Hydraulic control device

Abstract

To accurately determine an adhesion state of an application valve while reducing costs of a hydraulic control device and improving efficiency by selectively supplying hydraulic pressure to two hydraulic engagement elements via the application valve from one pressure regulation valve.SOLUTION: When a signal pressure is not supplied from a signal pressure output valve, a selector valve of a hydraulic pressure control device permits supply of a hydraulic pressure to a second hydraulic engagement element side from a common pressure regulation valve. When a signal pressure is supplied from the signal pressure output valve, the selector valve permits supply of a hydraulic pressure to a first hydraulic engagement element side from the common pressure regulation valve and flowout of oil which has been separately supplied from the signal pressure output valve. When oil from the signal pressure output valve is not supplied via the selector valve, an application valve permits supply of a hydraulic pressure from the common pressure regulation valve to the second hydraulic pressure engagement element. When oil from the signal pressure output valve is supplied via the selector valve, the application valve permits supply of a hydraulic pressure from the common pressure regulation valve to the first hydraulic pressure engagement element.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present disclosure relates to a hydraulic control device for a transmission that selectively engages at least any two of a plurality of hydraulic engagement elements to form a plurality of forward and reverse gears. [Background technology]

[0002] Conventionally, there is known an automatic transmission equipped with five hydraulic engaging elements, including a first hydraulic engaging element (B2) that is engaged when first forward gear and reverse gear are established, a second hydraulic engaging element (C1) that is engaged when first forward gear is established and disengaged when reverse gear is established, and a third hydraulic engaging element (C3) that is disengaged when first forward gear is established and engaged when third forward gear and reverse gear are established (see, for example, Patent Document 1). This automatic transmission establishes first to sixth forward gears and reverse gear by engaging any two of the five hydraulic engaging elements, and establishes first forward gear by engaging the first hydraulic engaging element (B2) and the second hydraulic engaging element (C1). The hydraulic control device, which supplies hydraulic pressure to the five hydraulic engagement elements, includes a first solenoid valve capable of outputting a first signal hydraulic pressure, a second solenoid valve capable of outputting a second signal hydraulic pressure, a first changeover valve, a second changeover valve, and five linear solenoid valves that adjust source pressures (line pressures) to generate engagement pressures for the corresponding hydraulic engagement elements. The first changeover valve selectively outputs the source pressure as a forward range pressure and outputs the source pressure as a non-forward range pressure by supplying or discharging the first signal hydraulic pressure. The second changeover valve selectively outputs a first state, in which a forward range pressure supplied to a first input port is output from a first output port, and a second state, in which a non-forward range pressure supplied to a second input port is output from a first output port by supplying or discharging the second signal hydraulic pressure. Furthermore, the five linear solenoid valves include a first linear solenoid valve that adjusts the source pressure to generate a first engagement pressure for the first hydraulic engagement element, a second linear solenoid valve that adjusts the forward range pressure to generate a second engagement pressure for the second hydraulic engagement element, and a third linear solenoid valve that adjusts the hydraulic pressure output from the first output port of the second switching valve to generate a third engagement pressure for the third hydraulic engagement element.

[0003] In this hydraulic control device, even if a failure occurs in two of the first selector valve, the first linear solenoid valve, and the second linear solenoid valve, causing at least one of the second engaging element and the first engaging element to engage, unintended shifting can be prevented by controlling the remaining valve. The second selector valve selectively switches between a state in which forward range pressure or non-forward range pressure is supplied to the third hydraulic engaging element and a state in which the supply of forward range pressure or non-forward range pressure to the third hydraulic engaging element is blocked. Furthermore, when the gear is shifted from reverse to first forward gear, the second selector valve is maintained in the second state by the second signal hydraulic pressure from the second solenoid valve until the second engaging element changes from a disengaged state to at least an engaged state. This allows the second selector valve to block the supply of forward range pressure to the third linear solenoid valve even if an open failure occurs in the third linear solenoid valve, thereby suppressing shock caused by the third hydraulic engaging element and the first hydraulic engaging element remaining engaged. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2019-065963 Summary of the Invention [Problem to be solved by the invention]

[0005] In the conventional hydraulic control device described above, a linear solenoid valve is provided for each of the multiple hydraulic engagement elements of the automatic transmission, but linear solenoid valves are expensive and have a large amount of oil leakage, so in order to reduce the cost and improve the efficiency of the hydraulic control device, it is preferable to reduce the number of linear solenoid valves in the hydraulic control device. Also, the conventional hydraulic control device described above cannot accurately determine the sticking state of the second selector valve that selectively supplies forward range pressure or non-forward range pressure to the third hydraulic engagement element.

[0006] Therefore, the main object of the present disclosure is to selectively supply hydraulic pressure from one pressure regulating valve to two hydraulic engagement elements via an apply valve, thereby reducing the cost and improving the efficiency of the hydraulic control device, while making it possible to accurately determine the stuck state of the apply valve. [Means for solving the problem]

[0007] The hydraulic control device of the present disclosure is a hydraulic control device (60) for a transmission (25) that selectively engages at least any two of a first hydraulic engagement element (C2), a second hydraulic engagement element (B2) that is not simultaneously engaged with the first hydraulic engagement element (C2), and remaining hydraulic engagement elements (C1, C3, C4, B1) to form a plurality of forward and reverse gears, the hydraulic control device comprising: a dual-purpose pressure regulating valve (SL2) that adjusts a source pressure (PL) to generate hydraulic pressure (Psl2) to the first hydraulic engagement element (C1) and the second hydraulic engagement element (B2); and at least one dedicated pressure regulating valve (SL1, SL3, SL4, SL5) that adjusts the source pressure (PL) to generate hydraulic pressure to the corresponding remaining hydraulic engagement elements (C1, C3, C4, B1).a signal pressure output valve (SC2) that outputs a signal pressure (Psc2); and a signal pressure output valve (SC2) that allows the supply of the hydraulic pressure (Psl2) from the dual-purpose pressure regulating valve (SL2) to the second hydraulic engagement element (B2) side when the signal pressure (Psc2) is not being supplied from the signal pressure output valve (SC2), and also allows the supply of the hydraulic pressure (Psl2) from the dual-purpose pressure regulating valve (SL2) to the first hydraulic engagement element (C2) side and the hydraulic pressure (Psl2) separately supplied from the signal pressure output valve (SC2). a switching valve that forms a first communication state that restricts the outflow of oil supplied from the signal pressure output valve (SC2) to the first hydraulic engagement element (C2) side and the outflow of oil separately supplied from the signal pressure output valve (SC2) when the signal pressure (Psc2) is being supplied from the signal pressure output valve (SC2), and that forms a second communication state that restricts the supply of the oil pressure (Psl2) from the dual-purpose pressure regulating valve (SL2) to the second hydraulic engagement element (B2) side. and when the oil (Psc2) is not supplied from the signal pressure output valve (SC2) via the switching valve (200), a first supply state is formed in which the supply of the oil pressure (Psl2) from the dual-purpose pressure regulating valve (SL2) to the first hydraulic engagement element (C2) from the switching valve (200) is restricted and the supply of the oil pressure (Psl2) from the dual-purpose pressure regulating valve (SL2) to the second hydraulic engagement element (B2) is permitted, and and an apply valve (300) that forms a second supply state in which, when the oil (Psc2) is supplied from the signal pressure output valve (SC2) through the switch valve (200), the oil pressure (Psl2) is allowed to be supplied from the combined pressure regulating valve (SL2) to the first hydraulic engagement element (C2) from the switch valve (200) and the oil pressure (Psl2) is restricted to be supplied from the combined pressure regulating valve (SL2) to the second hydraulic engagement element (B2).

[0008] In the hydraulic control device disclosed herein, hydraulic pressure generated (adjusted) by the dual-purpose pressure regulating valve can be selectively supplied from the apply valve to a first hydraulic engagement element and a second hydraulic engagement element that is not simultaneously engaged with the first hydraulic engagement element. This allows the number of pressure regulating valves in the hydraulic control device to be reduced, thereby reducing costs and improving efficiency by reducing oil leakage. Furthermore, when signal pressure from the signal pressure output valve is not supplied to the switching valve, the switching valve, which establishes a first communication state, allows hydraulic pressure to be supplied from the dual-purpose pressure regulating valve to the second hydraulic engagement element and restricts the supply of oil from the signal pressure output valve to the apply valve. The apply valve establishes a first supply state by not receiving oil (signal pressure) from the signal pressure output valve via the switching valve. As a result, the apply valve restricts the supply of hydraulic pressure from the dual-purpose pressure regulating valve to the first hydraulic engagement element, and hydraulic pressure from the dual-purpose pressure regulating valve is supplied to the second hydraulic engagement element via the apply valve. Furthermore, when signal pressure from the signal pressure output valve is supplied to the changeover valve, the switching valve establishing the second communication state allows hydraulic pressure to be supplied from the dual-purpose pressure regulating valve to the first hydraulic engagement element and allows oil to be supplied from the signal pressure output valve to the apply valve, and the apply valve, which receives oil (signal pressure) from the signal pressure output valve via the changeover valve, establishes the second supply state. As a result, the apply valve restricts the supply of hydraulic pressure from the dual-purpose pressure regulating valve to the second hydraulic engagement element, and hydraulic pressure from the dual-purpose pressure regulating valve is supplied to the first hydraulic engagement element via the apply valve. Therefore, when the apply valve is stuck in the first supply state, even if signal pressure from the signal pressure output valve is supplied to the changeover valve and the changeover valve allows hydraulic pressure to be supplied from the dual-purpose pressure regulating valve to the first hydraulic engagement element and oil separately supplied from the signal pressure output valve to flow out, the first hydraulic engagement element cannot be engaged and the transmission enters the neutral state.In contrast, when the apply valve is stuck in the second supply state, signal pressure is no longer supplied from the signal pressure output valve to the switching valve, and even if the switching valve allows hydraulic pressure to be supplied from the dual-purpose pressure regulating valve to the second hydraulic engagement element, the second hydraulic engagement element cannot be engaged and the transmission enters a neutral state. As a result, the hydraulic control device of the present disclosure can accurately determine the stuck state of the apply valve from the presence or absence of signal pressure output from the signal pressure output valve and the state of the gear stage of the transmission. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a schematic configuration diagram of a vehicle equipped with a power transmission device including a hydraulic control device of the present disclosure. [Figure 2] FIG. 2 is a schematic diagram showing the configuration of a power transmission device mounted on the vehicle of FIG. [Figure 3] 3 is an operation table showing the relationship between each gear position of the transmission included in the power transmission device of FIG. 2 and the operating state of the hydraulic engagement elements. [Figure 4] 1 is a system diagram showing a main part of a hydraulic control device of the present disclosure. [Figure 5] 4 is an operation table showing energization states of solenoid valves included in the hydraulic control device of the present disclosure. [Figure 6] FIG. 2 is a system diagram for explaining the operation of the hydraulic control device of the present disclosure. [Figure 7] FIG. 2 is a system diagram for explaining the operation of the hydraulic control device of the present disclosure. [Figure 8] FIG. 2 is a system diagram for explaining the operation of the hydraulic control device of the present disclosure. [Figure 9] FIG. 2 is a system diagram for explaining the operation of the hydraulic control device of the present disclosure. [Figure 10] FIG. 2 is a system diagram for explaining the operation of the hydraulic control device of the present disclosure. [Figure 11] FIG. 2 is a system diagram for explaining the operation of the hydraulic control device of the present disclosure. [Figure 12] FIG. 2 is a system diagram for explaining the operation of the hydraulic control device of the present disclosure. [Figure 13] FIG. 2 is a system diagram for explaining the operation of the hydraulic control device of the present disclosure. [Figure 14] 4 is a flowchart for explaining the operation of the hydraulic control device of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0010] Next, embodiments of the present disclosure will be described with reference to the drawings.

[0011] Fig. 1 is a schematic configuration diagram of a vehicle 10 equipped with a power transmission device 20 including a hydraulic control device 60 according to the present disclosure. The vehicle 10 shown in the figure is a front-wheel drive vehicle having an engine 12 and a power transmission device 20 that transmits power from the engine 12 to left and right drive wheels (front wheels) DW. As shown in Fig. 1, the vehicle 10 also includes an engine electronic control unit (hereinafter referred to as "EGECU") 14 that controls the engine 12, a brake electronic control unit (hereinafter referred to as "brake ECU") 16 that controls an electronically controlled hydraulic brake unit (not shown), and a transmission electronic control unit (hereinafter referred to as "TMECU") 21 that controls the power transmission device 20.

[0012] The EGECU 14 is a microcomputer including a CPU (not shown) and receives signals from various sensors, such as a crankshaft position sensor (not shown) that detects the rotational position of the crankshaft of the engine 12, an accelerator pedal position sensor 92 that detects the depression amount (operation amount) of an accelerator pedal 91, and a vehicle speed sensor 99, as well as signals from the brake ECU 16 and the TMECU 21. Based on these signals, the EGECU 14 controls electronically controlled throttle valves, fuel injection valves, spark plugs, and other components (not shown). The brake ECU 16 is also a microcomputer including a CPU (not shown) and receives signals from various sensors, such as a master cylinder pressure sensor 94 that detects a master cylinder pressure corresponding to the depression amount of a brake pedal 93, and a vehicle speed sensor 99, as well as signals from the EGECU 14. The brake ECU 16 controls a brake actuator (hydraulic actuator), and other components (not shown), based on these signals.

[0013] The TMECU 21 is also a microcomputer including a CPU (not shown) and receives signals from various sensors such as a shift position sensor 96 that detects the shift position, which is the operating position of the shift lever 95, an accelerator pedal position sensor 92, an input rotation speed sensor 97 that detects the input rotation speed of the automatic transmission 25 (the rotation speed of the turbine runner 23b or the input shaft 26 of the automatic transmission 25), an output rotation speed sensor 98 that detects the output rotation speed of the automatic transmission 25 (the rotation speed of the ring gear 37 of the second planetary gear mechanism 35), and a vehicle speed sensor 99, as well as signals from the EGECU 14 and the brake ECU 16. The TMECU 21 controls the power transmission device 20 based on these signals. In addition, in this embodiment, the shift positions of the shift lever 95 include a parking position (P) selected when parking, a reverse position (R) for driving backward, a neutral position (N) for cutting off the transmission of power by the automatic transmission 25, and a drive position (D) for normal forward driving, as well as a sport position (S) that allows the driver to select any gear.

[0014] As shown in FIG. 2, the power transmission device 20 includes a transmission case 22, a starting device (fluid transmission device) 23 housed within the transmission case 22, a mechanical oil pump 24 driven by power from the engine 12, an automatic transmission 25, a gear mechanism (gear train) 40, a differential gear (differential mechanism) 50, a hydraulic control device 60, and the like.

[0015] The transmission case 22 includes a housing 22a, a transaxle case 22b fastened (fixed) to the housing 22a, a front support 22c fastened (fixed) to the transaxle case 22b so as to be positioned between the housing 22a and the transaxle case 22b, and a center support 22d fastened (fixed) to the transaxle case 22b. In this embodiment, the housing 22a, the transaxle case 22b, and the center support 22d are made of, for example, an aluminum alloy, and the front support 22c is made of steel (iron alloy) or an aluminum alloy.

[0016] The starting device 23 includes a front cover connected to the crankshaft of the engine 12 via a drive plate or the like (not shown), an input-side pump impeller 23p having a pump shell tightly fixed to the front cover, an output-side turbine runner 23t connected to an input shaft 26 of an automatic transmission 25, a stator 23s arranged inside the pump impeller 23p and turbine runner 23t to straighten the flow of hydraulic oil from the turbine runner 23t to the pump impeller 23p, and a one-way clutch 23o supported by a stator shaft (not shown) and limiting the rotation direction of the stator 23s to one direction. The pump impeller 23p, turbine runner 23t, and stator 23s form a torque converter that has a torque amplifying effect.

[0017] Furthermore, the starting device 23 includes a lockup clutch 23c that connects and disconnects the front cover and the input shaft 26 of the automatic transmission 25, and a damper device 23d that damps vibrations between the front cover and the input shaft 26 of the automatic transmission 25. In this embodiment, the lockup clutch 23c is configured as a multi-plate friction hydraulic clutch having a plurality of friction engagement plates (friction plates and separator plates). However, the lockup clutch 23c may also be a single-plate friction hydraulic clutch. The starting device 23 may also include a fluid coupling that does not have a stator 23s.

[0018] The mechanical oil pump 24 is a gear pump that includes an external gear (inner rotor) 241 connected to the pump impeller 23p of the starting device 23 via a wrapping transmission mechanism 240, an internal gear (outer rotor) 242 meshing with the external gear 241, a pump body and a pump cover (neither of which are shown) that define a gear chamber (not shown) that houses the external gear 241 and the internal gear 242, and is disposed on an axis separate from the input shaft 26 of the automatic transmission 25. The mechanical oil pump 24 is driven by power from the engine 12 via the wrapping transmission mechanism 240, and draws in hydraulic oil (ATF) stored in a hydraulic oil reservoir (not shown) provided at the bottom of the transaxle case 22b, and pumps it out to the hydraulic control device 60. The wrapping transmission mechanism 240 includes a drive sprocket that rotates integrally with the pump impeller 23p of the starting device 23, a driven sprocket that rotates integrally with the external gear 241 of the mechanical oil pump 24, and a chain that is wrapped around the drive sprocket and driven sprocket.

[0019] The automatic transmission 25 is configured as an eight-speed transmission, and as shown in FIG. 2, includes a double-pinion first planetary gear mechanism 30, a Ravigneaux second planetary gear mechanism 35, four clutches C1, C2, C3, and C4 as hydraulic engagement elements for changing the power transmission path from the input side to the output side, and two brakes B1 and B2.

[0020] The first planetary gear mechanism 30 has a sun gear (fixed element) 31 which is an external gear, a ring gear 32 which is an internal gear arranged concentrically with the sun gear 31, and a planetary carrier 34 which holds a plurality of pairs of two pinion gears 33a, 33b which mesh with each other and in which one meshes with the sun gear 31 and the other with the ring gear 32, so that the pairs can rotate (rotate) and revolve. As shown in the figure, the sun gear 31 of the first planetary gear mechanism 30 is non-rotatably connected (fixed) to the transmission case 22 via the front support 22c, and the planetary carrier 34 of the first planetary gear mechanism 30 is connected to the input shaft 26 so as to be rotatable integrally therewith. The first planetary gear mechanism 30 is also used as a so-called reduction gear, and reduces the speed of power transmitted to the planetary carrier 34, which is the input element, and outputs the reduced power from the ring gear 32, which is the output element.

[0021] The second planetary gear mechanism 35 has a first sun gear 36a and a second sun gear 36b which are external gears, a ring gear 37 which is an internal gear arranged concentrically with the first and second sun gears 36a, 36b, a plurality of short pinion gears 38a which mesh with the first sun gear 36a, a plurality of long pinion gears 38b which mesh with the second sun gear 36b and the plurality of short pinion gears 38a and also mesh with the ring gear 37, and a planetary carrier 39 which holds the plurality of short pinion gears 38a and the plurality of long pinion gears 38b so that they can rotate freely (rotate freely) and revolve freely. The ring gear 37 of the second planetary gear mechanism 35 functions as an output member of the automatic transmission 25, and the power transmitted from the input shaft 26 to the ring gear 37 is transmitted to the left and right drive wheels via the gear mechanism 40, the differential gear 50 and the drive shaft 51.

[0022] The clutch C1 connects and disconnects the ring gear 32 of the first planetary gear mechanism 30 and the first sun gear 36a of the second planetary gear mechanism 35 to and from each other. The clutch C2 connects and disconnects the input shaft 26 and the planetary carrier 39 of the second planetary gear mechanism 35 to and from each other. The clutch C3 connects and disconnects the ring gear 32 of the first planetary gear mechanism 30 and the second sun gear 36b of the second planetary gear mechanism 35 to and from each other. The clutch C4 connects and disconnects the planetary carrier 34 of the first planetary gear mechanism 30 and the second sun gear 36b of the second planetary gear mechanism 35 to and from each other. In this embodiment, clutches C1, C2, C3 and C4 are multi-plate friction hydraulic clutches including a piston, a plurality of friction engagement plates (friction plates and separator plates), an engagement oil chamber to which engagement oil pressure (hydraulic oil) is supplied from the hydraulic control device 60, a centrifugal oil pressure cancellation chamber to which hydraulic oil is supplied from the hydraulic control device 60 to cancel the centrifugal oil pressure generated in the engagement oil chamber, etc.

[0023] Brake B1 fixes (connects) second sun gear 36b of second planetary gear mechanism 35 to transmission case 22 so as not to rotate, and releases the fixation of second sun gear 36b to transmission case 22. Brake B2 fixes planetary carrier 39 of second planetary gear mechanism 35 to transmission case 22 so as not to rotate, and releases the fixation of planetary carrier 39 to transmission case 22. In this embodiment, multi-plate friction hydraulic brakes including a piston, a plurality of friction engagement plates (friction plates and separator plates), an engagement oil chamber to which hydraulic oil is supplied, and the like are used as brakes B1 and B2.

[0024] These clutches C1-C4 and brakes B1 and B2 operate by receiving hydraulic fluid supplied and discharged from the hydraulic control device 60. FIG. 3 shows an operation table illustrating the relationship between each gear of the automatic transmission 25 and the operating states of the clutches C1-C4 and brakes B1 and B2. The automatic transmission 25 provides forward first through eighth gears and reverse first and second gears by setting the clutches C1-C4 and brakes B1 and B2 to the states shown in the operation table of FIG. 3. In other words, each gear of the automatic transmission 25 is formed by engaging any two of the clutches C1-C4 and brakes B1 and B2. Note that at least one of the clutches C1-C4 and brakes B1 and B2 may be a meshing engagement element such as a dog clutch.

[0025] The gear mechanism 40 includes a counter drive gear 41, a counter shaft 42, a counter driven gear 43, a drive pinion gear 44, and a differential ring gear 45. The counter drive gear 41 is connected to the ring gear 37 of the second planetary gear mechanism 35 of the automatic transmission 25, and the counter shaft 42 extends parallel to the input shaft 26 of the automatic transmission 25. The counter driven gear 43 is fixed to the counter shaft 42 and meshes with the counter drive gear 41. The drive pinion gear 44 is formed on (or fixed to) the counter shaft 42, and the differential ring gear 45 meshes with the drive pinion gear 44 and is connected to a differential gear 50.

[0026] 4 is a system diagram showing the main parts of a hydraulic control device 60 of the present disclosure. The hydraulic control device 60 is connected to the above-mentioned mechanical oil pump 24, which is capable of drawing and discharging hydraulic oil from a hydraulic oil reservoir in the transaxle case 22b through a strainer. The hydraulic control device 60 is controlled by the TMECU 21, and generates the hydraulic pressure required by the starting device 23 and the automatic transmission 25, while supplying hydraulic oil to low-pressure oil supply parts (lubricated parts) such as lubrication targets such as various bearings and the centrifugal hydraulic cancel chambers of the clutches C1-C4. As shown in the figure, the hydraulic control device 60 includes a valve body 600B in which a plurality of oil passages and the like are formed, a primary regulator valve, a secondary regulator valve, and a modulator valve (none of which are shown), linear solenoid valves SL1, SL2, SL3, SL4, and SL5, a first signal pressure output valve SC1, a second signal pressure output valve SC2, a third signal pressure output valve SC3, a first changeover valve 100, a second changeover valve (changeover valve) 200, and a third changeover valve (apply valve) 300. In this embodiment, the hydraulic control device 60 does not have a manual valve that operates in conjunction with the shift lever 95, and constitutes a shift-by-wire device together with the TMECU 21. In other words, the TMECU 21 controls the hydraulic control device 60 so that the automatic transmission 25 is in a state corresponding to the shift position of the shift lever 95 set by the driver.

[0027] The valve body 600 is attached to, for example, a side portion of the transaxle case 22b that constitutes the transmission case 22. A primary regulator valve (not shown) of the hydraulic control device 60 adjusts the pressure of hydraulic oil supplied from the mechanical oil pump 24 to an oil passage L21 of the valve body 600, i.e., line pressure PL, in response to a signal pressure supplied from a linear solenoid valve (not shown). The linear solenoid valve that outputs the signal pressure is controlled by the TMECU 21 to adjust the pressure of hydraulic oil from the mechanical oil pump 24 side (e.g., a modulator valve) and output a pressure corresponding to the accelerator opening or throttle valve opening of the vehicle 10. The secondary regulator valve adjusts the pressure of hydraulic oil drained from the primary regulator valve in response to the signal pressure from the linear solenoid valve to generate a secondary pressure (circulation pressure) lower than the line pressure PL. Furthermore, the modulator valve reduces (adjusts) the line pressure PL from the oil passage L1 to generate a substantially constant modulator pressure Pmod.

[0028] The linear solenoid valves SL1-SL5 have a common configuration and include an electromagnetic part that is energized and controlled by the TMECU 21, a spool that is axially movably disposed within a sleeve held by the valve body 600, a spring that biases the spool toward the electromagnetic part, an input port that communicates with oil passage L1 of the valve body 600 via oil passage L2 or oil passage L3, an output port, a feedback port that communicates with the output port, and a drain port. In this embodiment, the linear solenoid valves SL1-SL5 are normally closed valves that open when current is supplied to the electromagnetic part, and adjust the line pressure PL that is supplied to the input port as the source pressure in accordance with the current applied to the electromagnetic part and output it from the output port. That is, in the linear solenoid valves SL1-SL5, the pressure of the hydraulic oil supplied to the input port (line pressure PL) is adjusted to the desired pressure by balancing the thrust generated by supplying power to the electromagnetic part (coil), the spring force, and the thrust toward the electromagnetic part acting on the spool due to the hydraulic pressure supplied from the output port to the feedback port.

[0029] In this embodiment, linear solenoid valve SL1 adjusts line pressure PL to generate hydraulic pressure for clutch C1, and linear solenoid valve SL2 adjusts line pressure PL to generate hydraulic pressure Psl2 for clutch C2 and brake B2. Furthermore, linear solenoid valve SL3 adjusts line pressure PL to generate hydraulic pressure for clutch C3, linear solenoid valve SL4 adjusts line pressure PL to generate hydraulic pressure for clutch C4, and linear solenoid valve SL5 adjusts line pressure PL to generate hydraulic pressure for brake B1. That is, in hydraulic control device 60, linear solenoid valves SL1, SL3-SL5 are dedicated pressure regulating valves that generate hydraulic pressure for the corresponding clutches C1, C3, C4 or brake B1, respectively, and linear solenoid valve SL2 is a dual-purpose pressure regulating valve that corresponds to both clutch C2 and brake B2. In this embodiment, the input ports of linear solenoid valves SL1, SL4, and SL5 corresponding to clutches C1, C4 or brake B1, which are engaged only when first to eighth forward speeds (forward stages) are established, communicate with oil passage L21 via first selector valve 100 and oil passage L22. Furthermore, the input port of linear solenoid valve SL2 communicates with oil passage L21 via oil passage L23, and the input port of linear solenoid valve SL3 communicates with oil passage L21 via oil passage L24.

[0030] The first signal pressure output valve SC1 is, for example, a normally closed on-off solenoid valve that is energized and controlled by the TMECU 21, and the input port of the first signal pressure output valve SC1 is connected to an oil passage L21 formed in the valve body 600 or an output port of a modulator valve. When current is supplied to the electromagnetic part, the first signal pressure output valve SC1 causes the line pressure PL or modulator pressure Pmod, which is supplied to the input port as the source pressure, to flow from the output port as a first signal pressure Psc1.

[0031] The second signal pressure output valve SC2 is also, for example, a normally closed on / off solenoid valve that is energized and controlled by the TMECU 21, and the input port of the second signal pressure output valve SC2 communicates with an oil passage L1 formed in the valve body 600 or an output port of a modulator valve. When current is supplied to the electromagnetic part, the second signal pressure output valve SC2 causes the source pressure (line pressure PL or modulator pressure Pmod) that is common to the first signal pressure output valve SC1 and that is supplied to the input port to flow out from the output port as a second signal pressure Psc2.

[0032] The third signal pressure output valve SC3 is also, for example, a normally closed on-off solenoid valve that is energized and controlled by the TMECU 21, and the input port of the third signal pressure output valve SC3 communicates with an oil passage L1 formed in the valve body 600 or an output port of a modulator valve. When current is supplied to the electromagnetic part, the third signal pressure output valve SC3 causes the source pressure (line pressure PL or modulator pressure Pmod) that is supplied to the input port and is common to the first and second signal pressure output valves SC1, SC2, to flow out from the output port as a third signal pressure Psc3.

[0033] The first switching valve 100 is a spool valve including a first spool S1 having a plurality of lands and arranged axially movably within the valve body 600, and a first spring SP1 that urges the first spool S1 upward in Fig. 4. Furthermore, the first switching valve 100 includes a source pressure input port 101, a source pressure output port 102, a first signal pressure input port 105, a holding pressure input port 106, an inlet port 111, an outlet port 112, and a parking port 117.

[0034] The source pressure input port 101 of the first switching valve 100 communicates with an oil passage L21 in the valve body 600, and the source pressure output port 102 communicates with an oil passage L22 formed in the valve body 600. The first signal pressure input port 105 is located on the opposite side of the spring chamber in which the first spring SP1 is disposed and communicates with the output port of the first signal pressure output valve SC1 via an oil passage L25 formed in the valve body 600. The holding pressure input port 106 communicates with the spring chamber in which the first spring SP1 is disposed and also communicates with an oil passage L26 formed in the valve body 600. The inlet port 111 communicates with the output port of the second signal pressure output valve SC2 via an oil passage L27 formed in the valve body 600, and the outlet port 112 communicates with an oil passage L28 formed in the valve body 600. The oil passage L26, which communicates with the holding pressure input port 106, branches off from the oil passage L28. As a result, the holding pressure input port 106 communicates with the outflow port 112 via oil passage L26 and a part of oil passage L28. Furthermore, the parking port 117 communicates with the hydraulic inlet of the shift-by-wire parking lock mechanism 70 via an oil passage formed in the valve body 600.

[0035] In this embodiment, the installation state of the first switching valve 100 is a first state (the state of the left half in FIG. 4) in which the first spool S1 is urged upward in FIG. 4 by the first spring SP1 without the first or second signal pressure Psc1, Psc2 from the first or second signal pressure output valve SC1, SC2 being supplied to the first signal pressure input port 105 and the holding pressure input port 106. In the first state (installed state) of the first switching valve 100, the first spool S1 communicates between the main pressure input port 101 and the main pressure output port 102, and also communicates between the inlet port 111 and the outlet port 112.

[0036] Furthermore, when the first switching valve 100 is in the first state, if current is supplied to the electromagnetic part of the second signal pressure output valve SC2, the hydraulic oil (second signal pressure Psc2) from the second signal pressure output valve SC2 flows into the inlet port 111 via the oil passage L27 and flows out to the oil passage L28 via the outlet port 112. Furthermore, a portion of the hydraulic oil from the second signal pressure output valve SC2 flows into the holding pressure input port 106 via the oil passage L28 and the oil passage L26. As a result, the second signal pressure Psc2 from the second signal pressure output valve SC2 acts on the pressure-receiving surface of the first spool S1 on the first spring SP1 side, and the first switching valve 100 is in the first state. Furthermore, in this embodiment, the pressure-receiving surface of the first spool S1 on the first signal pressure input port 105 side and the pressure-receiving surface on the holding pressure input port 106 (first spring SP1) side have the same area. Therefore, when the first switching valve 100 forms the first state and the second signal pressure output valve SC2 outputs the second signal pressure Psc2, even if the first signal pressure Psc1 from the first signal pressure output valve SC1 is supplied to the first signal pressure input port 105, the first switching valve 100 continues to form the first state.

[0037] On the other hand, when the second signal pressure Psc2 from the second signal pressure output valve SC2 is not supplied to the holding pressure input port 106 and the first signal pressure Psc1 from the first signal pressure output valve SC1 is supplied to the first signal pressure input port 105, the first spool S1 moves downward in FIG. 4 against the biasing force of the first spring SP1 due to a thrust acting on the first spool S1 by the first signal pressure Psc1, and the first changeover valve 100 is in the second state (the state of the right half in FIG. 4). In the second state of the first changeover valve 100, the first spool S1 blocks communication between the main pressure input port 101 and the main pressure output port 102 and also blocks communication between the inlet port 111 and the outlet port 112. Furthermore, in the second state, the first spool S1 connects the inlet port 111 to the parking port 117.

[0038] The second switching valve 200 is a spool valve including a second spool S2 having a plurality of lands and arranged axially movably within the valve body 600, and a second spring SP2 that biases the second spool S2 upward in Fig. 4. Furthermore, the second switching valve 200 includes an input port 201, a first output port 203, a second output port 204, a second signal pressure input port 205, a first inflow port 211, a second inflow port 212, and a signal pressure outlet port 215.

[0039] The input port 201 of the second switching valve 200 communicates with the output port of the linear solenoid valve SL2 via an oil passage L31 formed in the valve body 600, the first output port 203 communicates with an oil passage L33 formed in the valve body 600, and the second output port 204 communicates with an oil passage L34 formed in the valve body 600. Furthermore, the second signal pressure input port 205 is located on the opposite side of the spring chamber in which the second spring SP2 is disposed, and communicates with the outflow port 112 of the first switching valve 100 via oil passages L30 and L28 formed in the valve body 600. Furthermore, the first inflow port 211 communicates with the outflow port 112 of the first switching valve 100 via an oil passage L28 formed in the valve body 600. Furthermore, the second inflow port 212 communicates with output ports of linear solenoid valves SL3, SL4, and SL5, which serve as dedicated pressure regulating valves, via an oil passage L32 formed in the valve body 600. The signal pressure outflow port 215 communicates with an oil passage L35 formed in the valve body 600.

[0040] In this embodiment, the mounted state of the second switching valve 200 is a first communication state (a state of the left half in FIG. 4 ) in which the second spool S2 is urged upward in FIG. 4 by the second spring SP2 without hydraulic oil (second signal pressure Psc2) being supplied to the second signal pressure input port 205 from the second signal pressure output valve SC2 via the inlet port 111, the outlet port 112, and the oil passages L28 and L30 of the first switching valve 100. In the first communication state (mounted state) of the second switching valve 200, the second spool S2 communicates between the input port 201 and the second output port 204 and between the second inlet port 212 and the signal pressure outlet port 215. Furthermore, in the first communication state, the second spool S2 blocks communication between the input port 201 and the first output port 203 and between the first inlet port 211 and the signal pressure outlet port 215.

[0041] On the other hand, when hydraulic oil, i.e., the second signal pressure Psc2, is supplied to the second signal pressure input port 205 from the second signal pressure output valve SC2, the second spool S2 moves downward in FIG. 4 against the biasing force of the second spring SP2 due to a thrust force acting on the second spool S2 due to the second signal pressure Psc2, and the second changeover valve 200 is in the second communication state (the state of the right half in FIG. 4). In the second communication state of the second changeover valve 200, the second spool S2 communicates between the input port 201 and the first output port 203 and between the first inflow port 211 and the signal pressure outlet port 215. Furthermore, in the second communication state, the second spool S2 blocks communication between the input port 201 and the second output port 204 and between the second inflow port 212 and the signal pressure outlet port 215.

[0042] The third switching valve 300 is a spool valve including a third spool S3 having a plurality of lands and arranged axially movably within the valve body 600, and a third spring SP3 that urges the third spool S3 upward in Fig. 4. The third switching valve 300 also includes a first input port 311, a second input port 312, a first supply port 313, a second supply port 314, a third signal pressure input port 315, a switching port 316, a holding pressure inlet port 317, a holding pressure outlet port 318, and a holding pressure introduction port 319.

[0043] The first input port 311 of the third changeover valve 300 communicates with the first output port 203 of the second changeover valve 200 via an oil passage L33 formed in the valve body 600, and the second input port 312 communicates with the second output port 204 of the second changeover valve 200 via an oil passage L34 formed in the valve body 600. The first supply port 313 communicates with an engagement oil chamber of the clutch C2 via an oil passage or the like formed in the valve body 600, and the second supply port 314 communicates with an engagement oil chamber of the brake B2 via an oil passage or the like formed in the valve body 600. The third signal pressure input port 305 is disposed on the opposite side of the spring chamber in which the third spring SP3 is disposed, and communicates with the signal pressure outlet port 215 of the second changeover valve 200 via the oil passage L35 of the valve body 600. The switching port 316 is also connected to a spring chamber in which the first spring SP1 is disposed, and is also connected to an output port of the third signal pressure output valve SC3 via an oil passage formed in the valve body 600. The holding pressure inlet port 317 is supplied with a substantially constant modulator pressure Pmod generated by the modulator valve. The holding pressure outlet port 318 is also connected to an oil passage L36 formed in the valve body 600. The holding pressure introduction port 319 faces a holding pressure receiving surface S3p formed in the third spool S3, and is also connected to the holding pressure outlet port 318 via the oil passage L36. The holding pressure inlet port 317 may be supplied with line pressure PL instead of the modulator pressure Pmod.

[0044] In this embodiment, the installation state of the third switching valve 300 is a first supply state (the state of the left half in FIG. 4 ) in which the third spool S3 is urged upward in FIG. 4 by the third spring SP3 without hydraulic oil (second signal pressure Psc2) from the second signal pressure output valve SC2 or hydraulic oil (hydraulic pressure) from any one of the linear solenoid valves SL3, SL4, and SL5 being supplied to the third signal pressure input port 315 via the second switching valve 200 and the oil passage L35. In the first supply state (installed state) of the third switching valve 300, the third spool S3 blocks communication between the first input port 311 and the first supply port 313 and establishes communication between the second input port 312 and the second supply port 314.

[0045] On the other hand, when hydraulic oil (second signal pressure Psc2) from second signal pressure output valve SC2 or hydraulic oil (hydraulic pressure) from any one of linear solenoid valves SL3, SL4, and SL5 is supplied to third signal pressure input port 315 via second selector valve 200 and oil passage L35, third spool S3 moves downward in FIG. 4 against the biasing force of third spring SP3 due to a thrust acting on third spool S3 by second signal pressure Psc2, and third selector valve 300 establishes the second supply state (the state of the right half in FIG. 4). In the second supply state of third selector valve 300, third spool S3 connects first input port 311 and first supply port 313 and blocks communication between second input port 312 and second supply port 314.

[0046] In addition, in the hydraulic control device 60, when the third switching valve 300 establishes the second supply state, the hydraulic oil supplied from the modulator valve to the holding pressure inlet port 317, i.e., the modulator pressure Pmod, is supplied to the holding pressure introduction port 319 via the holding pressure outlet port 318 and acts on the holding pressure pressure receiving surface S3p of the third spool S3. Furthermore, the pressure receiving area of ​​the holding pressure pressure receiving surface S3p is determined so that the thrust generated by the modulator pressure Pmod acting on the holding pressure pressure receiving surface S3p balances with the biasing force generated by the third spring SP3 in the second supply state. As a result, once the third switching valve 300 establishes the second supply state by supplying hydraulic oil (hydraulic pressure) to the third signal pressure input port 315, the third switching valve 300 continues to establish (maintain) the second supply state even if the supply of hydraulic oil (hydraulic pressure) to the third signal pressure input port 315 is cut off. In contrast, when the third signal pressure is supplied from the third signal pressure output valve SC3 to the switching port 316 (spring chamber), the third switching valve 300 forms the first supply state regardless of whether or not hydraulic oil (hydraulic pressure) is supplied to the third signal pressure input port 315.

[0047] Next, the operation of the hydraulic control device 60 will be described with reference to FIGS.

[0048] When the ignition switch (start switch) of the vehicle 10 is turned on with the shift lever 95 set to the parking position, the TMECU 21 supplies current to the electromagnetic parts of the first and second signal pressure output valves SC1, SC2 so that the first and second signal pressures Psc1, Psc2 are output, as shown in Fig. 5. As a result, as shown in Fig. 6, the first switching valve 100 establishes the second state, blocking communication between the source pressure input port 101 and the source pressure output port 102 and between the inlet port 111 and the outlet port 112, and establishing communication between the inlet port 111 and the parking port 117. Therefore, when the shift lever 95 is set to the parking position, as shown in Fig. 6, the second signal pressure Psc2 from the second signal pressure output valve SC2 is supplied to the parking lock mechanism 70 via the first switching valve 100 (the inlet port 111 and the parking port 117), thereby establishing the parking lock state.

[0049] Furthermore, by blocking communication between the inlet port 111 and the outlet port 112 of the first switching valve 100, the second signal pressure Psc2 from the second signal pressure output valve SC2 is not supplied to the second signal pressure input port 205 (and the first inlet port 211) of the second switching valve 200, and the second switching valve 200 establishes the first communication state. As a result, the input port 201 communicates with the second output port 204, and the second inlet port 212 communicates with the signal pressure outlet port 215. Furthermore, by blocking communication between the first inlet port 211 and the signal pressure outlet port 215 of the second switching valve 200, the second signal pressure Psc2 from the second signal pressure output valve SC2 is not supplied to the third signal pressure input port 315 of the third switching valve 300, and even if the modulator pressure Pmod is supplied to the holding pressure inlet port 317, the third switching valve 300 establishes the first supply state. As a result, the second input port 312 and the second supply port 314 are connected to each other, and the first input port 311 and the first supply port 313 are disconnected from each other. Furthermore, when the shift lever 95 is set to the neutral position, the TMECU 21 supplies current to the electromagnetic part of the first signal pressure output valve SC1 so that the first signal pressure Psc1 is output, and de-energizes the second and third signal pressure output valves SC2, SC3, as shown in Fig. 5. This stops the supply of the second signal pressure Psc2 from the second signal pressure output valve SC2 to the parking lock mechanism 70, thereby enabling the parking lock state to be released.

[0050] On the other hand, when the driver sets the shift lever 95 to the reverse position, the TMECU 21 supplies current to the electromagnetic parts of the first and third signal pressure output valves SC1, SC3 so that the first and third signal pressures Psc1, Psc3 are output, as shown in FIG. 5. Furthermore, the TMECU 21 controls the linear solenoid valves SL2 and SL3 according to a predetermined procedure. As a result, as shown in FIG. 7, the first switching valve 100 establishes the second state, and the second switching valve 200 establishes the first communication state. Furthermore, by supplying the third signal pressure from the third signal pressure output valve SC3 to the switching port 316 (spring chamber), the third switching valve 300 establishes the first supply state, regardless of whether or not hydraulic oil (hydraulic pressure) is supplied to the third signal pressure input port 315. Then, hydraulic oil (line pressure PL) from the primary regulator valve side is supplied to the input port of linear solenoid valve SL3 via oil passages L21 and L24, and hydraulic oil whose pressure is adjusted by linear solenoid valve SL3 is supplied to the engagement oil chamber of clutch C3. Also, hydraulic oil (line pressure PL) from the primary regulator valve side is supplied to the input port of linear solenoid valve SL2 via oil passage L23, and hydraulic oil whose pressure is adjusted by linear solenoid valve SL2 (hydraulic pressure Psl2) is supplied to the engagement oil chamber of brake B2 via input port 201 and second output port 204 of second changeover valve 200 and second input port 312 and second supply port 314 of third changeover valve 300.

[0051] As a result, the clutch C3 and the brake B2 can be engaged to establish first reverse gear. When the shift lever 95 is set to the reverse position, the TMECU 21 starts controlling the linear solenoid valves SL2 and SL3 after the third signal pressure Psc3 is supplied from the third signal pressure output valve SC3 to the switching port 316 of the third changeover valve 300. This makes it possible to maintain the third changeover valve 300 in the first supply state even when hydraulic oil (hydraulic pressure) from the linear solenoid valve SL3 is supplied to the third signal pressure input port 315 via the second inlet port 212 and the signal pressure outlet port 215 of the second changeover valve 200.

[0052] Furthermore, when the driver sets the shift lever 95 to the drive position or sport position (forward driving position), the TMECU 21 stops the power supply to the electromagnetic parts of the first, second and third signal pressure output valves SC1, SC2 and SC3 to stop the output of all of the first, second and third signal pressures Psc1, Psc2 and Psc3, as shown in Fig. 5. As a result, as shown in Fig. 8, the first switching valve 100 establishes the first state, and the main pressure input port 101 and the main pressure output port 102 communicate with each other, and the inlet port 111 and the outlet port 112 communicate with each other. Furthermore, since the second signal pressure Psc2 is not output from the second signal pressure output valve SC2, even if the inlet port 111 and outlet port 112 of the first selector valve 100 are in communication with each other, the second selector valve 200 establishes the first supply state, and the input port 201 and second output port 204 are in communication with each other, and the second inlet port 212 and signal pressure outlet port 215 are in communication with each other. Furthermore, even if the second inlet port 212 and signal pressure outlet port 215 of the second selector valve 200 are in communication with each other, if no hydraulic pressure is output from any of the linear solenoid valves SL3, SL4, and SL5, the third selector valve 300 establishes the first supply state, and the second input port 312 and second supply port 314 are in communication with each other.

[0053] When the shift lever 95 is set to a forward drive position such as the drive position, hydraulic oil (line pressure PL) from the primary regulator valve is supplied from oil passage L21 of the valve body 600 to input ports of linear solenoid valves SL1, SL4, and SL5 corresponding to the clutches C1, C4 and brake B1, which are engaged only when the forward gear is established, via a source pressure input port 101 and a source pressure output port 102 of the first selector valve 100, oil passage L22, etc. The input port of linear solenoid valve SL2 is also in communication with oil passage L1 via oil passage L23. Therefore, by controlling the linear solenoid valves SL1 and SL2 by the TMECU 21, hydraulic oil whose pressure is adjusted by the linear solenoid valve SL1 is supplied to the engagement oil chamber of the clutch C1, and hydraulic oil whose pressure is adjusted by the linear solenoid valve SL2 (hydraulic pressure Psl2) is supplied to the engagement oil chamber of the brake B2 via the oil passage L31, the input port 201 and the second output port 204 of the second changeover valve 200, the oil passage L34, and the second input port 312 and the second supply port 314 of the third changeover valve 300. This makes it possible to engage the clutch C1 and the brake B2 and establish the first forward speed.

[0054] Furthermore, when an upshift condition for upshifting the gear to second forward speed or the like is satisfied while the first forward speed is established, the TMECU 21 supplies current to the electromagnetic parts of the second signal pressure output valve SC2 while de-energizing the electromagnetic parts of the first and third signal pressure output valves SC1 and SC3, as shown in FIG. 5. As a result, as shown in FIG. 9, the first changeover valve 100 establishes the first state, and the source pressure input port 101 and the source pressure output port 102 communicate with each other, and the inlet port 111 and the outlet port 112 communicate with each other. Furthermore, the second signal pressure Psc2 from the second signal pressure output valve SC2 is supplied to the second signal pressure input port 205 via the inlet port 111, the outlet port 112, and the oil passage L28 of the first changeover valve 100, thereby establishing the second communication state of the second changeover valve 200. As a result, the input port 201 communicates with the first output port 203. Furthermore, when second switching valve 200 establishes the second communication state, first inflow port 211 and signal pressure outflow port 215 communicate with each other, thereby allowing the outflow of hydraulic oil (second signal pressure Psc2) supplied from second signal pressure output valve SC2 to first inflow port 211 via oil passage L28, separately from second signal pressure input port 205. Then, the hydraulic oil from second signal pressure output valve SC2 supplied to first inflow port 211 is supplied to third signal pressure input port 315 of third switching valve 300 via signal pressure outflow port 215 of second switching valve 200 and oil passage L35. As a result, third switching valve 300 establishes the second supply state, and first input port 311 and first supply port 313 communicate with each other.

[0055] Additionally, hydraulic oil (line pressure PL) from the primary regulator valve side is supplied from oil passage L21 of valve body 600 via source pressure input port 101 and source pressure output port 102 of first selector valve 100, oil passage L22, etc. to input ports of linear solenoid valves SL1, SL4, and SL5 corresponding to clutches C1 and C4 and brake B1, which are engaged only when a forward gear is established. Furthermore, the input port of linear solenoid valve SL2 communicates with oil passage L1 via oil passage L23, and the input port of linear solenoid valve SL3 communicates with oil passage L1 via oil passage L24. Therefore, depending on the vehicle speed and accelerator pedal position of vehicle 10, hydraulic pressure from two of linear solenoid valves SL1-SL5 can be used to engage any two of clutches C1-C4 and brake B1 to establish a desired gear from second forward gear to eighth forward gear.

[0056] Here, if an abnormality such as sticking of the second spool S2 occurs in the second switching valve 200 of the hydraulic control device 60, even though the second signal pressure Psc2 from the second signal pressure output valve SC2 is supplied to the second signal pressure input port 205, the second switching valve 200 may form a first communication state that allows the supply of hydraulic pressure Psl2 from the linear solenoid valve SL2 to the brake B2 (second hydraulic engagement element) side, as shown in Figure 10. Furthermore, the fifth forward speed through the eighth forward speed of the automatic transmission 25 are formed by engaging the clutch C2 (first engagement element) with one of the clutches C1, C3, C4 and the brake B1, but if the second switching valve 200, which should normally form the second communication state, forms the first communication state when one of the fifth forward speed through the eighth forward speed should be formed, and hydraulic pressure Psl2 from the linear solenoid valve SL2 is supplied to the brake B2, a gear other than the fifth forward speed through the eighth forward speed will be formed.

[0057] That is, when the fifth forward gear is established, if the second selector valve 200 establishes the first communication state and hydraulic pressure Psl2 from the linear solenoid valve SL2 is supplied to the brake B2, there is a risk that the first forward gear will be established and the vehicle 10 will suddenly decelerate, as can be seen from Fig. 3. Also, when the sixth forward gear is established, if the second selector valve 200 establishes the first communication state and hydraulic pressure Psl2 from the linear solenoid valve SL2 is supplied to the brake B2, there is a risk that the second reverse gear will be established, as can be seen from Fig. 3. Furthermore, when the seventh forward gear is established, if the second selector valve 200 establishes the first communication state and hydraulic pressure Psl2 from the linear solenoid valve SL2 is supplied to the brake B2, there is a risk that the first reverse gear will be established, as can be seen from Fig. 3.

[0058] In consideration of these, the second switching valve 200 of the hydraulic control device 60 is configured, when the first communication state is established, to communicate the second inflow port 212 with the signal pressure outflow port 215 and supply hydraulic oil (hydraulic pressure) from any of the linear solenoid valves SL3, SL4, and SL5 serving as dedicated pressure regulating valves to the third signal pressure input port 315 of the third switching valve 300. Furthermore, once the second supply state is established by supplying hydraulic oil (hydraulic pressure) to the third signal pressure input port 315, the third switching valve 300 of the hydraulic control device 60 continues to establish (maintain) the second supply state even if the supply of hydraulic oil (hydraulic pressure) to the third signal pressure input port 315 is cut off. As a result, even if the second selector valve 200 were to become stuck in the first supply state, hydraulic oil (hydraulic pressure) from one of the linear solenoid valves SL3, SL4, and SL5 is supplied to the third signal pressure input port 305 of the third selector valve 300 depending on whether second, third, fourth, sixth, seventh, or eighth forward gear is being established, thereby maintaining the third selector valve 300 in the second supply state in which communication between the second input port 312 and the second supply port 314 is blocked. As a result, even if the second selector valve 200 becomes stuck in the first supply state, hydraulic pressure Psl2 from the linear solenoid valve SL2 is not supplied to the brake B2 when any of the fifth, seventh, or eighth forward gears should be established, thereby placing the automatic transmission 25 in neutral. Therefore, the hydraulic control device 60 effectively prevents sudden deceleration of the vehicle 10 due to a downshift from fifth forward gear to first forward gear.

[0059] On the other hand, if an abnormality occurs that prevents the second signal pressure Psc2 from being output from the second signal pressure output valve SC2 when any of the forward fifth, fifth, eighth, and eighth gears should be established, the second changeover valve 200 establishes the first communication state, which connects the input port 201 and the second output port 204, due to the biasing force of the second spring SP2, as shown in FIG. 11 . In this case, too, the third changeover valve 300 can be maintained in the second supply state, which blocks communication between the second input port 312 and the second supply port 314, depending on whether any of the forward second, third, fourth, sixth, seventh, and eighth gears is established. This prevents the hydraulic pressure Psl2 from being supplied to the brake B2 from the linear solenoid valve SL2, thereby placing the automatic transmission 25 in neutral. Therefore, in this case too, sudden deceleration of the vehicle 10 due to a downshift from forward fifth to forward first gear can be effectively suppressed.

[0060] Continuing with reference to FIGS. 12 to 14, the procedure for determining whether the third switching valve (apply valve) 300 in the hydraulic control device 60 is in a stuck state will be described.

[0061] 12 , when the gear position of the automatic transmission 25 is any one of the fifth to eighth forward speeds, the second changeover valve 200 establishes a second communication state in which the input port 201 communicates with the first output port 203 and the first inlet port 211 communicates with the signal pressure outlet port 215 by supplying the second signal pressure Psc2 from the second signal pressure output valve SC2 to the second signal pressure input port 205 via the first changeover valve 100. At this time, if the third spool S3 of the third changeover valve 300 is in a state that establishes the first supply state, that is, if the third spring SP3 is stuck in an extended state, the second input port 312 communicates with the second supply port 314 and the communication between the first input port 311 and the first supply port 313 is blocked. Therefore, if the third switching valve 300 is stuck in a state forming the first supply state when any of the forward fifth to eighth gears is formed, even if the second switching valve 200 allows the supply of oil pressure Psl2 from the linear solenoid valve SL2, which serves as a dual-purpose pressure regulating valve, to the clutch C2 and the outflow of hydraulic oil (second signal pressure Psc2) from the second signal pressure output valve SC2, the clutch C2 cannot be engaged and the automatic transmission 25 enters a neutral state.

[0062] 13 , when the gear position of the automatic transmission 25 is the first reverse speed or the first forward speed, the second changeover valve 200 does not supply the second signal pressure Psc2 from the second signal pressure output valve SC2 to the second signal pressure input port 205 via the first changeover valve 100, thereby establishing a first communication state in which the input port 201 communicates with the second output port 204 and the second inlet port 212 communicates with the signal pressure outlet port 215. At this time, if the third spool S3 of the third changeover valve 300 is in a state that establishes the second supply state, that is, if the third spring SP3 is stuck in a compressed state, the first input port 311 communicates with the first supply port 313 and the communication between the second input port 312 and the second supply port 314 is blocked. Therefore, if the third switching valve 300 is stuck in a state forming the second supply state when the first reverse gear or the first forward gear is formed, even if the second switching valve 200 allows the supply of hydraulic pressure Psl2 from the linear solenoid valve SL2 as a dual-purpose pressure regulating valve to the brake B2 and the outflow of hydraulic oil (hydraulic pressure) from the linear solenoid valve SL3 as a dedicated pressure regulating valve, the brake B2 cannot be engaged and the automatic transmission 25 will be in a neutral state.

[0063] In consideration of these characteristics of the hydraulic control device 60, in the vehicle 10, the TMECU 21 as a determination unit repeatedly executes a routine shown in Fig. 14 at predetermined time intervals (very short time intervals) while the automatic transmission 25 is in operation, i.e., while the vehicle 10 is traveling, to determine whether the third switching valve 300 is stuck. When the routine of Fig. 14 starts, the TMECU 21 acquires information necessary for determining whether the third switching valve 300 is stuck, such as the target gear position of the automatic transmission 25 set based on the accelerator pedal position and the vehicle speed, the input rotation speed of the automatic transmission 25 detected by the input rotation speed sensor 97, and the output rotation speed of the automatic transmission 25 detected by the output rotation speed sensor 98 (step S100). Next, the TMECU 21 calculates the actual gear ratio set by the automatic transmission 25 based on the input rotation speed and the output rotation speed acquired in step S100 (step S110). Furthermore, the TMECU 21 determines whether or not the calculated actual speed ratio is outside a relatively narrow predetermined range that includes the speed ratio of the target gear position acquired in step S100 (step S120).

[0064] If it is determined that the actual gear ratio calculated in step S110 is within the predetermined range (step S120: NO), the TMECU 21 determines that the actual gear ratio generally matches the gear ratio of the target gear and that the automatic transmission 25 is not in a neutral state due to sticking of the third changeover valve 300, and temporarily ends the routine of Fig. 14. On the other hand, if it is determined that the actual gear ratio calculated in step S110 is outside the predetermined range (step S120: YES), the TMECU 21 determines that the actual gear ratio does not generally match the gear ratio of the target gear and that the automatic transmission 25 is in a neutral state due to sticking of the third changeover valve 300, and determines whether the target gear is first reverse (step S130).

[0065] When the automatic transmission 25 is in neutral and the target gear is first reverse, as shown in Fig. 13, the third spool S3 of the third changeover valve 300 is stuck in a state that forms the second supply state, i.e., the third spring SP3 is compressed, and hydraulic pressure Psl2 from the linear solenoid valve SL2 is not supplied to the brake B2. Therefore, when it is determined in step S130 that the target gear is first reverse (step S130: YES), the TMECU 21 turns on the compression-side sticking flag Fs (step S140) to indicate that the third changeover valve 300 is stuck in a state that forms the second supply state (a state that the third spring SP3 is compressed), and ends the routine of Fig. 14. When the compression-side sticking flag Fs is turned on in step S140, a fail-safe process is executed that takes into account the third changeover valve 300 being stuck in a state that forms the second supply state.

[0066] Furthermore, when it is determined in step S130 that the target gear is not first reverse gear (step S130: NO), the TMECU 21 determines whether the target gear is first forward gear (step S150). Even when a positive determination is made in step S120 and then a determination is made in step S150 that the target gear is first forward gear, the third spool S3 of the third switching valve 300 is stuck in a state that forms the second supply state (a state in which the third spring SP3 is compressed), as shown in Fig. 13. Therefore, when it is determined in step S150 that the target gear is first forward gear (step S150: YES), the TMECU 21 turns on the compression-side sticking flag Fs (step S140) and ends the routine of Fig. 14.

[0067] Furthermore, if it is determined in step S150 that the target gear is not first forward gear (step S150: NO), the TMECU 21 determines whether the target gear is any one of fifth, sixth, seventh, and eighth forward gears (step S160). If the TMECU 21 determines that the target gear is not any one of fifth to eighth forward gears (step S160: NO), the TMECU 21 temporarily ends the routine in FIG. 14 at that point. On the other hand, if a positive determination is made in step S120 and then the TMECU 21 determines that the target gear is any one of fifth to eighth forward gears in step S160, as shown in FIG. 12, the third spool S3 of the third switching valve 300 is stuck in a state that forms the first supply state, that is, the third spring SP3 is extended and stuck, and therefore hydraulic pressure Psl2 from the linear solenoid valve SL2 is not supplied to the clutch C2. Therefore, when it is determined in step S160 that the target gear is any one of the fifth to eighth forward speeds (step S160: YES), the TMECU 21 turns on the extension side sticking flag Fe to indicate that the third switching valve 300 is stuck in the first supply state (the third spring SP3 is extended) (step S170), and ends the routine in Fig. 14. When the extension side sticking flag Fs is turned on in step S170, fail-safe processing is executed in consideration of the third switching valve 300 being stuck in the first supply state.

[0068] As described above, in the hydraulic control device 60 of the present disclosure, the hydraulic pressure Psl2 generated (adjusted) by the linear solenoid valve SL2 (dual-purpose pressure regulating valve) can be selectively supplied from the third switching valve 300 serving as an apply valve to the clutch C2 (first hydraulic engagement element) and the brake B2 (second hydraulic engagement element) that is not simultaneously engaged with the clutch C2. This makes it possible to reduce the number of linear solenoid valves (pressure regulating valves) in the hydraulic control device 60, thereby reducing costs by reducing the number of linear solenoid valves and improving efficiency by reducing oil leakage.

[0069] Furthermore, when the second signal pressure Psc2 from the second signal pressure output valve SC2 is not supplied to the second signal pressure input port 205 of the second switching valve 200, the second switching valve 200, which forms the first communicating state, allows the supply of hydraulic pressure Psl2 from the linear solenoid valve SL2, which serves as a dual-purpose pressure regulating valve, to the brake B2, which serves as the second hydraulic engagement element, and restricts the supply of hydraulic oil (second signal pressure Psc2) from the second signal pressure output valve SC2 to the third switching valve 300 and the supply of hydraulic oil (second signal pressure Psc2) from the second signal pressure output valve SC2 to the third switching valve 300, and the third switching valve 300 forms the first supply state by not receiving the supply of hydraulic oil (second signal pressure Psc2) from the second signal pressure output valve SC2 via the second switching valve 200. As a result, the third switching valve 300 restricts the supply of hydraulic pressure Psl2 from the linear solenoid valve SL2 to the clutch C2 serving as the first hydraulic engagement element, and the hydraulic pressure Psl2 from the linear solenoid valve SL2 is supplied to the brake B2 via the third switching valve 300. Furthermore, when the second signal pressure Psc2 is supplied to the second switching valve 200 from the second signal pressure output valve SC2, the second switching valve 200, which establishes the second communication state, allows the supply of hydraulic pressure Psl2 from the linear solenoid valve SL2 to the clutch C2 and allows the supply of hydraulic oil (second signal pressure Psc2) from the second signal pressure output valve SC2 to the third switching valve 300, and the third switching valve 300 receives the supply of hydraulic oil (second signal pressure Psc2) from the second signal pressure output valve SC2 via the second switching valve 200, establishing the second supply state. As a result, the third changeover valve 300 restricts the supply of the hydraulic pressure Psl2 from the linear solenoid valve SL2 to the brake B2, and the hydraulic pressure Psl2 from the linear solenoid valve SL2 is supplied via the third changeover valve 300 to the clutch C2.

[0070] Therefore, when the third changeover valve 300 is stuck in the first supply state, even if the second signal pressure Psc2 from the second signal pressure output valve SC2 is supplied to the second changeover valve 200 and the second changeover valve 200 allows the supply of hydraulic pressure Psl2 from the linear solenoid valve SL2 to the clutch C2 side and the outflow of hydraulic oil (second signal pressure Psc2) separately supplied from the second signal pressure output valve SC2, the clutch C2 cannot be engaged and the automatic transmission 25 is in the neutral state. On the other hand, when the third changeover valve 300 is stuck in the second supply state, even if the second signal pressure Psc2 from the second signal pressure output valve SC2 is not supplied to the second changeover valve 200 and the second changeover valve 200 allows the supply of hydraulic pressure Psl2 from the linear solenoid valve SL2 to the brake B2 side, the brake B2 cannot be engaged and the automatic transmission 25 is in the neutral state. As a result, the hydraulic control device 60 can accurately determine the stuck state of the third switching valve 300 based on whether or not the second signal pressure Psc2 is output by the second signal pressure output valve SC2 according to the gear stage of the automatic transmission 25 and the formation state of the gear stage of the automatic transmission 25.

[0071] In the automatic transmission 25, the clutch C2 is engaged when a plurality of low forward gears including the start gear are established, i.e., when forward fifth gear through forward eighth gear, which are higher than forward first gear through forward fourth gear, are established, and the brake B2 is engaged when reverse first gear and reverse second gear are established and when forward first gear, which is the start gear, is established. Furthermore, the second signal pressure output valve SC2 outputs a second signal pressure Psc2 when forward second gear through eighth gear (low forward gears and high forward gears other than forward first gear, which is the start gear) are established. In addition, the TMECU 21, which serves as a determination unit, determines that the third changeover valve 300 is stuck in a state that establishes the first supply state (a state in which the third spring SP3 is extended) when the automatic transmission 25 is in neutral and the target gear of the automatic transmission 25 is one of forward fifth gear through eighth gear (high forward gears). Furthermore, when the automatic transmission 25 is in neutral and the target gear position is first reverse gear or first forward gear which is the starting gear, the TMECU 21 determines that the third changeover valve 300 is stuck in a state that establishes the second supply state (a state in which the third spring SP3 is compressed). This makes it possible to accurately determine the stuck state of the third changeover valve 300 while the automatic transmission 25 is operating.

[0072] Furthermore, the second switching valve 200 of the hydraulic control device 60 has a second spool S2, a second spring SP2 that biases the second spool S2, an input port 201 to which hydraulic pressure Psl2 from the linear solenoid valve SL2 is supplied, a first inlet port 211 to which hydraulic oil (second signal pressure Psc2) from the second signal pressure output valve SC2 is supplied, a first output port 203, a second output port 204, a signal pressure outlet port 215, and a second signal pressure input port 205 to which the second signal pressure Psc2 from the second signal pressure output valve SC2 is supplied. Furthermore, when the second signal pressure Psc2 is not supplied to the second signal pressure input port 205, the second switching valve 200 forms a first communication state in which the input port 201 and the second output port 204 are connected to each other and the communication between the first inlet port 211 and the signal pressure outlet port 215 is blocked, and when the second signal pressure Psc2 is supplied to the second signal pressure input port 205, the second switching valve 200 forms a second communication state in which the input port 201 and the first output port 203 are connected to each other and the first inlet port 211 and the signal pressure outlet port 215 are connected to each other. Furthermore, the third switching valve 300 of the hydraulic control device 60 has a third spool S3, a third spring SP3 that biases the third spool S3, a first input port 311 that communicates with the first output port 203 of the second switching valve 200, a second input port 312 that communicates with the second output port 204 of the second switching valve 200, a first supply port 313 that communicates with the oil chamber of the clutch C2, a second supply port 314 that communicates with the oil chamber of the brake B2, and a third signal pressure input port 315 that communicates with the signal pressure outlet port 215 of the second switching valve 200. In addition, when hydraulic oil (second signal pressure Psc2) is not supplied to the third signal pressure input port 315 from the signal pressure outlet port 215 of the second switching valve 200, the third switching valve 300 forms a first supply state that connects the second input port 312 and the second supply port 314, and when hydraulic oil (second signal pressure Psc2) is supplied to the third signal pressure input port 315 from the signal pressure outlet port 215 of the second switching valve 200, it forms a second supply state that connects the first input port 311 and the first supply port 313.This makes it possible to selectively supply hydraulic pressure Psl2 from one linear solenoid valve SL2 to the clutch C2 and the brake B2 via the third changeover valve 300, while accurately determining whether the third changeover valve 300 is stuck during operation of the automatic transmission 25. The hydraulic control device 60 may be applied to a transmission that provides a plurality of gears by selectively engaging three or more hydraulic engagement elements.

[0073] The present invention is not limited to the above-described embodiment, and various modifications can be made within the scope of the present disclosure. Furthermore, the above-described embodiment is merely a specific form of the invention described in the Summary of the Invention, and does not limit the elements of the invention described in the Summary of the Invention. [Industrial Applicability]

[0074] The invention of the present disclosure can be used in the hydraulic control device manufacturing industry and the like. [Explanation of symbols]

[0075] 10 vehicle, 12 engine, 20 power transmission device, 21 transmission electronic control unit (TMECU), 24 mechanical oil pump, 25 automatic transmission, 60 hydraulic control device, 600 valve body, 100 first switching valve, 101 main pressure input port, 102 main pressure output port, 105 first signal pressure input port, 106 holding pressure input port, 111 inlet port, 112 outlet port, 117 parking port, 200 second switching valve, 201 input port, 203 first output port, 204 second output port, 205 second signal pressure input port, 211 first inlet port, 212 second inlet port, 215 signal pressure outlet port, 300 third switching valve, 311 first input port, 312 second input port, 313 first supply port, 314 second supply port, 315 third signal pressure input port, 316 Switching port, 317 holding pressure inlet port, 318 holding pressure outlet port, 319 holding pressure introduction port, B1, B2 brake, C1, C2, C3, C4 clutch, S1 first spool, S2 second spool, S3 third spool, SC1 first signal pressure output valve, SC2 second signal pressure output valve, SC3 third signal pressure output valve, SL1, SL2, SL3, SL4, SL5 linear solenoid valve, SP1 first spring, SP2 second spring, SP3 third spring.

Claims

1. A hydraulic control device for a transmission that forms a plurality of forward gears and reverse gears by selectively engaging at least two of a first hydraulic engagement element, a second hydraulic engagement element that is not simultaneously engaged with the first hydraulic engagement element, and remaining hydraulic engagement elements, a plurality of pressure regulating valves including a dual-purpose pressure regulating valve that regulates a source pressure to generate hydraulic pressure to the first hydraulic engagement element and the second hydraulic engagement element, and at least one dedicated pressure regulating valve that regulates the source pressure to generate hydraulic pressure to the corresponding remaining hydraulic engagement element; a signal pressure output valve that outputs a signal pressure; a switching valve that, when not receiving the signal pressure from the signal pressure output valve, forms a first communication state that allows the hydraulic pressure to be supplied from the dual-purpose pressure regulating valve to the second hydraulic engagement element side and restricts the supply of the hydraulic pressure from the dual-purpose pressure regulating valve to the first hydraulic engagement element side and the outflow of oil separately supplied from the signal pressure output valve, and that, when receiving the signal pressure from the signal pressure output valve, forms a second communication state that allows the hydraulic pressure to be supplied from the dual-purpose pressure regulating valve to the first hydraulic engagement element side and the outflow of oil separately supplied from the signal pressure output valve and restricts the supply of the hydraulic pressure from the dual-purpose pressure regulating valve to the second hydraulic engagement element side; an apply valve that, when the oil is not supplied from the signal pressure output valve via the changeover valve, forms a first supply state in which the oil pressure is restricted from being supplied from the dual-purpose pressure regulating valve to the first hydraulic engagement element and allows the oil pressure to be supplied from the dual-purpose pressure regulating valve to the second hydraulic engagement element from the changeover valve, and that, when the oil is supplied from the signal pressure output valve via the changeover valve, forms a second supply state in which the oil pressure is allowed to be supplied from the dual-purpose pressure regulating valve to the first hydraulic engagement element from the changeover valve and restricts the oil pressure to be supplied from the dual-purpose pressure regulating valve to the second hydraulic engagement element from the changeover valve; a determination unit that determines whether the apply valve is stuck in the first supply state or the second supply state based on whether the signal pressure is output by the signal pressure output valve and the state of the gear stage of the transmission; and A hydraulic control device comprising:

2. The hydraulic control device according to claim 1, the first hydraulic engagement element is engaged when a plurality of high forward speed stages are formed that are higher than a plurality of low forward speed stages including the start speed of the transmission, the second hydraulic engagement element is engaged when the reverse gear is established and when the start gear is established, the signal pressure output valve outputs the signal pressure when the low forward speed and the high forward speed other than the start speed are established, The determination unit determines that the apply valve is stuck in a state that forms the first supply state when the transmission is in a neutral state and a target gear position of the transmission is one of the high forward gear positions, and determines that the apply valve is stuck in a state that forms the second supply state when the transmission is in a neutral state and a target gear position of the transmission is the reverse gear position or the start gear position.

3. The hydraulic control device according to claim 1 or 2, the switching valve has a spool, a spring that biases the spool, an input port to which the hydraulic pressure from the dual-purpose pressure regulating valve is supplied, an inflow port to which the oil from the signal pressure output valve is supplied, a first output port, a second output port, a signal pressure outflow port, and a signal pressure input port to which the signal pressure from the signal pressure output valve is supplied, and when the signal pressure is not supplied to the signal pressure input port, the switching valve establishes the first communication state in which the input port communicates with the second output port and the communication between the inflow port and the signal pressure outflow port is blocked, and when the signal pressure is supplied to the signal pressure input port, the switching valve establishes the second communication state in which the input port communicates with the first output port and the communication between the inflow port and the signal pressure outflow port, The apply valve includes a spool, a spring for biasing the spool, and a switch. a first input port communicating with the first output port of a valve, a second input port communicating with the second output port of the switching valve, a first supply port communicating with an oil chamber of the first hydraulic engagement element, a second supply port communicating with an oil chamber of the second hydraulic engagement element, and a signal pressure input port communicating with the signal pressure outflow port of the switching valve, wherein the hydraulic control device establishes the first supply state in which the second input port and the second supply port are communicated when the oil is not supplied to the signal pressure input port from the signal pressure outflow port of the switching valve, and establishes the second supply state in which the first input port and the first output port are communicated when the oil is supplied to the signal pressure input port from the signal pressure outflow port of the switching valve.

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