Patent Application
20150260278
The present invention relates to a hydraulic control device for an automatic transmission to be mounted on an automobile, and in particular to a control device for a line pressure which is a hydraulic pressure for operating friction engagement elements of an automatic transmission.
In the related art, a primary regulator valve regulates a pump pressure from an oil pump to generate a line pressure. In the primary regulator valve, basically, an urging force of a spring and a throttle pressure from a throttle valve act against a feedback pressure of the line pressure acting on a spool, and the line pressure is set by a linear function defined by the minimum proof pressure and the maximum proof pressure (see Patent Document 1).
In general, the minimum pressure of the line pressure is set to be equal to or more than a hydraulic pressure that secures a minimum drive force (evacuation drive force) for ensuring vehicle travel in consideration of a failure.
[Patent Document 1] Japanese Patent Application Publication No. 1-238750 (JP 1-238750 A)
In the primary valve, the urging force of the spring is set to be strong so as to secure the evacuation drive force, because the drive force may be insufficient in the case where the throttle valve is constituted of a linear solenoid valve, for example, and the linear solenoid valve is subjected to a full-closure failure and does not output the throttle pressure. Therefore, the minimum pressure of the line pressure defined by the linear function is set to be high, as a result of which the line pressure is also set to be high overall. In fact, the line pressure may be set to be excessively high compared to a hydraulic pressure required for normal travel. Here, as the line pressure becomes higher, the resistance against the engine (i.e. the load on the engine) generated by the oil pump which pumps working oil becomes larger, which hinders improvement in fuel efficiency.
It is therefore an object of the present invention to provide a hydraulic control device for an automatic transmission that addresses the foregoing issue which enables the minimum pressure of a line pressure to be set to be low, and enables a vehicle travel drive force to be secured when a throttle valve is subjected to a failure.
With reference to
a throttle valve (SLT, 22) that includes an input port (22a) to which a source pressure (Pmod) is input, an output port (22b), and a discharge port (22c), and that outputs a throttle pressure (PSLT) regulated in accordance with torque input to the automatic transmission from the output port (22b);
a primary regulator valve (20) that includes a control oil chamber (20c) that communicates with the output port (22b) of the throttle valve, a pressure regulation port (20a) that communicates with a line pressure oil passage (21) that extends from an oil pump, and a feedback pressure port (20b) to which a feedback pressure from the line pressure oil passage is supplied, and that regulates a hydraulic pressure at the pressure regulation port (20a) to a line pressure with a hydraulic pressure in the control oil chamber (20c) and an urging force of a spring (20s) acting on one end of a spool (20p) and with the feedback pressure from the feedback pressure port (20b) acting on the other end of the spool; and a failure circuit (F1 to F4) that includes a first solenoid valve (S1) that is switched when the throttle valve (22) is subjected to a failure in which the throttle valve (22) is unable to output the throttle pressure, and that leads a predetermined hydraulic pressure (PS1, Pmod) based on switching of the first solenoid valve to the control oil chamber (20c) of the primary regulator valve (20).
With reference to
when the throttle valve (22) is subjected to a failure in which the throttle valve (22) is unable to output the throttle pressure, the switching valve (26′) is switched by switching the first solenoid valve (S1) such that the input port (26l) and the communication port (26m) of the switching valve communicate with each other and the predetermined hydraulic pressure is supplied to the control oil chamber (20c) of the primary regulator valve (20) via the input port (26l) and the communication port (26m) of the switching valve.
With reference to
when the throttle valve (22) is subjected to a failure in which the throttle valve (22) is unable to output the throttle pressure, the switching valve (26) is switched by switching the first solenoid valve (S1) such that the input port (26l) and the first port (26j) of the switching valve communicate with each other and the predetermined hydraulic pressure is supplied to the discharge port (22c) of the throttle valve (22) via the input port (26l) and the first port (26j) of the switching valve, and further supplied from the discharge port (22c) of the throttle valve (22) to the control oil chamber (20c) of the primary regulator valve (20) via the output port (22b).
With reference to
With reference to
With reference to
With reference to
a second solenoid valve (S2); and
a supply/discharge switching valve (27) that switches between supply and discharge of a control pressure (PSL3) from a predetermined linear solenoid valve (SL3) to and from a hydraulic servo (B2) for an engine brake friction engagement element that is engaged to apply engine brake at a first forward speed using an output pressure (PS2) from the second solenoid valve (S2), and the predetermined hydraulic pressure is the output pressure (PS2) from the second solenoid valve (S2).
The supply/discharge switching valve (27) is switched by the output pressure (PS2) from the second solenoid valve (S2) to a blocked state in which supply of the control pressure (PSL3) to the hydraulic servo (B2) for the engine brake friction engagement element is blocked during forward travel at a higher shift speed with a gear ratio that is lower than that of the first forward speed; and the supply/discharge switching valve (27) is switched to a supply state in which the control pressure (PSL3) can be supplied to the hydraulic servo (B2) for the engine brake friction engagement element during travel at the first forward speed or a reverse speed.
The supply/discharge switching valve includes a distribution valve that selectively supplies the control pressure (PSL3) for the predetermined linear solenoid valve (SL3) to one of a hydraulic servo (C3) for a first friction engagement element that is engaged to establish a predetermined forward speed (e.g. a third speed or a seventh speed) and the hydraulic servo (B2) for the engine brake friction engagement element; and
the switching valve is integrally constituted to be used also as the distribution valve.
With reference to
means (501) for detecting a failure of the throttle valve (22) in which the input port (22a) and the output port (22b) are fully closed, and
the first solenoid valve (S1) is switched to output an output pressure when the detection means detects a failure.
The symbols in the above parentheses are provided for reference to the drawings, and should not be construed as affecting the scope of the claims in any way.
With the invention according to claim 1, in the case where the throttle valve is subjected to a full-closure failure, the first solenoid valve is switched so that the predetermined hydraulic pressure is supplied from the failure circuit to the control oil chamber of the primary regulator valve. Thus, a hydraulic pressure that is equal to or more than a drive force that can drive the vehicle can be secured as the line pressure. In addition, the minimum pressure of the line pressure can be set to an appropriate value without considering a full-closure failure of the throttle valve. Thus, a pressure loss (a resistance caused by an oil pump, i.e. a load on the engine) can be reduced to improve the fuel efficiency.
With the invention according to claim 2, the switching valve is switched by the first solenoid valve so that the predetermined hydraulic pressure is supplied to the control oil chamber of the primary regulator valve.
With the invention according to claim 3, the predetermined hydraulic pressure from the switching valve is supplied from the discharge port of the throttle valve to the control oil chamber of the primary regulator valve via the output port. Thus, an oil passage for supplying the throttle pressure to the primary regulator valve can be used also for another purpose, which eliminates the need for a check valve or the like to suppress the cost and also simplifies the oil passage structure.
With the invention according to claim 4, the output pressure of the first solenoid valve which operates when the throttle valve is subjected to a full-closure failure is used as the predetermined hydraulic pressure to be supplied to the primary regulator valve. Thus, the predetermined hydraulic pressure can be supplied to the switching valve or the like only when necessary to suppress a waste of oil.
With the invention according to claim 5, the predetermined hydraulic pressure supplied when the throttle valve is subjected to a full-closure failure is a modulator pressure that is the same as the source pressure for the throttle valve which is constituted of a linear solenoid valve. Thus, the predetermined hydraulic pressure can be regulated to a line pressure that is the same as that when the throttle valve is fully open, which can secure a line pressure that ensures a drive force that enables travel under any circumstances. In addition, the source pressure which is the same as that during normal times is supplied to the input port of the line pressure regulation linear solenoid valve. Therefore, the durability of the line pressure regulation linear solenoid valve is less affected than in the case where a pressure that is higher than that during normal times is supplied to the input port (e.g. a case where the line pressure is supplied to the input port when the throttle valve is subjected to a full-closure failure) or the like.
With the invention according to claim 6, it is possible to prevent the throttle pressure led from the output port of the throttle valve to the control oil chamber of the primary regulator valve from flowing to other valves.
With the invention according to claim 7 or 8, the output pressure from the second solenoid valve is used as the predetermined hydraulic pressure. Therefore, the second solenoid valve for switching the supply/discharge switching valve can be used in a shared manner in a hydraulic circuit for securing the line pressure which ensures a drive force when the throttle valve is subjected to a full-closure failure. Thus, there is no need to add a dedicated solenoid valve, and it is possible to suppress an increase in number of components of the hydraulic control device.
With the invention according to claim 9, the switching valve is integrally constituted to be used also as the distribution valve which distributes the control pressure for the predetermined linear solenoid valve to the hydraulic servo for a predetermined forward speed and the hydraulic servo for engine brake at the first speed. Thus, it is possible to prevent the configuration of the hydraulic control device from being complicated.
With the invention according to claim 10, a full-closure failure of the throttle valve is detected by the detection means.
First, the basic configuration of a hydraulic control device U having a failure circuit F1 according to the present invention will be described with reference to
The throttle valve 22 is constituted of a line pressure regulation linear solenoid valve (SLT), and controls the throttle pressure PSLT by controlling the proportion of communication of an output port 22b and a discharge port 22c with an input port 22a in accordance with an accelerator operation by a driver during normal times. Thus, a modulator pressure Pmod from the input port 22a is output from the output port 22b as the throttle pressure PSLT, and a part of the modulator pressure Pmod is discharged from the discharge port 22c. The throttle pressure PSLT from the output port 22b is supplied to the control oil chamber 20c of the primary regulator valve 20 to regulate and control the line pressure PL. Oil discharged from the discharge port 22c is drained via a switching valve 26. That is, the throttle pressure PSLT is regulated in accordance with torque input to an automatic transmission. The torque input to the automatic transmission is estimated from engine output torque estimated from the operating state of an engine, an engine output torque signal received from an engine EUC, and the throttle opening.
During normal times, the switching valve 26 is in a first state in which a first port 26j communicates with a drain port 26k with a first solenoid valve S1 turned off. In the case where the throttle valve 22 is subjected to a full-closure failure, however, the switching valve 26 is switched to a second state in which the first port 26j communicates with an input port 26l by turning on the solenoid valve S1. Consequently, the modulator pressure Pmod is supplied to the discharge port 22c of the throttle valve 22 via the ports 26l and 26j. Preferably, a second solenoid valve S2 is turned on as discussed later so that the modulator pressure Pmod from the solenoid valve S2 is supplied to the port 26l. A predetermined hydraulic pressure supplied to the input port 26l of the switching valve 26 is not limited to the modulator pressure Pmod, and may be equal to or more than a hydraulic pressure (minimum evacuation pressure) that allows securing a minimum drive force for vehicle travel.
In this state, the throttle valve 22 is brought into a fully closed state in which the throttle valve 22 is unable to output the throttle pressure, that is, a state in which the input port 22a and the output port 22b are fully closed and the output port 22b and the discharge port 22c communicate with each other. Thus, the modulator pressure Pmod from the first port 26j of the switching valve 26 is led from the discharge port 22c to the output port 22b. The modulator pressure acts on the control oil chamber 20c at the lower end of the spool of the primary regulator valve 20.
Thus, in the related art, as illustrated in
Consequently, as illustrated in
An embodiment of the present invention will be described below with reference to the drawings. An automatic transmission according to the present invention is an automatic transmission that is suitably mounted on FF (front-engine front-drive) vehicles. The left-right direction in
A schematic configuration of an automatic transmission 1 to which the present invention may be applied will be described with reference to
The torque converter 2 includes a pump impeller 2a connected to the input shaft 5 of the automatic transmission 1, and a turbine runner 2b to which rotation of the pump impeller 2a is transferred via a working fluid. The turbine runner 2b is connected to an input shaft 7 of the automatic speed change mechanism 3. The torque converter 2 also includes a lock-up clutch 2c. When the lock-up clutch 2c is engaged, rotation of the input shaft 5 of the automatic transmission 1 is directly transferred to the input shaft 7 of the automatic speed change mechanism 3.
The automatic speed change mechanism 3 includes, on the input shaft 7, a planetary gear (speed-reducing planetary gear) DP and a planetary gear unit PU provided on a downstream side of transmission from the planetary gear DP. The planetary gear DP is a so-called double-pinion planetary gear, which includes a first sun gear Su1, a first carrier CR1, and a first ring gear R1 and in which the first carrier CR1 has pinions P2 meshed with the first sun gear Su1 and pinions P1 meshed with the first ring gear R1 in such a manner that the pinions P2 and the pinions P1 are meshed with each other.
Meanwhile, the planetary gear unit PU is a so-called Ravigneaux type planetary gear, which includes four rotary elements, namely a second sun gear Su2, a third sun gear Su3, a second carrier CR2, and a second ring gear R2 and in which the second carrier CR2 has long pinion gears P3 meshed with the second sun gear Su2 and the second ring gear R2 and short pinion gears P4 meshed with the third sun gear Su3 in such a manner that the long pinion gears P3 and the short pinion gears P4 are meshed with each other.
The first sun gear Su1 of the planetary gear DP is stationary in terms of rotation with respect to a transmission case 6. In addition, the first carrier CR1 is connected to the input shaft 7 so as to make the same rotation (hereinafter referred to as “input rotation”) as rotation of the input shaft 7, and connected to a fourth clutch C4. Further, the first ring gear R1 makes reduced-speed rotation that is reduced in speed compared to the input rotation through the first sun gear Su1 which is stationary and the first carrier CR1 which makes the input rotation, and is connected to a first clutch C-1 and a third clutch (second friction engagement element) C-3.
The second sun gear Su2 of the planetary gear unit PU is connected to a first brake B-1 to be selectively stationary with respect to the transmission case 6. In addition, the second sun gear Su2 is connected to the fourth clutch C-4 and the third clutch C-3 so as to selectively receive the input rotation of the first carrier CR1 via the fourth clutch C-4 and the reduced-speed rotation of the first ring gear R1 via the third clutch C-3. Further, the third sun gear Su3 is connected to the first clutch C-1 so as to selectively receive the reduced-speed rotation of the first ring gear R1.
In addition, the second carrier CR2 is connected to a second clutch C-2 to which rotation of the input shaft 7 is input so as to selectively receive the input rotation via the second clutch C-2, and connected to a one-way clutch F-1 and a second brake (first friction engagement element) B-2. Therefore, the second carrier CR2 is restricted from rotating in one direction with respect to the transmission case 6 via the one-way clutch F-1, and selectively stationary in terms of rotation with respect to the transmission case 6 via the second brake B-2. In addition, the second ring gear R2 is connected to a counter gear 8. The counter gear 8 is connected to drive wheels via a counter shaft and a differential device (not illustrated).
In the automatic transmission 1 discussed above, the clutches and the brakes are operated in combinations indicated in the operation table of
As illustrated in
The SLT full-closure failure detection means 501 determines a full-closure failure (i.e. a failure in which the throttle valve is unable to output a throttle pressure) by detecting the throttle pressure PSLT using the hydraulic pressure sensor 52 which is provided in a throttle pressure (PSLT) oil passage 37 illustrated in
Now, a hydraulic control device for the automatic transmission will be described with reference to
As illustrated in
In the C3-B2 apply control valve 26, in addition, the working oil chamber 26a is connected to an output port f of the first on/off solenoid valve S1 of a normally closed type that makes no output when not energized (a solenoid valve that, when energized, outputs the modulator pressure Pmod generally as it is as an output pressure PS1 that may switch the valve 26). Therefore, when the output pressure (first switching pressure) PS1 is output from the first on/off solenoid valve S1 to the working oil chamber 26a, the C3-B2 apply control valve 26 is switched from a first state (left-half position) to a second state (right-half position).
When the C3-B2 apply control valve 26 is in the first state (left-half position), the first output port 26b and the drain port 26h communicate with each other, the reverse range pressure first input port 26c and the first output port 26d communicate with each other, the control pressure input port 26e and the third output port 26f communicate with each other, and the first port 26j and the drain port 26k communicate with each other. When the C3-B2 apply control valve 26 is in the second state (right-half position), the reverse range pressure first input port 26c and the first output port 26b communicate with each other, the input port 26e and the second output port 26d communicate with each other, the reverse range pressure second input port 26g and the third output port 26f communicate with each other, and the first port 26j and the input port 26l communicate with each other.
The solenoid relay valve (supply/discharge switching valve) 27 includes a spool 27p, a spring 27s that urges the spool 27p upward in the drawing, and a working oil chamber 27a provided above the spool 27p in the drawing. The solenoid relay valve (supply/discharge switching valve) 27 further includes an input port (first input port) 27b, an input port (second input port) 27c, and an output port 27d connected to a hydraulic servo for the second brake B-2.
When an output pressure PS2 from the second on/off solenoid valve S2 of a normally closed type that makes no output when not energized (i.e. a solenoid valve that, when energized, outputs the modulator pressure Pmod generally as it is as an output pressure PS2 that may switch the valve 27) is output to the working oil chamber 27a, the solenoid relay valve (supply/discharge switching valve) 27 is switched from the left-half position to the right-half position.
When the solenoid relay valve (supply/discharge switching valve) 27 is at the left-half position, the first input port 27b and the output port 27d communicate with each other. When the solenoid relay valve (supply/discharge switching valve) 27 is at the right-half position, the second input port 27c and the output port 27d communicate with each other.
The throttle valve (SLT) 22 which is constituted of a linear solenoid valve includes the input port 22a to which the modulator pressure Pmod is input, the output port 22b to which the throttle pressure PSLT which has been regulated and controlled in accordance with the throttle opening is output, and the discharge port 22c. The output port 22b communicates with the control oil chamber 20c of the primary regulator valve 20. Meanwhile, the discharge port 22c communicates with the first port 26j of the C3-B2 apply control valve 26. Similarly, the third linear solenoid valve SL3 regulates and controls the modulator pressure such that the control hydraulic pressure PSL3 is output from an output port h. The output port h communicates with the input port 26e of the C3-B2 apply control valve 26.
The primary regulator valve 20 includes a spool 20p and a spring 20s disposed in the control oil chamber 20c to urge the spool 20p in one direction together with the throttle pressure PSLT. Further, the line pressure oil passage 21 which communicates with the discharge side of the oil pump communicates with the pressure regulation port 20a, and communicates with the feedback pressure port 20b so as to urge the spool 20p in the other direction as a feedback pressure. In addition, the primary regulator valve 20 includes a return port 20d that communicates with the input side of the oil pump, and a port 20e supplied to a secondary regulator valve. A part of the line pressure is supplied to a modulator valve to be regulated to the modulator pressure Pmod which is a generally constant pressure.
The function of the hydraulic control device U will be described. During forward travel in a D range, as illustrated in
The throttle valve 22 is operating normally, and regulates a modulator pressure Pmod to output a throttle pressure PSLT matching the throttle opening from the output port 22b. The throttle pressure PSLT acts on the control oil chamber 20c of the primary regulator valve 20 to output a line pressure PL that is proportional to the throttle pressure PSLT as illustrated in
In this state, with the third or seventh speed established, the control hydraulic pressure PSL3 output from the third linear solenoid valve SL3 is supplied to a hydraulic servo C3 for the third clutch C-3 through the input port 26e and the third output port 26f of the C3-B2 apply control valve 26 which functions as a distribution valve. Thus, the clutches C-1 to C-4 and the brake B-1 are controlled as illustrated in
During normal reverse travel in which the driver operates a shift lever into a reverse range, the first and second solenoid valves S1 and S2 are both turned off (not energized). In this state, as illustrated in
Meanwhile, in the case where the operation of the shift lever into the reverse range by the driver is performed when the vehicle is traveling forward at a speed that is equal to or more than a reverse permission speed, the second solenoid valve S2 is held on. In this state, the solenoid relay valve 27 is at the right-half position, and the reverse range pressure supplied via the ports 26c and 26d of the C3-B2 apply control valve 26 is blocked by the port 27b of the relay valve 27, and the hydraulic servo B2 for the second brake is drained via the ports 27d and 27c of the relay valve 27 and the ports 26b and 26h of the C3-B2 apply control valve 26. Consequently, establishment of a reverse speed is inhibited (reverse inhibit) until the vehicle speed becomes equal to or less than the reverse permission speed.
In the case where the driver operates the shift lever into the first forward speed to apply engine brake, the first solenoid valve S1 is turned on (energized), and the second solenoid valve S2 is turned off (not energized). In this state, as illustrated in
Thus, the control hydraulic pressure PSL3 from the third linear solenoid valve SL3 is supplied to the hydraulic servo B2 for the second brake B-2 via the input port 26e and the second output port 26d of the C3-B2 apply control valve 26 and the first input port 27b and the output port 27d of the relay valve 27. Consequently, the second brake B-2 is controlled so as to be engaged by the third linear solenoid valve SL3, which is combined with engagement control for the first clutch C-1 by the first linear solenoid valve SL1 to apply engine brake at the first speed. With the C3-B2 apply control valve (switching valve) 26 in the second state (right-half position), the reverse range pressure second input port 26g communicates with the third output port 26f. Because a reverse range pressure is not generated, however, a hydraulic pressure is not supplied to the hydraulic servo C3 for the third clutch.
With the C3-B2 apply control valve 26 in the second state (right-half position), communication between the first port 26j, which communicates with the discharge port 22c of the throttle valve 22, and the drain port 26k is blocked. However, oil at the throttle pressure discharged from the discharge port 22c is discharged via an orifice 30, and led to the output port c of the second solenoid valve S2 at the drain position through communication between the first port 26j and the input port 26l to be discharged from a drain port n. Consequently, the throttle valve 22 outputs a suitable throttle pressure PSLT matching the throttle opening so that the line pressure is suitably controlled by the primary regulator valve 20.
In the case where the SLT full-closure failure detection means 501 of the control section 50 detects that a throttle pressure is not output from the throttle valve (SLT) 22 which is constituted of a linear solenoid valve to determine a full-closure failure of the throttle valve 22 as discussed above, the first and second solenoid valves S1 and S2 are both controlled so as to be turned on (energized) as illustrated in
The throttle valve 22 which has been subjected to a full-closure failure is unable to output a throttle pressure with the input port 22a and the output port 22b fully closed (blocked), and with the output port 22b and the discharge port 22c communicating with each other. The second solenoid valve S2 is in the on position in which the input port e and the output port c communicate with each other, and the modulator pressure Pmod is output from the output port c. The output pressure (first switching pressure) PS2 is supplied to the discharge port 22c of the throttle valve 22 via the input port 26l and the first port 26j of the C3-B2 apply control valve (switching valve) 26. The modulator pressure supplied to the discharge port 22c is supplied to the control oil chamber 20c of the primary regulator valve 20 through the output port 22b in the communicated state.
Consequently, for the primary regulator valve 20, the modulator pressure, that is, the source pressure for the throttle valve 22, is controlled by the maximum pressure B achieved when the throttle valve 22 is at full throttle (fully open), and the line pressure PL is at the maximum pressure (B). Thus, it is not necessary to set a minimum proof pressure for securing a minimum evacuation drive force when the throttle valve is subjected to a full-closure failure as in the related art (see
Also in this state, during forward travel, each shift speed excluding the third and seventh speeds can be established by the linear solenoid valves SL1, SL2, SL4, and SL5 excluding the third linear solenoid valve SL3.
In a reverse state in which the shift lever is operated to a reverse speed, the reverse range pressure PR is supplied to the hydraulic servo B2 for the second brake via the first input port 26c and the first output port 26b of the C3-B2 apply control valve (switching valve) 26 and further the first input port 27b and the output port 27d of the solenoid relay valve 27, and supplied to the hydraulic servo C3 for the third clutch C-3 via the second input port 26g and the third output port 26f of the C3-B2 apply control valve 26. Consequently, a reverse speed is established to enable the vehicle to travel in reverse. During minimum evacuation in which the vehicle travels to a repair garage, the fifth speed is established to travel forward.
Now, a hydraulic control device having a failure circuit according to another partially modified embodiment will be described with reference to
In a failure circuit F2 illustrated in
In a failure circuit F3 illustrated in
In the embodiment, when the throttle valve 22 is normal, the throttle pressure PSLT from the output port 22b is supplied to the control oil chamber 20c of the primary regulator valve 20 via the check valve 36. In this event, the throttle pressure PSLT does not flow to the communication port 26m of the switching valve 26′ through the check valve 35. The check valve 35 may not be provided if the switching valve 26′ is configured to be blocked in this state. Then, when the throttle valve 22 is subjected to a full-closure failure, the first solenoid valve S1 is switched on, and the input port 26l and the communication port 26m communicate with each other. In this state, the predetermined hydraulic pressure (modulator pressure Pmod) is supplied to the control oil chamber 20c of the primary regulator valve 20 via the input port 26l, the communication port 26m, the check valve 35, and the oil passage 37. In this event, the predetermined hydraulic pressure in the oil passage 37 is inhibited from flowing to the output port 22b of the throttle valve 22 through the check valve 36, and does not leak from the discharge port 22c.
In a failure circuit F4 illustrated in
That is, in the present invention, a hydraulic pressure is supplied to the control oil chamber of the primary regulator valve via a failure circuit in the case where a full-closure failure of the throttle valve is detected. Particularly preferably, a switching valve is provided, and switched such that a predetermined hydraulic pressure based on the switching is supplied to the control oil chamber of the primary regulator valve.
The present invention is utilized for an automatic transmission to be mounted on a vehicle such as an automobile.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2012-283710 | Dec 2012 | JP | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/JP2013/084767 | 12/25/2013 | WO | 00 |
