JP2915107B2 - Hydraulic control device for automatic transmission - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a hydraulic control device for an automatic transmission, and more particularly to a measure for appropriately setting an operation timing between two friction elements.

(Prior Art) Conventionally, as disclosed in Japanese Patent Application Laid-Open No. 62-246652, for example, a plurality of friction elements are provided, and a power transmission path is switched to a plurality of stages by fastening or releasing operation of each friction element. There is a known gear shifter.

(Problems to be Solved by the Invention) At the time of a predetermined shift, there is a case where one friction element is released and another friction element is engaged to perform a shift. In this case, when the other friction element is fastened in a state where the friction element to be released is still fastened, an internal lock state is established in which both friction elements are fastened together, and the output torque temporarily decreases, Problems such as a shift shock occur.

For this reason, the applicant of the present application has previously described in Japanese Patent Application No. 63-265086, with regard to the releasing operation of the friction element, a mechanism in which the releasing pressure acts on the releasing oil chamber to perform the releasing operation. In the case of performing a gear shift by performing a fastening operation by the action of a fastening pressure to a fastening oil chamber of another friction element together with a releasing operation of an element to perform a shift, a hydraulic circuit is configured by a common oil passage through a release pressure passage and a fastening pressure passage. The passage is branched, the release pressure passage is connected to the release oil chamber of the friction element, the fastening pressure passage is connected to the engagement oil chamber of another friction element, and further to the engagement oil chamber of the other friction element. By providing a valve for switching the connection of the engagement pressure passage to a connected state when the release pressure of the release oil chamber of the friction element becomes equal to or higher than a set pressure, the friction to be released is provided for the connected engagement pressure oil passage. The first time the element has been released to some extent Te, as it begins to conclude the other friction element to be the fastening proposes that effectively prevent internal lock.

In that case, the shift may be due to acceleration by the driver depressing the accelerator pedal or deceleration by releasing the accelerator pedal.
In the former case of acceleration, it is desirable to fasten another friction element in a state where the release of the friction element has greatly progressed in order to reliably prevent deceleration due to the internal lock. On the other hand, at the time of the latter deceleration, it is desired to fasten another friction element in a state where the release of the friction element is not so advanced in order to effectively suppress the idle running of the vehicle. However, in the above-mentioned proposal, since the operation time of the switching valve is always constant (when the release pressure to the friction element to be released reaches the set value), it is not possible to respond to the above-described request for the shift. There is regret.

The present invention has been made in view of such a point, and an object of the present invention is to appropriately prevent the internal lock by appropriately setting the engagement and release timings of the two friction elements at the time of shifting, and to reduce the engagement and release timings. The purpose of the present invention is to respond to each shift request by acceleration or deceleration by making it variable.

(Means for Solving the Problems) In order to achieve the above object, a specific configuration of the present invention includes a first friction element that performs a release operation by applying a release pressure to a release oil chamber during a predetermined shift, An automatic transmission including a second friction element that performs a fastening operation by applying a fastening pressure to a fastening oil chamber during the above-described predetermined shift, and a shift valve that is switched during the shift and switches between supply and discharge of hydraulic pressure to and from the plurality of friction elements. Is assumed. The release oil passage and the engagement pressure passage branched from a common oil passage are connected to the release oil chamber of the first friction element and the engagement oil chamber of the second friction element, respectively. In the fastening pressure oil passage connected to the fastening oil chamber of the friction element,
A switching valve for switching the engagement pressure passage to the communicating state at a switching timing when the release pressure of the release oil chamber of the first friction element becomes equal to or higher than the set pressure is arranged. Further, an adjusting means for adjusting the switching timing of the switching valve by a hydraulic pressure switched at the time of switching the shift valve is provided.

(Operation) With the above configuration, according to the present invention, at the time of shifting, when the release pressure of the release oil chamber of the first frictional element to be released becomes higher than the set pressure and the frictional element is released to some extent at the switching timing,
Since the engagement pressure passage of the second friction element to be engaged for the first time is switched to the communicating state by the switching valve and the engagement of the friction element is started, the internal lock in which the two friction elements are engaged can be reliably prevented. .

In addition, the switching timing of the switching valve, that is, the set pressure of the release oil of the release oil chamber of the first frictional element to be released can be adjusted by the adjusting means by the hydraulic pressure switched at the time of switching the shift valve. In a state where the release of the friction element is greatly advanced, another friction element can be fastened, and deceleration due to the internal lock can be reliably prevented. In addition, when shifting by deceleration, other friction elements can be engaged in a state where the friction element to be engaged has not been released so much, so that idle running of the vehicle is effectively suppressed and good deceleration performance is secured. Is done.

Here, an existing shift valve is used as the adjusting means, and the switching timing of the switching valve is adjusted by a hydraulic pressure which is switched when the shift valve is switched, so that the above-described operation is achieved without providing an additional adjusting means. A hydraulic control circuit is provided.

(Effect of the Invention) As described above, according to the hydraulic control device for an automatic transmission of the present invention, the engagement and release timings of the two friction elements that operate during gear shifting are appropriately controlled, and the internal lock of the transmission is controlled. And can respond to different demands for gear shifting due to differences in driving conditions such as acceleration and deceleration.For example, when shifting due to deceleration when the driver releases the accelerator pedal, the vehicle is reliably prevented from being locked internally. The present invention can provide an inexpensive hydraulic control device for an automatic transmission, which can effectively suppress the idle running of the vehicle, and can obtain this effect by using an existing shift valve.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings.

FIG. 1 shows a mechanical configuration of the automatic transmission. In FIG. 1, the automatic transmission 10 includes a torque converter 20 and a transmission gear mechanism 30 driven by an output of the converter 20. The mechanism 30 is provided with a plurality of frictional engagement elements 41 to 46 such as clutches and brakes for switching the power transmission path and one-way clutches 51 and 52, and by these, D, 2, 1, R as a travel range is provided. Each range and 1 in the D range
4th speed, 1st to 3rd speed in 2 ranges, 1st to 2nd speed in 1 range.

The torque converter 20 includes a pump 22 fixed in a case 21 connected to the engine output shaft 1,
And a one-way clutch interposed between the pump 22 and the turbine 23 and connected to the transmission case 11.
Stator 25 which is supported via 24 and performs a torque increasing action
And a lock-up clutch 26 provided between the case 21 and the turbine 23 and directly connecting the engine output shaft 1 and the turbine 23 via the case 21. The rotation of the turbine 23 is output to the transmission gear mechanism 30 via the turbine shaft 27.
Here, the pump shaft 12 penetrating through the inside of the turbine shaft 27 is connected to the engine output shaft 1.
Thus, the oil pump 13 provided at the rear end of the transmission is driven.

The speed change gear mechanism 30 is constituted by a Ravigneaux type planetary gear device. That is, the mechanism 30 includes a small-diameter small sun gear 31 loosely fitted on the turbine shaft 27,
Behind the sun gear 31, the turbine shaft 27
A large-diameter large sun gear 32 loosely fitted thereon, a plurality of short pinion gears 33 meshed with the small sun gear 31, a first half meshed with the short pinion gear 33, and a second half meshed with the large sun gear 32. And a ring gear 36 meshed with the long pinion gear 34 and the front half of the long pinion gear 34.

A forward clutch 41 and a first one-way clutch 51 are interposed between the turbine shaft 27 and the small sun gear 31 in series.
A coast clutch 42 is interposed in parallel with 1. A reverse clutch 44 is interposed between the turbine shaft 27 and the large sun gear 32. Further, between the large sun gear 32 and the reverse clutch 44, the large sun gear 32 is fixed and configured with a band brake. -4 brake 45 is provided. A 3-4 clutch 43 is interposed between the turbine shaft 27 and the carrier 35.
A second one-way clutch 52 for receiving a reaction force of the carrier 35 between the carrier 35 of the 43 and the transmission case 11;
Low reverse brake 46 that fixes carrier 35
And are provided in parallel. And the ring gear 36
Are connected to an output gear 14, and rotation is transmitted from the output gear 14 to left and right wheels (not shown) via a differential device.

Next, the frictional engagement elements 41 such as the above clutches and brakes
The relationship between the operating state of the one-way clutches 46 and 46 and the one-way clutches 51 and 52 and the gear positions will be described.

First, in first speed, the forward clutch 41 is engaged, and the first and second one-way clutches 51 and 52 are locked. For this reason, the output rotation of the torque converter 20 is transmitted from the turbine shaft 27 to the forward clutch 41.
And via the first one-way clutch 51 to the small sun gear 31 of the planetary gear device 30. In this case, since the carrier 35 is fixed by the action of the second one-way clutch 52, the planetary gear device 30 performs the differential operation of transmitting rotation from the small sun gear 31 to the ring gear 36 via the short pinion gear 33 and the long pinion gear 34. It operates as a fixed gear train that does not perform As a result, a first speed state with a large reduction ratio corresponding to the diameter ratio between the small sun gear 31 and the ring gear 36 is obtained.

Next, in the second speed, the forward clutch 41 is engaged, the first one-way clutch 51 is locked,
In addition, the 2-4 brake 45 is engaged, the large sun gear 32 in the planetary gear device 30 is fixed, and the second one-way clutch 52 is idle. For this reason,
The rotation transmitted from the turbine shaft 27 to the small sun gear 31 is transmitted to the long pinion gear 34 via the short pinion gear 33, and the long pinion gear
Since the large sun gear 32 meshing with the gear 34 is fixed, the orbit 34 revolves on the large sun gear 32, and the carrier 35 rotates accordingly. As a result, compared to the first speed state, only the rotation of the carrier 35 (revolution of the long pinion gear 34)
The rotation of the ring gear 36 is accelerated, and a second speed state in which the reduction ratio is smaller than that in the first speed is obtained.

Further, in the third speed, the 2-4 brake 45 is released from the second speed state, and at the same time, the 3-4 clutch 43 is engaged. Therefore, the rotation of the turbine shaft 27 is input to the small sun gear 31 via the forward clutch 41 and the first one-way clutch 51, and is also input to the carrier 35 via the 3-4 clutch 43. .
As a result, the entire planetary gear device 30 rotates integrally,
A third speed state in which the ring gear 36 rotates at the same speed as the turbine shaft 27 is obtained.

Further, at the fourth speed, the 2-4 brake 45 once released at the third speed is engaged again. For this reason, the rotation of the turbine shaft 27 is input from the 3-4 clutch 43 to the carrier 35 of the planetary gear device 30 and the long pinion gear 34 revolves, but the large sun gear 32 meshed with the long pinion gear 34 2-4 brake
Long pinion gear 34 because it is fixed by 45
Will rotate while revolving with the carrier 35. As a result, the ring gear 36 meshing with the long pinion gear 34 is rotated at a speed corresponding to the rotation of the carrier 35 (rotation of the turbine shaft 27) by the rotation of the long pinion gear 34. Fourth gear is obtained. In this case, the forward clutch 41 is in the engaged state, but the first one-way clutch 51 in series with the forward clutch 41 is in the idling state, and the coast clutch 42 is not engaged. Is not input to the small sun gear 31.

Further, at the reverse speed, the reverse clutch 44 and the low reverse brake 46 are engaged, so that the rotation of the turbine shaft 27 is controlled by the large sun gear of the planetary gear device 30.
At the same time, the carrier 35 of the gear device 30 is fixed. Therefore, the rotation is transmitted through a fixed gear train from the large sun gear 32 to the ring gear 36 via the long pinion gear 34, and the large sun gear
A reduction ratio corresponding to the ratio of the diameter of the ring gear 36 to that of the ring gear 36 is obtained. In this case, since the rotation direction of the ring gear 36 is opposite to the rotation direction of the turbine shaft 27 and the large sun gear 32, a retreat state is obtained.

The first one-way clutch 51 that transmits rotation at the first to third speeds and the second one-way clutch 52 that receives the reaction force at the first speed idle during coasting, so that the engine brake does not operate at these speeds. Become. However, D range 3 speed, 2 range 2,3
In the first speed and the first and second speeds in one range, the coast clutch 42 in parallel with the first one-way clutch 51 is engaged.
At the first speed in the range, the low reverse brake 46 in parallel with the second one-way clutch 52 is engaged, so that engine braking can be obtained at these shift speeds.

Each of the above hydraulic fastening elements 41 to 46 and one-way clutch
Table 1 summarizes the relationship between the operations of 51 and 52 and the speeds.

Next, FIG. 2 shows a hydraulic control circuit 60 for supplying and discharging the hydraulic pressure to and from the actuators of the frictional engagement elements 41 to 46.

In FIG. 2, among the actuators, a hydraulic actuator 45 'of a 2-4 brake 45 (first friction element)
Is composed of a servo piston having an apply port 45a 'communicating with the fastening oil chamber 45x' and a release port 45b 'communicating with the release oil chamber 45y'. When hydraulic pressure is supplied only to the apply port 45a ', 2-
The four brakes 45 are engaged, while both ports 45a ', 45b'
Both when the hydraulic pressure is not supplied and when both ports 45a ', 45
When hydraulic pressure is supplied to both b 'and 2-4 brake 4
5 is to be released. Further, the actuators of the other frictional fastening elements 41 to 44 and 46 are configured by ordinary hydraulic pistons, and are configured to fasten the frictional engagement elements when hydraulic pressure is supplied.

The hydraulic control circuit 60 includes, as main components, a regulator valve 61 for adjusting the pressure of the hydraulic oil discharged from the oil pump 13 (see also FIG. 1) to the main line 110 to a predetermined line pressure, and a manual operation. A manual valve 62 for selecting a range according to the operation, and each frictional engagement element (actuator) which is switched at the time of shifting and operates according to the shift speed.
Switching the supply and discharge of hydraulic pressure to 41-46 1-2, 2-3, 3-4
And shift valves 63, 64, and 65.

The manual valve 62 has an input port e into which line pressure is introduced from the main line 110, and first to fourth output ports a to d.
The input port e is the first and second output ports a and b in the D range and the second range, and the first and third output ports a and c in the one range.
Also, in the R range, they are connected to the fourth output port d. And each output port a ~
The first to fourth output lines 111 to 114 are connected to d, respectively.

Also, the 1-2, 2-3, 3-4 shift valves 63, 64, 65 are configured such that their spools 63a, 64a, 65a are biased rightward in the drawing by springs (not shown). On the right side of the spools 63a, 64a, 65a, pilot ports 63b, 64b, 65b are provided. The main line 1 is connected to the pilot port 63b of the 1-2 shift valve 63.
The first pilot line 115 derived from 10 is connected,
2-3,3-4 shift valve 64,65 pilot port 64b,
65b has a first output line 111 to a line 116, respectively.
And third pilot lines 117 and 118 branched through
Are connected to each other and these pilot lines
115, 117, and 118 are provided with first, second, and third solenoid valves 66, 67, and 68, respectively. When the solenoid valves 66 to 68 are in the ON state, respectively, the pilot lines 115, 117, and 118 are drained to discharge the pilot pressure in the pilot ports 63b to 65b of the corresponding shift valves 63 to 65, respectively. 63a to 65a are positioned on the right side in the drawing. On the other hand, solenoid valves 66 to 68
Are in the OFF state, respectively.
Pilot pressures are introduced from the pilot lines 115, 117, and 118 to the spools 63a to 65a, respectively, so that the spools 63a to 65a are respectively located on the left side in the drawing.

Here, these solenoid valves 66 to 68 are controlled by a signal from the control circuit based on a map set in advance according to the vehicle speed of the automobile and the throttle opening of the engine.
It is configured to be turned ON and OFF. With the ON / OFF operation of these solenoid valves 66 to 68, each shift valve
The positions of the spools 63a to 65a of 63 to 65 are switched, and the oil passages leading to the respective friction fastening elements 41 to 46 are switched. As a result, the friction engagement elements 41 to 46 are engaged in the combinations shown in Table 1 so that the shift speed can be switched according to the operation state. In this case, the relationship between each shift speed and the combination pattern of the ON and OFF states of each of the solenoid valves 66 to 68 is set as shown in Table 2.
In addition, at the time of the 3-2 downshift, the vehicle passes through an intermediate pattern shown in the same table.

Next, among the first to fourth table output lines 111 to 114 connected to the respective output ports a to d in the manual valve 62, they are communicated with the main line 110 in each forward range of D, 2, 1. From the first output line 111, a line 116 branches, and this line 116 is used as a forward clutch line, and is led to the forward clutch 41 via the one-way orifice 71. Therefore, it is understood that the forward clutch 41 is always engaged in the D, 2, 1 range.
Here, the forward clutch line 116 has a line 119
ND for buffering when the forward clutch is engaged
An accumulator 72 is connected. The first output line 111 is guided to the 1-2 shift valve 63. When the first solenoid valve 66 is turned on and the spool 63a is located on the right side, the first output line 111 is Connects to servo apply line 120, one-way orifice 7
3 through the apply port 45a 'of the servo piston 45'
Leads to. Therefore, the first solenoid valve 6 in the D, 2,1 range
When 6 is ON, that is, at 2, 3, 4 speed in D range, 2, 3 speed in 2 range, and 2 speed in 1 range, hydraulic pressure (servo apply pressure) is introduced to the apply port 45a '. At this time, if no hydraulic pressure (servo release pressure) is introduced into the release port 45b ', the 2-4 brake 45 is engaged. The servo apply line 120
Is connected to a 1-2 accumulator 74 for buffering when the 2-4 brake is engaged.

A second output line 112 communicating with the main line 110 in the D, 2 range is led to the 2-3 shift valve 64. This line 112 is connected to the 3-4 clutch line 12 via the one-way orifice 75 when the second solenoid valve 67 is in the OFF state and the spool 64a is located on the left side.
It is designed to communicate with 1. In addition, this line 121
Furthermore, a 3-4 clutch is provided via a one-way orifice 76.
To 43. Therefore, the second solenoid valve 6
7 is in the OFF state, that is, 3rd, 4th,
At the third speed in the range, the 3-4 clutch 43 is engaged.

Here, from the 3-4 clutch line 121, the first, second
The drain lines 122 and 123 are branched, and the first drain line 122 is guided to the 3-4 shift valve 65, and the third solenoid valve 68 is turned off (the spool 65a is on the left side).
At the time of, the 2-3 shift valve 6
It leads to the drain port of 4. Also, the second drain line 123
Is similarly guided to the 3-4 shift valve 65 via the one-way orifice 77, the fixed orifice 78 and the one-way orifice 79, and is connected to the line 124 when the third solenoid valve 68 is in the ON state (the spool 65a is on the right side). It communicates with the drain port of the 2-3 shift valve 64.

That is, during the 3-2, 4-2 shift down shift in which the hydraulic pressure (3-4 clutch pressure) is discharged from the 3-4 clutch 43, an intermediate pattern in which the third solenoid valve 68 shown in Table 2 is in the OFF state. During 3-2 downshifting, the 3-4 clutch pressure is discharged by the first drain line 122, and at the 4-2 downshifting when the third solenoid valve 68 is kept ON, the second drain Line 123 will release 3-4 clutch pressure. still,
Between the one-way orifice 77 and the fixed orifice 78 of the second drain line 123, a 2-3 accumulator 80 for buffering when the 3-4 clutch is operated is connected.

Also, a line 125 connected to the first drain line 122
Like the 3-4 clutch line 121, when the second solenoid valve 67 is in the OFF state and the spool 64a of the 2-3 shift valve 64 is located on the left side, it communicates with the second output line 112. I have. This line 125 is led to the 3-4 shift valve 65, and the third solenoid valve 68 is turned off.
When the spool 65a is located on the left side in this state, it communicates with the servo release line 126. This line 126 reaches the release port 45b 'of the servo piston 45' via the one-way orifices 81, 82. Therefore, the second,
When the third solenoid valves 67 and 68 are both in the OFF state, that is, in the third speed of the D range and the third speed of the second range, the servo release pressure is introduced into the release port 45b 'of the servo piston 45', and 2-4 The brake 45 is released.

Furthermore, a line 127 branched from between the two one-way orifices 81 and 82 of the servo release line 126 includes a coast control valve 83, a one-way orifice 84,
And coast clutch line via ball valve 85
It leads to 128, leading to coast clutch 42. Therefore, D where hydraulic pressure is introduced into the servo release line 126
Coast clutch 42 at 3rd range and 2nd range 3rd speed
Is concluded.

On the other hand, when the third solenoid valve 68 is in the OFF state, the spool 65a of the 3-4 shift valve 65 is located on the left side, and the second
When the solenoid valve 67 is in the ON state and the spool 64a of the 2-3 shift valve 64 is located on the left side, the forward clutch line 116 has its branch line 129, 3-4 shift valve 65, line 130 and 2-3. It communicates with the line 131 via the shift valve 64. The line 131 further communicates with the coast clutch line 128 via the ball valve 85. Accordingly, the coast clutch 42 is engaged even when the second solenoid valve 67 is in the ON state and the third solenoid valve 68 is in the OFF state, that is, in the second range of the second range and the first and second speeds of the first range.

Further, a third output line 113 communicating with the main line 110 in one range by the manual valve 62 is led to a 1-2 shift valve 63 via a low reducing valve 86 as a pressure reducing valve and a line 132. And
This line 132 communicates with the low reverse brake line 133 via the one-way orifice 87 and the ball valve 88 and reaches the low reverse brake 46 when the first solenoid valve 66 is OFF and the spool 63a is located on the left side. . Therefore, the first solenoid valve 66 is turned off in one range.
In the F state, that is, at the first speed in one range, the low reverse brake 46 is engaged.

Further, a fourth output line 114 communicating with the main line 110 in the R range is a line 13 branched from the line 114.
4. It communicates with the low reverse brake line 133 via the one-way orifice 89 and the ball valve 88. Further, the fourth output line 114 is connected to the reverse clutch line 135
As a result, the vehicle reaches the reverse clutch 44 via the one-way orifice 90. Therefore, in the R range, the low reverse brake 46 and the reverse clutch 44 are always engaged.
Note that an N-R accumulator 91 for buffering when the reverse clutch is engaged is connected to the reverse clutch line 135.

Further, the hydraulic control circuit 60 is provided with a lock-up shift valve 92 for operating the lock-up clutch 26 in the torque converter 20 shown in FIG.
A torque converter line 136 from the regulator valve 61 is led to the valve 92, and a pilot port 92b provided at one end of the valve 92 is connected to a pilot line 137. A hydraulic pressure which is branched from the line 110 and reduced in pressure by the solenoid reducing valve 93 is introduced.

A fourth solenoid valve 94 for lock-up is provided on this line 137, and when the valve 94 is in the OFF state, the spool 92a is located on the right side, so that the torque converter line 136 The internal pressure of the torque converter 20 is increased and the lock-up clutch 26 is engaged. When the solenoid valve 94 is turned on and the spool 92a moves to the left, the torque converter line 136 communicates with the lock-up release line 139 via the lock-up control valve 92 ', and locks in the torque converter 20. An up-release pressure is introduced to release the lock-up clutch 26.

The hydraulic control circuit 60 includes a regulator valve.
For controlling the line pressure adjusted by 61, a throttle modulator valve 95, a duty solenoid valve 96 for operating the valve, and a cutback valve 97 are provided.

A line 140 branched from a line 137 leading to the main line 110 through a solenoid reducing valve 93 is guided to the throttle modulator valve 95, and a duty solenoid valve that opens and closes periodically.
The pilot pressure adjusted by the valve 96 is introduced to one end of the spool 95a, and generates a throttle modulator pressure corresponding to the duty ratio of the duty solenoid valve 96 (valve opening time ratio in one cycle). ing. In this case, the duty ratio is set according to the throttle opening of the engine, and the corresponding throttle modulator pressure is introduced into the pressure increasing port 61a of the regulator valve 61 by the line 141, whereby the duty ratio is set. The line pressure adjusted by the valve 61 is increased as the throttle opening of the engine increases.

In addition to the above configuration, the hydraulic control circuit 60 includes, in addition to the coast control valve 83, a bypass valve 121, a 2-3 control valve 102, And a timing valve 103.

As described above, the coast control valve 83 has a line 127 branched from the servo release line 126 and communicating with the coast clutch line 128 via the ball valve 85.
Along with the forward clutch line
A line pressure (forward clutch pressure) is led to the other end of the spool 83a by a line 147 branched from 116. Then, when the servo release pressure introduced to one end of the spool 83a by the line 127 and the urging force of the spring (not shown) in the valve 83 overcome the line pressure from the line 147, the line 127 is connected. It has become.

Therefore, the coast clutch 42
During the 2-3 shift up shift in the D range and the 2 range in which the coast clutch pressure is supplied to the coast clutch, the coast clutch is increased after the servo release pressure is sufficiently increased, that is, after the 2-4 brake 45 is securely released. 42 will be concluded. Therefore, the internal lock due to the simultaneous engagement of the 2-4 brake 45 and the coast clutch 42 is prevented. Since the line pressure is guided to one end of the spool 83a, the timing for communicating the line 127 is changed according to the line pressure, and the communication timing and the pressure level of the servo release pressure are changed. Can be set appropriately.

Also, the bypass valve 101 has a 3-4 clutch line 1
It is provided on a bypass line 148 that bypasses the one-way orifice 76 provided in 21. The hydraulic pressure (3-4 clutch pressure) downstream of the one-way orifice 76 of the 3-4 clutch line 121 is introduced to one end of the spool 101a of the bypass valve 101, is guided from the throttle modulator valve 95, and flows through the lines 149 and 150. The modulator pressure is introduced to the other end of the spool 101a of the bypass valve 101. When the 3-4 clutch pressure rises above a predetermined value and the spool 101a moves to the left, the bypass line 148 is shut off.

Therefore, at the start of the supply, the −34 clutch pressure is quickly supplied by the bypass line 148, but thereafter, the supply is moderated by the one-way orifice 76.
The engagement timing of the clutch 43 is adjusted.

In addition, the 2-3 control valve 102 is provided with a bypass line 151 that bypasses the one-way orifice 81 that performs a throttling operation in the hydraulic pressure supply direction on the servo release line 126.
It is provided above. At one end of the spool 102a of the valve 102, a hydraulic pressure (3-4 clutch pressure) in the 3-4 clutch line 121 is introduced, and at the center of the spool 102a, via a line 149 and a line 152, The aforementioned throttle modulator pressure is introduced, and a servo release pressure downstream of the bypass line 151 is introduced into the other end of the spool 102a. By the action of the 3-4 clutch pressure, the throttle modulator pressure, and the servo release pressure, the bypass line 151 is actuated.
Is opened or shut off, and the servo release pressure is adjusted in accordance with an increase in the 3-4 clutch pressure.

On the other hand, the timing valve 103 is a first valve that bypasses the one-way orifice 73 on the servo apply line 120.
A bypass line 153, a second bypass line 154 that bypasses the one-way orifice 82 (and 81) on the servo release line 126, and a fixed orifice 78 (and one-way orifice 79) in the second drain line 123 of 3-4 clutch pressure. The third bypass line 155 that bypasses the third bypass line 155 is provided. A pilot line 157 guided from the main line 110 via a line 156 is connected to one end of the spool 103a, and the line 157 is provided with a fifth solenoid valve 104.

This timing valve 103 is connected to the fifth solenoid valve 1
By the operation of 04, the first to third bypass lines 153, 154,
155 is opened and shut off, and during 1-2 shift up shifting, 3
It controls the supply / discharge timing of hydraulic pressure at the time of -2 downshift and 4-2 downshift. Hereinafter, a specific operation of the timing valve 103 at each shift will be described.

First, at the time of the 1-2 shift-up shift, the spool 63a of the 1-2 shift valve 63 moves from the left to the right by switching the first solenoid valve 66 from the OFF state to the ON state. When the first output line 111 communicates with the servo apply line 120, the servo apply pressure is supplied to the apply port 45a 'of the servo piston 45' through the one-way orifice 73, whereby the 2-4 brake 45 Will be concluded.

During this shifting operation, the fifth solenoid valve 104 for timing valve operation is first switched from the OFF state to the ON state at the start of shifting. Therefore, the timing valve 10
The third spool 103a moves to the right, and the first bypass line 153 that bypasses the one-way orifice 73 communicates. Therefore, in the first half of the shift operation, the servo apply pressure is promptly supplied to the apply port 45a '.

Then, when a predetermined time has elapsed from the start of the shift during the shift, the fifth solenoid valve 104 is turned ON from the ON state.
By switching to the FF state, the spool 103a of the timing valve 103 moves to the left and the first bypass line
Cut off 153. Therefore, in the latter half of the speed change operation, the servo apply pressure is gently supplied to the apply port 45a 'of the servo piston 45' via the one-way orifice 73.

Thus, at the time of the 1-2 shift-up shift, the servo apply pressure changes differently in the first half and the second half of the shift operation.
Since the bypass line 153 communicates, the moving time of the piston is shortened, the time lag of the shift-up operation is reduced, and in the latter half of the shift operation, the one-way orifice 73 and the 1-2 accumulator 74 operate to smoothly shift. Up will be realized.

Next, at the time of the 3-2 downshift in the D range, both the second and third solenoid valves 67 and 68 are turned off before the shift operation is started, and are turned on after the shift operation is completed. During the gear shift, the second solenoid valve 67 is turned on, and the third solenoid valve 68 is turned off. Therefore, during shifting, the spool 64a of the 2-3 shift valve 64
Is located on the right side and the spool 65a of the 3-4 shift valve 65
Is located on the left side. Therefore, the servo release pressure supplied to the release port 45b 'of the servo piston 45' is changed to the line 126, the one-way orifices 82, 8
It is discharged from the drain port 64c of the 2-3 shift valve 64 via the 1, 3-4 shift valve 65, the line 125 and the one-way orifice 75.

During this shift, the fifth solenoid valve 104
As in the case of the above-mentioned 1-2 shift-up shift, at the start of the shift, first, the state is switched from the OFF state to the ON state, and after a predetermined time has elapsed, the state is switched to the OFF state. Accordingly, the spool 103a of the timing valve 103 first moves to the right to open the second bypass line 154, and then moves to the left to shut off the second bypass line 154. For this reason,
The servo release pressure is quickly discharged through the second bypass line 154 in the first half of the speed change operation, and is gradually discharged in the second half by the one-way orifice 82 that performs a throttle action in the discharge direction on the line 126. In addition, the fixed orifice 105 is also provided in the second bypass line 154,
The diameter of the orifice 105 is set sufficiently larger than that of the one-way orifice 82.

Here, at the time of this 3-2 downshift, 3-4
3-4 clutch pressure is discharged from the clutch 43. In this case, as described above, since the third solenoid valve 68 is in the OFF state and the spool 65a of the 3-4 shift valve 65 is located on the left side, the 3-4 clutch pressure is subject to the throttle action by the line 121. Through the one-way orifice 76, the second drain line 122, the 3-4 shift valve 65 and the line 124, the water is quickly discharged from the drain port 64c of the 2-3 shift valve 64.

Accordingly, at the time of the 3-2 downshift, the 3-4 clutch 43 is disengaged early, the engine speed increases rapidly, and the opening time of the bypass line 154 for controlling the discharge of the servo release pressure and the one-way orifice 82
With the setting of the diameter, the engagement of the 2-4 brake 45 can be completed at the same timing as when the engine speed stops increasing, and a quick and smooth shift can be realized.

Next, during the 4-2 downshift,
As in the case of -2 shift down, the 3-4 clutch pressure is discharged. However, in this case, the third solenoid valve
Since the 68 is held in the ON state and the spool 65a of the 3-4 shift valve 65 is held at the right position, the 3-4 clutch pressure cannot pass through the first drain line 122. Instead, the 3-4 clutch pressure is controlled by the second drain line 123 via the one-way orifice 77, fixed orifice 78, one-way orifice 79, and 3-4 shift valve.
65, and through line 124, is discharged from the drain port 64c of the 2-3 shift valve 64, in which case it will be throttled by the fixed orifice 78.

However, at the time of the 4-2 downshift, the fifth solenoid valve 104 switches from the OFF state to the ON state when a predetermined time has elapsed from the start of the shift,
The spool 103a of the timing valve 103 moves from left to right to open the third bypass line 155. Therefore, at the time of this 4-2 downshift,
The −4 clutch pressure is quickly discharged through the third bypass line 155 in the first half of the shift operation. And
In the latter half of the shifting operation, the throttle action of the fixed orifice 78 works,
Also, from the 2-3 accumulator 80 to the second drain line 12
Since the hydraulic oil is discharged to 3, the 3-4 clutch is gradually lowered.

By the way, at the time of this 4-2 downshift, the one-way clutch 51 locks from the idling state, but immediately before that, the third bypass line 155 is shut off to lock the one-way clutch 51 in a state where the hydraulic pressure is stable. As a result, a smooth shift can be realized without increasing the time lag of the shift operation.

Note that this 4-2 downshifting is described in 2-3.
Without using the hydraulic pressure holding action of accumulator 80,
By reducing the diameter of the fixed orifice 78 on the second drain line 123, the same operation as described above can be obtained.

Also, the servo apply line 120 and the servo release line 126 provided with the orifices 73, 82 and 78, respectively.
And the 3-4 clutch pressure second drain line 123 performs a speed-change operation independently of each other, so that the diameter of each orifice and the bypass line that bypasses these orifices
The operation timing and the like of the timing valve 103 on 153, 154, and 155 can be set to an optimal state without affecting other shift operations.

Next, features of the hydraulic control device according to the embodiment of the present invention will be described in detail.

2, the oil passage 126 'connected to the downstream side of the 3-4 shift valve 65 is connected to the hydraulic actuator 45 of the 2-4 brake 45 (first friction element) via the release pressure passage 126 as described above. And a coasting control valve 83 serving as a switching means is connected to an engagement pressure passage 127 branched from a common oil passage 126 'downstream of the 3-4 shift valve 65. ing. The valve 83
3 has a spool 83a, which is urged rightward in the figure by a spring 83b, as shown in detail in FIG. The valve 83 is connected to the fastening pressure passage 127.
Have two ports 83c and 83d which are connected in communication with each other. The port 83c communicates with one end chamber 83e in which the spring 83b is compressed. Also, the other end chamber 83f of the spool 83a is
An oil passage 160 branched from a fastening oil passage 120 communicating with the fastening oil chamber 45x 'of the hydraulic actuator 45' of the 2-4 brake 45 from the 2 shift valve 63 is connected and connected. The fastening pressure of the fastening oil chamber 45x 'of the hydraulic actuator 45' of the 2-4 brake 45 is supplied.

Further, the coast control valve 83 is formed with a port 83g corresponding to the port 83d, and the port 83g is formed.
As shown in FIG. 2, the coast clutch 42 is connected to the oil passage 128 through a one-way orifice 84 and a ball valve 85.
(A second friction element). When the port 83d and the port 83g are cut off by the movement of the spool 83a to the left in FIG. 3, the coast clutch 42
When the clutch 83 is released by cutting off the supply of the engagement pressure to the port 83d, when the port 83d and the port 83g are disconnected by the rightward movement of the spool 83a in FIG. The clutch 42 is supplied to the coast clutch 42 to fasten the clutch 42.

With respect to the operation of the coast control valve 83, the supply and discharge of the engagement hydraulic pressure of the engagement oil chamber 45a 'of the hydraulic actuator 45' of the 2-4 brake 45 introduced into the other end chamber 83f are performed by a 1-2 shift valve (shift). valve)
When the engagement hydraulic pressure is supplied to the other end chamber 83f by this control, the total pressure of the urging force of the spring 83b and the release oil pressure acting on the one end chamber 83e is opposed to this engagement oil pressure, and In other words, when the release hydraulic pressure of the one-end chamber 83e exceeds the set pressure value obtained by subtracting the urging force of the spring 83b from the engagement hydraulic pressure of the other-end chamber 83f, the spool 83a is moved by the differential pressure as shown in FIG. The clutch 83 is moved rightward to supply the engagement hydraulic pressure to the coast clutch 42, and when releasing the engagement hydraulic pressure to the other end chamber 83f, the spool 83a is moved rightward in FIG. By supplying the engagement hydraulic pressure to the coast clutch 42 at the same time as the engagement hydraulic pressure of the passage 127 is supplied to the port 83d, the movement timing of the spool 83a (that is, the The switching timing) of the bets control valve 83 constitute adjusting means 161 so as to adjust the hydraulic pressure is switched to when switching the 1-2 shift valve 63.

Next, a description will be given of the control by the controller of the 2 → 3 shift assuming that the internal lock of the transmission occurs during the shift, based on the control flow of FIG.

And start, after is loaded the opening θ and turbine speed Nγ of the throttle valve of the engine in step S _1, it is determined whether or not the 2 → 3 or during shifting in step S _2, 2 → 3 if during the shift only the throttle valve opening theta as compared to the small opening .theta.o total closed neighborhood in step step S _3, in the case of theta> .theta.o in,
It is determined that the time shift request at normal acceleration operation by depression or vehicle speed increase of the accelerator pedal by the driver, the first, second and so immediately as in step S ₆ the "D3" position of the table 2 Set the 3rd solenoid b valve 66-68 to "ON, OFF, OFF"
And returns.

On the other hand, in the case of the theta ≦ .theta.o in step S _3, it is determined that the time shift request at the time of deceleration operation by releasing operation of the accelerator pedal by the driver, first, in step S _4, the first, second and third the third solenoid valve 66 to 68, as a "middle" position of the second table "OFF, OFF, OFF" are controlled, at the time the shift is finished by the control in step S _5, step
First, second and third normal solenoid valves 66 to 68 as "D3" in the second table with the S ₆ "ON, OFF, OFF" are controlled, the process returns.

Next, the operation of the above embodiment will be described. First, advance second
At the speed, the spool 63a of the 1-2 shift valve 63 is moved rightward in FIG. 2 by the ON operation of the first solenoid valve 66, so that the engagement oil chamber 45x of the hydraulic actuator 45 'of the 2-4 brake 45 ′ Is supplied with a fastening pressure via a fastening pressure passage 120. On the other hand, the release pressure of the hydraulic actuator 45 'of the 2-4 brake 45 to the release oil chamber 45y' is the third pressure.
3-4 shift valve by ON operation of solenoid valve 68
Since the 65 spool 65a is moving rightward in FIG. 2,
The release pressure passage 126 communicating with the release oil chamber 45y 'is a common oil passage.
Drain via 126 ', and no release hydraulic pressure acts on the release oil chamber 45y'. Accordingly, the 2-4 brake 45 is in the engaged state by the action of the engaging pressure on the engaging oil chamber 45x '. Also, since the spool 64a of the 2-3 shift valve 64 is moved rightward in FIG. 2 by the ON operation of the second solenoid valve 67, the engagement oil passage 121 to the 3-4 clutch 43 is drained, The 3-4 clutch 43 is in a released state. Further, as described above, the hydraulic actuator of the 2-4 brake 45
Since the release pressure passage 126 communicating with the release oil chamber 45y 'of 45' is drained at the portion of the 3-4 shift valve 65 through the common oil passage 126 ', the coast control valve 83 is connected to the release pressure passage connected thereto. The release hydraulic pressure is not acting due to the drain of the passage 127 through the common oil passage 126 ′, and the communication between the port 83d and the port 83e is cut off.
The oil passage 128 to the coast clutch 42 is shut off, and the coast clutch 42 is in the released state.

When shifting from the second speed to the third speed, the shift is caused by acceleration caused by the driver depressing the accelerator pedal (throttle valve opening θ has a relationship of θ> θo with respect to minute value θo). Sometimes, the first solenoid valve 66
The ON operation is maintained, and the second and third solenoid valves 67, 68
Switches from ON operation to OFF operation. Therefore, the second
When the solenoid valve 67 is turned off, the spool 64a of the 2-3 shift valve 64 moves leftward in FIG. 2 and the line pressure is supplied to the engagement oil passage 121 of the 3-4 clutch 43. The clutch 43 is engaged. Further, the 3-4 shift valve 65 is operated by turning off the third solenoid valve 68.
The spool 65a moves leftward in FIG. 2, and the line pressure is 2-4. The oil chamber of the hydraulic actuator 45 'of the brake 45 is released.
The line pressure is supplied to the release oil passage 45y 'which communicates with the release oil passage 45y'.
The -4 brake 45 is released. Further, as described above, the release oil chamber of the hydraulic actuator 45 'of the 2-4 brake 45
As the line pressure is supplied to the release pressure passage 126 communicating with 45y ', the line pressure is also supplied to the engagement pressure passage 127 of the coast control valve 83 which shares the release pressure passage 126 and the downstream oil passage 126'. Is done. In the coast control valve 83, the 1-2 solenoid valve 63
-4 Fastening oil chamber 45 of hydraulic actuator 45 'of brake 45
The fastening pressure of the fastening oil passage 120 communicating with x ′ is supplied to the other end chamber 83f via the oil passage 160. Therefore, the release hydraulic pressure of the release oil chamber 45y 'of the hydraulic actuator 45' of the 2-4 brake 45 acting on the one end chamber 83e via the engagement pressure passage 127 as shown in FIG. When the 2-4 brake 45 is released to some extent beyond a pressure value obtained by subtracting the urging force of the spring 83b from the fastening pressure of the other end chamber 83f), the spool 83a moves rightward in FIG. Since the port 83d communicates with the port 83f, the engagement hydraulic pressure of the engagement pressure passage 127 is
When the coast clutch 42 starts to be supplied, the coast clutch 42 is engaged. Therefore, the internal lock of the transmission due to the early engagement of the coast clutch 42 while the 2-4 brake 45 is still in the engaged state can be reliably prevented.

On the other hand, even in the 2 → 3 shift, when the driver releases the accelerator pedal (the throttle valve opening θ is in a relation of θ ≦ θo with respect to the minute value θo), the above-mentioned deceleration occurs. These are controlled to "OFF, OFF, OFF" prior to the normal control of each of the solenoid valves 66 to 68. That is, only the first solenoid valve 66 is turned on before the ON control.
OFF controlled. As a result, the 1-2 shift valve 6
3 moves to the left in FIG. 2 to drain the fastening oil passage 120 communicating with the fastening oil chamber 45x 'of the hydraulic actuator 45' of the 2-4 brake 45, and the fastening oil pressure is indicated by a dashed line in FIG. As shown, it begins to drop and the 2-4 brake 45 begins to release. In the coast control valve 83, the other end chamber 83f passes through the oil passage 160 at the 1-2 shift valve 63 in accordance with the release of the engagement oil pressure of the 2-4 brake 45 (drain of the engagement oil passage 120). Drain starts, spool 83a is 3rd
Since the force in the left direction in the drawing starts to be lost, the spool 83 has a low value in the process of increasing the fastening pressure in the one-end chamber 83e.
a moves rightward in FIG. 3 to advance the switching timing of the coast control valve 83. As a result, as shown by the broken line in FIG. The coast clutch 42 starts to be engaged earlier earlier than the rising time indicated by the solid line. Therefore, at the time of shifting by this deceleration,
The early engagement of the coast clutch 42 allows the effect of the engine brake to be obtained at an early stage, thereby reducing the feeling of idling of the vehicle given to the driver.

[Brief description of the drawings]

The drawings show an embodiment of the present invention. FIG. 1 is a skeleton diagram of an automatic transmission, FIG. 2 is a hydraulic circuit diagram, FIG. 3 is a configuration diagram of a coast control valve, and FIG. FIG. 5 is a flow chart showing the control, and FIG. 5 is an explanatory diagram showing how the oil pressure changes during shifting by acceleration and during shifting by deceleration. 42: Coast clutch (second friction element), 45: 2
-4 brake (first friction element), 45 '... hydraulic actuator, 45y' ... release oil chamber, 63 ... 1-2 shift valve, 83 ... coast control valve (switching means), 120 ... release Pressure passage, 126 ... Common passage, 127 ...
Fastening pressure passage, 161,... Adjustment means.

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Hidetoshi Kambara 3-1, Shinchi, Fuchu-cho, Aki-gun, Hiroshima Prefecture Inside Mazda Co., Ltd. (56) References JP-A-2-113150 (JP, A) JP-A-1 JP-A-35156 (JP, A) JP-A-2-120559 (JP, A) JP-A-2-80854 (JP, A) JP-A-63-312558 (JP, A) JP-A-62-106158 (JP, A) (58) Field surveyed (Int.Cl. ⁶ , DB name) F16H 59/00-61/12 F16H 61/16-61/24 F16H 63/40-63/48

Claims (3)

(57) [Claims] 1. A first friction element that releases when a release pressure acts on a release oil chamber during a predetermined shift, and a second friction element that performs engagement when a release pressure acts on a release oil chamber during the above-mentioned predetermined shift. An automatic transmission, comprising: a friction element; and a shift valve which is switched at the time of shifting to switch between supply and discharge of hydraulic pressure to and from the plurality of friction elements, wherein a release oil chamber of the first friction element and a fastening oil of a second friction element are provided. A release pressure passage and a fastening pressure passage branched from a common oil passage are respectively connected to the chamber, and the first friction oil passage connected to the fastening oil chamber of the second friction element is connected to the first friction member. A switching valve for switching the engagement pressure passage to the communicating state at a switching timing when the release pressure of the release oil chamber of the element becomes equal to or higher than the set pressure is arranged, and the switching timing of the switching valve is switched when the shift valve is switched. Adjusted by hydraulic pressure Hydraulic control apparatus for an automatic transmission characterized by comprising adjustment means that. 2. The switching valve, wherein the release pressure of the release oil chamber of the first friction element and the engagement pressure of the engagement oil chamber of the first friction element act in opposition to each other. The hydraulic control device for an automatic transmission according to claim 1, wherein a shift valve switches between operation and non-operation of a fastening pressure of the first friction element to the fastening oil chamber. 3. The automatic control system according to claim 1, wherein the adjusting means changes the switching timing of the switching valve between a shift due to an increase in the engine load or an increase in the vehicle speed and a shift due to a decrease in the engine load. Transmission hydraulic control unit.