JP3299011B2 - Hydraulic control device for automatic transmission - Google Patents

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 an automatic transmission, and more particularly, to an automatic hydraulic device which is set so as to reduce a shock at the time of shifting by adjusting a fastening hydraulic pressure to a friction element which is fastened at a predetermined shifting. The present invention relates to a hydraulic control device for a transmission.

[0002]

2. Description of the Related Art Generally, an automatic transmission mounted on an automobile combines a torque converter and a transmission mechanism, and switches a power transmission path of the transmission mechanism by selective operation of a plurality of friction elements such as clutches and brakes. The automatic transmission is configured to automatically shift to a predetermined gear. This type of automatic transmission is provided with a hydraulic control circuit that controls supply and discharge of hydraulic pressure to actuators of the friction elements.
The hydraulic control circuit includes, for example, a regulator valve that adjusts the discharge pressure of an oil pump to a predetermined line pressure, a manual valve that switches a range by manual operation, and an oil passage that operates according to an operation state and communicates with each of the actuators. A plurality of shift valves that selectively actuate a plurality of friction elements by switching are provided.

[0003] An optimal hydraulic pressure for the engagement is supplied as an engagement hydraulic pressure (an engagement pressure) to a friction element that is engaged during each gear shift, but is engaged at a low shift speed where a vehicle traveling load is large. In the case of such a friction element, a high oil pressure is supplied as the engagement pressure in order to correspond to the above-mentioned vehicle running load.

[0004] For example, when an engine brake is required at a time of running on a steep slope or at a low speed, L
When the automatic shift is performed from the second gear of the range to the first gear of the L range, or when the gear is manually shifted from the D range or the S range to the L range by manual shift, a low reverse brake engaged at the first gear of the L range is used. No.

[0005] However, when the friction element is fastened with such a high fastening pressure, an increase in a shock at the time of gear shifting (shift shock) accompanying a so-called hydraulic pressure change is brought about.

Therefore, Japanese Patent Laid-Open Publication No. 4-59 discloses a first method.
The on-off timing control valve adjusts the hydraulic pressure supplied to the friction element that is engaged at high speed, and turns off the control valve at the time of shifting, so that the hydraulic pressure is supplied after the shift is completed, compared with the high hydraulic pressure supplied for maximum torque transmission. There is disclosed a hydraulic pressure control device that suppresses a shock generated at the first speed shift by making a hydraulic pressure set low act as a so-called shelf pressure and completing engagement of a friction element during the supply of the shelf pressure.

[0007]

However, in the apparatus disclosed in the above publication, the supply of shelf pressure is controlled by an on / off timing control valve, so that the shelf pressure set to a certain fixed value acts on the friction element. In this case, control is performed only on whether or not to perform the operation. In this case, the following inconvenience may occur.

That is, if the shelf pressure is set to a value that can cope with the engine braking in a state where the vehicle speed is high (ie, when the input torque to the friction element is large) (ie, the oil pressure is increased), When the vehicle speed is low (that is, when the input torque is low), the shelf pressure becomes unnecessarily high with respect to the input torque, and a shock occurs at the time of fastening. On the contrary, when the shelf pressure is reduced, the vehicle speed decreases. If it is large, the time required for fastening is extended, and the shift feeling is degraded. Therefore, it is impossible to simultaneously solve the engagement shock and the feeling of the shift time during the shift.

To solve the above problem, it is conceivable to variably control the shelf pressure of the hydraulic pressure supplied to the friction element based on, for example, the vehicle speed. However, in order to precisely control the pressure regulation level in such a manner, components such as a duty solenoid valve must be newly provided, and the hydraulic control circuit becomes complicated.

In view of the above, an object of the present invention is to provide a new valve and other components in order to address the above-mentioned problem in the hydraulic control device for an automatic transmission that adjusts the hydraulic pressure for engaging a friction element to be engaged during a predetermined gear shift. An object of the present invention is to solve the above-mentioned problem by using the existing apparatus without any problem.

[0011]

That is, the invention of claim 1 of the present application (hereinafter referred to as a first invention) is a torque converter.
And a speed change mechanism, and the power transmission
The path is switched by the selective operation of multiple friction elements
A hydraulic control device for an automatic transmission configured to automatically shift to a first gear, wherein an engine brake is actuated.
A first friction element that is engaged when shifting to a lower gear stage,
A second friction element released during the shift, and a torque converter.
Supply / discharge of engagement pressure to lock-up clutch of motor
Fastening supplied to the switching function and the first friction element changing
A first valve member having a a use hydraulic adjustment function, the
Second adjusting the discharge of the fastening hydraulic pressure from the second friction element
A valve member, and the line pressure regulating solenoid valve for arbitrarily adjust the pressure regulating level of the line pressure by the regulator valve, or the line pressure adjusted by the solenoid valve to supply a control pressure to said second valve member a switching solenoid valve for switching the whether is branched from the supply oil passage of the control pressure to said second valve member, the upper
When a control pressure is supplied to the second valve member by the switching solenoid valve , an oil passage for guiding the control pressure to a control port of the first valve member is provided .
During the above-mentioned gear shifting, the valve member
When the control pressure is guided, the fastening oil is adjusted according to the control pressure.
Adjusting the pressure and supplying the oil pressure to the first friction element.
And features .

The invention of claim 2 of the present application (hereinafter referred to as “second
Invention of) is have you to the first invention, the second valve
When the control pressure is supplied during the shift,
Gradually reduces the discharge of the fastening hydraulic pressure from the second friction element.
It is characterized by performing .

[0013]

[0014]

According to the above arrangement, the following operation can be obtained.

In the first invention, the engine brake is operated.
When adjusting the engagement hydraulic pressure supplied to the first friction element that is engaged during the shift to the low gear speed by the first valve member, the pressure adjustment level of the oil pressure is adjusted to the existing line pressure adjustment. Since the line pressure arbitrarily adjusted by the solenoid valve is used and controlled as the control pressure, an arbitrary pressure adjustment level can be obtained without adding any new components such as a valve. In addition, an existing switching solenoid valve for switching whether or not to supply a control pressure to an existing second valve member that performs independent control separately from the first valve member is used, and the switching is performed to switch the second solenoid valve to the second valve member. When the control pressure is supplied to the first valve member, the control pressure is also supplied to the first valve member via the branch oil passage at the same time. The pressure regulating function of the first valve member can be performed at the time of the above-mentioned shift using parts already arranged in the circuit.

[0016] In addition, the first valve member top Symbol is, engine
It has a pressure regulation function for variably controlling the engagement pressure supplied to the first friction element that is engaged at a low shift speed at which the brake operates, and also has a switching function for supplying and discharging the engagement pressure to and from the lock-up clutch of the torque converter. As a result, in addition to being able to perform the functions required for various controls with one valve member, a precisely adjusted fastening pressure is supplied to the first friction element that is fastened at the shift speed with a large vehicle running load. Therefore, an appropriate shelf pressure according to the vehicle speed or the like can be obtained, so that the shift shock can be effectively reduced and the shift feeling can be improved by optimizing the time required for the engagement.

Further, in the second invention, the engine
When shifting to a low gear position where the rake operates, the second valve
The second friction element is gradually released by the
And

[0018]

Embodiments of the present invention will be described below.

First, the mechanical structure of the automatic transmission according to this embodiment will be described with reference to FIG.
Is a torque converter 20 as a main component,
Transmission mechanism 30 driven by the output of converter 20
And a plurality of friction elements 41 to 46 such as clutches and brakes for switching the power transmission path of the mechanism 30 and one-way clutches 51 and 52. And 1-4 speed in D range, 1-4 speed in S range, 1-2 in L range
Speed and speed are obtained.

The torque converter 20 includes a pump 2 fixed in a case 21 connected to the engine output shaft 1.
2 and the pump 22
A turbine 23 driven between the pump 22 and the turbine 23, and a stator 25 supported by the transmission case 11 via the one-way clutch 24 to perform a torque increasing action; Case 21 above
And a lock-up clutch 26 that is provided between the engine 23 and the turbine 23 and directly connects the engine output shaft 1 and the turbine 23 via the case 21. The rotation of the turbine 23 is output to the transmission 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.
Thereby, the oil pump 13 provided at the rear end of the transmission is driven.

On the other hand, the transmission mechanism 30 is composed of a Ravigneaux type planetary gear device,
A small-diameter small sun gear 31 loosely fitted thereon, and a 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, and a short half of the short pinion gear 33
A long pinion gear 34, the latter half of which meshes with the large sun gear 32, a carrier 35 rotatably supporting the long pinion gear 34 and the short pinion gear 33, and a ring gear 36 meshed with the long pinion gear 34. It is configured.

A forward clutch 41 and a first one-way clutch 51 are interposed between the turbine shaft 27 and the small sun gear 31, and a coast clutch 42 is interposed in parallel with the clutches 41 and 51. A 3-4 clutch 43 is interposed between the turbine shaft 27 and the carrier 35, and the turbine shaft 27 and the large sun gear 3
2, a reverse clutch 44 is interposed. Further, between the large sun gear 32 and the reverse clutch 44, a 2-4 brake 45 which is a band brake for fixing the large sun gear 32 is provided, and between the carrier 35 and the transmission case 11 is provided. The second one-way clutch 5 for receiving the reaction force of the carrier 35
2 and a low reverse brake 4 for fixing the carrier 35
6 are provided in parallel. The ring gear 36 is connected to the output gear 14, and rotation is transmitted from the output gear 14 to left and right wheels (not shown) via a differential device.

Here, the friction elements 41 to 46 such as the above-mentioned clutches and brakes and the one-way clutches 51 and 52 are provided.
Table 1 summarizes the relationship between the operation state and the shift speed.

[0024]

[Table 1] Next, a hydraulic control circuit 60 that supplies and discharges hydraulic pressure to the actuators of the friction elements 41 to 46 will be described with reference to FIG. Here, of the above actuators, 2
The hydraulic actuator 45a of the -4 brake 45 is composed of a servo piston having an apply port 45b and a release port 45c. When the hydraulic pressure is supplied only to the apply port 45b, the 2-4 brake 45 is engaged, and both ports 45b , 45c are released when the hydraulic pressure is not supplied to both ports 45b, 45c and when the hydraulic pressure is supplied to both ports 45b, 45c. Further, the actuators of the other friction elements 41 to 44, 46 are constituted by normal hydraulic pistons and fasten the friction 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 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 speed, and each of the friction elements (actuators) 41 to 4 which are operated according to the shift speed.
The shift valves 63, 64, and 65 of 1-2, 2-3, and 3-4 for supplying and discharging the hydraulic pressure to and from the pump 6 are provided.

The manual valve 62 has an input port e through which line pressure is introduced from the main line 110, and first to fourth output ports a to d. The first and second output ports a and b are connected to the D range and the S range, the first and third output ports a and c are connected to the L range, and the fourth output port d is connected to the R range. ing. And
First to fourth output lines 111 to 114 are connected to the output ports a to d, respectively. The above 1-
2,2-3,3-4 shift valves 63,64,65
Each of the spools is biased to the right in the drawing by a spring (not shown), and pilot ports 63a, 64a, 65a are provided on the right side of these spools.

A first pilot line 115 branched from the main line 110 is connected to the pilot port 63a of the 1-2 shift valve 63.
A second pilot line 116 branched from the first output line 111 is connected to a pilot port 64 a of the three-shift valve 64.
A third pilot line 118 guided from the first pilot line 115 via a line 117 is connected to the pilot port 65a, and the pilot lines 115, 116, First, second, and third solenoid valves 66, 6
7, 68 are provided. These solenoid valves 66 to 68 release the pilot pressure of the pilot ports 63a to 65a when they are ON, respectively, and position the spools of the corresponding shift valves 63 to 65 on the right side in the drawing. Sometimes, pilot lines 115, 116,
Pilot pressure is introduced from 118 to position the spools respectively on the left side.

Here, as shown in FIG. 3, the first, second and third solenoid valves 66-68 for shifting and solenoid valves 90 and 96 for lock-up and bypass control, which will be described later, Controller 200 for controlling operation of second duty solenoid valves 88 and 91
The controller 200 includes a signal from a vehicle speed sensor 201 for detecting the vehicle speed of the vehicle and a throttle opening sensor 2 for detecting the throttle opening of the engine.
02 and a shift position sensor 2 for detecting a position (range) of a shift lever provided in the automatic transmission.
03, a signal from a turbine speed sensor 204 for detecting the turbine speed of the torque converter 20, and a signal from an oil temperature sensor 205 for detecting the oil temperature of the working oil. I have. Then, for each range selected by a shift lever (not shown), the controller 200 controls the solenoids for gear shifting based on a map preset according to the vehicle speed of the vehicle and the throttle opening of the engine. ON / OFF the valves 66-68
Control. As a result, the positions of the spools of the shift valves 63 to 65 are switched, and the oil passages communicating with the friction elements 41 to 46 are selectively communicated.
46 are engaged in the combinations shown in Table 1, and the shift speed is switched according to the operating state. In that case, each shift speed and each solenoid valve 66 in the forward range of D, S, L
Table 2 shows the relationship with ON / OFF combination patterns of ~ 68.
It is set as shown in

[0029]

[Table 2] On the other hand, the first to fourth output lines 111 to 11 connected to the output ports a to d in the manual valve 62, respectively.
4 out of 4, main line 1 in each forward range of D, S, L
Line 1 from the first output line 111 connected to
19 is branched, and this line 119 is used as a forward clutch line, and is led to the forward clutch 41 via the one-way orifice 71. Therefore,
The forward clutch 41 is always engaged in the D, S, and L ranges. The accumulator 72 for buffering when the forward clutch is engaged is connected to the branch line 120 of the forward clutch line 119.

The first output line 111 is connected to
The first solenoid valve 6 is guided to the two-shift valve 63
When 6 is turned on and the spool of the shift valve 63 is located on the right side, it communicates with the servo apply line 121 and reaches the apply port 45b of the servo piston 45a via the one-way orifice 73 and the exhaust pressure control valve 74. Therefore, the first in the D, S, and L ranges
When the solenoid valve 66 is ON, that is, at the second, third, and fourth speeds in the D range, the second, third, and fourth speeds of the S range, and the second speed of the L range, hydraulic pressure (servo apply pressure) is introduced into the apply port 45b. When the hydraulic pressure (servo release pressure) is not introduced into the release port 45c, 2-4
The brake 45 will be engaged. Here, the one-way orifice 73 is set to have a diameter such that the hydraulic oil is appropriately restricted and discharged when the servo apply pressure is discharged. The apply port 45b is connected via a line 122 to a buffer accumulator 75 when the 2-4 brake is engaged.

Here, the exhaust pressure control valve 74 will be described with reference to FIG. 4. The exhaust pressure control valve 74 has a downstream port 74a whose top communicates with the downstream portion 121a of the servo apply line 121.
In FIG. 4, a valve 74b having a U-shaped cross section is slidably inserted in the vertical direction in FIG. 4, and the valve 74b communicates with the upstream portion 121b of the servo apply line 121 by a spring 74c. It is urged to shut off the communication between the relief port 74d and the downstream port 74a. The valve element 74b is provided with an orifice 74e having a large throttle amount at a position facing the downstream port 74a, and an upstream port separately provided with the downstream port 74a via the orifice 74e. It is always in communication with the upstream portion 121b of the servo apply line 121 via 74f.

Therefore, when the servo application pressure is released, the valve body 74b moves downward against the urging force of the spring 74c, thereby causing the downstream port 74a to move downward.
And the relief port 74d are communicated with each other, and the servo apply pressure is promptly discharged. Then, when the servo apply pressure decreases to a set pressure defined by a spring force or the like, the urging force of the spring 74c pushes back the valve element 74b, thereby interrupting the communication between the downstream port 74a and the relief port 74d, Thereafter, the servo apply pressure is gradually discharged through the upstream port 74f by the throttle action of the orifice 74e.

As shown in FIG. 2, the first output line 111 is also led to the 3-4 shift valve 65, and when the third solenoid valve 68 is turned off, the shift valve 6 is turned off.
When the spool No. 5 is located on the left side, it communicates with the coast clutch line 123. The coast clutch line 123 reaches the coast clutch 42 via the coast reducing valve 76 and the one-way orifice 77. Therefore, when the third solenoid valve 68 is OFF in the D, S, L range, that is, when the third solenoid valve 68 is in the D, S range,
The coast clutch 42 is engaged in the second speed of the high speed and the L range.

On the other hand, the main line 110 in the D and S ranges
Are connected to the 2-3 shift valve 64. The line 112 communicates with the 3-4 clutch line 124 when the second solenoid valve 67 is OFF and the spool of the 2-3 shift valve 64 is located on the left side. This line 124 is further connected via a one-way orifice 78 to a 3-4 clutch 4
3 has been reached. Therefore, when the second solenoid valve 67 is OFF in the D and S ranges, that is, in the 3rd and 4th speeds of the D range and the 3rd and 4th speeds of the S range, the 3-4 clutch 4
No. 3 will be concluded. The accumulator 79 for buffering when the 3-4 clutch 43 is engaged is connected to the branch line 125 of the 3-4 clutch line 124.

Here, the 3-4 clutch line 124
The line 126 branched from the 3-4 shift valve 65
When the third solenoid valve 68 is turned off and the spool of the shift valve 65 is located on the left side, it communicates with the servo release line 127 communicating with the release port 45c of the servo piston 45a. Therefore, D,
When both the second and third solenoid valves 67 and 68 are OFF in the S range, that is, in the third speed of the D range and the third speed of the S range, the release port 4 of the servo piston 45a is set.
Servo release pressure is introduced to 5c, 2-4 brake 4
5 is released.

The third output line 1 communicating with the main line 110 in the L range in the manual valve 62
13 is guided to a 1-2 shift valve 63 via a line 151, a one-way orifice 81, a ball valve 82, and a line 128 provided via a low reducing valve 80. When the first solenoid valve 66 is OFF and the spool of the 1-2 shift valve 63 is located on the left side, the line 128 is connected to the low reverse brake line 12 that communicates with the low reverse brake 46.
Communicate with 9. Therefore, when the first solenoid valve 66 is OFF in the L range, that is, at the first speed in the L range, the low reverse brake 46 is engaged.

Further, a fourth output line 114 communicating with the main line 110 in the R range includes a line 130 branched from the line 114, a one-way orifice 83,
1-2 via the ball valve 82 and the line 128
Guided by the shift valve 63, the first solenoid valve 66
Is OFF, and the valve 63 is connected to the low reverse brake line 129 when the spool of the valve 63 is located on the left side. Further, the fourth output line 114 becomes a reverse clutch line 131 and reaches the reverse clutch 44. Therefore, in the R range, when the first solenoid valve 66 is OFF, the low reverse brake 46
Is engaged, while the reverse clutch 44 is always engaged. The one-way orifice 83
A line 132 branched from the line 130 between the ball valve 82 and the ball valve 82 is connected to an accumulator 84 for buffering when the reverse clutch is engaged.

The hydraulic control circuit 60 includes a lock-up clutch 2 in the torque converter 20 shown in FIG.
6. Lock-up shift valve 85 for operating 6
And a lock-up control valve 86 for adjusting the hydraulic pressure supplied to the torque converter 20 via the lock-up shift valve 85.

This lock-up control valve 86
The pilot line 86a at one end of the
A pilot line 133 that is guided from 10 via a solenoid reducing valve 87 is connected, and the pilot line 133 is provided with a first duty solenoid valve 88.

On the other hand, the lock-up shift valve 85
, The relief valve 89 from the regulator valve 61
And a pilot port 85a provided at one end of the shift valve 85 is connected to a pilot line 117 connected to the main line 110 via a line 115.
Is connected. A lock-up solenoid valve 90 is provided on this line 117, and the spool of the lock-up shift valve 85 is located on the left side when the solenoid valve 90 is OFF, so that the torque converter line 135 is The lock-up clutch release line 136 communicates with the lock-up clutch release chamber 26b, thereby completely releasing the lock-up clutch 26 to enter the converter state.

On the other hand, if the solenoid valve 90 is turned on and the spool of the lock-up shift valve 85 moves to the right, the torque converter line 135 communicates with the lock-up fastening line 137 communicating with the lock-up clutch fastening chamber 26a. On the other hand, the lock-up release line 136 communicates with the lock-up control valve 86 via the line 138. The pilot pressure introduced from the pilot line 133 to the pilot port 86 a at one end of the lock-up control valve 86 is adjusted by the first duty solenoid valve 88, so that the engagement pressure guided through the lock-up engagement line 137. And the release pressure guided through the lock-up release line 136 is controlled, and the lock-up clutch 26 is controlled to a completely engaged state or a predetermined slip state.

Here, a control chamber 86 provided at one end of the lock-up control valve 86 on the spring side is provided.
b, a line 160 led from a low reducing valve 80 installed on the third output line 113 is connected, and a control port 80a provided at one end of the low reducing valve 80 has: A line 150 branched from a line 146 leading to a pilot port 94a of the timing valve 94 described later is connected.

A downstream hydraulic pressure (coast clutch pressure) is fed back to one end of the spool to a coast reducing valve 76 which communicates with the coast clutch 42 via the coast clutch line 123. On the other hand, the operation of the second duty solenoid valve 91 for line pressure control generates a throttle modulator pressure corresponding to the engine load, and supplies the throttle modulator pressure to the regulator valve 61 from the throttle modulator valve 92. Rator pressure is introduced via line 139 to the other end of the spool in the reducing valve 76. A line 140 connected to an intermediate portion of the course reducing valve 76 is led to the 2-3 shift valve 64,
When the second solenoid valve 67 is turned on, the shift valve 6
When the spool No. 4 is located on the right side, the main line 11
The line 140 communicates with the line 141 leading to zero. Therefore, the line pressure acts together with the throttle modulator pressure to urge the spool to the right in the drawing. As a result, the coast clutch pressure is increased at the second speed in the L range where the second solenoid valve 67 is turned on, and the shared torque of the coast clutch 42 increases. On the other hand, the second solenoid valve 67
Is turned off, the spool of the 2-3 shift valve 64 moves to the left, and the line 1
The communication state between 40 and line 141 is cut off. As a result, the increased state of the coast clutch pressure at the third speed in the D and S ranges where the second solenoid valve 67 is turned off is suppressed, and the shared torque of the coast clutch 42 is reduced.

In addition to the above configuration, the hydraulic control circuit 6
0 is provided with a 2-3 bypass valve 93 and a timing valve 94 for adjusting the supply / discharge timing of the hydraulic pressure at each shift.

Of these, the 2-3 bypass valve 93 is
The clutch is provided on a bypass line 142 that bypasses the one-way orifice 78 provided on the −4 clutch line 124.
Hydraulic pressure (3-4 clutch pressure) downstream of the one-way orifice 78 is introduced to one end of the spool. A throttle modulator pressure generated by the throttle modulator valve 92 is introduced into the other end of the spool of the bypass valve 93 via a line 143 branched from the line 139. And 3-
When the four-clutch pressure rises above a predetermined pressure and the spool moves to the left, the bypass line 142 is cut off. Therefore, the 3-4 clutch pressure is
At the start of the supply, the supply is promptly performed through the bypass line 142, but thereafter the supply is moderated by the one-way orifice 78, and thus the engagement timing of the 3-4 clutch 43 during the 2-3 shift-up shift is adjusted. The timing is changed according to the throttle opening of the engine. Here, in a line 144 for supplying the throttle modulator pressure to the regulator valve 61, an accumulator 95 for buffering the oil pressure is provided.

On the other hand, the timing valve 94
It is installed on a bypass line 145 that bypasses the one-way orifice 73 on the servo apply line 121 led from the two-shift valve 63 and the exhaust pressure control valve 74. A pilot port 94 a provided at one end of the spool has a pilot line 14 branched from a line 115 leading to the main line 110.
6, and a solenoid valve 96 for bypass control (hereinafter, referred to as a solenoid valve for bypass control) is provided in the line 146. Here, a line 150 branched from the line 146 on the downstream side of the bypass control solenoid valve 96 is connected to the control port 8 provided at one end of the low reducing valve 80.
0a.

On the other hand, in the 2-3 shift valve 64,
A drain port 64b communicating with the 3-4 clutch line 124 when the spool is located on the right side in the drawing is provided, and a first orifice 97 is provided on a first drain line 147 connected to the drain port 64b. Is provided. The second branch branched from the first drain line 147 upstream of the first orifice 97.
The drain line 148 is guided to the timing valve 94 through the second orifice 98, and when the spool of the valve 94 is located on the right side in the drawing, the second drain line 148 is connected to the valve 94. It communicates with the provided drain port 94b. That is, when the second solenoid valve 67 is turned on and the spool of the 2-3 shift valve 64 is located on the right side in the drawing, the 3-4 clutch line 124 communicating with the 3-4 clutch 43 is connected to the first drain line 147. Communicate. Therefore, the 3-4 clutch pressure is applied to the first orifice 9 on the first drain line 147.
Due to the throttle action of 7, the pressure is gradually released. On the other hand, in this state, when the bypass control solenoid valve 96 is turned on to move the spool of the timing valve 94 to the right side in the drawing, the first drain line 147
Is connected to the timing valve 9 through the second drain line 148.
Since the communication with the fourth drain port 94b is made, the above-mentioned 3-4 clutch pressure is rapidly discharged.

Next, the characteristic portion of the present invention in the hydraulic control circuit will be described with reference to FIG.

FIG. 4 shows the state of each valve at the second speed in the D range (or S range). In this state, the first solenoid valve 66 is ON and the spool of the 1-2 shift valve 63 is located on the right side in the drawing. Accordingly, the line 111 communicates with the line 121 and the apply port 45b of the 2-4 brake (servo piston) 45
Servo apply pressure is supplied to the 2-4 brake 45
Is in the fastened state.

The lock-up solenoid valve 9
0 is OFF at this time, and the spool of the lock-up shift valve 85 is located on the left side,
Converter line 135 is lock-up release line 13
6, the converter line pressure is supplied to the release chamber 26b of the lock-up clutch 26, and the lock-up clutch 26 is in a completely released state (converter state).

When shifting down from the second gear to the first gear, the first solenoid valve 66 is used.
Is turned off, control pressure is introduced into the pilot port 63a of the 1-2 shift valve 63 via the line 115, and the spool of the shift valve 63 moves to the left side in the drawing. Therefore, the line 121 communicates with the drain port 63b of the 1-2 shift valve 63, so that
The servo apply pressure is discharged from the apply port 45b of the 4 brake 45, and the brake 45 is released.

At this time, one of the D range or S range
In the case of downshifting to the high speed, the solenoid valve 96 for bypass control is turned ON, the control pressure is discharged from the control port 94a of the timing valve 94, and the spool of the valve 94 is located on the right side. And the servo apply pressure passes through the bypass line 145 via the line 121 and the 1-2 shift valve 6.
3 is quickly discharged from the drain port 63b. That is, since the downshift from the second speed to the first speed in the D range or the S range is generally performed during acceleration, responsiveness is required, and the servo apply pressure is rapidly increased to promptly release the 2-4 brake 45. To be discharged. When the shift operation to the first speed is completed, the bypass control solenoid valve 96 is turned off, and control pressure is introduced into the control port 94a of the timing valve 94 to prepare for the next shift operation.

On the other hand, when the downshift to the first speed is a downshift to the first speed in the L range for operating the engine brake, the bypass control solenoid valve 96 is held in the OFF state. You. Accordingly, the control pressure is supplied to the control port 94a of the timing valve 94, and the spool of the valve 94 is maintained at the left side as shown in the figure, and the bypass line 145 is cut off by the valve 94. , Thereby increasing the servo apply pressure to the servo apply line 12
1 and the exhaust pressure control valve 74 provided on the line and the one-way orifice 73 are guided to the drain port 63b of the 1-2 shift valve 63, and the 2-4 brake 45 is gradually released. .

When the bypass control solenoid valve 96 is turned off as described above, the line pressure guided from the main line 110 via the line 115 is applied via the line 146 to the control port 94a of the timing valve 94. At the same time as the control pressure, and is also supplied to a control port 80a provided at one end (the right end in FIG. 4) of the low reducing valve 80 via a line 150 branched from the line 146.

The low reducing valve 80 is balanced by the control pressure supplied to the control port 80a and the spring force for urging the spool in a direction opposite to the control pressure (rightward in FIG. 4). Third output line 11
The working pressure introduced from 3 is adjusted and output on line 151. The adjusted operating pressure is supplied to the 1-2 shift valve 63 via the ball valve 82 and the line 128.
At this time, since the spool of the shift valve 63 has already moved to the left,
8 communicates with the line 129 so that the operating pressure is supplied to the low reverse brake 46 via the line 129.

As a result, the low reverse brake 46 is engaged to shift down to the first speed in the L range where the engine brake operates.
The engagement pressure supplied to the low reverse brake 46 is adjusted by the low reducing valve 80 to a hydraulic pressure corresponding to the control pressure supplied to the control port 80a of the valve 80. At this time, since the line pressure adjusted by the regulator valve 61 is supplied to the control port 80a as the control pressure via the line 110, the line 115, and the line 150, the engagement pressure with respect to the low reverse brake 46 becomes Regulator valve 6
The hydraulic pressure is set according to the line pressure adjusted in step 1.

The line pressure is, as described above, the throttle modulator pressure generated by the throttle modulator valve 92 in accordance with the duty ratio of the second duty solenoid valve 91 for line pressure control. , Is regulated by being supplied to the regulator valve 61 via the line 144, so that the engagement pressure supplied to the low reverse brake 46 is electrically controlled by the control of the second duty solenoid valve 91. The Rukoto.

Next, the control of the solenoid valve 96 for bypass control and the second duty solenoid valve 91 performed by the controller 200 shown in FIG. 3 will be described with reference to FIGS.
This will be specifically described with reference to FIG.

First, based on FIG.
The control of the solenoid valve 96 for bypass control will be described. In step S1, it is determined whether or not a downshift to the first speed is performed. If YES, the downshift to the first speed in the L range is further performed in step S2. It is determined whether or not a shift is performed. If it is a downshift to the first speed in the L range, the solenoid valve 96 for bypass control is turned off in step S3. As a result, the timing valve 94 shuts off the bypass line 145,
The servo apply pressure is gradually discharged from the apply port 45b, and the 2-4 brake 45 is gradually released.

On the other hand, if it is determined in step S2 that the downshift is not the downshift to the first speed in the L range, the bypass control solenoid valve 96 is turned ON for a fixed time (t).
First, in step S4, a timer value (t) for turning on the valve 96 is read. The timer value (t) is a value set in advance based on the oil temperature, for example, as shown in FIG. 6, and is input to the controller 200 from the oil temperature sensor 205 that detects the oil temperature of the hydraulic oil. This is a value obtained by applying the temperature signal to the oil temperature map shown in FIG. As is clear from the map, as the oil temperature increases, the valve 96 is turned on.
The timer value (t) to be set to N is set to be small.

Then, in the next step S5, the solenoid valve 96 for bypass control is turned ON for the predetermined time (t).
By setting N, the bypass line 145 communicates,
As a result, the servo apply pressure is quickly discharged, and the 2-4 brake 45 is released quickly. At this time, as the temperature of the hydraulic oil increases, the fluidity of the hydraulic oil increases, and the discharge speed of the hydraulic oil increases compared to when the temperature is low. Therefore, as shown in FIG. By setting the time during which the valve 96 is turned on to be short, the discharge amount of the servo apply pressure from the apply port 45b can be adjusted. afterwards,
When the predetermined time is over, the solenoid valve 96
Is turned off to prepare for the next shift operation.

Next, based on FIG.
The control of the second duty solenoid valve 91 by 0 will be described. First, at step S1, the L range 1
It is determined whether or not the shift to the high speed is being performed. If NO, the adjustment of the engagement pressure supplied to the low reverse brake 46 is not performed. Here, the line pressure in the normal state is, for example, based on a map set in advance according to, for example, the throttle opening, the vehicle speed, the turbine speed, and the like.
It is read by applying a signal from the throttle opening sensor 202, a signal from the vehicle speed sensor 201, a signal from the turbine speed sensor 204, and the like input to the controller 200.

On the other hand, during the shift to the first speed in the L range, the engagement pressure supplied to the low reverse brake 46 is adjusted. At that time, in step S3, it is further determined whether or not the throttle opening θ is equal to or smaller than a predetermined value θo. Here, the predetermined value θo is an opening corresponding to fully closed or almost fully closed. And the throttle opening θ
Is less than or equal to the predetermined value θo, that is, when deceleration is required and engine braking is required, in step S4, the line pressure (PL) is read using the shift line pressure map (A). Here, the shift-time line pressure map (A) is, for example, as shown in FIG.
By applying a vehicle speed signal input from the vehicle speed sensor 201 for detecting the vehicle speed of the vehicle to the controller 200 to the map in a map in which the line pressure is set in advance based on the vehicle speed, the shift to the first speed in the L range is performed. And determines the line pressure when the throttle opening θ is equal to or less than a predetermined value θo.

As is apparent from the map shown in FIG. 8, the read line pressure is set higher as the vehicle speed increases. Therefore, when the input torque to the low reverse brake based on the inertia of the vehicle body is large, a high oil pressure shelf pressure corresponding to the input torque is obtained, and the time required for fastening is not extended more than necessary. On the other hand, when the vehicle speed is low and the input torque based on the vehicle body inertia is low, the shelf pressure is set low, so that the occurrence of a shock at the time of engagement is suppressed.

If it is determined in step S3 that the throttle opening .theta. Is equal to or greater than the predetermined value .theta.o, then in step S5 the line pressure (P) is determined using the shifting line pressure map (B).
L) is read. Here, the shift line pressure map (B) is a map in which the line pressure is set in advance based on the throttle opening θ as shown in FIG. 9, for example, and is a throttle opening sensor 202 for detecting the throttle opening. By applying the throttle opening signal input from the controller 200 to the controller 200 to the map, during the shift to the first speed in the L range and when the throttle opening θ is equal to or greater than the predetermined value θo, This is to determine the line pressure in the case of a gear shift accompanying the depression.

The map shown in FIG. 9 is also set so that the read line pressure increases as the throttle opening θ increases. Therefore, based on the engine output, the engagement pressure is variably controlled according to the magnitude of the torque input to the low reverse brake, and as a result, the extension of the time required for engagement is avoided, and the shock during engagement is reduced. .

As described above, the line pressure (P) read in step S2, step S4 or step S5 is read.
In step S6, the duty ratio of the second duty solenoid valve 91 is determined based on L).
At this time, when controlling the position of the spool of the regulator valve 61 so that the line pressure to be adjusted by the regulator valve 61 becomes the line pressure read in each step S2, S4 or S5, the valve 61 is controlled via the line 144. While the throttle model Interview <br/> regulator pressure as the control pressure supplied becomes possible to adjust the throttle model Interview Retabarubu 92, the adjustment of the throttle model Interview regulator pressure, the duty ratio of the second duty solenoid valve 91 Is electrically 0% (for example, completely OFF)
To 100% (for example, complete ON).

As described above, the adjustment of the engagement pressure supplied to the low reverse brake is variably controlled by the vehicle speed or the throttle opening. FIG. 10 shows a change over time of the engagement pressure supplied to the low reverse brake during the shift to the first speed in the L range.

For example, at a certain vehicle speed or throttle opening, the fastening pressure changes as shown by the solid line. At this time, if the shelf pressure is at the hydraulic pressure Po and the vehicle speed or the throttle opening is larger than this, As is clear from FIG. 8 or FIG. 9, the read line pressure increases and the shelf pressure increases to the high pressure side (oil pressure P1) (indicated by the two-dot chain line). On the other hand, when the vehicle speed or the throttle opening decreases, the line pressure is read low and the shelf pressure drops to the low pressure side (oil pressure P2) (indicated by the two-dot chain line).

[0070]

As described above, according to the present invention, the pressure regulation level of the fastening pressure supplied at the time of fastening a certain friction element is determined as follows.
Since the variable control is performed in accordance with the vehicle speed or the throttle opening during shifting, a fastening operation suitable for the magnitude of the torque applied to the friction element during shifting is performed, and shift shock and extension of shift time are avoided, and pressure regulating level of the engagement pressure, so carried out by the existing line pressure regulating solenoid valve the discharge pressure to vacuum controller from the oil pump, necessary to add a new de Interview Ti controller parts such as the hydraulic circuit There is no.

When a control pressure for variable control is supplied to or discharged from a valve member for supplying the engagement pressure, an existing switching solenoid valve is used. The above control can be performed without providing a component such as a switching valve.

Further , in the present invention, the pressure regulating function for variably controlling the engagement pressure supplied to the friction element and the switching function for supplying and discharging the engagement pressure to and from the lock-up clutch are performed by one valve member. Simplifies the hydraulic control circuit of the vehicle, and supplies a fastening pressure that is precisely reduced and adjusted to a friction element that is fastened at a shift speed with a large vehicle running load. good Ri resulting effect is further increased.

Further, in the present invention, when performing variable control of the engagement hydraulic pressure, that is, when the control pressure is supplied from the switching solenoid valve, the existing timing valve which is ON / OFF controlled by the switching solenoid valve is used. The control pressure is supplied to the control valve. In other cases, independent control as the original timing valve can be performed by turning on and off the control pressure, so that the independent controls do not interfere with each other. Smooth control can be performed.

[Brief description of the drawings]

FIG. 1 is a skeleton diagram of an automatic transmission according to an embodiment.

FIG. 2 is a circuit diagram illustrating a hydraulic control circuit of the automatic transmission according to the embodiment.

FIG. 3 is a control system diagram for each valve in the hydraulic control circuit of FIG. 2;

FIG. 4 is an enlarged view of a main part of a hydraulic control circuit during a 2-1 shift.

FIG. 5 is a flowchart illustrating release control of a 2-4 brake by a solenoid valve for bypass control in the embodiment.

FIG. 6 is an explanatory diagram of a map used in the control.

FIG. 7 is a flowchart illustrating variable control of low reverse brake pressure by a second duty solenoid valve in the embodiment.

FIG. 8 is an explanatory diagram of a map used in the control.

FIG. 9 is an explanatory diagram of a map similarly used in the control.

FIG. 10 is a time chart showing a change in low reverse brake pressure in the embodiment.

[Explanation of Signs] 45 2-4 brake ( second friction)
Friction element ) 46 low reverse brake (first friction element) 80 low reducing valve (first valve)
91 ) 2nd duty solenoid valve (line)
Pressure regulating solenoid valve) 94 data Imingubarubu (second valve member) 96 bypass control solenoid valve (switching
Solenoid valve) 150 Branch line (branch oil passage)

────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Hiroshi Takada 3-1 Shinchi, Fuchu-cho, Aki-gun, Hiroshima Prefecture Inside Mazda Co., Ltd. (56) References JP-A 1-176841 (JP, A) (58) Survey Field (Int.Cl. ⁷ , DB name) F16H 61/00-61/24

Claims (2)

(57) [Claims] 1. A combination of a torque converter and a speed change mechanism.
And the power transmission path of the transmission mechanism is selected from a plurality of friction elements.
Automatically shifts to a predetermined gear by switching by selective operation
A hydraulic control device for an automatic transmission configured to perform a shift to a low shift speed where an engine brake operates.
A first friction element to be fastened and a second friction element
2 friction element and torque converter lock-up
Switching function for switching the supply and discharge of the fastening pressure to the
A first valve member having a function of adjusting a hydraulic pressure for fastening supplied to the first friction element;
A second valve member for adjusting the discharge of consolidating hydraulic, and line pressure regulating solenoid valve for arbitrarily adjust the pressure regulating level of the line pressure by the regulator valve, the line pressure adjusted by the solenoid valve a second of the switching solenoid valve for switching whether to supply a control pressure to the valve member, is branched from the supply oil passage of the control pressure to said second valve member, the switching solenoid Bal
When the control pressure to the second valve member is supplied and the oil passage for guiding the control pressure to the control port of the first valve member is provided by blanking, said first valve member, said variable
When the control pressure is guided through the branch oil passage at speed
Adjusts the fastening hydraulic pressure according to the control pressure, and raises the hydraulic pressure.
A hydraulic control apparatus for an automatic transmission, wherein the hydraulic control apparatus supplies the first friction element . The second valve member is configured to move upward during the speed change.
When the control pressure is supplied, the tightening from the second friction element is performed.
The hydraulic control device for an automatic transmission according to claim 1, wherein the hydraulic pressure is gradually discharged .