JPH04277369A - Hydraulic control device for automatic transmission - Google Patents

Abstract

PURPOSE:To improve the device so as not to generate speed change shock. CONSTITUTION:Speed change from a third speed to a fourth speed can be attained by disengaging a first clutch C1 and engaging a first brake B1. It is constituted so that a 3-4 shift valve 70 is simultaneously changed over to charge and discharge pressure oil against these engaging elements, a brake port 76 communicated to the first brake B1 among these ports is connected to a B1 control valve 80 controlled with a fourth solenoid valve 92, and the first brake B1 is controlled with this control valve 80 independently from the first clutch C1.

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 setting a plurality of gears by engaging or disengaging engagement elements such as clutches and brakes in an automatic transmission.

0002

[Prior Art] Automatic transmissions for vehicles change the torque transmission path through a gear train consisting of multiple sets of planetary gear mechanisms by changing the engagement/disengagement state of engagement elements such as clutches and brakes. It is well known that the transmission gear is configured to be set to a predetermined gear position. When performing a shift in this type of automatic transmission, the engagement of one engagement element and the release of another engagement element may be performed in parallel, but in such a shift Therefore, it is necessary to appropriately control the timing of engagement and release of each engagement element. That is, when switching between the engaged and disengaged states of these two engaging elements, as a transitional state, both engaging elements become substantially engaged together, or conversely, when they become released, This causes inconveniences such as a locking condition, engine revving, etc., and sudden changes in output torque that increase shift shock.

[0003] Conventionally, therefore, the timing of engagement and release of the engagement element has generally been controlled using an accumulator or a control valve.
Japanese Patent No. 76967 describes a hydraulic control device configured to adjust the engagement speed of one of two input clutches using a control valve. this is,
Specifically, as an oil passage for supplying hydraulic pressure to the oil chamber of the first input clutch, a first oil passage with an orifice with a large degree of restriction interposed therebetween, a control valve, and an orifice with a small degree of restriction are arranged in series. The hydraulic pressure from the accumulator control valve is used as a signal pressure to switch the control valve, and high-pressure hydraulic pressure is supplied from the accumulator control valve during power-on and downshift. As a result, the control valve operates to close the second oil passage, and as a result, hydraulic pressure is supplied to the first input clutch through the orifice with a large degree of restriction, so that its engagement speed becomes slow. Conversely, during power-off/downshift, the hydraulic pressure from the accumulator control valve becomes low, so the control valve opens the second oil passage, and as a result, the first input clutch receives hydraulic pressure from the two oil passages. is supplied, so the engagement speed becomes faster.

[0004] As described above, since the engagement speed of the first input clutch can be changed between power-on downshift and power-off downshift, it is possible to improve shift shock and shift with good engine braking effect. can be achieved.

[0005]

[Problems to be Solved by the Invention] However, the device described in the above-mentioned publication does not allow the oil passage on the downstream side of the first input clutch switching valve that controls the engagement/disengagement of the first input clutch to be connected to the first input clutch. Therefore, as stated in the above publication, the first input clutch is engaged only during downshifting. Unable to control speed. Moreover, the engagement speed of the first input clutch, that is, the oil pressure supply speed is uniquely determined by the degree of throttling of the first oil passage and the second oil passage described above.

[0006] For this reason, the above-mentioned conventional device lacks diversity in control, and there is a high possibility that a situation in which shift shock cannot be avoided may occur.

The present invention has been made in view of the above-mentioned circumstances, and an object of the present invention is to provide a hydraulic control device capable of controlling various switching operation timings of two engaging elements that are simultaneously controlled to switch. It is something.

[0008]

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a plurality of engagement elements whose engagement and release are controlled by hydraulic pressure, and engagement and release of these engagement elements. In a hydraulic control device for an automatic transmission equipped with a gear train that is set to a plurality of gear stages according to a combination of and a control valve that is interposed in the oil passage leading to one of the two engaging elements and controlling the supply and discharge of hydraulic pressure to the one engaging element. This is a characteristic feature.

Further, in the present invention, one of the two engaging elements is an engaging element that is engaged to set a high speed stage, and the other of the two engaging elements is an engaging element that is engaged to set a high speed stage. The engagement element may be an engagement element that is engaged in order to set a low speed gear that has a larger gear ratio than the high speed gear.

0010

[Operation] In the automatic transmission to which the present invention is directed, two engaging elements are simultaneously switched in order to achieve a predetermined gear position. When performing this speed change, a switching valve is operated to simultaneously switch the state of supplying and discharging hydraulic pressure to these two engaging elements. In that case, hydraulic pressure is supplied and discharged to one engagement element via a control valve, so by controlling the switching operation of this control valve, the switching timing between the two engagement elements can be adjusted. can be changed in various ways.

[0011] Furthermore, if a control valve is interposed in the oil passage on the side of one of the engaging elements to be engaged in order to set the high speed stage, the one engaging element will be engaged due to a failure of the control valve or the like. Even if the vehicle runs out, it is possible to set the low speed gear necessary for driving, thus ensuring driving in the event of a failure.

0012

Embodiments Next, embodiments of the present invention will be explained based on the drawings.

FIGS. 1 and 2 are hydraulic circuit diagrams showing one embodiment of the present invention. In these diagrams, an oil pump, a means for regulating the hydraulic pressure generated by the oil pump to line pressure PL, or a lock-up The means for controlling the clutch and the means for controlling the accumulator back pressure are omitted because conventionally known means can be used. Further, in FIGS. 1 and 2, the numbers with circles indicate that the parts indicated by the same numbers are connected.

FIG. 3 shows an example of a gear train whose speed is controlled by the hydraulic control device shown in FIGS. 1 and 2. This uses two sets of planetary gear mechanisms 1 and 2, and is configured to set four forward speeds and one reverse speed. That is, the carrier 3 of the first planetary gear mechanism 1 and the ring gear 4 of the second planetary gear mechanism 2 are connected, and the ring gear 5 of the first planetary gear mechanism 1 and the carrier 6 of the second planetary gear mechanism 2 are connected. There is.

An input shaft 7 is arranged along the center axis of these planetary gear mechanisms 1 and 2, and the input shaft 7 and the first
A first clutch C1 is provided between the sun gear 8 in the planetary gear mechanism 1, and a second clutch C2 is provided between the input shaft 7 and the carrier 6 in the second planetary gear mechanism 2. Furthermore, a third clutch C3 is provided between the input shaft 7 and the sun gear 9 of the second planetary gear mechanism 2. On the other hand, a fourth clutch C4 and a first one-way clutch F1 are provided between the carrier 6 and the sun gear 9 in the second planetary gear mechanism 2, which are arranged in series with each other. This first one-way clutch F1 is the fourth clutch C
4, that is, the rotation direction of the sun gear 9 when the fourth clutch C4 is engaged is in the forward rotation direction with respect to the carrier 6 (the same rotation direction as the input shaft 7 rotation direction). It is designed to engage in certain cases. Between the clutch drum of this fourth clutch C4 and the casing 10, the clutch drum rotates in reverse (
A second one-way clutch F2 is provided which is engaged when the input shaft 7 is about to rotate in the opposite direction.

As a braking means, a first brake B1 which is a band brake is provided on the outer periphery of the clutch drum of the fourth clutch C4, and the ring gear 5 of the first planetary gear mechanism 1 and the second planetary gear mechanism are connected to each other. The second brake B2 stops the rotation of the second carrier 6.
is provided. Therefore, the first brake B1 is
Fourth clutch C4 or first one-way clutch F1
Through this, the rotation of the carrier 6 and the rotation of the sun gear 9 in the second planetary gear mechanism 2 are selectively stopped.

In the gear train shown in FIG. 3, four forward speeds and one reverse speed are set by engaging engaging elements such as clutches and brakes as shown in FIG. In FIG. 4, the ○ mark indicates the engaged state, the ◎ mark indicates the engaged state during engine braking, and the blank space indicates the disengaged state.

That is, when the first clutch C1 is engaged, torque is transmitted from the input shaft 7 to the sun gear 8 of the first planetary gear mechanism 1, but the load from the drive gear 11 is applied to the carrier 3. Therefore, a torque in the reverse rotation direction is applied to the ring gear 5. As a result, ring gear 5
The first one-way clutch F1 connected to the first one-way clutch F1 is engaged, and the second one-way clutch F2 disposed in series with the first one-way clutch F1 is engaged, so that the ring gear 5 is connected to the casing 10.
A reaction torque is applied from the carrier 3 to prevent the reverse rotation, and therefore the carrier 3 and the drive gear 11 connected thereto are rotated in the forward direction and set to the first speed. If torque is input from the drive gear 11 side in this state, each one-way clutch F1, F2 will be released, so by engaging the second brake B2 and fixing the ring gear 5, the engine brake will not be applied. can be set.

In the first speed state described above, the sun gear 9 of the second planetary gear mechanism 2 is rotating in the opposite direction. Therefore, when the fourth clutch C4 is engaged in this state, the second one-way clutch F2 is rotating in the reverse direction. The second
The rotation of the sun gear 9 of the planetary gear mechanism 2 is stopped. In this case, since the ring gear 5 of the first planetary gear mechanism 1 and the carrier 6 of the second planetary gear mechanism 2 rotate forward at low speed, the carrier 3 of the first planetary gear mechanism 1, that is, the drive gear 1
1 rotates faster than the first speed, and the second speed is set. Incidentally, by engaging the first brake B1 in this second speed state, engine braking can be applied by preventing either forward or reverse rotation of the sun gear 9 in the second planetary gear mechanism 2.

[0020] First and fourth clutches C1 and C4
In addition, if the second clutch C2 is engaged, in the first planetary gear mechanism 1, the sun gear 8 connected to the first clutch C1 and the second Ring gear 5 connected to clutch C2
Since the two rotating members 1 and 2 are connected to the input shaft 7, the entire first planetary gear mechanism 1 rotates together with the input shaft 7. That is, the third speed is a direct connection stage, and the rotational speed of the drive gear 11 is equal to that of the input shaft 7. In this case, the first planetary gear mechanism 2 as a whole rotates forward together with the first planetary gear mechanism 1, and the first one-way clutch F1 becomes engaged. Further, engine braking can be applied without particularly engaging other engaging elements.

The fourth speed, which is an overdrive stage, is set by releasing the first clutch C1 and engaging the first brake B1 in the third speed state. That is, by engaging the fourth clutch C4 and the first brake B1, the sun gear 9 of the second planetary gear mechanism 2 is fixed, and in this state, the carrier 6 rotates together with the input shaft 7, so that the ring gear 4 and the sun gear 9 rotate together with the input shaft 7. The drive gear 11 connected to the input shaft 11 is accelerated to rotate in the forward direction relative to the input shaft 11. This fourth speed is one-way clutch F1, F
2 is not set by engagement, engine braking can be applied.

The reverse gear is set by engaging the third clutch C3 and engaging the second brake B2. That is, since the sun gear 9 of the second planetary gear mechanism 2 rotates together with the input shaft 7 while the carrier 6 of the second planetary gear mechanism 2 is fixed, the ring gear 4 and the drive gear 11 connected thereto rotate in the opposite direction.

The hydraulic control device shown in FIGS. 1 and 2 uses a manual valve 2 to set each of the above-mentioned gears.
0, 1-2 shift valve 30, 2-3 shift valve 50, 3-4 shift valve 70, B1 control valve 80, and solenoid valves 90, 91, 92 that control each shift valve 30, 50, 70. .

The manual valve 20, like the conventional one, can be operated manually to select the P (parking) range, R (reverse) range, N (neutral) range, D (drive) range, S range, and L range. When the P range is selected, the spool 21 moves to the left from the position shown in the figure, and the line pressure oil path 1
00 is connected to the D port 23, and when the S range is selected, the spool 2
1 further moves to the left side of the figure to connect the input port 22 to the D port 23 and the S port 24, and when the L range is selected, the spool 21 moves to the left end of the figure and connects the input port 22 to the D port 23 and the S port 24. D port 23 and S port 2
4 and L port 25. On the other hand, when the R range is selected, the spool 21 moves to the right from the illustrated position, causing the input port 22 to communicate only with the R port 26. Furthermore, when the N range is selected, the spool 21 is in the position shown in the figure, and communication between the input port 22 and other ports is blocked, and when the P range is selected, the input port 22 is closed by the spool 21. It has become.

The 1-2 shift valve 30 has a spool 31 on which five lands are formed and a spring 32 that presses the spool 31 in one direction (upward in the figure). A control port 33 formed at an end opposite to the opposite end is communicated with the D port 23 of the manual valve 20 via an oil passage 101. A second solenoid valve 91 is interposed in this oil passage 101 via a strainer 102 and an orifice 103. When this second solenoid valve 91 is OFF, pressure is discharged from the oil passage 101, and when it is ON, pressure is discharged from the oil passage 101.
1 to generate line pressure PL. In addition, the first D port 34 in the 1-2 shift valve 30 is connected to the strainer 102 and the second solenoid valve 9.
It is communicated with the D port 23 of the manual valve 20 through an oil passage 104 that bypasses the first D port 34, and is communicated with the first D port 34 when the spool 31 is pushed by the spring 32 and is in the position shown on the right side of the figure. clutch port 35
A fourth clutch C4 is connected to the fourth clutch C4. Note that an accumulator 105 is attached to this fourth clutch C4.

Furthermore, the 1-2 shift valve 30 includes a second D port 36, an S port 37, a brake port 38, a drain port 39, and an R port 40, which are selectively communicated with the clutch port 35 from the upper side in the illustrated state. , a brake port 41, an L port 42, a third D port 43, a clutch port 44, and a hold port 45. Of these, the second brake B2 is connected to the brake port 41.
is connected.

On the other hand, the 2-3 shift valve 50 has two spools 51, which are consecutively arranged on the same axis.
52, and a spring 53 that presses these spools 51, 52 in one direction (upward in the figure), and is formed at the end opposite to the end where the spring 53 is arranged. The control port 54 is connected to the line pressure oil passage 100.
branching from the strainer 106 and orifice 10
7 and the oil passage 1 equipped with the first solenoid valve 90
08 is connected. Therefore, when this first solenoid valve 90 is OFF, pressure is exhausted from the control port 54, and the spools 51 and 52 are pushed by the spring 53 and move to the position shown on the left side of the figure, and conversely, the first solenoid valve 90 is turned ON. At this time, the line pressure PL acts on the control port 54, and the spools 51 and 52 are pushed down to the position shown on the right side of the figure.

The 2-3 shift valve 50 is also formed with first and second D ports 55 and 56 connected to the D port 23 of the manual valve 20. A clutch port 57 that is communicated and disconnected is connected to the third D port 43 of the 1-2 shift valve 30. Further, a clutch port 59 that selectively communicates with the second D port 56 and the drain port 58 is connected to the second D port 36 and the hold port 45 in the 1-2 shift valve 30. On the other hand, this clutch port 59 is connected to the second clutch C2. Note that the reference numeral 109 is an accumulator.

Further, the 2-3 shift valve 50 is formed with an L port 60 connected to the L port 25 of the manual valve 20, and a brake port 60 is selectively communicated with the L port 60 and the drain port 61. Port 62 is connected via low coast modulator valve 110 to
-2 It is connected to the L port 42 of the shift valve 30. Note that the low coast modulator valve 110 is for reducing shift shock when switching to the L range, and may be a commonly used one. An S port 63 connected to the S port 24 of the manual valve 20 is formed in the 2-3 shift valve 50, and a brake port 65 selectively communicates with the S port 63 and the drain port 64.
It is connected to the S port 37 in the 1-2 shift valve 30. Furthermore, a clutch port 67 is provided which selectively communicates with the second D port 56 and another drain port 66.

The 3-4 shift valve 70 is for simultaneously switching the supply and discharge of hydraulic pressure to two engaging elements, the first clutch C1 and the first brake B1.
The spool 71 that formed two lands and the spool 71
It has a spring 72 that presses in one direction (upward in the figure). A control port 73 provided at the end opposite to the end where the spring 72 is arranged is connected to the control port 33 of the 1-2 shift valve 30.
Therefore, the control port 7 of this 3-4 shift valve 70
The second solenoid valve 91 applies the line pressure PL to the line pressure PL and discharges it.

[0031] Also, this 3-4 shift valve 70 includes:
Brake port 38 in 1-2 shift valve 30
An S port 74 connected to the manual valve 2 is formed through the S port 74 and the oil passage 104.
A brake port 76 is formed that selectively communicates with a first D port 75 connected to the D port 23 of No. 0. Furthermore, a second D port 77 and a hold port 78 are formed which are connected to the clutch port 67 in the 2-3 shift valve 50 described above, and are selectively communicated with the first D port 75 and the second D port 77. A first clutch C1 is connected to the clutch port 79. Hydraulic pressure is supplied from this clutch port 79 to the first clutch C1 via an accumulator 111.

[0032] Note that the first clutch C1 is
It is also connected to a clutch port 44 in the 1-2 shift valve 30.

A B1 control valve 8 is installed downstream of the 3-4 shift valve 70, that is, downstream of the supply of hydraulic pressure from the 3-4 shift valve 70 to the first brake B1.
0 is placed. This B1 control valve 8
0 is for controlling the hydraulic pressure supplied from the 3-4 shift valve 70 to the first brake B1, and this spool 81 is connected to the spool 81 on which three lands are formed. It has a spring 82 that presses in the direction (upward in the figure). An oil passage 112 branched from the aforementioned oil passage 108 on the downstream side of the strainer 106 is connected to the control port 83 at the end opposite to the end where the spring 82 is disposed.
An orifice 113 and a normally closed solenoid valve (temporarily referred to as a fourth solenoid valve) 92 are interposed in the second solenoid valve. Therefore, when the fourth solenoid valve 92 is OFF, the line pressure PL acts on the control port 83, causing the spool 81 to fall against the elastic force of the spring 82, as shown on the right side of the figure, and conversely, when the fourth solenoid valve 92 is ON. control port 8
3, the spool 81 is pushed up to the position shown on the left side of the figure.

This B1 control valve 80 includes:
A first D port 84 connected to the brake port 76 of the 3-4 shift valve 70 is formed.
A first brake B1 is connected to a brake port 86 that selectively communicates with a port 84 and a drain port 85. Note that an accumulator 114 is attached to this first brake B1. Further, the B1 control valve 80 is formed with a second D port 87 connected to the clutch port 59 in the 2-3 shift valve 50 described above, and a clutch port 88 that is communicated with and disconnected from the second D port 87 is formed. 2nd clutch C2
is connected.

Note that in order to set the reverse gear when the R range is selected by the manual valve 20, the R port 26 is connected to the third clutch C3 and 1-2.
It is connected to the R port 40 of the shift valve 30. An accumulator 115 is attached to this third clutch C3.

Next, the operation of the above-described device will be explained. Each shift valve 30, 50 shown in FIGS. 1 and 2,
Line pressure P for control ports 33, 54, 73 of 70
L is supplied and discharged using the first solenoid valve 90 or the second solenoid valve 90.
This is done by the solenoid valve 91, and therefore each forward gear is set by the combination of ON and OFF of these solenoid valves 90 and 91. The ON and OFF states of these solenoid valves 90 and 91 and the associated engagement and release states of each engagement element are as shown in FIG. In Fig. 5, the circle mark in the SOL column indicates that the solenoid valve is in the ON state, and the × mark indicates that the solenoid valve is in the ON state.
The mark indicates the OFF state. Furthermore, a circle in the engagement element column indicates an engaged state, a blank indicates a released state, and a Δ mark indicates a released state during coasting. Note that the third speed in parentheses in FIG. 5 indicates the third speed state when the solenoid valve fails.

First, the first speed is set by turning on the first and second solenoid valves 90 and 91 while selecting one of the D range, S range, or L range. Therefore, each shift valve 30, 50
, 70, the line pressure PL is applied to the control ports 33, 54, 73.
acts, and in the 1-2 shift valve 30 and the 2-3 shift valve 50, the respective spools 31, 51,
52 moves in a direction that compresses the springs 32 and 53. And in the 2-3 shift valve 50, the spool 51
, 52 are lowered as shown on the right side of the figure, the D port 56 connected to the D port 23 of the manual valve 20
and the clutch port 67, and as a result, the 3-4 shift valve 7 is connected to the clutch port 67.
Line pressure PL acts on hold port 78 of 0. Therefore, in the 3-4 shift valve 70, the control port 7
Even if the line pressure PL acts on the end 3, the line pressure PL and the elastic force of the spring 72 act on the opposite end, so the spool 71 is pushed up as shown on the left side of the figure. maintain. Therefore, since the first D port 75 connected to the D port 23 of the manual valve 20 communicates with the clutch port 79, hydraulic pressure is supplied to the first clutch C1, and the first clutch C1 is engaged.

[0038] Also, if the L range is selected, 2
Hydraulic pressure is supplied to the L port 60 of the -3 shift valve 50, and since this L port 60 communicates with the brake port 62, it is supplied to the L port 42 of the 1-2 shift valve 30 via the low coast modulator valve 110. Hydraulic pressure is supplied. Since this L port 42 communicates with the brake port 41 by lowering the spool 31 as shown on the left side of the figure, hydraulic pressure is supplied to the second brake B2 and it is engaged.

Although detailed explanation will be omitted, in the first speed state, other clutches C2, C3, C4 and brake B1
is kept free.

To set the second speed, only the first solenoid valve 90 is turned on. Therefore, in the 2-3 shift valve 50, the spools 51 and 52 remain lowered as shown on the right side of the figure, as in the first speed described above, whereas in the 1-2 shift valve 30, the control port 33 Since the pressure is exhausted from the spool 31, the spool 31 is pushed by the spring 32 and moves to the position shown on the right side of the figure. In this case, if the D range is selected, the 1-2 shift valve 30
Hydraulic pressure is supplied to the first D port 34 through the oil passage 104, and this first D port 34 is connected to the brake port 35.
Since the fourth clutch C4 is in communication with the fourth clutch C4, hydraulic pressure is supplied to the fourth clutch C4 and the fourth clutch C4 is engaged.

Furthermore, if the S range or L range is selected, the first clutch C1 and the fourth clutch C4
In addition, the first brake B1 is engaged. In other words, in S range or L range, manual valve 20
Since the S port 24 of is connected to the input port 22, 2
-3 Hydraulic pressure is supplied to the S port 63 of the shift valve 50. This S port 63 communicates with a brake port 65, and this brake port 65 is connected to an S port 37 of the 1-2 shift valve 30, which further communicates with a brake port 38, and this brake port 38. The brake port 7 is connected to the S port 74 of the 3-4 shift valve 70, and the S port 74 communicates with the brake port 76.
The first of the B1 control valves 80 connected to the
Hydraulic pressure is supplied to the D port 84. In this B1 control valve 80, the fourth solenoid valve 92
is OFF, line pressure PL acts on the control port 83, and the spool 81 is lowered as shown on the left side of the figure, so the first D port 84 and the brake port 86 communicate with each other, and as a result, Hydraulic pressure is supplied to the first brake B1 and it is engaged.

To set the third speed, each solenoid valve 90, 91 is turned OFF. Therefore, in the 2-3 shift valve 50, the spools 51 and 52 are pushed up to the position shown on the left side of the figure by exhausting pressure from the control port 54. And D port 23 of manual valve 20
The second D port 56 connected to the clutch port 67
Since the clutch port 59 is switched to another clutch port 59 for communication, hydraulic pressure is supplied to the second clutch C2 connected to this clutch port 59, and the second clutch C2 is engaged. That is, the first, second, and fourth clutches C1, C2, and C4 are engaged. At the same time, oil pressure is supplied to the hold port 45 of the 1-2 shift valve 30, so this 1-2 shift valve 30 is supplied with hydraulic pressure.
In the two-shift valve 30, even if the line pressure PL acts on the control port 33, the spool 31 is held at the position shown on the right side of the figure. Furthermore, since the pressure is exhausted from the hold port 78 of the 3-4 shift valve 70 connected to the clutch port 67, the 3-4 shift valve 70 becomes controllable by the second solenoid valve 91.

The fourth speed is a gear stage that is set only when the D range is selected, and the second solenoid valve 9
1 to ON and set. Therefore, the control port 33 of the 1-2 shift valve 30 and the 3-4 shift valve 70
The line pressure PL acts on the control port 73 of the 1-2 shift valve 30, but the hydraulic pressure supplied via the 2-3 shift valve 50 acts on the hold port 43 of the 1-2 shift valve 30, so the control port 33 line pressure PL
Even if the spool 31 is applied, the spool 31 remains pushed up to the position shown on the right side of the figure.

On the other hand, in the 3-4 shift valve 70, the line pressure PL acts on the control port 73, so that the spool 71 is pushed down against the spring 72 to the position shown on the right side of the figure. As a result, the first clutch C1
The clutch port 79 connected to the first D port 75
At the same time, the brake port 76 is switched from the S port 74 to the second D port 77 for communication.
5 and communicated. The second D port 77 is 2-3
The 2-3 shift valve 50 is connected to the clutch port 67 of the shift valve 50, but when the 2-3 shift valve 50 is in fourth gear, the spools 51 and 52 are pushed up as shown on the left side of the figure, and the clutch port 67 is connected to the drain port 66. Therefore, from the first clutch C1, these
3-4 shift valve 70 and 2-3 shift valve 5
0 and the first clutch C1 is released. On the other hand, since oil pressure is constantly supplied to the first D port 75 of the 3-4 shift valve 70 in the D range, oil pressure is supplied to the first D port 84 of the B1 control valve 80 via the brake port 76 communicating therewith. Sent. At this time, if the fourth solenoid valve 92 is OFF and the spool 81 is lowered as shown on the right side of the figure, the first D port 84 and the brake port 86 communicate with each other, and hydraulic pressure is sent to the first brake B1. , which engages.

That is, the 3-4 shift valve 70 controls the release of the first clutch C1 and the engagement of the first brake B1 at the same time.

Note that the reverse gear is set by selecting the R range using the manual valve 20. In other words, in the R range, the input port 22 is communicated only with the R port 26, so the third clutch C3 connected here is engaged and also connected to the R port 26.
-2 Oil pressure is sent to the R port 40 of the shift valve 30. In this 1-2 shift valve 30, when the second solenoid valve 91 is OFF, the spool 31 is pushed up to the position shown on the right side of the figure, so the R port 40 communicates with the brake port 41. Therefore, hydraulic pressure is supplied to the second brake B2 connected here, and it is engaged.

By the way, as is clear from the above description, hydraulic pressure is supplied and discharged to and from the first brake B1 via the B1 control valve 80, and this B1 control valve 80 is not connected to the fourth brake B1, which is not involved in setting the gear.
Since it is configured to be controlled by the solenoid valve 92, even if the supply and discharge of hydraulic pressure to and from the first clutch C1 and the first brake B1 are switched by one 3-4 shift valve 70, the control is performed by the first clutch C1 and the first brake B1.
The relative timing of engagement and release with 1 can be controlled as appropriate.

As an example of control based on such timing adjustment, so-called double lock prevention control will be described.

In order to shift between the third and fourth speeds in the automatic transmission equipped with the gear train shown in FIG. 3, the first clutch C1 is released and the first brake B1 is simultaneously engaged. Alternatively, the opposite control may be performed; therefore, since the aforementioned 3-4 shift valve 70 performs such control with one valve, both the first clutch C1 and the first brake B1 This is effective in preventing oil pressure from being supplied to the However, oil viscosity, oil path resistance, centrifugal oil pressure, etc. act on the supply and discharge of hydraulic pressure, and changes in the torque capacity of the engagement element vary depending on the situation.

For example, in the example described above, when shifting from 3rd speed to 4th speed, even if the 3-4 shift valve 70 is switched, the pressure is not immediately discharged from the first clutch C1, and the torque capacity remains. On the other hand, the supply of hydraulic pressure to the first brake B1 may proceed quickly, and in such a case, the exhaust pressure from the first clutch C1 and the first brake B1
If the supply of hydraulic pressure to and from the engine are started at the same time, there will be a period in which both have a certain amount of torque capacity. This is shown diagrammatically in FIG. 6, and a period in which the first brake B1 has a certain amount of torque capacity while the first clutch C1 has remaining torque capacity is a double lock state. In this state, the torque of the drive gear 11, which is the output means, temporarily and rapidly decreases, resulting in a large shift shock.

[0051] Therefore, in the above-mentioned device, from the third speed to the fourth speed
When upshifting to a higher speed, the fourth solenoid valve 92 is turned on to exhaust pressure from the control port 83 of the B1 control valve 80, thereby pushing the spool 81 up to the right side in the figure and shifting the brake port 86 to the drain port 85. I will communicate with you. Also, in this state, the 1st D
Port 84 is closed. Therefore, when the second solenoid valve 91 is turned ON and the 3-4 shift valve 70 is switched in order to perform an upshift from 3rd speed to 4th speed, the first clutch C1 transmits the signal as described above.
3-4 shift valve 70 and 2-3 shift valve 5
Although the pressure is exhausted after reaching 0, no hydraulic pressure is supplied to the first brake B1, and the released state is maintained. When the fourth solenoid valve 92 is turned off after the torque capacity of the first clutch C1 has sufficiently decreased, line pressure PL is applied to the control port 83 of the B1 control valve 80, and the spool 81 is moved to the position shown on the right side of the figure. As a result, the brake port 86 and the first D port 84 communicate with each other, and hydraulic pressure is supplied to the first brake B1, which is engaged.

That is, since the torque capacity of the first brake B1 appears in a state where the first clutch C1 transmits almost no torque, the double lock state described above can be avoided. This state is shown in FIG. 6 by a broken line.

Furthermore, when downshifting from 4th speed to 3rd speed, unless the B1 control valve 80 is specifically activated, the exhaust pressure from the first brake B1 will be 3-
4 Brake port 76 and S port 74 of shift valve 70, 1-2 Brake port 3 of shift valve 30
This is done through the 8 and S ports 37, the brake port 65 and the drain port 66 of the 2-3 shift valve 50, but if the B1 control valve 80 is activated, pressure can be immediately exhausted from the first brake B1. That is, when downshifting from the fourth speed to the third speed, the fourth solenoid valve 92 is temporarily turned on prior to switching the second solenoid valve 91 from ON to OFF. As a result, first, the spool 81 in the B1 control valve 80 rises as shown on the right side of the figure, the brake port 86 communicates with the drain port 85, and the pressure from the first brake B1 is rapidly exhausted. After that, turn off the second solenoid valve 91 3-4
By switching the shift valve 70 and turning off the fourth solenoid valve 92, the first brake B1
After the torque capacity of the first clutch C1 has decreased sufficiently, the first clutch C1
This increases the torque capacity of the gearbox, making it possible to prevent the aforementioned double lock and the resulting deterioration of shift shock.

Note that the speed at which hydraulic pressure is supplied and discharged to and from the first clutch C1 and the first brake B1, and the speed at which the torque capacity increases and decreases accordingly, depend on various factors such as oil viscosity (oil temperature) and centrifugal oil pressure. Although influenced by various factors, the fourth solenoid valve 92 can be controlled independently, so the B1 control valve 80 can be controlled in accordance with various situations and operating conditions, and the first clutch C1 and first brake B1 can be controlled independently.
The relative engagement/disengagement timing can be made appropriate.

ON/OFF of the second solenoid valve 91 that controls the above 3-4 shift valve 70 and B1
There are four combinations of ON/OFF of the fourth solenoid valve 92 that controls the control valve 80, as shown in FIG. It is also shown in FIG. Each solenoid valve 91, 9 like this
The ON/OFF combination of 2 is the 3rd speed and 4th speed mentioned above.
This occurs when controlling the timing of engagement and release of the first clutch C1 and the first brake B1 when changing gears between the two speeds.If the second solenoid valve 91 is OFF, the first solenoid valve 90 is By being OFF, whether the fourth solenoid valve 92 is ON or OFF, the first clutch C1 and the second clutch C
2. The third clutch, which is a direct-coupling stage, in which the fourth clutch C4 is engaged
speed is set. This is the same whether it is driven by applying torque from the engine or driven by applying torque from the wheels.

On the other hand, if the second solenoid valve 91 is turned on, the fourth solenoid valve 92 is turned on, and the first clutch C1 is released and the second clutch C2 and the fourth clutch C4 are turned on. engage. In this case, when driving by applying torque from the engine side, the sun gear 9 in the second planetary gear mechanism 2 tries to rotate forward faster than the carrier 6, so the first one-way clutch F1 is engaged, and as a result, the second planetary gear Since the entire gear mechanism 2 rotates as one, it is in the third speed, which is a direct gear. On the contrary, when the wheel is being driven, where torque is applied from the wheel side, torque in the reverse direction is applied to the sun gear 9, so the second one-way clutch F2 is engaged instead of the first one-way clutch F1. , As a result, the fourth gear, which is an overdrive stage, is set.

Furthermore, if the second solenoid valve 91 is ON and the fourth solenoid valve 92 is OFF, the first
Since the brake B1 is engaged, the fourth speed is set both when driving and when being driven.

Therefore, in the above-described device, even if the B1 control valve 80 becomes stuck and oil pressure cannot be supplied to the first brake B1, that is, even if the first brake B1 is no longer engaged, the first speed It is possible to set the first to third speeds, and in this way, running in the event of a failure can be ensured.

By the way, in the automatic transmission having the gear train shown in FIG. 3, engine braking can be applied in both the third and fourth gears, and the shifting between these gears is limited to the first gear. This must be achieved by switching the two engaging elements, the clutch C1 and the first brake B1, in a timely manner. Although it is generally difficult to perform a shift in which two engaging elements are switched in this manner with little shift shock and without causing excessive wear of the engaging elements, in the above-mentioned hydraulic control device, the B1 control valve 80 By providing this, it becomes easy to shift between the third speed and the fourth speed, both of which have engine braking.

That is, as shown in FIG. 7, both the second solenoid valve 91 and the fourth solenoid valve 92 are turned on.
In this state, the vehicle is in third speed when driving and fourth speed when being driven. Moreover, these are set by engaging the first one-way clutch F1 or the second one-way clutch F2. Therefore, both the second solenoid valve 91 and the fourth solenoid valve 92 are turned ON, and the state in which the second clutch C2 and the fourth clutch C4 are engaged is changed to
If set temporarily when changing gears between the two speeds, the so-called clutch (brake) to one-way clutch or one-way clutch to
- Clutch (brake) speed change becomes possible, making control easier.

As an example, the case of power-off downshift from 4th gear to 3rd gear will be explained as shown in FIG.
is a flowchart for the shift control, and FIG. 9 is a time chart for the shift control. When there is a shift decision for power-off/downshift at time t1 while driving in 4th gear ("YES" at step 1), ”), performs control to prohibit engine braking (step 2). Specifically, this is control to turn on the fourth solenoid valve 92 and release the first brake B1. As a result, the second one-way clutch F2 engages to fix the sun gear 9 of the second planetary gear mechanism 2, or the first one-way clutch F1 engages to connect the sun gear 9 and the carrier 6. , as shown in FIG. 7, the state is in the third speed when driving and the fourth speed when being driven. That is, in this case, since it is a power-off downshift, the fourth gear is maintained, and the engine braking state in the third gear does not occur.

After that, when a predetermined time has elapsed (
(“Yes” in step 3), and outputs a gear change command (step 4). This is the time point indicated by t2 in FIG. Then, at a time point indicated by t3, the gear shift is started, and a decrease in the input rotational speed is suppressed. Therefore, the end of the shift can be determined from the input rotation speed Ni, the output rotation speed No, and the gear ratio ρ after the shift.Therefore, in step 5, the condition of Ni ≧No×ρ−α (α is a constant) is determined. , and at time t4 when this is satisfied, engine brake permission control is performed (step 6). Specifically, the second solenoid valve 91 is turned off and the first clutch C1 is engaged. As a result, it becomes substantially the third speed.

Note that when performing the control shown in FIG. 8, the engine rotational speed and the rotational speed of other rotating members may be used as determination data in order to determine whether engine braking is permitted.

A brief explanation of the power-on upshift from the third speed to the fourth speed and the power-on downshift from the fourth speed to the third speed is as follows.

FIG. 10 is a time chart for a power-on upshift. When a shift to 4th gear is determined at time t1 while driving in 3rd gear, the first clutch C1 is immediately released. Disable engine braking in 3rd gear. In this case, the third speed state is maintained by engaging the first one-way clutch F1. And t2 when the first one-way clutch F1 is transmitting torque
When a shift command is output at time t3, and immediately after that at time t3, hydraulic pressure is supplied to the first brake B1 to start shifting, the first one-way clutch F1 loses torque and the first brake B1 is almost completely engaged. By doing so, the fourth speed is achieved.

FIG. 11 is a time chart in the case of power-on downshift. When it is determined at time t1 while driving in 4th gear to shift to 3rd gear due to an increase in throttle opening, the shift to 3rd gear is immediately performed. Brake B1 is released to prohibit engine braking in third gear, and immediately after that, at time t2, a shift command is output, and at time t3, shift is started, and the second
The first clutch C1 is engaged after the shift end time t4, when the sun gear 9 and the carrier 6 of the planetary gear mechanism 2 reach approximately the same rotational speed and the first one-way clutch F1 engages to transmit torque. to enable engine braking.

Although the above embodiment has been described with reference to an automatic transmission equipped with the gear train shown in FIG. 3, the present invention is not limited to the above embodiment, and may be applied to other gear trains. It is also possible to implement the automatic transmission with the automatic transmission.

Further, the B1 control valve of the present invention may be similar to that shown in the above embodiment in terms of function.

[0069]

[Effect of the invention] As is clear from the above explanation, claim 1
According to the invention described in , a control valve provided successively to the switching valve engages and releases one of the two engaging elements whose hydraulic pressure supply/discharge state is simultaneously switched by the switching valve. Since it is possible to control the relative engagement and release timing of these two engaging elements, it is possible to arbitrarily adjust the relative engagement and release timing of these two engaging elements, and as a result, it is possible to prevent double lock and the accompanying shift shock, and perform smooth gear shifts. .

Further, in the invention set forth in claim 2, since the control valve is provided on the side of the engagement element that is engaged to set the high speed gear, a plurality of low speed gears can be set even when the control valve fails. Therefore, failsafe can be established.

[Brief explanation of the drawing]

FIG. 1 is a hydraulic circuit diagram showing a part of an embodiment of the present invention.

FIG. 2 is a hydraulic circuit diagram showing other parts of this embodiment.

FIG. 3 is a skeleton diagram showing an example of a gear train targeted in an embodiment of the present invention.

FIG. 4 is an engagement operation table for setting each gear stage.

FIG. 5 is an engagement operation table including ON/OFF states of each solenoid valve in each shift range.

FIG. 6 is a time chart for explaining double lock.

FIG. 7 is a table showing ON/OFF combinations of the second solenoid valve and the fourth solenoid valve and the gear stages set accordingly.

FIG. 8 is a flowchart for explaining control for prohibiting engine braking when powering off and downshifting from fourth speed to third speed.

FIG. 9 is a time chart when the control shown in FIG. 8 is performed.

FIG. 10 is a time chart during power-on upshift from third speed to fourth speed.

FIG. 11 is a time chart for a power-on downshift from 4th speed to 3rd speed.

[Explanation of symbols]

70 3-4 shift valve 80　B1　Control valve C1 1st clutch B1 1st brake

Claims (2)

[Claims] [Claim 1] A plurality of engagement elements whose engagement and disengagement are controlled by hydraulic pressure, and a gear train that is set to a plurality of gear stages according to the combination of engagement and disengagement of these engagement elements. A hydraulic control device for an automatic transmission equipped with a switching valve that simultaneously switches the supply and discharge state of hydraulic pressure to two engaging elements, and engagement of one of the oil passages from the switching valve to the two engaging elements. A hydraulic control device for an automatic transmission, comprising a control valve that is interposed in an oil path leading to the element and controls supply and discharge of hydraulic pressure to the one engagement element. 2. The one of the two engagement elements is an engagement element that is engaged to set a high speed stage, and the other of the two engagement elements is an engagement element that is engaged to set a high speed stage. Claim 1, wherein is an engagement element that is engaged to set a low speed gear that has a larger gear ratio than the high speed gear.
A hydraulic control device for an automatic transmission described in .