for controlling the hydraulic pressure, a high hydraulic pressure generating means for generating a predetermined high hydraulic pressure in the hydraulic circuit, and an engagement hydraulic pressure control means for generating an engagement hydraulic pressure from the high hydraulic pressure to the discharge pressure. A hydraulic control for an automatic transmission having an integrated valve that selectively switches the engagement hydraulic pressure applied to the friction engagement device by one or more hydraulic valves that control the gear shift, and valve control means that directs communication of the integrated valves. The apparatus is provided with drive adjusting means for driving the integrated valve after adjusting the hydraulic pressure by the engaging hydraulic pressure control means at the time of downshifting the shift stage of the automatic transmission to the low speed side. The control method of the invention is an automatic transmission including a plurality of friction engagement devices for selectively coupling a plurality of rotary elements, and a hydraulic circuit for switching control of connection of the friction engagement devices. In a hydraulic control method for an automatic transmission, wherein the hydraulic pressure, the discharge pressure, and the engagement hydraulic pressure of an engagement hydraulic control valve are selectively switched by a hydraulic valve of an integrated valve to communicate with each other at the time of shifting, and a shift control is performed. By shifting the engagement hydraulic pressure by controlling the engagement hydraulic pressure control valve at the time of downshifting the gear to the low speed side, the integrated valve is driven to move the hydraulic pressure valve to the low speed mode position. is there.

[0007]

The hydraulic control for the friction engagement device in the AT is performed by changing the hydraulic pressure using the hydraulic control valve or switching the hydraulic communication passage with the hydraulic valve. Regardless of the increase in the hydraulic valve operation, the mode in which the procedure for switching the hydraulic valve is performed after the change in the hydraulic pressure that directly controls the hydraulic pressure is set, so that the shift process does not delay due to the moving time of the hydraulic valve, and there is a time lag for downshift operation. Does not occur.

[0008]

As described above, since the shift-down shift processing does not include the operation time of the hydraulic valve, which requires a long operation time, the time until the end of the shift is shortened, and an AT having a good shift responsiveness to the operator is realized.

[0009]

EXAMPLES The present invention will be described below based on specific examples. FIG. 1 is a cross-sectional view of an integrated valve (integrated valve) 60 and engagement hydraulic control valves 61, 62 which constitute a hydraulic control device of an embodiment in which the present invention is applied to a vehicle AT. In the operation of the vehicle AT, as is well known, the gear connection in the transmission 300 is automatically or manually switched, and the rotational force from the engine (not shown) connected to the end of the torque converter 200 in FIG. Or transmitted to the front wheels. Although FIG. 1 best shows the features of the present invention, the overall configuration of the hydraulic control device is as shown in the configuration diagram of the hydraulic control device 400 shown in FIG. 2, and the integrated valve 60 and its peripheral devices are shown. The whole is inside the AT, inside an oil pan (not shown) provided under the transmission 300, and the environment of the hydraulic control device 400 inside the oil pan is the drain (drain pressure, discharge pressure) of the hydraulic circuit. There is.

In the integrated valve 60, as shown in FIG.
The high pump hydraulic pressure with fluctuation generated by the hydraulic pump in the transmission 300 causes the line pressure control valve (see FIG. 2).
EV inside is an electromagnetic valve) 64, engagement hydraulic control valves 61, 6
2 (collectively referred to as a hydraulic control valve) via stable pressure (high hydraulic pressure) or engagement hydraulic pressure through the pressure control ports 36 and 38 of the integrated valve 60 and the line pressure port 3.
5, 37, and communication ports 39, 40, 4
1, 42, 43, 44, 45, frictional engagement devices (multi-plate clutches C ₀ , C ₁ , C ₂ and multi-plate brakes B ₀ , B ₁ , B ₂ , B ₃ not shown) in the transmission 300. It is connected to the. Further, the connecting portion 11 is mechanically connected to the select lever 500 manually operated by the operator. Further, a part of the line pressure is connected to the torque converter 200 via the lockup hydraulic control valve 65 in order to perform lockup (L / U) slip control of the torque converter 200.

The integrated valve 60 shown in FIG. 1 includes a housing 28, a side housing 30, a port case 31,
32 and the like. A cylindrical camshaft (hereinafter, also referred to as a camshaft) 1 having a substantially cylindrical shape in the housing 28 includes bearings 9 and 2 such as ball bearings and roller bearings.
9 has bearing portions that are freely inserted and inserted into the cam shaft 9, and the main surface of the cam shaft 1 is provided with unevenness as a cam.
And the rack 52 in the shaft axial direction on a part of the circumferential surface,
Further, the pinion 53 is provided on a part of the circumference. Bearing 9,2
Reference numeral 9 supports the camshaft 1 so as to be rotatable and movable in parallel in the axial direction. Pinion 5 provided on the camshaft 1
A rack 10 engages with the rack 3, and the rack 10 is connected to a connecting portion 11 that interlocks with an external select lever 500 operated by an operator. The step motor 12 in which the pinion gear 13 meshes is attached to the rack 52 of the camshaft 1, and the camshaft 1 is moved in the shaft axial direction by an electronic control operation.

The bearing 9 is mounted on one end of the housing 28 by a circlip 34, and the bearing 29 is fixed to the housing 28 with a bolt (not shown).
It is attached by a circlip 33 to the. Then, a return spring 54 is fitted into the camshaft 1, one end of the return spring 54 is abutted against the housing 28, and the other end is compressed by a spring stopper 55 fixed to the camshaft 1 so that the camshaft 1 can be moved as shown in FIG.
The pushing force is stored on the right side of.

Further, spool valves (hydraulic valves) 2, 3, 4, 5, 6, 7, 8 for switching the oil passages are arranged side by side on both sides of the camshaft in a direction perpendicular to the axis of the cylindrical camshaft 1. , Provided in the housing 28. Spool valve 2
˜8 are slidable in the axial direction of the cylindrical hole provided in the housing 28 and have a cylindrical shape having a cavity inside the valve,
One groove (oil passage groove) is formed around the outer surface of the cylinder, and a hole communicating with the inside of the cylinder is formed in this groove. One end of the cylinder is open, and the groove is provided in the port cases 31 and 32. Each of them communicates with the communication ports 39 to 45.

Between the cylindrical cam shaft 1 and the bottoms (non-open side) of the spool valves 2 to 8, pins 14, 15, 16, 17 are provided in the direction perpendicular to the axis of the cylindrical cam shaft 1.
18, 19 and 20 are slidably fitted in and transmit the movement of the cam of the camshaft 1 to the spool valves 2 to 8. Since the spool valves 2 to 8 slide in the cylindrical hole according to the movement of the camshaft 1, the pin 1 should be moved smoothly.
A small hole for pressure relief is provided on the unopened side of the spool valve against which 4 to 20 hit. Further, all the spool valves 2 to 8 are pressed against the cylindrical cam shaft side together with the pins by the springs 21, 22, 23, 24, 25, 26 and 27, and are fixed to the housing 28 with bolts (not shown). It is sealed in a cylindrical hole of the housing by 32 so as not to project outside.

Line pressure ports 35 and 37 are formed in the side housing 30, and a line pressure (high pressure oil) is supplied from a line pressure control valve 64. The line pressure communication passage 4 provided in the housing 28 is one of the hydraulic communication passages.
Line pressure is transmitted from the line pressure ports 35 and 37 to 6 and 51, and the line pressure is supplied to the friction engagement device through the grooves and holes of each spool valve and the communication ports 39 to 45. Similarly, pressure control ports 36 and 38 to which the pressure-adjusted engagement hydraulic pressure (or control pressure) is supplied are formed in the side housing 30, and a control pressure communication passage 47, which is also one of hydraulic pressure communication passages, is opened from this port. It is configured to communicate with the spool valve through 50 and to be supplied to the friction engagement device. Further, the control pressure communication passage 4 in the housing 28
7, 50 in parallel with each other, a hydraulic communication passage communicating with a drain outside the housing, that is, a drain pressure communication passage (drain pressure port,
Hereinafter, also referred to as a drain) 48 and 49, each spool valve communicates with the outside of the housing, and the communication port side communicates with the drain. As shown in FIG. 1, the three hydraulic communication passages are arranged so that the drain pressure, the control pressure, and the line pressure are applied from the camshaft side.

Of the communication ports 39 to 45 connected to the transmission 300, the two ports that communicate with the multi-disc clutch C ₀ and the multi-disc brake B ₀ installed in the transmission 300 are operated simultaneously. A double bond prevention valve 63 is interposed to prevent manipulation (FIG. 2). Other communication ports are other multi-disc clutches C ₁ , C ₂ , such as found in known transmissions.
The multi-plate brakes B ₁ , B ₂ , and B ₃ are communicated with each other, and these clutches and brakes are subjected to shift control as AT by hydraulic pressure from the communication port. The brakes are substantially the same friction elements as the clutch, and one of the clutches fixed is the brake.

The cylindrical camshaft 1 shown in FIG. 1 is an ECU for AT.
Controlled by an instruction from 70 (hydraulic valve control means),
The step motor 12 moves the cam shaft 1 in the shaft axial direction, and the positions of the spool valves 2 to 8 are controlled via the pins 14 to 20 by the unevenness provided on the side surface circumference of the cam shaft. A groove provided on the communication port communicates with each communication passage to transmit a predetermined hydraulic pressure to each communication port. As shown in FIG. 3, the AT ECU 70 transmits a motor position signal for driving the step motor 12 while exchanging data with the engine ECU 72 by a kickdown signal, a select lever signal, and a signal from the engine ECU 72. At the same time, each hydraulic pressure control signal is output to each hydraulic pressure control valve 61, 62, 64, 65 described above.

Further, since the cylindrical camshaft 1 is connected to the select lever 500 by the connecting portion 11, when the position of the select lever 500 is manually selected by an operator of the vehicle, the rack 10 connected to the connecting portion 11 is connected. The cylindrical cam shaft 1 is rotated around the shaft axis, and the pins 14 to 20 in contact with the cam shaft are moved by the circumferential unevenness of the cylindrical cam shaft 1 to control the spool valves 2 to 8. Of course, at this time, since the cylindrical camshaft 1 is also controlled by the AT ECU 70, the select lever signal is also input to the AT ECU 70. Therefore, the cam shape of the cylindrical camshaft 1 has irregularities in the axial direction and the circumferential direction of the shaft side surface, and the irregularity shape is designed to be the spool valve position determined by the hydraulic communication mode shown in FIG. It The operating states of the clutches and brakes of the AT controlled in this manner are as shown in FIG. In other words, in this embodiment, the AT having the configuration as shown in FIG. 5 is the control target.

The cam shape of the cylindrical camshaft 1 is not limited to the structure integrated with the shaft, but a cam ring having a cam around the circumference may be fitted into the shaft to have the camshaft structure shown in FIG. 1, in which case It becomes easier to respond to changes in the number of ports and port combinations. Also, this figure 1
As described above, when the spool valves are arranged on both sides of the camshaft 1, the integrated valve 60 is configured in a compact and substantially flat plate shape, and there is no upper / lower restriction on the arrangement, so that the arrangement in the oil pan is easy. .

Engagement hydraulic pressure control valves (pressure adjusting valves) 61 and 62, which are part of the engagement hydraulic pressure control means of FIG. 1, are solenoid valves that directly control the engagement hydraulic pressure, and are one of the important components of this system. However, since the technology of the solenoid valve is well known, it will be briefly described.
Inside the adjusting valve, there is a moving core 66 driven by a coil 67, and the degree to which the coil 67 is energized is controlled by a duty drive instruction of the AT ECU 70, The desired hydraulic pressure is obtained by adjusting the line pressure supply rate and the drain pressure discharge rate. The engagement oil pressures Pc ₁ and Pc ₂ by the engagement oil pressure control valves 61 and 62 have the same oil pressure value only in different systems, but may have different oil pressure values depending on the target AT.

Next, the operation of this embodiment will be described.
With the hydraulic control device for an automatic transmission as shown in FIGS. 1 and 2, it is possible to control the hydraulic pressure applied to the clutches in the transmission in two different modes. That is, in order to raise the hydraulic pressure from the drain pressure to the line pressure for any of the communication ports,
An engagement hydraulic pressure controlled in the range of the line pressure to the drain pressure is interposed. Ideally, all the spool valves can be controlled only by this engagement hydraulic communication passage, but the combination of the AT frictional engagement devices to be applied cannot simply be controlled only by the engagement hydraulic communication passage. For this reason, the line pressure and drain pressure are also supplementarily connected to each other. Therefore, the drain pressure can be set as the drain pressure either in the state of communicating with the drain pressure communicating port or in the state of the engaging hydraulic pressure being reduced to the drain pressure while communicating with the control pressure port. The control may be performed either in a state in which the hydraulic valve is in communication with the drain pressure communication port or in a state in which the control hydraulic pressure is the drain pressure in the state of being connected to the pressure control port.

FIG. 6 shows the relationship between the movement of the spool valve and the hydraulic pressure. In the above-mentioned state, that is, the movement of the hydraulic valve does not have two movements but has four choices, and any one of them is selected. However, since it is advantageous for the movement of the spool valve to be small, the ideal engagement hydraulic communication passage position (see FIG. 6)
Fixed to. And when moving the spool valve when it can not be controlled by that, when the hydraulic pressure rises, raise the pressure control and then move the hydraulic valve of the integrated valve, and when the hydraulic pressure falls, move the hydraulic valve and then pressure control To lower the hydraulic pressure. Alternatively, when the hydraulic pressure is increased, the hydraulic valve of the integrated valve is moved, and then the hydraulic pressure is increased by pressure control, and when the hydraulic pressure is decreased, the hydraulic pressure is lowered by the pressure control, and then the hydraulic valve of the integrated valve is moved. Will be selected (and in FIG. 6).

However, which one is selected is fixed depending on the shape of the camshaft 1 to be used. Here, in order to enhance the responsiveness at the time of downshift, which is the object of the present invention, it is better to directly change the pressure by a natural method.
As compared with the above case, the operation of the clutch is affected earlier by the operation time of the hydraulic valve of the integrated valve. Therefore, since the downshift operation causes the AT ECU 70 to generate a signal,
The camshaft 1 is configured to switch the hydraulic pressure according to the procedure at the time of downshifting, and the processing program of the AT ECU 70 is also configured to correspond to it. When shifting up, the movement of the camshaft is reversed, so that the spool valve of the integrated valve moves first, and then the hydraulic control is performed to perform the shift operation.

From FIG. 4, as an example of downshifting, the movement from the 4th speed to the 3rd speed mode in the D range will be seen. The friction engagement device that changes the hydraulic pressure is a clutch C ₀ and a brake B _0.
Is. The clutch C ₀ is connected to Pc ₁ (control pressure, engagement hydraulic pressure) in the fourth speed mode and Ps (line pressure) in the third speed mode.
In the 4th speed mode, Pc ₁ is equal to the lowest drain pressure (Dr) in a stable state, so when shifting down from the 4th speed to the 3rd speed mode, Pc ₁ first rises to the line pressure Ps. After that, the camshaft 1 is driven so that the spool valve 3 communicates with the line pressure communication passage. Similarly, the brake B ₀ is in communication with Pc ₂ (control pressure and engagement hydraulic pressure) in the fourth speed mode and Dr in the third speed mode. Since the line pressure (Ps) is stable in Pc _{2 in the} 4th speed mode, 4
When shifting down from the third speed mode to the third speed mode, it suffices to reduce Pc ₂ from the line pressure to the drain pressure. Therefore, downshifting from the 4th speed to the 3rd speed mode in the D range can be realized without operating the integrated valve simply by controlling the engagement hydraulic pressure, which results in a quick downshift.

In the case of shifting up from the 3rd speed to the 4th speed mode of the D range, the movement opposite to the above is performed, so that the operation time of the integrated valve comes earlier, and the start of the speed change process is slightly delayed. However, when the spool valve position has just passed the intermediate position of the hydraulic pressure supply communication passage, the spool valve is brought into communication with the next communication passage, so that the change in hydraulic pressure can be started and the processing time can be shortened.

The above operation is shown in a flow chart in FIG.
become that way. However, FIG. 7 is a convenient flowchart. A shift-up flowchart is also shown at the same time.
Note that these programs are constantly in a monitoring state. Figure 7
(a) shows the one corresponding to downshift. It is in the state of step 502 until the downshift occurs. Here, it is assumed that the shift down determination is made. Since this determination is a conventionally known technique, detailed description thereof will be omitted.
AT using various signals as shown in step 502
ECU 70 makes a decision. Therefore, in step 504, pressure reduction valves (solenoid valves) 61 and 62 are immediately decompressed, and when a predetermined hydraulic pressure is reached in step 506, the flow proceeds to step 508 to drive the hydraulic valve of the integrated valve (MV) 60 (MV Drive). Therefore, step 504 immediately after the downshift determination
Immediately after, the oil pressure of the clutch changes, and the shift process starts immediately after the instruction.

On the contrary, in the case of the shift-up operation, FIG.
As described above, since there is a portion determined by the movement of the camshaft as described above, the same processing as downshift is not performed. Step 602 (this is step 502
After the upshift determination is made in step S604, a command to drive the spool valve of the integrated valve (MV) 60 is issued. Then, in step 606, the spool valve becomes 1 /
2 Since the spool valve has been switched to the communicating state when it is driven, in step 612, pressure increase of the pressure control valves (electromagnetic valves) 61 and 62 is started. Integrated valve hydraulic valve movement processing (MV drive) in step 608 and step 61
Since it may be performed in parallel with the pressure increasing process of the solenoid valve No. 2, it is described in parallel in this flowchart for convenience.

As described above, if the shift operation is performed by the above method with the configuration shown in FIGS. 1 and 2, when downshifting, the hydraulic pressure is first adjusted by the solenoid valve before driving the spool valve. Control the clutch directly, then
By controlling the spool valve to switch the mechanical mode, the shift down operation does not include the spool valve drive time, which shortens the hydraulic transmission time. It is possible to improve the response speed of the shift as compared with the case where the control is performed, to perform an appropriate downshift, and to achieve an AT with good operation responsiveness.

The AT using the integrated valve and the pressure control valve as shown in FIG. 2 is mainly used in vehicles,
There are various types of transmissions in vehicles, and there are conditions specific to the target AT, such as the number and characteristics of friction engagement devices. Therefore, the number of individual spool valves,
The movement, the characteristics of the control hydraulic pressure, and the like change depending on each AT, and are not shown here.

Further, when the present invention is applied to a vehicle as shown in this embodiment, the notation of the invention is that a plurality of friction engagement devices for selectively coupling a plurality of rotary elements, and the friction engagement. An automatic transmission including a hydraulic circuit for switching and controlling connection of devices, a high hydraulic pressure generating means for generating stable high hydraulic pressure in the hydraulic circuit, and a member for generating engagement hydraulic pressure from the high hydraulic pressure to the discharge pressure. Synthetic oil pressure control means, integrated valve for selectively switching engagement hydraulic pressure applied to the friction engagement device by switching one or more hydraulic valves by a cam mechanism at the time of shifting, and a valve for instructing communication of the integrated valve In a hydraulic control device for an automatic transmission having a control means, the gear mechanism is driven by the engagement hydraulic pressure control means after the hydraulic pressure is adjusted by the engaging hydraulic pressure control means at the time of downshifting to shift the shift speed of the automatic transmission to a low speed side. On the high speed side During shifting-up, after driving the cam mechanism, the engagement oil pressure control unit automatic transmission hydraulic pressure control device, characterized in that it comprises a drive adjusting means for hydraulic adjustment, so the. Further, the cam mechanism can be driven independently by an automatic means and a manual means.

Here, supplementary explanation will be given of the correspondence of the terms shown in the claims. (1) The valve control means means means for driving a cam mechanism such as a cam shaft or a cam plate for driving the spool valve of the integrated valve. Then, the spool valve is controlled by a cam driving means such as a step motor by an electric signal from the AT ECU. (2) Engagement hydraulic pressure control means means an engagement hydraulic pressure control valve such as a solenoid valve that generates an engagement hydraulic pressure, and a hydraulic control device drive signal from the AT ECU. (3) Adjusting the hydraulic pressure means two hydraulic pressure controls performed by the engaging hydraulic pressure control means, that is, a change from the line pressure to the drain pressure,
The change from the drain pressure to the line pressure is performed for each necessary frictional engagement device. (4) The driving force adjusting means is the engagement hydraulic control valve and the EC for AT.
An engagement hydraulic control valve control signal from U and a hydraulic circuit related to the control valve, which are used when the shift down drive and the shift up drive for gear shift are driven according to the hydraulic communication mode shown in FIG. It has the structure of item 1.

[Brief description of drawings]

FIG. 1 is a structural sectional view and a connection diagram of an integrated valve and a pressure regulating valve of a hydraulic control device showing an embodiment of the present invention.

FIG. 2 is a system diagram showing an entire hydraulic control device mechanism.

FIG. 3 is a connection diagram of an AT ECU showing signal input / output.

FIG. 4 is an operation mode diagram showing an operating state of the hydraulic control device.

FIG. 5 is an operation state diagram of clutches and brakes of the transmission.

FIG. 6 is an explanatory diagram showing a relationship between an engagement hydraulic pressure and a spool valve position.

FIG. 7 is a schematic flow chart of a shift operation according to the present invention, where (a) shows a case of downshifting and (b) shows a case of upshifting.

[Explanation of symbols]

1 Cylindrical camshaft (camshaft) 2-8 Spool valve (hydraulic valve) 9,39 Bearing 10,52 Rack 11 Connection part 39-45 Communication port 35,37 Line pressure port 36,38 Pressure control port 33,34 Circlip 14-18 pin 12 step motor 13, 53 pinion 28 housing 31, 32 port case 30 side housing 21-27 spring 46, 51 line pressure communication passage (hydraulic pressure supply passage) 47, 50 control pressure communication passage (hydraulic pressure supply passage) 48 , 49 Drain pressure communication passage (hydraulic supply communication passage) 200 Torque converter 300 Transmission (including friction engagement device and hydraulic pump) 500 Select lever 60 Integrated valve 61, 62 Engagement hydraulic control valve (hydraulic adjustment valve) 64 Line pressure control Valve (hydraulic pressure adjustment valve) 66 movie Gukoa 67 ECU coil 70 AT for ECU 72 engine

Claims (2)

[Claims] 1. An automatic transmission comprising a plurality of friction engagement devices for selectively connecting a plurality of rotary elements and a hydraulic circuit for switching control of connection of the friction engagement devices, wherein a predetermined hydraulic circuit is provided in the hydraulic transmission. A high hydraulic pressure generating means for generating a high hydraulic pressure, an engagement hydraulic pressure control means for generating an engagement hydraulic pressure from the high hydraulic pressure to the discharge pressure, and an engagement hydraulic pressure applied to the friction engagement device at the time of shifting. In a hydraulic control device for an automatic transmission, which has an integrated valve that is selectively switched by one or more hydraulic valves and valve control means that directs communication between the integrated valves, a downshift that shifts a shift stage of the automatic transmission to a low speed side. At the same time, the hydraulic control device for an automatic transmission is provided with drive adjusting means for driving the integrated valve after adjusting the hydraulic pressure by the engagement hydraulic control means. 2. An automatic transmission comprising a plurality of friction engagement devices for selectively coupling a plurality of rotary elements and a hydraulic circuit for switching control of the connection of the friction engagement devices, wherein a high hydraulic pressure and a discharge pressure are provided. In the hydraulic control method for an automatic transmission, in which the hydraulic pressure of the integrated hydraulic control valve and the hydraulic pressure of the engagement hydraulic control valve are selectively switched and communicated by the hydraulic valve of the integrated valve at the time of shifting, the shift speed of the automatic transmission is set to the low speed side. When downshifting to
After controlling the engagement hydraulic control valve to change the engagement hydraulic pressure, the integrated valve is driven to move the hydraulic valve to a low speed mode position. .