Hydraulic pressure control device

Provided is a hydraulic pressure control device. A hydraulic pressure control device includes a solenoid valve configured to supply hydraulic pressure to switch between an engaged state and a released state of a lock-up clutch, and a transmission control device configured to control the solenoid valve. The solenoid valve supplies hydraulic pressure to switch between a parking locked state and a parking released state of a parking lock mechanism, in addition to switching of the lock-up clutch.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the priority of Japan patent application serial no. 2017-066126, filed on Mar. 29, 2017. The entirety of the above-mentioned patent application is hereby incorporated by reference herein and made a part of this specification.

BACKGROUND

Technical Field

The present disclosure relates to a hydraulic pressure control device configured to control hydraulic pressure of a transmission.

Description of Related Art

In the related art, a hydraulic pressure control device configured to control a lock-up clutch or the like of an automatic transmission using a working oil pressure (for example, see Patent Document 1) is known.

In general, in an automatic transmission, a parking lock mechanism configured to prevent drive wheels from rotating such that they do not move during parking of a vehicle is installed. It is conceivable that the parking lock mechanism may also be controlled by a hydraulic pressure control device. Here, it is conceivable that a parking piston for a parking lock mechanism installed in a hydraulic pressure control device be switched by hydraulic pressure supplied through a control valve so as to switch between a parking locked state and a parking released state of the parking lock mechanism with the hydraulic pressure control device.

In addition, a control valve configured to control engagement/release of a lock-up clutch installed in a torque converter is also installed in the hydraulic pressure control device.

In this way, since the hydraulic pressure control device includes a plurality of control valves, there is a limitation in achieving reduction in size and weight.

SUMMARY

The present disclosure provides a hydraulic pressure control device in which size and weight can be reduced further than in the related art.

The present invention provides a hydraulic pressure control device including a control valve (for example, a solenoid valve (122C) of the embodiment, the same below) configured to supply hydraulic pressure to switch between an engaged state and a released state of a lock-up clutch (for example, a lock-up clutch (2a) of an embodiment, the same below); and a control unit configured to control the control valve (for example, a transmission control device (ECU) of the embodiment, the same below), wherein the control valve supplies hydraulic pressure to switch between a parking locked state and a parking released state of a parking lock mechanism, in addition to switching of the lock-up clutch.

DESCRIPTION OF THE EMBODIMENTS

According to the present disclosure, the one control valve can be responsible for both of a switching function of the lock-up clutch and a switching function of the parking lock mechanism, and reduction in size and weight of the hydraulic pressure control device can be achieved.

In addition, in the embodiment, when a range is a reverse range, or when a range is a forward range, switching control of the lock-up clutch may be processed prior to switching control of the parking lock mechanism. According to the above-mentioned configuration, the lock-up clutch and the parking mechanism can be appropriately controlled using a common control valve.

In addition, in the present disclosure, when the range is a parking range, when the range is being switched between the parking range and other ranges, or when the range is a neutral range, switching control of the parking lock mechanism may be processed prior to switching control of the lock-up clutch. According to the above-mentioned configuration, the lock-up clutch and the parking mechanism can be appropriately controlled using a common control valve.

In addition, in the present disclosure, the control unit may control the control valve such that the parking lock mechanism is in the parking released state when the range is being switched from the parking range to the neutral range, and control the control valve such that the parking lock mechanism is in the parking locked state when the range is being switched from the other ranges to the parking range, or when the range is being switched from the parking range to the forward range or the reverse range. According to the above-mentioned configuration, the lock-up clutch and the parking mechanism can be appropriately controlled using a common control valve.

A transmission including a hydraulic pressure control device of embodiments and a vehicle in which the transmission is mounted will be described with reference to the accompanying drawings.

As shown inFIG. 1, in a vehicle V on which a transmission including a hydraulic pressure control device of the embodiment is mounted, a drive source E (an internal combustion engine, an engine, an electric motor may be used instead of an internal combustion engine) is laterally mounted in a vehicle body such that a crankshaft1is directed in a vehicle body leftward/rightward direction. A driving force output from the drive source E is transmitted to a power transmission PT. Then, the power transmission PT adjusts a driving force of the drive source E to correspond to a selected gear ratio, and transmits the adjusted driving force to the left and right front wheels WFL and WFR.

The power transmission PT is constituted by an automatic transmission3having a torque converter2connected to the crankshaft1, and a front differential gear4connected to the automatic transmission3.

The front differential gear4is connected to the left and right front wheels WFL and WFR via a front section left axle7L and a front section right axle7R.

FIG. 2is a skeleton view showing a portion of the automatic transmission3other than the torque converter2. The automatic transmission3includes an input shaft11serving as an input member rotationally and axially supported in a transmission case10that is a housing and to which a driving force output from the drive source E is transmitted via the torque converter2having a lock-up clutch and a damper, and an output member13disposed concentrically with the input shaft11and constituted by an output gear.

Rotation of the output member13is transmitted to left and right drive wheels (the front wheels WFL and WFR) of the vehicle via an idle gear21meshed with the output member13, an idle shaft23configured to axially support the idle gear21, a final drive gear25axially supported by the idle shaft23, and the front differential gear4including a final driven gear27meshed with the final drive gear25. Further, a single disk type or a multi-disk type departure clutch that is frictionally engageably configured may be installed instead of the torque converter2. In addition, a propeller shaft may be connected instead of the front differential gear4and applied to a rear wheel drive vehicle. In addition, the propeller shaft may be connected to the front differential gear4via a transfer and applied to a four-wheel drive vehicle.

In addition, the automatic transmission3of the embodiment includes a parking lock mechanism40. A parking gear42of the parking lock mechanism40is fixed to the idle shaft23to be integrally rotated therewith. A parking pawl44pivoted in a spindle44ais disposed in the vicinity of the parking gear42. A locking claw46is formed on an end portion of the parking pawl44close to the parking gear42. When the locking claw46is engaged with the parking gear42, the parking gear reaches a state in which the drive wheels (the front wheels WFL and WFR) are not rotatable via the idle shaft23(a parking locked state). The parking pawl44is biased by a detachment spring48in a direction in which the locking claw46disengages from the parking gear42.

A cam50is disposed on the other end of the parking pawl44and freely advances and retreats. When the cam50advances, the parking pawl44swings against a biasing force of the detachment spring48, and the locking claw46is engaged with the parking gear42. When the cam50retreats, the parking pawl44is returned to an original position by the biasing force of the detachment spring48, and engagement between the locking claw46and the parking gear42is released.

A parking piston54is connected to the cam50via a link52. The parking piston54is configured to be freely moved by hydraulic pressure in an axial direction thereof. Thus, as the parking piston54moves in the axial direction, the cam50is configured to advance or retreat via the link52.

Four planetary gear mechanisms, which are the first to fourth planetary gear mechanisms PG1to PG4, are disposed in the transmission case10serving as a housing in sequence from the drive source E side concentrically with the input shaft11.

The first planetary gear mechanism PG1is configured by a so-called single pinion type planetary gear mechanism constituted by a sun gear Sa, a ring gear Ra, and a carrier Ca configured to axially support a pinion Pa meshed with the sun gear Sa and the ring gear Ra freely rotatably and revolvingly.

The so-called single pinion type planetary gear mechanism is also referred to as a minus planetary gear mechanism or a negative planetary gear mechanism because the ring gear and the sun gear are rotated in different directions when the carrier is fixed and the sun gear is rotated. Further, in the so-called single pinion type planetary gear mechanism, when the ring gear is fixed and sun gear is rotated, the carrier and the sun gear are rotated in the same direction.

When the three elements Sa, Ca and Ra of the first planetary gear mechanism PG1are set as a seventh element, an eighth element and a ninth element at intervals corresponding to gear ratios in an alignment diagram in an arrangement order from a left side with reference to the alignment diagram of the first planetary gear mechanism PG1shown in a third stage from the top inFIG. 3, the seventh element is the sun gear Sa, the eighth element is the carrier Ca, and the ninth element is the ring gear Ra. A ratio between an interval between the sun gear Sa and the carrier Ca and an interval between the carrier Ca and the ring gear Ra is set to h:1 when a gear ratio of the first planetary gear mechanism PG1is h.

The second planetary gear mechanism PG2is also configured by a so-called single pinion type planetary gear mechanism constituted by a sun gear Sb, a ring gear Rb, and a carrier Cb configured to axially support a pinion Pb meshed with the sun gear Sb and the ring gear Rb freely rotatably and revolvingly.

When the three elements Sb, Cb and Rb of the second planetary gear mechanism PG2are set as a tenth element, an eleventh element and a twelfth element at intervals corresponding to gear ratios in an alignment diagram in an arrangement order from a left side with reference to the alignment diagram of the second planetary gear mechanism PG2shown in a fourth stage (the lowermost stage) from the top inFIG. 3, the tenth element is the ring gear Rb, the eleventh element is the carrier Cb, and the twelfth element is the sun gear Sb. A ratio between an interval between the sun gear Sb and the carrier Cb and an interval between the carrier Cb and the ring gear Rb is set to i:1 when a gear ratio of the second planetary gear mechanism PG2is i.

The third planetary gear mechanism PG3is configured by a so-called single pinion type planetary gear mechanism constituted by a sun gear Sc, a ring gear Rc, and a carrier Cc configured to axially support a pinion Pc meshed with the sun gear Sc and the ring gear Rc freely rotatably and revolvingly.

When the three elements Sc, Cc and Rc of the third planetary gear mechanism PG3are set as a first element, a second element and a third element at intervals corresponding to gear ratios in an alignment diagram (the number of teeth of the ring gear/the number of teeth of the sun gear) in an arrangement order from a left side with reference to the alignment diagram of the third planetary gear mechanism PG3shown in a second stage from the top inFIG. 3(a view in which a ratio between relative rotational speeds of three elements including the sun gear, the carrier and the ring gear is represented by straight lines (speed lines)), the first element is the sun gear Sc, the second element is the carrier Cc, and the third element is the ring gear Rc.

Here, a ratio between an interval between the sun gear Sc and the carrier Cc and an interval between the carrier Cc and the ring gear Rc is set to j:1 when a gear ratio of the third planetary gear mechanism PG3is j. Further, in the alignment diagram, a lower horizontal line and an upper horizontal line (overlapping 4thand 6thlines) show that rotational speeds are “0” and “1” (the same rotational speed as that of the input shaft11).

The fourth planetary gear mechanism PG4is also configured by a so-called single pinion type planetary gear mechanism constituted by a sun gear Sd, a ring gear Rd, and a carrier Cd configured to axially support a pinion Pd meshed with the sun gear Sd and the ring gear Rd to freely rotated and revolve.

When the three elements Sd, Cd and Rd of the fourth planetary gear mechanism PG4are set as a fourth element, a fifth element and a sixth element at intervals corresponding to gear ratios in an alignment diagram in sequence from a left side with reference to the alignment diagram of the fourth planetary gear mechanism PG4shown in a first stage (the uppermost stage) from the top inFIG. 3, the fourth element is the ring gear Rd, the fifth element is the carrier Cd, and the sixth element is the sun gear Sd. A ratio between an interval between the sun gear Sd and the carrier Cd and an interval between the carrier Cd and the ring gear Rd is set to k:1 when a gear ratio of the fourth planetary gear mechanism PG4is k.

The sun gear Sc (the first element) of the third planetary gear mechanism PG3is connected to the input shaft11. In addition, the ring gear Rb (the tenth element) of the second planetary gear mechanism PG2is connected to the output member13constituted by an output gear.

In addition, the carrier Cc (the second element) of the third planetary gear mechanism PG3, the carrier Cd (the fifth element) of the fourth planetary gear mechanism PG4and the ring gear Ra (the ninth element) of the first planetary gear mechanism PG1are connected to constitute a first connecting body Cc-Cd-Ra. In addition, the ring gear Rc (the third element) of the third planetary gear mechanism PG3and the sun gear Sb (the twelfth element) of the second planetary gear mechanism PG2are connected to constitute a second connecting body Rc-Sb. In addition, the carrier Ca (the eighth element) of the first planetary gear mechanism PG1and the carrier Cb (the eleventh element) of the second planetary gear mechanism PG2are connected to constitute a third connecting body Ca-Cb.

In addition, the automatic transmission of the embodiment includes seven engaging mechanisms constituted by three clutches, which are the first to third clutches C1to C3, three brakes, which are the first to third brakes B1to B3, and a two-way clutch F1.

The first clutch C1is a hydraulic operation type and wet type multi-plate clutch, which is configured to be switchable between a connected state in which the sun gear Sc (the first element) of the third planetary gear mechanism PG3and the third connecting body Ca-Cb are connected and an open state in which the connection is cut.

The third clutch C3is a hydraulic operation type and wet type multi-plate clutch, which is configured to be switchable between a connected state in which the sun gear Sc (the first element) of the third planetary gear mechanism PG3and the ring gear Rd (the fourth element) of the fourth planetary gear mechanism PG4are connected and an open state in which the connection is cut.

The second clutch C2is a hydraulic operation type and wet type multi-plate clutch, which is configured to be switchable between a connected state in which the sun gear Sd (the sixth element) of the fourth planetary gear mechanism PG4and the second connecting body Rc-Sb are connected and an open state in which the connection is cut.

The two-way clutch F1, which functions as a fourth brake, is configured to allow normal rotation of the third connecting body Ca-Cb (rotation in a rotational direction of the input shaft11and/or the same direction as the rotational direction of the output member13upon advancement of the vehicle, and to be switchable between a reverse rotation prevention state in which reverse rotation (in a rotational direction opposite to the normal rotation) is prevented and a fixed state in which the third connecting body Ca-Cb is fixed to the transmission case10.

When a force attempting rotation in a normal rotational direction is applied to the third connecting body Ca-Cb in the reverse rotation prevention state, the two-way clutch F1reaches an open state in which rotation is allowed, and when a force attempting rotation in a reverse rotational direction is applied, the two-way clutch F1reaches a fixed state in which the rotation is prevented and the two-way clutch F1is fixed to the transmission case10. In the embodiment, the two-way clutch corresponds to a switching mechanism.

The first brake B1is a hydraulic operation type and wet type multi-plate brake, which is configured to be switchable between a fixed state in which the sun gear Sa (the seventh element) of the first planetary gear mechanism PG1is fixed to the transmission case10and an open state in which the fixing is released.

The second brake B2is a hydraulic operation type and wet type multi-plate brake, which is configured to be switchable between a fixed state in which the sun gear Sd (the sixth element) of the fourth planetary gear mechanism PG4is fixed to the transmission case10and an open state in which the fixing is released. The third brake B3is a hydraulic operation type and wet type multi-plate brake, which is configured to be switchable between a fixed state in which the ring gear Rd (the fourth element) of the fourth planetary gear mechanism PG4is fixed to the transmission case10and an open state in which the fixing is released.

The states of the clutches C1to C3, the brakes B1to B3and the two-way clutch F1are switched by a transmission control device ECU constituted by a transmission control unit (TCU) shown inFIG. 1on the basis of vehicle information such as a traveling speed or the like of the vehicle transmitted from an integrated control unit or the like (not shown).

The transmission control device ECU is configured by an electronic unit constituted by a CPU, a memory, and so on (not shown), can receive predetermined vehicle information such as a traveling speed or an accelerator position of the vehicle V, a rotational speed or an output torque of the drive source E, and operation information or the like of a paddle shift lever33, and controls the automatic transmission3(a transmission mechanism) by executing a control program held on a storage device such as a memory or the like using a CPU.

As shown inFIG. 1, the paddle shift lever33is installed on a handle31of the vehicle V of the embodiment, upshifted by a manual operation when a right paddle33uis pulled toward a driver, and downshifted by a manual operation when a left paddle33dis pulled toward a driver. An operation signal of the paddle shift lever33is transmitted to the transmission control device ECU.

Further, an operation unit for a manual operation is not limited to the paddle shift lever33of the embodiment and may be another operation unit, for example, a button disposed on a shift lever or a paddle disposed between a driver's seat and a passenger seat.

As shown inFIG. 2, the first clutch C1, the first planetary gear mechanism PG1, the second planetary gear mechanism PG2, the third planetary gear mechanism PG3, the second clutch C2, the fourth planetary gear mechanism PG4and the third clutch C3are sequentially disposed on an axis of the input shaft11from the drive source E and the torque converter2side.

Then, the third brake B3is disposed at an outer side of the fourth planetary gear mechanism PG4in a radial direction, the second brake B2is disposed at an outer side of the second clutch C2in the radial direction, the first brake B1is disposed at an outer side of the first clutch C1in the radial direction, and the two-way clutch F1is disposed at an outer side of the first planetary gear mechanism PG1in the radial direction.

In this way, as the three brakes B1to B3and the two-way clutch F1are disposed at the outer side of the planetary gear mechanism or the clutch in the radial direction, reduction in an axial length of the automatic transmission3can be achieved in comparison with the case in which the brakes B1to B3and the two-way clutch F1are disposed parallel to the axis of the input shaft11together with the planetary gear mechanism and the clutch. Further, the third brake B3may be disposed at an outer side of the third clutch C3in the radial direction, and the second brake B2may be disposed at an outer side of the fourth planetary gear mechanism PG4in the radial direction.

Next, the case in which gear shifting stages of the automatic transmission3of the embodiment are established will be described with reference toFIG. 3andFIG. 4.

When a first speed stage is established, the two-way clutch F1is in the reverse rotation prevention state (R inFIG. 4), and the first brake B1and the second brake B2are in the fixed state. As the two-way clutch F1in the reverse rotation prevention state (R) and the first brake B1is in the fixed state, reverse rotation of the third connecting body Ca-Cb and the sun gear Sa (the seventh element) of the first planetary gear mechanism PG1is prevented, and a rotational speed of the third connecting body Ca-Cb and the sun gear Sa (the seventh element) of the first planetary gear mechanism PG1becomes “0.”

Accordingly, the transmission is in a locked state in which the three elements, the seventh to ninth elements Sa, Ca and Ra, of the first planetary gear mechanism PG1are not relatively rotatable, and a rotational speed of the first connecting body Cc-Cd-Ra including the ring gear Ra (the ninth element) of the first planetary gear mechanism PG1also becomes “0.” Then, a rotational speed of the ring gear Rb (the tenth element) of the second planetary gear mechanism PG2to which the output member13is connected becomes “1st” shown inFIG. 3, and the first speed stage is established.

Further, while it is possible that the first speed stage is established without causing the second brake B2to be in the fixed state, the second brake B2is in the fixed stage in the first speed stage such that gear shifting can be smoothly performed from the first speed stage to a second speed stage, which will be described below. In addition, when an engine brake is to be effective in the first speed stage, the two-way clutch F1is switched from the reverse rotation prevention state (R) to the fixed state (L).

When a second speed stage is established, the two-way clutch F1is in the reverse rotation prevention state (R), the first brake B1and the second brake B2are in the fixed state, and the second clutch C2is in the connected state. As the two-way clutch F1is in the reverse rotation prevention state, normal rotation of the third connecting body Ca-Cb is allowed. In addition, as the first brake B1is in the fixed state, a rotational speed of the sun gear Sa (the seventh element) of the first planetary gear mechanism PG1becomes “0.” In addition, as the second brake B2is in the fixed state, a rotational speed of the sun gear Sd (the sixth element) of the fourth planetary gear mechanism PG4becomes “0.”

In addition, as the second clutch C2is in the connected state, a rotational speed of the second connecting body Rc-Sb becomes “0” that is the same speed as the rotational speed of the sun gear Sd (the sixth element) of the fourth planetary gear mechanism PG4. Then, a rotational speed of the ring gear Rb (the tenth element) of the second planetary gear mechanism PG2to which the output member13is connected becomes “2nd” shown inFIG. 3, and the second speed stage is established.

When a third speed stage is established, the two-way clutch F1is in the reverse rotation prevention state, the first brake B1and the second brake B2are in the fixed state, and the third clutch C3is in the connected state. As the two-way clutch F1is in the reverse rotation prevention state, normal rotation of the third connecting body Ca-Cb is allowed. In addition, as the first brake B1is in the fixed state, a rotational speed of the sun gear Sa (the seventh element) of the first planetary gear mechanism PG1becomes “0.” In addition, as the second brake B2is in the fixed state, a rotational speed of the sun gear Sd (the sixth element) of the fourth planetary gear mechanism PG4becomes “0.”

In addition, as the third clutch C3is in the connected state, a rotational speed of the ring gear Rd (the fourth element) of the fourth planetary gear mechanism PG4becomes “1” that is the same speed as the rotational speed of the sun gear Sc (the first element) of the third planetary gear mechanism PG3connected to the input shaft11. Since the rotational speed of the sun gear Sd (the sixth element) of the fourth planetary gear mechanism PG4is “0” and the rotational speed of the ring gear Rd (the fourth element) is “1,” the rotational speed of the carrier Cd (the fifth element), i.e., the rotational speed of the first connecting body Cc-Cd-Ra becomes k/(k+1).

Then, a rotational speed of the ring gear Rb (the tenth element) of the second planetary gear mechanism PG2to which the output member13is connected becomes “3rd” shown inFIG. 3, and the third speed stage is established.

When a fourth speed stage is established, the two-way clutch F1is in the reverse rotation prevention state, the first brake B1is in the fixed state, and the second clutch C2and the third clutch C3are in the connected state. As the two-way clutch F1is in the reverse rotation prevention state, normal rotation of the third connecting body Ca-Cb is allowed. In addition, as the first brake B1is in the fixed state, a rotational speed of the sun gear Sa (the seventh element) of the first planetary gear mechanism PG1becomes “0.”

In addition, as the second clutch C2is in the connected state, the sun gear Sd (the sixth element) of the fourth planetary gear mechanism PG4and the second connecting body Rc-Sb are rotated at the same speed. Accordingly, the carrier Cc (the second element) and the carrier Cd (the fifth element) are connected and the ring gear Re (the third element) and the sun gear Sd (the sixth element) are connected between the third planetary gear mechanism PG3and the fourth planetary gear mechanism PG4, and in the fourth speed stage in which the second clutch C2is in the connected state, an alignment diagram constituted by four elements can be drawn by the third planetary gear mechanism PG3and the fourth planetary gear mechanism PG4.

Then, as the third clutch C3is in the connected state, the rotational speed of the ring gear Rd (the fourth element) of the fourth planetary gear mechanism PG4and the rotational speed of the sun gear Sc (the first element) of the third planetary gear mechanism PG3have the same speed of “1” and the rotational speeds of the two elements of the four elements constituted by the third planetary gear mechanism PG3and the fourth planetary gear mechanism PG4have the same speed of “1.”

Accordingly, the transmission reaches the locked state in which the elements of the third planetary gear mechanism PG3and the fourth planetary gear mechanism PG4are not relatively rotatable, and the rotational speeds of all the elements of the third planetary gear mechanism PG3and the fourth planetary gear mechanism PG4become “1.” Then, the rotational speed of the third connecting body Ca-Cb becomes h/(h+1), the rotational speed of the ring gear Rb (the tenth element) of the second planetary gear mechanism PG2to which the output member13is connected becomes “4th” shown inFIG. 3, and the fourth speed stage is established.

When a fifth speed stage is established, the two-way clutch F1is in the reverse rotation prevention state, the first brake B1is in the fixed state, and the first clutch C1and the third clutch C3are in the connected state. As the two-way clutch F1is in the reverse rotation prevention state, normal rotation of the third connecting body Ca-Cb is allowed. In addition, as the first brake B1is in the fixed state, a rotational speed of the sun gear Sa (the seventh element) of the first planetary gear mechanism PG1becomes “0.”

In addition, as the first clutch C1is in the connected state, the rotational speed of the third connecting body Ca-Cb becomes the same speed of “1” as the rotational speed of the sun gear Sc (the first element) of the third planetary gear mechanism PG3. Then, the rotational speed of the ring gear Rb (the tenth element) of the second planetary gear mechanism PG2to which the output member13is connected becomes “5th” shown inFIG. 3, and the fifth speed stage is established.

Further, it is possible that the fifth speed stage is established without causing the third clutch C3to be in the connected state. However, since the third clutch C3should be in the connected state in the fourth speed stage and a sixth speed stage, which will be described below, the third clutch C3is in the connected state even in the fifth speed stage such that a downshift from the fifth speed stage to the fourth speed stage and an upshift from the fifth speed stage to the sixth speed stage, which will be described below, are smoothly performed.

When the sixth speed stage is established, the two-way clutch F1is in the reverse rotation prevention state, the three clutches, the first to third clutches C1to C3, are in the connected state. As the two-way clutch F1is in the reverse rotation prevention state, normal rotation of the third connecting body Ca-Cb is allowed.

In addition, as the second clutch C2and the third clutch C3are in the connected state, as described in the fourth speed stage, the elements of the third planetary gear mechanism PG3and the fourth planetary gear mechanism PG4are not relatively rotatable, and a rotational speed of the second connecting body Rc-Sb becomes “1.” In addition, as the first clutch C1is in the connected state, a rotational speed of the third connecting body Ca-Cb becomes “1.”

Accordingly, the second planetary gear mechanism PG2is in a locked state in which the carrier Cb (the eleventh element) and the sun gear Sb (the twelfth element) have the same speed of “1,” and the elements are not relatively rotatable. Then, a rotational speed of the ring gear Rb (the tenth element) of the second planetary gear mechanism PG2to which the output member13is connected becomes “1” of “6th” shown inFIG. 3, and the sixth speed stage is established.

When a seventh speed stage is established, the two-way clutch F1is in the reverse rotation prevention state, the second brake B2is in the fixed state, and the first clutch C1and the third clutch C3are in the connected state. As the two-way clutch F1is in the reverse rotation prevention state, normal rotation of the third connecting body Ca-Cb is allowed.

In addition, as the second brake B2is in the fixed state, a rotational speed of the sun gear Sd (the sixth element) of the fourth planetary gear mechanism PG4becomes “0.” In addition, as the third clutch C3is in the connected state, a rotational speed of the ring gear Rd (the fourth element) of the fourth planetary gear mechanism PG4is the same speed of “1” as the rotational speed of the sun gear Sc (the first element) of the third planetary gear mechanism PG3, and a rotational speed of the first connecting body Cc-Cd-Ra including the carrier Cd (the fifth element) of the fourth planetary gear mechanism PG4becomes k/(k+1).

In addition, as the first clutch C1is in the connected state, a rotational speed of the third connecting body Ca-Cb is the same speed of “1” as the rotational speed of the sun gear Sc (the first element) of the third planetary gear mechanism PG3connected to the input shaft11. Then, a rotational speed of the ring gear Rb (the tenth element) of the second planetary gear mechanism PG2to which the output member13is connected becomes “7th” shown inFIG. 3, and the seventh speed stage is established.

When an eighth speed stage is established, the two-way clutch F1is in the reverse rotation prevention state, the second brake B2is in the fixed state, and the first clutch C1and the second clutch C2are in the connected state. As the two-way clutch F1is in the reverse rotation prevention state, normal rotation of the third connecting body Ca-Cb is allowed.

In addition, as the second brake B2is in the fixed state, a rotational speed of the sun gear Sd (the sixth element) of the fourth planetary gear mechanism PG4becomes “0.” In addition, as the second clutch C2is in the connected state, a rotational speed of the second connecting body Rc-Sb is the same speed of “0” as the rotational speed of the sun gear Sd (the sixth element) of the fourth planetary gear mechanism PG4.

In addition, as the first clutch C1is in the connected state, the rotational speed of the third connecting body Ca-Cb is the same speed of “1” as the rotational speed of the sun gear Sc (the first element) of the third planetary gear mechanism PG3. Then, a rotational speed of the ring gear Rb (the tenth element) of the second planetary gear mechanism PG2to which the output member13is connected becomes “8th” shown inFIG. 3, the eighth speed stage is established.

When a ninth speed stage is established, the two-way clutch F1is in the reverse rotation prevention state, the second brake B2and the third brake B3are in the fixed state, and the first clutch C1is in the connected state. As the two-way clutch F1is in the reverse rotation prevention state, normal rotation of the third connecting body Ca-Cb is allowed.

In addition, as the second brake B2is in the fixed state, a rotational speed of the sun gear Sd (the sixth element) of the fourth planetary gear mechanism PG4becomes “0.” As the third brake B3is in the fixed state, a rotational speed of the ring gear Rd (the fourth element) of the fourth planetary gear mechanism PG4also becomes “0.” For this reason, the second brake B2is in the locked state in which the elements Sd, Cd and Rd of the fourth planetary gear mechanism PG4are not relatively rotatable, and a rotational speed of the first connecting body Cc-Cd-Ra including the carrier Cd (the fifth element) of the fourth planetary gear mechanism PG4also becomes “0.”

In addition, as the first clutch C1is in the connected state, a rotational speed of the third connecting body Ca-Cb is the same speed of “1” as the rotational speed of the sun gear Sc (the first element) of the third planetary gear mechanism PG3. Then, a rotational speed of the ring gear Rb (the tenth element) of the second planetary gear mechanism PG2to which the output member13is connected becomes “9th” shown inFIG. 3, and the ninth speed stage is established.

When a tenth speed stage is established, the two-way clutch F1is in the reverse rotation prevention state, the third brake B3is in the fixed state, and the first clutch C1and the second clutch C2are in the connected state. As the two-way clutch F1is in the reverse rotation prevention state, normal rotation of the third connecting body Ca-Cb is allowed.

In addition, as the second clutch C2is in the connected state, the second connecting body Rc-Sb and the sun gear Sd (the sixth element) of the fourth planetary gear mechanism PG4are rotated at the same speed. In addition, as the third brake B3is in the fixed state, a rotational speed of the ring gear Rd (the fourth element) of the fourth planetary gear mechanism PG4becomes “0.” In addition, as, the first clutch C1is in the connected state, a rotational speed of the third connecting body Ca-Cb is the same speed of “1” as the rotational speed of the sun gear Sc (the first element) of the third planetary gear mechanism PG3. Then, a rotational speed of the ring gear Rb (the tenth element) of the second planetary gear mechanism PG2to which the output member13is connected becomes “10th” shown inFIG. 3, the tenth speed stage is established.

When a reverse travel stage is established, the two-way clutch F1is in the fixed state (L inFIG. 4), the second brake B2is in the fixed state, and the third clutch C3is in the connected state. As the second brake B2is in the fixed state and the third clutch C3is in the connected state, a rotational speed of the first connecting body Cc-Cd-Ra becomes k/(k+1). In addition, as the two-way clutch F1is in the fixed state, a rotational speed of the third connecting body Ca-Cb becomes “0.” Then, a rotational speed of the ring gear Rb (the tenth element) of the second planetary gear mechanism PG2to which the output member13is connected becomes “Rvs” of a reverse rotation shown inFIG. 3, and the reverse travel stage is established.

Further, a speed line shown by a broken line inFIG. 3represents that elements of another planetary gear mechanism are rotated (revolved) to follow the planetary gear mechanism, which is configured to transmit power, among the four planetary gear mechanisms PG1to PG4.

FIG. 4is a view collectively showing states of the clutches C1to C3, the brakes B1to B3and the two-way clutch F1in the above-mentioned gear shifting stages, “0” in rows of the three clutches, the first to third clutches C1to C3, and the three brakes, the first to third brakes B1to B3, represents a connected state or a fixed state, and a blank represents an open state. In addition, “R” of the row of the two-way clutch F1shows the reverse rotation prevention state, and “L” shows the fixed state.

In addition, underlined “R” and “L” show that the two-way clutch F1moves and a rotational speed of the third connecting body Ca-Cb becomes “0.” In addition, while “R/L” is “R” of the reverse rotation prevention state during a normal time, the two-way clutch F1is switched to “L” of the fixed state when the engine brake is to be effective.

In addition,FIG. 4also shows gear ratios of the gear shifting stages (a rotational speed of the input shaft11/a rotational speed of the output member13) and a common ratio (a ratio between gear ratios between the gear shifting stages, a value obtained by dividing a gear ratio of a predetermined gear shifting stage by a gear ratio of a gear shifting stage that is one stage higher than the predetermined gear shifting stage) when a gear ratio h of the first planetary gear mechanism PG1is 2.681, a gear ratio i of the second planetary gear mechanism PG2is 1.914, a gear ratio j of the third planetary gear mechanism PG3is 2.734 and a gear ratio k of the fourth planetary gear mechanism PG4is 1.614, and accordingly, the common ratio can be appropriately set.

Next, the two-way clutch F1will be described in detail with reference toFIG. 5toFIG. 8. The two-way clutch F1is configured to be switchable between a fixed state in which the third connecting body Ca-Cb is fixed to the transmission case10and a reverse rotation prevention state in which normal rotation of the third connecting body Ca-Cb is allowed and reverse rotation is prevented.

As shown by cross sections inFIG. 5andFIG. 6, the two-way clutch F1includes a fixed plate TW11fixed to the transmission case10, and a rotating plate TW12. As shown inFIG. 7, the fixed plate TW11is formed in an annular shape (a doughnut shape). In addition, while not shown inFIG. 7, like the fixed plate TW11, the rotating plate TW12is also formed in an annular shape (a doughnut shape), and the fixed plate TW11and the rotating plate TW12are disposed concentrically.

As shown inFIG. 5, a plate-shaped normal rotation prevention-side swing section TW13having an end TW13aat the other side in a circumferential direction (a direction in which the rotating plate TW12is reversely rotated) that swings about an end portion of the fixed plate TW11at one side in the circumferential direction (in a direction in which the rotating plate TW12is normally rotated) as a shaft and a plate-shaped anti-reverse-side swing section TW14having an end TW14aat one side in the circumferential direction (a normal rotational direction) that swings about an end portion of the fixed plate TW11at the other side in the circumferential direction (a reverse rotational direction) as a shaft are installed on the facing surface TW11aof the fixed plate TW11that faces the rotating plate TW12.

In addition, accommodating sections TW15and TW16that are recessed to accommodate the normal rotation prevention-side swing section TW13and the anti-reverse-side swing section TW14are formed in a facing surface TW11aof the fixed plate TW11. Biasing members TW17aand TW17bconstituted by springs configured to bias the swing sections TW13and TW14are installed on bottom surfaces of the accommodating sections TW15and TW16such that the ends TW13aand TW14a, about which the corresponding swing sections TW13and TW14swing, protrude from the accommodating sections TW15and TW16.

Hole sections TW18and TW19are formed in a facing surface TW12aof the rotating plate TW12that faces the fixed plate TW11at positions corresponding to the swing sections TW13and TW14. A first engaging section TW18adisposed at the other side of the rotating plate TW12in the circumferential direction (a side in the reverse rotational direction) and formed in a stage shape to be engageable with the end TW13aabout which the normal rotation prevention-side swing section TW13swings is formed in a first hole section TW18formed at a position corresponding to the normal rotation prevention-side swing section TW13.

A second engaging section TW19adisposed at one side of the rotating plate TW12in the circumferential direction (a side in the normal rotational direction) and formed in a stage shape to be engageable with the end TW14aabout which the anti-reverse-side swing section TW14swings is formed in a second hole section TW19formed at a position corresponding to the anti-reverse-side swing section TW14.

As shown inFIG. 5andFIG. 7, when the end TW13aof the normal rotation prevention-side swing section TW13and the first engaging section TW18aare in an engageable state and the end TW14aof the anti-reverse-side swing section TW14and the second engaging section TW19aare in an engageable state, both of normal rotation and reverse rotation of the rotating plate TW12are prevented. Accordingly, a state in which the ends TW13aand TW14aand the engaging sections TW18aand TW19acorresponding thereto are engaged with each other becomes a fixed state of the two-way clutch F1of the embodiment.

A switching plate TW20is sandwiched between the fixed plate TW11and the rotating plate TW12. As shown inFIG. 7, the switching plate TW20is also formed in an annular shape (a doughnut shape). The notch holes TW20aand TW20bare formed in the switching plate TW20at positions corresponding to the swing sections TW13and TW14.

A protrusion TW20cprotruding outward in the radial direction is formed on an outer edge of the switching plate TW20. As shown inFIG. 8, the switching plate TW20is swingable with respect to the fixed plate TW11.

When the switching plate TW20swings from the fixed state shown inFIG. 7to a state shown inFIG. 8, as shown inFIG. 6, the first notch hole TW20acorresponding to the normal rotation prevention-side swing section TW13exceeds the normal rotation prevention-side swing section TW13, and the normal rotation prevention-side swing section TW13is pressed to the switching plate TW20and accommodated in the accommodating section TW15against a biasing force of the biasing member TW17a. Accordingly, engagement between the end TW13aof the normal rotation prevention-side swing section TW13and the first engaging section TW18ais prevented. Accordingly, rotation of the rotating plate TW12on a normal rotation side is allowed.

In addition, as shown inFIG. 8, the second notch hole TW20bcorresponding to the anti-reverse-side swing section TW14is configured such that the end TW14acan be engaged with the second engaging section TW19awhile the anti-reverse-side swing section TW14is not accommodated in the accommodating section TW16even when the switching plate TW20swings from the fixed state shown inFIG. 7to the state shown inFIG. 8.

The states shown inFIG. 6andFIG. 8become a reverse rotation prevention state of the two-way clutch F1of the embodiment due to this.

Next, a hydraulic pressure control device100included in the automatic transmission3of the embodiment will be described with reference toFIG. 9. As shown inFIG. 9, the hydraulic pressure control device100is configured to control an operation of the parking piston54of the parking lock mechanism40.

The hydraulic pressure control device100includes an ON/OFF type solenoid valve122C configured to supply a line pressure supplied from a hydraulic pump (not shown) to an oil path L1to a first locking oil chamber112A, and an ON/OFF type solenoid valve122E configured to supply a line pressure of an oil path L2connected to a downstream side of the oil path L1to a second locking oil chamber112B. The check valve124disposed upstream from the solenoid valve122E is installed in the oil path L2. While the solenoid valve122C is opened to directly support a line pressure to the first locking oil chamber112A, the solenoid valve122E is opened to open a first ball valve126A. The solenoid valve122C is a normal close type, and the solenoid valve122E is a normal open type.

In addition, the hydraulic pressure control device100includes an ON/OFF type solenoid valve122F configured to supply a line pressure to a first unlocking oil chamber114A via an oil path L3, and an ON/OFF type solenoid valve122D configured to supply a line pressure of an oil path L4branching off upstream from a check valve124to a second unlocking oil chamber114B.

A line pressure is directly supplied to the second unlocking oil chamber114B via a brake cut valve128operated by the solenoid valve122D.

The solenoid valve122F supplies a line pressure to the first unlocking oil chamber114A as the solenoid valve122F is opened to move a spool of a parking inhibition valve130toward a right side inFIG. 9against a biasing force of a spring. In contrast, a line pressure of the first unlocking oil chamber114A is drained as the spool of the parking inhibition valve130is biased by the spring to move toward a left side inFIG. 9due to closing of the solenoid valve122F. The solenoid valve122F is a normal close type, and the solenoid valve122D is a normal close type.

A second choke132in which a flow path is narrowed is installed upstream from the parking inhibition valve130of the oil path L3. The second choke132is constituted by a slot groove of a separator plate. In this way, when the second choke132is constituted by the slot groove of the separator plate, there is no need to form a separate member for a second choke, reduction in the number of parts can be achieved, and simplification in assembly of the parking lock apparatus can be achieved.

In addition, a second check valve134in parallel with the second choke132and configured to stop supply of hydraulic pressure to the first unlocking oil chamber114A and allow release of the hydraulic pressure from the first unlocking oil chamber114A is installed. Release of the hydraulic pressure can be rapidly performed by installing the second check valve134.

A pressure accumulating chamber136aof an accumulator136is connected to the oil path L2between the check valve124and the solenoid valve122E.

A lock-up clutch shift valve138is connected to the oil path L1downstream from the solenoid valve122C, and a lock-up clutch pressure of an oil path L5is supplied to a lock-up clutch2aof the torque converter2that is a starting mechanism via the lock-up clutch shift valve138.

In addition, the first brake B1that is a hydraulic engaging apparatus for transmission is connected to an oil path L6downstream from the check valve124, and the linear solenoid valve140G and the brake cut valve128are disposed in the oil path L6. The brake cut valve128is driven by the solenoid valve122D to be opened or closed. A linear solenoid valve140G includes an in-port42a, an out-port142band a drain port142c, and can adjust hydraulic pressure input from the in-port42aand output the adjusted hydraulic pressure from the out-port142b, or release the hydraulic pressure from the out-port142bvia the drain port142c.

In addition, the hydraulic pressure control device100includes a two-way piston212configured to engage with the protrusion TW20cof the switching plate TW20of the two-way clutch F1and switch the switching plate TW20between a side to be the reverse rotation prevention state and a side to be the fixed state using the hydraulic pressure.

Like the parking piston54, the two-way piston212is accommodated in a cylinder (not shown), and a first oil chamber222A for anti-reverse rotation and a second oil chamber222B for anti-reverse rotation configured to move the two-way piston212toward the side to be the reverse rotation prevention state (“OWC” inFIG. 9) are installed at one end portion of the two-way piston212.

A first fixing oil chamber224A and a second fixing oil chamber224B configured to move the two-way piston212to the side to be the fixed state (“LOCK” inFIG. 9) are installed at the other end portion of the two-way piston212.

The first oil chamber222A for anti-reverse rotation is connected to the oil path L4. The line pressure can be supplied to the second oil chamber222B for anti-reverse rotation via the solenoid valve122B. The line pressure can be supplied to the first fixing oil chamber224A via a linear solenoid valve140B.

The linear solenoid valve140B includes an in-port144a, an out-port144band a drain port144c, and can adjust the line pressure input from the in-port144ato output the adjusted line pressure from the out-port144b, or release the hydraulic pressure from the out-port144bvia the drain port144c.

A line pressure can be supplied to the second fixing oil chamber224B via the solenoid valve122A.

Next, an action of the embodiment including the configuration will be described.

When a driver selects a D range or an R range using a shift operation unit such as a shift lever or the like and the vehicle travels at a predetermined gear shifting stage, the line pressure generated by a hydraulic pump driven by the internal combustion engine is transmitted to the oil path L1and the oil path L3, and the hydraulic pressure of the oil path L1passes through the check valve124to be transmitted to the oil path L2, the oil path L4and the oil path L6. The line pressure is supplied to the oil path L2and the hydraulic pressure is accumulated in the pressure accumulating chamber136aof the accumulator136.

The normal close type solenoid valve122F is excited to be opened by electric conduction, and the normal close type solenoid valve122D is also excited to be opened by electric conduction. Then, as the spool of the parking inhibition valve130is moved toward the right side inFIG. 9due to opening of the solenoid valve122F, the line pressure of the oil path L3is transmitted to the first unlocking oil chamber114A via the parking inhibition valve130. In addition, the line pressure of the oil path L4is transmitted to the second unlocking oil chamber114B due to opening of the solenoid valve122D.

Meanwhile, the normal close type solenoid valve122C is closed as supply of electric power is stopped, and the normal open type solenoid valve122E is excited to be closed by electrical conduction. Then, oil in the first locking oil chamber112A is drained from the solenoid valve122C due to closing of the solenoid valve122C, and oil in the second locking oil chamber112B is drained from the first ball valve126A as the first ball valve126A is closed due to closing of the solenoid valve122E. As a result, the parking piston54is moved toward the left side inFIG. 9, and the parking lock is unlocked (a parking released state).

While a flow rate of the oil that is able to pass through the solenoid valve122E is relatively small, a flow rate of the oil that is able to pass through the first ball valve126A opened/closed by the solenoid valve122E is relatively large. For this reason, operation responsiveness of the parking piston54can be increased by interposing the first ball valve126A.

As described above, as the solenoid valve122C and the solenoid valve122E are closed and the solenoid valve122F and the solenoid valve122D are opened during traveling of the vehicle, the parking piston54can be operated at an unlocked position to unlock the parking lock (a parking released state).

In addition, the parking lock mechanism40includes two locking oil chambers, that is, the first locking oil chamber112A and the second locking oil chamber112B, at one end portion of the parking piston54, and includes two unlocking oil chambers, that is, the first unlocking oil chamber114A and the second unlocking oil chamber114B, at the other end portion. For this reason, even when one of the solenoid valve122F and the solenoid valve122D is fixed in a closed state not to supply hydraulic pressure to the first unlocking oil chamber114A or the second unlocking oil chamber114B, or even when one of the solenoid valve122C and the solenoid valve122E is fixed in an open state to supply hydraulic pressure to the first locking oil chamber112A or the second locking oil chamber112B, the parking piston54can be operated at an unlocked position (not the P position, in the parking released state) to secure redundancy without difficulty.

Further, the solenoid valve122F is opened in a first predetermined gear shifting stage, the solenoid valve122D is opened in a second predetermined gear shifting stage, and the first predetermined gear shifting stage and the second predetermined gear shifting stage partially overlap each other. Accordingly, while the case in which the line pressure is supplied to only the first unlocking oil chamber114A, the case in which the line pressure is supplied to only the second unlocking oil chamber114B and the case in which the line pressure is supplied to both of the first unlocking oil chamber114A and the second unlocking oil chamber114B are present according to the gear shifting stage established at this time, the parking piston54is moved toward the left side inFIG. 9even in this case and the parking lock is unlocked without difficulty. Then, in the overlapping gear shifting stage, since the line pressure is supplied to both of the first unlocking oil chamber114A and the second unlocking oil chamber114B, even when the solenoid valve122F or the solenoid valve122D is failed to stop supply of the line pressure, the parking lock is held in an operation unlocked state (the parking released state) to increase redundancy.

When the shift operation unit such as a shift lever or the like is operated to a P range and the vehicle stops while the internal combustion engine is operated, the solenoid valve122C and the solenoid valve122E are opened and the solenoid valve122F and the solenoid valve122D are closed. The line pressure of the oil path L1is transmitted to the first locking oil chamber112A due to opening of the solenoid valve122C, the first ball valve126A is opened due to opening of the solenoid valve122E, and the line pressure of the oil path L2is transmitted to the second locking oil chamber112B.

Meanwhile, the working oil in the first unlocking oil chamber114A is discharged from the parking inhibition valve130due to closing of the solenoid valve122F, and the working oil in the second unlocking oil chamber114B is discharged from the solenoid valve122D due to closing of the solenoid valve122D. As a result, the parking piston54is moved toward the right side inFIG. 9and the parking lock is operated (the parking locked state).

As described above, when a driver selects a P range using the shift operation unit while the internal combustion engine is operated, as the solenoid valve122C and the solenoid valve122E are opened and the solenoid valve122F and the solenoid valve122D are closed, the parking piston54can be operated to a parking lock position. Here, since the parking lock mechanism40includes two of the first locking oil chamber112A and the second locking oil chamber112B and two of the first unlocking oil chamber114A and the second unlocking oil chamber114B, even when one of the solenoid valve122F and the solenoid valve122D is fixed in a valve open state to supply hydraulic pressure to the first unlocking oil chamber114A or the second unlocking oil chamber114B or even when one of the solenoid valve122C and the solenoid valve122E is fixed in a valve closed state not to supply hydraulic pressure to the first locking oil chamber112A or the second locking oil chamber112B, the parking piston54can be operated to the parking lock position (the P position) without difficulty to secure redundancy (the parking locked state).

When an ignition (a vehicle power supply) is turned ON by operating the shift operation unit to the P range, the line pressure by the pump driven by the internal combustion engine is caused to disappear as the internal combustion engine stops. However, according to the embodiment, the parking lock mechanism40can be operated to be in the parking locked state by the hydraulic pressure accumulated in the accumulator136without difficulty.

Then, while the hydraulic pressure of the accumulator136is transmitted to the second locking oil chamber112B due to opening of the solenoid valve122E, the working oil in the first unlocking oil chamber114A is discharged from the parking inhibition valve130due to closing of the solenoid valve122F and the working oil in the second unlocking oil chamber114B is discharged from the solenoid valve122D due to closing of the solenoid valve122D. As a result, the parking piston54is moved toward the right side inFIG. 9and the parking lock is operated (the parking locked state).

As described above, even when the line pressure is caused to disappear by selecting the P range using the shift operation unit and turning the ignition OFF, the parking lock mechanism40can be operated by the hydraulic pressure accumulated in the accumulator136without difficulty (the parking locked state).

In addition, the vehicle of the embodiment enables idling stop control, and the pump is also stopped and the line pressure is caused to disappear by stopping the internal combustion engine during temporary halting such as waiting for a traffic light or the like.

Since the line pressure does not generate instantly even when the internal combustion engine is started upon returning from the idling stop control, the hydraulic pressure cannot be supplied to the first brake B1that is the hydraulic engaging apparatus required for departure, and rapid departure may be prohibited. However, according to the embodiment, the first brake B1can be operated with the hydraulic pressure in the accumulator136held during the idling stop control with no delay.

Describing this in detail, simultaneously with returning from the idling stop control, the hydraulic pressure accumulated in the accumulator136is supplied from the oil path L2to the oil path L6. Here, since the solenoid valve122D installed in the oil path L4is opened due to stoppage of supply of electric power, the spool of the brake cut valve128is moved toward the left side inFIG. 9. Accordingly, as the linear solenoid valve140G installed in the oil path L6is opened to a predetermined opening angle, the hydraulic pressure accumulated in the accumulator136can be supplied to the first brake B1, and the vehicle can be rapidly departed.

While an operation of the first brake B1during returning from the idling stop control has been described in the above-mentioned description, even during conventional traveling of the vehicle, the brake cut valve128can be operated by the solenoid valve122D to control the first brake B1. When the spool of the brake cut valve128is moved toward the left side inFIG. 9and the solenoid valve122D is closed to block communication between the linear solenoid valve140G and the first brake B1, while supply of the hydraulic pressure to the second unlocking oil chamber114B is blocked, since the first brake B1is held at the unlocked position by the hydraulic pressure supplied to the first unlocking oil chamber114A, there is no risk that the parking lock will operate (the parking released state).

In addition, according to the embodiment, the solenoid valve122C is also used for an operation of the lock-up clutch2aof the torque converter2. That is, since the solenoid valve122C is closed during traveling of the vehicle, the spool of the lock-up clutch shift valve138is moved toward the right side inFIG. 9, and the lock-up clutch pressure is supplied to the lock-up clutch2aof the torque converter2. When the solenoid valve122C is opened from this state, as the spool of the lock-up clutch shift valve138is moved toward the left side inFIG. 9and the hydraulic pressure of the lock-up clutch2ais discharged, engagement of the lock-up clutch2acan be released.

When the solenoid valve122C is open, while the line pressure is supplied to the first locking oil chamber112A, since the line pressure is supplied to both of the first unlocking oil chamber114A and the second unlocking oil chamber114B at this time, the parking piston54is not moved to the parking lock position even though the line pressure is supplied to the first locking oil chamber112A, and there is no risk that the parking lock will operate.

As described above, according to the parking lock mechanism40of the embodiment, since the solenoid valve122C and the solenoid valve122D configured to control the operation of the parking piston54are used for both of control of the lock-up clutch2aand control of the first brake B1of the torque converter2, the number of solenoid valves can be reduced and a structure of the hydraulic pressure control device100can be simplified, and moreover, since the accumulator136is not only used for only the operation of the parking lock and is also used for the operation of the first brake B1that is the hydraulic engaging apparatus upon returning from the idling stop control, the number of accumulators can be reduced and the structure of the hydraulic pressure control device100can be further simplified.

The transmission control device ECU combines a function as a control unit of the hydraulic pressure control device100with the function thereof. The transmission control device ECU is configured to receive shift switching request information on the basis of the current shift position information and the operation of the operation unit by a driver.

In addition, the transmission control device ECU receives a request instruction signal of parking input. Further, a parking input instruction signal (or a parking input instruction flag) may be output by determining whether the parking input is needed on the basis of predetermined vehicle information such as a traveling speed or the like of the vehicle received by the control unit.

In addition, the transmission control device ECU is configured such that a countdown timer is installed, a numerical value is decremented from a preset initial value, and the passage of time is planned.

In addition, while the transmission control device ECU receives a signal of a stroke sensor56installed on the parking piston54, it is possible to determine whether the parking piston54is disposed at the unlock side, or is disposed on the parking lock side.

Next, first, the transmission control device ECU checks whether RVS preparation control is performed in STEP1with reference toFIG. 10. Here, “RVS preparation control” is control of switching from other ranges except for an R range (for example, a forward range (a D range), a neutral range (an N range), a parking range (a P range)) to the R range on the basis of switching requirement to the reverse range (the R range) when operation information of the shift operation unit by a driver is received by the transmission control device ECU.

When the RVS preparation control is not performed, the processing proceeds to STEP2, and it is checked whether the range is the P range. When the range is not the P range, the processing proceeds to STEP3, it is checked whether switching control to the P range by switching requirement from other ranges except for the P range (for example, the D range, the N range and the R range) to the P range is performed.

When the switching control to the P range is not performed, the processing proceeds to STEP4, and it is checked whether the range is the N range. When the range is not the N range, the processing proceeds to STEP5, and it is checked whether the range is the R range. When the range is not the R range (for example, when the range is the D range, when the switching control to the R range or the P range is not performed, or the like), the processing proceeds to STEP6, LC priority control which gives priority to the lock-up clutch2ais performed, and flow processing inFIG. 10of this time is terminated. In the embodiment, flow processing inFIG. 10is repeatedly performed at a predetermined control period (for example, 10 millimeter seconds). In the LC priority control in STEP6, whether electric power is supplied to the solenoid valve122C is determined by a prior determination condition as whether the lock-up clutch2ais engaged.

Here, “LC priority control” is performed such that control of engaging the lock-up clutch2aand synchronizing output of the drive source E and a rotational speed of the input shaft of the automatic transmission3is performed prior to control of operating the parking lock. While the torque converter2amplifies a torque of the drive source E to transmit the amplified torque to the input shaft of the automatic transmission3, a difference in rotational speed between the drive source E and the input shaft of the automatic transmission3may occur.

The lock-up clutch2ais configured such that an output of the drive source E is directly transmitted to the input shaft of the automatic transmission3under a circumstance (for example, during high speed traveling) in which suppression of a difference in rotation between the drive source E in the torque converter2and the input shaft of the automatic transmission3is preferable rather than amplification of the torque of the drive source E in the torque converter2.

In STEP1, when the RVS preparation control is performed, the processing is branched off in STEP7, the LC priority control of controlling the lock-up clutch2aprior to the parking lock mechanism40is performed, supply of electric power to the solenoid valve122C is blocked, and the flow processing inFIG. 10of this time is terminated. Further, in STEP7, since the range is being switched to the R range, the two-way clutch F1is in the fixed state. Then, an engine stall may occur if electric power is supplied to the solenoid valve122C when the two-way clutch F1is in the fixed state. Accordingly, in the LC priority control in STEP7, supply of electric power to the solenoid valve122C is blocked.

In STEP2, when the range is the P range, the processing is branched off in STEP8, the P priority control of prioritizing processing of the P range is performed, supply of electric power to the solenoid valve122C is blocked, the parking lock mechanism40is in the parking locked state, and flow processing inFIG. 10of this time is terminated.

In STEP3, when the range is in switching to P, the processing is branched off to STEP9, and it is checked whether the range is in P input. When the range is not in P input, the processing proceeds to STEP10, it is checked whether the range is the N range. When the range is not the N range (for example, when control of switching from the P range to the D range or the R range is in process), the processing proceeds to STEP8, P priority control of prioritizing processing of the P range is performed, supply of electric power to the solenoid valve122C is blocked, the parking lock mechanism40is in the parking locked state, and flow processing inFIG. 10of this time is terminated.

When the range is in P input in STEP9, the processing proceeds to STEP8, P priority control of prioritizing processing of the P range is performed, supply of electric power to the solenoid valve122C is blocked, the parking lock mechanism40is in the parking locked state, and flow processing inFIG. 10of this time is terminated.

When the range is the N range in STEP10(when switching control from the (P range to the N range is in process), the processing is branched off in STEP11, P priority control of prioritizing processing of the P range is performed, electric power is supplied to the solenoid valve122C, the parking lock mechanism40is in the parking released state, flow processing inFIG. 10of this time is terminated.

When the range is the N range in STEP4, the processing is branched off in STEP11, P priority control of prioritizing processing of the P range is performed, electric power is supplied to the solenoid valve122C, the parking lock mechanism40is in the parking released state, flow processing inFIG. 10of this time is terminated.

When the range is the R range in STEP5, the processing is branched off in STEP7, LC priority control of prioritizing the lock-up clutch2ais performed, supply of electric power to the solenoid valve122C is blocked to prevent an engine stall, flow processing inFIG. 10of this time is terminated.

According to the hydraulic pressure control device100of the embodiment, the one solenoid valve122C can include both of a switching function of the lock-up clutch2aand a switching function of the parking lock mechanism, and in comparison with the case in which a solenoid valve for switching the lock-up clutch and a solenoid valve for switching the parking lock mechanism are separately provided, reduction in size and weight of the hydraulic pressure control device100can be achieved.

In addition, as the flow processing inFIG. 10is performed, switching control of the lock-up clutch2aand switching control of the parking lock mechanism40can be processed using the solenoid valve122C with no trouble.

In addition, while the embodiment of the present disclosure has been described, various design changes may be made without departing from the spirit of the present disclosure.

For example, the number of solenoid valves configured to cause the parking lock mechanism40to be in the parking locked state is not limited to two of the solenoid valve122C and the solenoid valve122E of the embodiment and may be one or three or more.

In addition, the number of solenoid valves for unlocking is not limited to two of the solenoid valve122F and the solenoid valve122D of the embodiment and may be one or three or more.