JP3446543B2 - Transmission 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 device for controlling a gear shift in an automatic transmission for a vehicle, and more particularly to a device for controlling a gear shift stage in which an engine brake is effective.

[0002]

2. Description of the Related Art In a general automatic transmission for a vehicle, a one-way clutch is engaged in setting the middle and low speed stages in order to facilitate a shift. Therefore, in these middle and low speed stages, the one-way clutch is released in the coast state in which the direction in which the torque is applied reverses, and the torque cannot be transmitted by the one-way clutch. The multi-disc brake or clutch is engaged during coasting so that the engine brake works.

Conventionally, in order to apply the engine braking in the middle and low speed stages, the shift lever is operated to select the engine braking range, and the manual valve is switched accordingly, so that the friction for applying the engine braking is obtained. The hydraulic pressure is supplied to the engagement device (that is, the coast brake). On the other hand, recently, by electrically controlling the solenoid valve,
Automatic transmissions that are configured to engage the coast brake as needed have become available. That is, in this type of so-called electronically controlled automatic transmission,
The shift range can be switched electrically.

A vehicle capable of so-called uphill / downhill control has been put into practical use by utilizing a function capable of electrically switching such a shift range. This is to detect an uphill condition or a downhill condition based on the condition of engine load or output demand such as throttle opening and the actual driving condition such as acceleration of the vehicle, and perform an upshift to a predetermined gear or higher. This is a control that prohibits the engine braking and also applies the engine braking at a predetermined medium and low speed. According to such control, a relatively large gear ratio is maintained without upshifting even if the vehicle speed increases to some extent when climbing a slope.
The lack of driving force can be avoided in advance. In addition, when the vehicle is descending a slope, the engine brake can be applied with a relatively large gear ratio without performing a range switching operation, so that smooth running is possible.

However, since the engine braking state at the middle and low speed stages in the above-described automatic transmission is set by electrical control, the engine braking can be activated when an electrical failure such as a solenoid valve occurs. Therefore, the above-mentioned uphill / downhill control is substantially not established.

Conventionally, there has been developed a device configured so that the engine brake state can be set even if an electric failure of a control system for applying the engine brake occurs, and an example thereof is described in Japanese Patent Laid-Open No. 3-113161. Has been done. In the device described in this publication, a solenoid valve that adjusts the hydraulic pressure supplied to the coast brake is connected to a solenoid valve whose signal pressure becomes the maximum pressure in the off state, while the hydraulic pressure that opposes the signal pressure is controlled by another control system. It is configured to be supplied to the pressure regulating valve from. Therefore, even if the solenoid valve goes off-fail and the maximum signal pressure continues to be output,
The oil pressure that opposes the signal pressure can set the pressure adjustment level of the oil pressure of the coast brake to a predetermined value, so that the coast brake can be engaged to bring the engine brake state.

[0007]

SUMMARY OF THE INVENTION In an automatic transmission constructed so that the engine braking state is directly set by electric means, if an abnormality occurs in the electric means, the engine braking state at the gear stage is immediately set. Becomes impossible. Further, as described in the above publication, in an automatic transmission configured to set the engine braking state by electric means such as a solenoid valve and the hydraulic pressure of another hydraulic system, a failure of the electric means causes the engine to immediately stop. Although the braking state does not become impossible, the signal pressure becomes the maximum pressure due to the failure as described above, and the hydraulic pressure of other hydraulic systems is opposed to this, so the pressure regulation level of the coast brake is lowered, and the coast brake is lowered. The engagement pressure of becomes low. That is, the torque capacity of the coast brake becomes insufficient, and it becomes difficult to apply sufficient engine braking.

As described above, in the related art, a situation may occur in which the engine brake cannot be activated due to an electrical failure or the like. Further, in an automatic transmission in which the gear stage is set by electrical control, it may be impossible to set the gear stage in which engine braking works due to electrical failure. In this case, there is a disadvantage that uphill slope control described above can not stand Ri substantially formed.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a shift control device capable of preventing a situation in which an engine brake state cannot be set due to a failure. is there.

[0010]

In order to achieve the above object, the present invention is based on the running state of a vehicle.
To prevent or suppress upshifts,
In the shift control device of the automatic transmission to perform control to twist down brake, determine the establishment of the condition for executing the control
The first judging means for refusing and the first judging means
Turn on the engine braking after determining that the conditions have been established.
And failure determination means for determining that you can not set the intermediate gear stage in a state that, if the fail decision means has determined that you can not set the previous Symbol intermediate shift gear, the intermediate gear stage
The shift speed at which the engine brake on the
Execution means for executing the control by using as an alternative to the speed stage
Ru der which is characterized in that it comprises. Also this
According to the invention, as described in claim 2, the above control is performed.
Is determined by judging whether the vehicle is climbing or descending.
It is possible to perform uphill / downhill control that limits the high-speed stage.

Therefore, according to the gear shift control device of the present invention, if the gear stage where the engine braking is selectively set based on the traveling state cannot be set due to the occurrence of the failure, the gear shift speed is higher than that gear stage. The gear stage where the engine braking on the gear side is effective is selectively set based on the running state. Despite Therefore engine braking state is required, can be prevented a situation such as shift stage ineffective engine braking by failure is set, the operation by the time of uphill slope, to ensure error emissions Gin brake state It is possible to avoid a shift operation by a person and improve drivability.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Next, the present invention will be described with reference to specific examples shown in the drawings. First, the overall control system will be described. In FIG. 2, an engine 2 to which the automatic transmission 1 is connected has an intake pipe line 3 having a main throttle valve 4 and a sub-throttle valve 5 located upstream thereof. The main throttle valve 4 is connected to an accelerator pedal 6 and is opened / closed according to the amount of depression of the accelerator pedal 6. The sub-throttle valve 5 is adapted to be opened and closed by a motor 7.
An electronic control unit (E-ECU) 8 for an engine for controlling the motor 7 for adjusting the opening of the sub-throttle valve 5 and for controlling the fuel injection amount and ignition timing of the engine 2 is provided. There is. The electronic control unit 8 includes a central processing unit (CPU) and a storage device (R).
AM, ROM) and an input / output interface, and the electronic control unit 8 has engine (E / G) rotation speed N, intake air amount Q, intake air temperature as data for control. Various signals such as throttle opening, vehicle speed, engine water temperature, and signals from the brake switch are input.

The gear shift, lockup clutch and line pressure in the automatic transmission 1 are controlled by the hydraulic control device 9. The hydraulic control device 9 is configured to be electrically controlled, and also has first to third shift solenoid valves S1 to S for executing a shift.
3. A linear solenoid valve SLT for controlling the line pressure, a linear solenoid valve SLN for controlling the back pressure of the accumulator, and a linear solenoid valve SLU for controlling the lockup clutch are provided.

An electronic control unit (T-ECU) 10 for an automatic transmission that outputs signals to these solenoid valves to control gear shift, line pressure, accumulator back pressure, etc.
Is provided. This automatic transmission electronic control unit 10
Is a central processing unit (CPU) and a storage device (RA
M, ROM) and an input / output interface, and the electronic control unit 10 has a throttle opening, a vehicle speed, an engine water temperature, a signal from a brake switch, a shift position, as data for control.
Signal from the pattern select switch, signal from the overdrive switch, signal from the C0 sensor that detects the rotational speed of the clutch C0, which will be described later, signal from the vehicle speed sensor, oil temperature of the automatic transmission, signal from the manual shift switch, etc. Has been entered. The electronic control unit 10 for the automatic transmission and the electronic control unit 8 for the engine are connected to each other so that data communication is possible, and the electronic control unit 8 for the engine is connected to the electronic control unit 10 for the automatic transmission. A signal such as the intake air amount per rotation (Q / N) is transmitted, and the electronic control unit 10 for the automatic transmission transmits to the electronic control unit 8 for the engine the same as the instruction signal for each solenoid valve. A signal and a signal for instructing the shift speed are transmitted.

That is, the electronic control unit 10 for the automatic transmission
On the basis of the input data, determines the gear position, the lock-up clutch on / off, the line pressure adjustment level, etc., and outputs an instruction signal to a predetermined solenoid valve based on the determination result. It is designed to judge the failure and control it. The engine electronic control unit 8 controls the fuel injection amount, the ignition timing, the opening degree of the sub-throttle valve 5 and the like on the basis of the input data, and also controls the fuel injection amount at the time of shifting in the automatic transmission 1. The output torque is temporarily reduced by reducing the amount, changing the ignition timing, or narrowing the opening of the sub-throttle valve 5.

FIG. 3 is a diagram showing an example of a gear train of the automatic transmission 1 described above, and in the configuration shown here, it is configured to set five forward gears and one reverse gear. That is, the automatic transmission 1 shown here has the torque converter 30.
And a sub-transmission unit 31 and a main transmission unit 32. The torque converter 30 includes a lockup clutch 33.
The lock-up clutch 33 has a front cover 35 that is integrated with the pump impeller 34.
A member (hub) 3 in which the turbine runner 36 and the turbine runner 36 are integrally attached.
It is provided between 7 and. An engine crankshaft (not shown) is connected to a front cover 35, and a turbine runner 36 is connected to an input shaft 38.
Is connected to the carrier 30 of the overdrive planetary gear mechanism 39 that constitutes the auxiliary transmission unit 31.

The carrier 4 in this planetary gear mechanism 39
A multi-plate clutch C0 and a one-way clutch F0 are provided between 0 and the sun gear 41. The one-way clutch F0 is engaged when the sun gear 41 rotates forward relative to the carrier 40 (rotates in the rotation direction of the input shaft 38). Further, a multi-plate brake B0 for selectively stopping the rotation of the sun gear 41 is provided.
The ring gear 4 which is an output element of the sub transmission unit 31
2 is connected to the intermediate shaft 43 which is an input element of the main transmission unit 32.

Therefore, in the sub-transmission unit 31, the entire planetary gear mechanism 39 rotates integrally with the multi-plate clutch C0 or the one-way clutch F0 engaged, so that the intermediate shaft 43 has the same speed as the input shaft 38. It will rotate at low speed. Further, in the state where the brake B0 is engaged and the rotation of the sun gear 41 is stopped, the ring gear 42 is accelerated to the normal rotation with respect to the input shaft 38, and the high speed stage is established.

On the other hand, the main transmission unit 32 is provided with three sets of planetary gear mechanisms 50, 60, 70, and their rotating elements are connected as follows. That is, the sun gear 51 of the first planetary gear mechanism 50 and the sun gear 61 of the second planetary gear mechanism 60 are integrally connected to each other, and the ring gear 53 of the first planetary gear mechanism 50 and the carrier 62 of the second planetary gear mechanism 60 are connected. The third planetary gear mechanism 70 and the carrier 72 are connected to each other, and the carrier 72 is connected to the output shaft 80. Further, the ring gear 63 of the second planetary gear mechanism 60 is connected to the sun gear 71 of the third planetary gear mechanism 70.

In the gear train of the main transmission unit 32, a reverse gear and four gears on the forward side can be set, and a clutch and a brake therefor are provided as follows. First, the clutch will be described. The ring gear 63 and the third gear of the second planetary gear mechanism 60 which are connected to each other.
A first clutch C1 is provided between the sun gear 71 of the planetary gear mechanism 70 and the intermediate shaft 43, and the sun gear 51 of the first planetary gear mechanism 50 and the sun gear 61 and the intermediate shaft of the second planetary gear mechanism 60 are connected to each other. A second clutch C2 is provided between the first clutch 43 and the second clutch C2.

Next, the brake will be described. The first brake B1 is a band brake, and the sun gears 51 and 6 of the first planetary gear mechanism 50 and the second planetary gear mechanism 60 are used.
It is arranged to stop the rotation of 1. A first one-way clutch F1 and a second brake B2, which is a multi-disc brake, are arranged in series between the sun gears 51 and 61 (that is, the common sun gear shaft) and the casing 81. One way clutch F1 is sun gear 41,5
1 engages when it tries to rotate in the reverse direction (rotation in the direction opposite to the rotation direction of the input shaft 38). The third brake B3, which is a multi-disc brake, is the first planetary gear mechanism 5
It is provided between the zero carrier 52 and the casing 81. Then, as a brake for stopping the rotation of the ring gear 73 of the third planetary gear mechanism 70, the fourth brake B4 and the second one-way clutch F2, which are multi-plate brakes, are provided in the casing 8.
It is arranged in parallel with 1 and 1. The second one-way clutch F2 is adapted to be engaged when the ring gear 73 tries to rotate in the reverse direction.

Of the rotating members of the above-mentioned transmission portions 31 and 32, C for detecting the rotational speed of the clutch C0 of the sub transmission portion 31 is used.
A sensor 82 and a vehicle speed sensor 83 that detects the number of rotations of the output shaft 80 are provided.

In the above-described automatic transmission 1, it is possible to set five forward speeds and one reverse speed by engaging and disengaging each clutch and brake as shown in the operation table of FIG. In FIG. 4, a circle indicates an on state or an engaged state, a cross indicates an off state or a released state, a circle indicates a lock-up clutch on control state, and a circle indicates duty control during gear shifting.

As shown in the operation table of FIG. 4, the auxiliary transmission unit 31
The control for switching between the overdrive state and the direct connection state and the control for applying the engine brake in the first speed and the third speed are performed by the third solenoid valve S3. Therefore, the hydraulic circuit shown in FIG. It is provided. FIG. 5 shows only the main parts relating to the present invention, and the more characteristic parts of them are schematically shown in FIG.

The third solenoid valve S3 is a normal open type valve that outputs a signal pressure in the off state, and is provided mainly for switching control of the auxiliary transmission section 31, and is shown in FIGS. In the configuration, this is diverted to control the engine braking of the first speed and the third speed. More specifically, the third solenoid valve S3 is off-controlled at the fifth speed and reverse speed for setting the subtransmission unit 31 in the overdrive state and outputs the signal pressure (pilot pressure), and also the drive ( D) The signal pressure is output by being off-controlled in the first speed and the third speed of the range. In the first speed and the third speed of the D range, the signal pressure of the third solenoid valve S3 is controlled by the B2 release control valve. The so-called reversal control is performed to cut off the supply of hydraulic pressure to the brakes B1 and B4 for applying the engine brake at the first speed or the third speed.

That is, in FIG. 6, the 3-4 shift valve 100 is a spool valve in which the respective ports are communicated with each other in the first to third speeds and the fourth and fifth speeds, as indicated by the symbols at the bottom of the drawing, The third solenoid valve S3 is connected to the port 101. This port 101 is
In 3rd speed, it is connected to port 102, and this port 10
The signal pressure is sent from 2 to the control port 131 of the B2 release control valve 130. Also, the port 101 is connected to the port 103 at the 4th and 5th speeds,
From here, the signal pressure is sent to the 4-5 shift valve.

B2 release control valve 130
Has a spool 132 with four lands,
When the signal pressure is supplied to the control port 131, the spool 132 is lowered to the position shown in the left half of FIG. 6, and conversely, when the pressure is discharged from the control port 131, the spool 132 is moved to the position shown in the right half of FIG. It is designed to be pushed up to. Of the ports of this B2 release control valve 130, the engine brake pressure output port 1
A D range pressure input port 134 and an engine brake range pressure input port 135 are formed across 33.
When the spool 132 is in the position shown in the left half of FIG. 6 because the third solenoid valve S3 outputs the signal pressure, the engine brake range pressure input port 1
35 communicates with the engine brake pressure output port 133.

When the spool 132 is in the position shown in the right half of FIG. 6 because the third solenoid valve S3 does not output the signal pressure, the D range pressure input port 13
4 communicates with the engine brake pressure output port 133.
Here, the third solenoid valve S3 is turned off at the first speed to the third speed in the D range to output the signal pressure. In this case, the D range pressure input port 134 is closed,
Also, because the engine brake range pressure is not generated,
No hydraulic pressure is output from the engine brake pressure output port 133.

The above engine brake pressure output port 13
3 is connected to the input port 151 of the coast brake control valve 150. The coast brake control valve 150 is a valve that regulates and outputs an input hydraulic pressure, and includes a spool 152 having two lands and a plunger 153 arranged at one end thereof.
And a spring 154 arranged between the spool 152 and the plunger 153. The land on the side of the input port 151 is formed with through holes that open at both end surfaces thereof so that the output pressure acts on the end surface of the spool 152. Further, the accumulator back pressure control pressure PACC is supplied to the end portion of the plunger 153, whereby the pressure regulation level is changed. The output port 155, which is selectively communicated with the input port 151, outputs hydraulic pressure to the first brake B1 or the fourth brake B4, which is a friction engagement device for engine braking at the first speed or the third speed. It has become.

That is, in the first speed and the third speed in the D range where the D range pressure is generated, the third solenoid valve S3
Is controlled to be off and outputs the signal pressure, the D range pressure is shut off by the B2 release control valve 130, so the hydraulic pressure is not sent to the first brake B1 or the fourth brake B4, and these are released. So, the edin brake doesn't work. That is, the third solenoid valve S3
Is so-called inverted control.

On the other hand, in the L range in which the engine brake is applied at the first speed, the third solenoid valve S3 is on-controlled and the signal pressure is not output. Therefore, the spool 132 of the B2 release control valve 130 has the spool 132 on the right side of FIG. It is pushed up to the half position, and as a result, the D range pressure input port 134 and the output port 133 communicate with each other, the D range pressure is sent to the fourth brake B4, and this is engaged. Also in the third to the engine brake at speed "3" Renjia <br/> Rui "2" ovens, because the third solenoid valve S3 is controlled to be turned on, first at the L-range described above
As in the case of the speed, the hydraulic pressure is sent to the first brake B1 via the coast brake control valve 150, and the first brake B1 is engaged with the hydraulic pressure to enable the engine braking.

When the third solenoid valve S3 is off-failed in the D range, the D range pressure input port 134 of the B2 release control valve 130 is closed so that the engine braking does not work and therefore the shift shock is prevented. be able to.

Further, B2 release control valve 1
When a so-called valve stick occurs in which the spool 132 of 30 is fixed at the position shown in the right half of FIG. 6,
Engine brake pressure input port 135 and output port 13
Since 3 is always in communication, hydraulic pressure can be output from the output port 133 in the engine brake range "3" range or "2" range, and the engine brake is activated by engaging the first brake B1 in the third speed. be able to.

The engine brake pressure input port 13
The reason why the orifice 136 is provided in the oil passage communicating with 5 is to avoid the interference between the first brake B1 and the second brake B2, and when the first brake B1 is engaged at the third speed, The orifice 136 slows the supply speed of the hydraulic pressure in order to advance the engagement of the brake B2.

Next, the hydraulic circuit shown in FIG. 5 will be described more specifically. For convenience of drawing, the following description will be given with reference to FIG. 6 to FIG. 8 in which FIG. 5 is divided into a plurality of parts.

First, the B2 release control valve 1
Referring to FIG. 30, the B2 release control valve 130 is shown in FIG. 7 upside down with respect to FIG. 6, and in addition to the connection state of each port described above, the second brake B2 is connected to the B2 port 137. Has been done, this B2
The port 138 selectively connected to the port 137 is connected to the oil passage 14 via an orifice 139 with a check ball.
0 is connected. The second brake B2 is communicated with the oil passage 140 via the orifice 141. Therefore, by communicating the B2 port 137 with the port 138, the second brake B2 is communicated with the oil passage 140 not only through the orifice 141 but also through the orifice 139 with a check ball, so that the exhaust pressure speed thereof is increased. Thus, B2 release control valve 1
30 supplies the signal pressure of the third solenoid valve S3 to its control port 131 or discharges the signal pressure,
The exhaust pressure speed from the second brake B2, that is, the release speed of the second brake B2 is configured to be switched gradually.

On the other hand, the oil passage 142 connected to the engine brake range pressure input port 135 has the above-mentioned orifice (double orifice) 136, and the orifice 143 with a check ball opened in the exhaust pressure direction is parallel to the double orifice 136. It is provided in. The oil passage 142 is connected to a 1-2 shift valve described later.

Explaining the 3-4 shift valve 100, the spool 104 for switching the communication state of the ports 101, 102 and 103 described above has six lands, and the brake port 105 formed in the middle portion.
A first brake B1 is connected to. The input port 106 adjacent to the brake port 105 is communicated with the coast brake control valve 150 via a 2-3 shift valve described later. The above-mentioned port 103 is connected to the 4-5 shift valve 1 through the oil passage 107.
70 is connected to the control port 171. The 4-5 shift valve 170 is a valve for controlling the sub-transmission unit 31 to the overdrive state or the direct connection state, and the input port 17 to which the line pressure oil passage PL is connected.
Brake port 173 selectively connected to 2
The brake B0 in the subtransmission unit 31 is connected to the. The brake port 1 is connected to the input port 172.
The output port 174 located on the side opposite to 73 is connected to the oil passage 1
It is connected via 75 to a C0 exhaust valve 190.

The 4-5 shift valve 170 is constructed so that the communication state of the ports is switched by a spool 176 having five lands, and the signal pressure of the third solenoid valve S3 is transmitted via the oil passage 107 to the control port 1.
71, pushes spool 176 down to the position shown in the right half of FIG. 7, resulting in input port 172.
Communicates with the brake port 173, and hydraulic pressure is supplied to the brake B0. When the pressure is discharged from the control port 171, on the contrary, the spool 176 is pushed up to the position shown in the left half of FIG.
Hydraulic pressure is sent to. In FIG. 7, reference numeral 210 denotes a solenoid relay valve, which is configured to control the supply / discharge of signal pressure from the lock-up linear solenoid valve SLU, and to control the supply / discharge of hydraulic pressure to the third brake B3. ing. The connection states of the other oil passages are as shown in FIG.

In FIG. 8, the above-mentioned B is connected to the input port 151 of the coast brake control valve 150.
2 An oil passage 156 connected to the port 133 of the release control valve 130 is connected, and an oil for outputting the regulated brake pressure to the first brake B1 or the fourth brake B4 is connected to the output port 155. Road 1
57 is connected. In addition, these oil passages 156, 1
57 are connected to each other via an orifice 158 with a check ball, and the orifice 158 with a check ball is opened when the pressure is discharged from the first brake B1 or the fourth brake B4.

The control for switching the supply destination of the brake pressure to the first brake B1 or the fourth brake B4 is performed by the 2-3 shift valve 230. 2-3 shift valve 2
Reference numeral 30 denotes a valve for switching the communication state of the ports by a spool 231 having seven lands. A spring 232 is provided at one end of the spool 231 and a hold port 2 opened at this end.
The L range pressure is supplied to 33.
The oil passage 157 for supplying the brake pressure is provided at the port 2 in the middle portion.
The output port 235 on the upper side in FIG. 8 is connected to the input port 106 of the 3-4 shift valve 100 described above. Further, the second output port 236 located on the lower side in FIG. 8 with respect to the port 234 is connected to the 1-2 shift valve via the oil passage 237. The 2-3 shift valve 230 is a valve mainly controlled by the second solenoid valve S2, and the spool 231 is at the position shown in the left half of FIG. 8 in the first speed, the second speed, the neutral range and the R range. Pushed up and spool 2 at 3rd or 5th speed
31 is configured to be pushed down to the position shown in the right half of FIG.

Therefore, when the engine brake is applied at the first speed, the port 234 is the second output port 23.
6 to output the brake pressure from here, and when the engine brake is applied at the third speed, the port 234 is communicated to the output port 235 and the brake pressure is supplied from here to the 3-4 shift valve 100. It is configured to be supplied to the first brake B1 via. The second brake B2 is connected to the port 238.

The fourth brake B4, which is engaged when the engine brake is applied at the first speed, is the shuttle valve 2
It is connected to the 1-2 shift valve 250 via 40. The 1-2 shift valve 250 is a valve that switches the communication state of the ports by a spool having four lands, and the second output port 236 of the 2-3 shift valve 230 is connected to the input port 252. A shuttle valve 240 is connected to an output port 254 that selectively communicates with the input port 252 and the drain port 253.

Further, the engine brake range pressure is set to the above B2.
Oil passage 14 supplied to the release control valve 130
2 is connected to another output port 255, and an oil passage 257 for supplying a “3” range pressure to an engine brake port 256 which is selectively communicated with this output port 255.
And an oil passage 258 for supplying the “2” range pressure. The spool 251 of the 1-2 shift valve 250 is pushed down to the position shown in the right half of FIG. 8 in the first speed, the neutral range and the R range. Therefore, in this state, the input port 252 communicates with the output port 254. Further, in the second to fifth speeds, the spool 251 is pushed up to the position shown in the left half of FIG. 8, and as a result, the engine brake port 256 communicates with the other output port 255. The connection state of the other oil passages is as shown in FIG.

The manual valve 260 will now be described. This is the same as that conventionally known, that is, the parking (P) range, the R range, the neutral (N) range, the D range, and the "3" range. It is a valve that can set 7 positions of “2” range and L range. When D range is set, D range pressure is output from D port 261 and when “3” range is set. The hydraulic pressure is output from the D port 261 and the "3" port 262, and the hydraulic pressure output from the "3" port is the so-called "3" range pressure. Further, when the "2" range is set, hydraulic pressure is output from the D port 261, the "3" port 262, and the "2" port 263.

The above-mentioned oil passage 257 is connected to the "3" port 262, and the "2" port 263 is connected to the "2" port 263.
The oil passage 258 is connected. When the L range is set, the D port 261 and the "3" port 26
2, the hydraulic pressure is output from the "2" port 263 and the L port 264, and the hydraulic pressure output from the L port 264 is
2-3 is supplied to the hold port 233 of the shift valve 230. Furthermore, the hydraulic pressure output from the "2" port 263 is the so-called "2" range pressure.

Further, reference numeral 270 in FIG. 8 denotes a B3 control valve, which supplies the signal pressure of the linear solenoid valve SLU supplied through the solenoid relay valve 210 to the control port 271 to change the pressure adjusting level, Third brake B to be engaged when setting the speed
It is configured to control the hydraulic pressure supplied to 3. Since the construction of the B3 control valve 270 is conventionally known, the connection state of the main oil passages is shown in FIG. 8 and its explanation is omitted.

The C0 exhaust valve 190 is used.
Is a valve for controlling the clutch C0 of the auxiliary transmission unit 31, and is the first control port 191 in the second speed of the D range.
The hydraulic pressure is supplied to the first input port 192 to which the D range pressure is supplied in the first speed to the fourth speed and the N range. Also at this time, "2"
The second input port 193 to which the range pressure is input is connected to the output port 194. Therefore D
In the second speed range, the clutch C0 is released because no hydraulic pressure is output. In the "2" range and the L range, the "2" range pressure is supplied to the second input port 193, so the clutch C0 is engaged. The engine brake works well together. Further, the signal pressure of the linear solenoid valve SLU is supplied to the second control port 195.

In FIG. 9, reference numeral 280 is a relay valve controlled by the linear solenoid valve SLT, and reference numeral 290 is an accumulator. Further, reference numeral 295 indicates an accumulator control valve for adjusting the accumulator back pressure PACC.

Therefore, in the control device provided with the hydraulic circuit shown in FIG. 5 or FIGS. 7 to 9, the third solenoid valve S3 is turned off at the first speed in the D range, and the signal pressure is 3-4 shift valve 100. Is input to the control port 131 of the B2 release control valve 130 via. As a result, B2 release control valve 1
The spool 132 of 30 is pushed up to the position shown in the right half of FIG. 5 or 7 to shut off the port 134 to which the D range pressure is supplied. Therefore, the D range pressure is not sent to the coast brake control valve 150, so the fourth brake B4 remains released, and the engine brake does not work. Therefore, when setting the first speed in the D range, the fourth brake B4 will not be engaged even if the third solenoid valve S3 is off-failed. Therefore, shifting from the first speed to the first speed No inconvenience such as aggravation of gear shift shock occurs during gear shifting.

In the L range where it is necessary to apply the engine brake at the first speed, the third solenoid valve S3 is on-controlled, so that the pressure is exhausted from the control port 131 of the B2 release control valve 130. As a result, The spool 132 is pushed down to the position shown in the left half of FIG.
And to the coast brake control valve 150 via the port 133, and the hydraulic pressure is supplied from this to the fourth brake B4 via the 2-3 shift valve 230, the 1-2 shift valve 250 and the shuttle valve 240. That is, the fourth brake B4 is engaged and the engine brake can be activated.

On the other hand, since the third solenoid valve S3 is controlled to be off when the third speed in the D range is set,
Similar to the case of the first speed, the port 134 of the B2 release control valve 130 is closed to cut the D range pressure, so that the hydraulic pressure is not supplied to the first brake B1.
The engine brake will not work because it remains released.

On the other hand, in the "3" range and the "2" range in which the engine braking is effective at the third speed, the third solenoid valve S3 is on-controlled, so that the control port 131 of the B2 release control valve 130 is exhausted. Pressure, and as a result, the D range pressure is supplied to the coast brake control valve 150 via the port 134 and the port 133, and the engine brake pressure adjusted here is supplied to the 2-3 shift valve 230 and the 3-4 shift valve 100. It is supplied to the first brake B1 via the engine, and the engagement of the first brake B1 enables the engine brake to be activated. In other words, since the D range pressure is used to apply the engine brake in the third speed, the engine brake can be applied in the third speed by performing the same control in the D range.

In the third speed of the "3" range or the "2" range, if the third solenoid valve S3 fails off, the B2 release control valve 130
Since the hydraulic pressure is supplied to the control port 131, the D range pressure input port 134 to which the D range pressure is input is closed, and the engine brake range pressure input port 135 to which the engine brake range pressure is supplied is closed. Since it communicates with the output port 133, the engine brake range pressure is supplied from here to the coast brake control valve 150. As a result, the engine brake pressure adjusted here is supplied to and engaged with the first brake B1, so that the engine brake can be activated even if the third solenoid valve S3 fails. Therefore, if the third solenoid valve S3 fails in the D range, the engine braking cannot be activated.

B2 release control valve 1
When the engine brake range pressure input port 135 of 30 is supplied with the engine brake range pressure, since it is supplied through the double orifice 136, the rise of the hydraulic pressure of the first brake B1 can be mitigated, and as a result, Interference between the first brake B1 and the second brake B2 can be avoided.

In the above-described automatic transmission 1, five forward speeds can be set, and the fourth speed and the fifth speed are set without using a one-way clutch. The engine brake can be activated at the gear position. On the other hand, since the third speed is set by engaging the first one-way clutch F1, the engine brake cannot be applied as it is, but if the third solenoid valve S3 is ON-controlled, the first speed is set. By engaging the brake B1, the engine braking can be activated in the third speed. Therefore, during the uphill / downhill control, the third to fifth speeds are appropriately set.

Here, the uphill / downhill control will be described. This control is a control for prohibiting or suppressing the upshift based on the running state of the vehicle and for applying the engine brake. Specifically, when the vehicle is traveling in the D (drive) range, an uphill state or a downhill state is determined based on the throttle opening and the acceleration of the vehicle. (Overdrive stage)
To limit. Therefore, in the above-described automatic transmission, the third speed or the fourth speed is set by starting the uphill / downhill control even in the traveling state of the fifth speed.

However, since the setting of these shift speeds for the uphill / downhill control is executed by electrically controlling the solenoid valve, when an electrical failure occurs,
Uphill / downhill control cannot be performed. Therefore, the control device of the present invention executes the determination of the failure and the setting of the shift speed based on the determination as described below.

FIG. 1 is a flow chart for explaining the control example. Whether or not the condition for executing the uphill / downhill control is satisfied after the processing of the input signal such as reading of data (step 1) is performed. Is determined (step 2). This uphill / downhill control is as described above. Therefore, in this step 2, it is judged whether or not it is required to apply the engine brake at the intermediate shift speed. Therefore, this step 2 is the first judgment of the present invention .
Equivalent to Dante stage.

If a negative determination is made in step 2 because the uphill / downhill control is not being executed, the process returns without performing any particular control, and the condition for performing the uphill / downhill control is satisfied. When the determination is affirmative, it is determined whether or not the third solenoid valve S3 has failed (step 3). Here, the off-fail is a failure state that remains in the off state and cannot be switched to the on state, and includes an electrical failure such as disconnection and a mechanical failure such as a valve stick. The determination in step 3 can be made based on the output state of the electrical instruction signal and the hydraulic pressure state of the automatic transmission 1.

As described above, the third solenoid valve S3
Is on-controlled at the third speed to supply a hydraulic pressure to the first brake B1 which is a coast brake to engage the same, and is on-controlled at the fourth speed to set the fourth speed. This is as shown in FIG. Therefore, if a failure (failure) occurs in which the third solenoid valve S3 is fixed in the off state, engine braking cannot be applied at the third speed, and the fourth speed cannot be set. That is step 3 corresponds to the fail decision hand stage of the present invention, when an affirmative determination in step 3, that is, the third solenoid valve S3 if the off failure, stops the uphill slope control (Step 4) . The 4th speed that should be set due to the limitation of the 5th speed, which is the overdrive stage, cannot be set due to a failure, and the engine braking cannot be applied at the 3rd speed lower than that. Is.

On the other hand, when the third solenoid valve S3 is functioning normally and a negative determination is made in step 3, it is determined whether the second solenoid valve S2 is off-failed (step 5). As shown in FIG. 4, the third
The speed is set by controlling the first solenoid valve S1 to be off and the second solenoid valve S2 to be on. Therefore, in this step 5, it is judged whether or not the third speed can be set. Therefore, this step 5 together with the above step 3 corresponds to the fail judgment means of the present invention.

Therefore, when the affirmative determination is made in step 5 because the second solenoid valve S2 is off-failed, the uphill / downhill control is performed using the 4th speed and the 5th speed (step 6). Second solenoid valve S2
This is because the engine brake can be applied in the fourth and fifth speeds instead of being unable to set the third speed due to the off-fail of. Since the uphill / downhill control is a control for limiting the overdrive stage during the uphill / downhill, the fourth speed is actually set instead of the fifth speed during uphill / downhill. Therefore, this step 6 is
It corresponds to the actual line means.

If a negative determination is made in step 5, there is no fail, so the third speed to the fifth speed.
Use the gear position of the speed to run the uphill slope control (Step
7) . That is, the third speed, the fourth speed, and the fifth speed with the engine brake applied are appropriately selected and set according to the traveling state of the vehicle. Since the uphill / downhill control is a control for limiting the overdrive stage during the uphill / downhill, the third speed or the fourth speed in which the engine braking is effective is actually set by detecting the uphill / downhill state.

The reason why the third speed is adopted as the shift speed for the uphill / downhill control as described above is that the engine braking can be applied at the third speed, and therefore, the third speed is used before the step 7. It may be possible to determine whether or not the engine brake can be applied at the third speed. Specifically, this determination may be performed by determining the failure of the linear solenoid valves SLN and SLT or the coast brake control valve 150 required to achieve the engine braking state at the third speed.

Therefore, according to the above control device, the third
If the engine braking cannot be applied at high speeds, except for the third speed, the uphill / downhill control is performed using the shift speed on the higher speed side, so the engine brake does not work during the uphill / downhill control. It is possible to prevent inconvenience such as occurrence of a state.

Although the above example is an example of the control device for the automatic transmission having the gear train shown in FIG. 3, the present invention is not limited to the above example, and other examples are possible. The present invention can also be applied to a control device intended for an automatic transmission provided with a gear train, and therefore, the gear stage for determining failure is not limited to the third speed. Further, in the above example, the case where a failure occurs during uphill / downhill control has been described as an example, but the present invention is basically a control for automatically setting the engine braking state based on the traveling state of the vehicle. The present invention can be applied to the case of performing the above, and is not limited to the specific example described above.

[0068]

As described above, according to the control device of the present invention, in the automatic transmission in which the gear stage in which the engine brake is effective is selected and set according to the traveling state, the selected gear in which the engine brake is effective is selected. If there is something wrong with the gear setting and the gear cannot be set or the engine cannot be brought into the engine braking state, the gear with the engine brake that is higher than the gear above the gear is selectively set. since thereby the engine brake Te, it is possible to secure an engine brake state as much as possible, as a result, by suitably execute the uphill slope control during failure, reduce the frequency of the shift operation by the oPERATION person, Drivability can be improved.

[Brief description of drawings]

FIG. 1 is a flow chart for explaining an example of control according to the present invention.

FIG. 2 is a block diagram schematically showing an embodiment of the present invention.

FIG. 3 is a skeleton diagram mainly showing a gear shift mechanism of an automatic transmission targeted by the present invention.

FIG. 4 is a table showing an on / off state of a solenoid valve and an engagement / release state of each friction engagement device at each travel range and shift speed.

FIG. 5 is a diagram showing a main hydraulic circuit portion of an embodiment of the present invention.

FIG. 6 is a partial hydraulic circuit diagram schematically showing a main hydraulic circuit portion according to the present invention.

7 is a diagram showing a part of the hydraulic circuit shown in FIG.

8 is a diagram showing another portion of the hydraulic circuit shown in FIG.

9 is a diagram showing still another portion of the hydraulic circuit shown in FIG.

[Explanation of symbols]

1 automatic transmission 150 coast brake control valve B1 First brake S2 Second solenoid valve S3 Third solenoid valve

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Claims (2)

(57) [Claims] 1. Upshifting based on a running state of a vehicle
To prevent or suppress the
In the shift control device of the automatic transmission to perform a control that, the first judgment hand to determine the establishment of the condition for executing the control
And a state in which the first judging means judges that the condition is satisfied.
Then, set the intermediate gear with the engine brake applied.
And failure determining means for determining that it will not be constant, pre SL when the failure determining means can not be set to the intermediate shift speed is determined, the more intermediate shift stage higher speed engine
Use the above-mentioned intermediate gears instead of the gears where the brakes work effectively.
Shift control device for an automatic transmission, characterized in that in use and an execution unit configured to execute the control. 2. The control is uphill or downhill
Is characterized by uphill / downhill control that limits the maximum speed
The shift control device for an automatic transmission according to claim 1.