JP2017115973A - Hydraulic controller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress working oil from being supplied from a circulation pressure control valve when no working oil needs to be supplied to a torque converter even if each circulation pressure control valve varies in valve diameter or if an internal elastic member thereof has variance in reaction force.SOLUTION: A hydraulic controller which comprises a circulation control valve and a lock-up selector valve provided in an oil passage for supplying hydraulic oil from an oil pump to a torque converter having a lock-up mechanism, and controls hydraulic pressure of working oil supplied to the torque converter comprises a proportional control solenoid which can perform proportional control over output pressure of the working oil, and switches the lock-up selector valve with first output pressure from a valve state corresponding to a lock-up off state to a valve state corresponding to a lock-up on state or flexible control state and also switches the lock-up selector valve with second output pressure from the valve state corresponding to the lock-up off state to the valve state corresponding to the lock-up on state or flexible control state, the second output pressure being set to output pressure which is predetermined pressure higher than the first output pressure.SELECTED DRAWING: Figure 7

Description

  The present invention relates to a hydraulic control device.

  In general, an oil pump system is known that includes a high-pressure oil passage that is supplied with hydraulic oil from an oil pump at a high hydraulic pressure and a low-pressure oil passage that is supplied with hydraulic oil at a low hydraulic pressure. Supplying hydraulic oil to the torque converter when the hydraulic oil is supplied to the torque converter through the high-pressure oil passage in this oil pump system, such as when the lockup clutch is engaged and the torque converter does not need to be cooled. May be unnecessary. In this case, a method is conceivable in which a switching valve is provided in the high-pressure oil passage, and the supply of hydraulic oil to the torque converter is shut off by this switching valve.

  For example, in Patent Document 1, in an oil pump system that supplies hydraulic oil to a torque converter, a switching valve is provided in an oil passage through which hydraulic oil is supplied from the oil pump to the torque converter in order to reduce drive loss of the oil pump. The structure to provide is described.

  In Patent Document 2, when the temperature of the hydraulic oil is detected and the hydraulic oil temperature is equal to or lower than the set temperature, the discharge amount of the variable displacement pump is reduced and the hydraulic oil is supplied to the torque converter. A configuration for blocking is described.

Japanese Examined Patent Publication No. 61-25945 JP 59-62763 A

  By the way, in the oil pump system as described above, a method using a hydraulic pressure adjusting valve (circulation pressure control valve) capable of controlling the pressure (hydraulic pressure) of hydraulic oil supplied to the torque converter is conceivable instead of the switching valve. In this case, the solenoid for the circulating pressure control valve is a linear solenoid or duty solenoid capable of proportionally controlling the control pressure of the hydraulic oil output from the solenoid (hereinafter referred to as the solenoid output pressure) to supply the torque converter. Oil supply can be adjusted.

  However, when the solenoid of the circulation pressure control valve is a solenoid whose output pressure can be proportionally controlled, it is necessary to control the output pressure of the solenoid when switching the circulation pressure control valve to the output pressure derived in advance. The output pressure of the solenoid when switching the circulation pressure control valve is derived from the valve diameter of the circulation pressure control valve and the reaction force of the internal elastic member. Therefore, when the circulation pressure control valve is manufactured, if there is a variation in the valve diameter or reaction force for each circulation pressure control valve, the output pressure of the solenoid derived in advance and the actual solenoid pressure when the circulation pressure control valve is switched There is a possibility that the output pressure is different. As a result, even when the lockup clutch is in an open state or the like and it is necessary to continue to cut off the supply of hydraulic oil to the torque converter and switching of the circulation pressure control valve is not desired, the circulation pressure control valve It is possible to switch. When switching of the circulation pressure control valve is not desired, when the circulation pressure control valve is switched, the supply of hydraulic oil to the torque converter is started, which causes a problem that drive loss of the oil pump occurs.

  The present invention has been made in view of the above. The purpose of the present invention is to supply hydraulic oil to a torque converter even if there are variations in the valve diameter and the reaction force of an internal elastic member for each circulation pressure control valve. It is an object of the present invention to provide a hydraulic control device that can suppress the supply of hydraulic oil from a circulation pressure control valve when it is unnecessary.

  In order to solve the above-described problems and achieve the above object, a hydraulic control device according to the present invention provides a circulating pressure control provided in an oil passage through which hydraulic oil is supplied from an oil pump to a torque converter having a lock-up mechanism. A hydraulic control device comprising a valve and a lock-up switching valve for controlling the hydraulic pressure of the hydraulic oil supplied to the torque converter, wherein the output pressure of the hydraulic oil can be proportionally controlled, and the lock-up switching is performed at a first output pressure The valve is switched from a valve state corresponding to a lock-up off state in the lock-up mechanism to a valve state corresponding to a lock-up on state or a flex control state in the lock-up mechanism, and the circulation pressure control valve is switched at a second output pressure. Proportional switching from the supply state to the supply state of the hydraulic oil to the torque converter Comprising a control solenoid, the second output pressure, to the first output pressure, characterized in that it is set to higher than a predetermined pressure higher output pressure.

  According to the hydraulic control device of the present invention, even if there is a variation in the valve diameter and the reaction force that is present in each circulation pressure control valve, it operates from the circulation pressure control valve when supply of hydraulic oil to the torque converter is unnecessary. It becomes possible to suppress supply of oil.

FIG. 1 is a diagram showing a vehicle to which a hydraulic control circuit according to an embodiment of the present invention is applied. FIG. 2 is a diagram showing a configuration of a hydraulic control circuit according to an embodiment of the present invention. FIG. 3 is a cross-sectional view showing a configuration of a normally open switching valve that is normally opened in a hydraulic control circuit according to an embodiment of the present invention. FIG. 4 is a cross-sectional view showing the configuration of a normally closed switching valve that is normally closed in a hydraulic control circuit according to an embodiment of the present invention. FIG. 5 is a graph showing the torque converter circulating pressure of hydraulic oil in the lock-up on state and the flex control state. FIG. 6 is a block diagram showing a hydraulic control circuit according to an embodiment of the present invention. FIG. 7 is a graph showing a state of the lockup switching valve according to an embodiment of the present invention and a state of change of the torque converter circulation pressure due to the solenoid output pressure. FIG. 8 is a flowchart for explaining a hydraulic oil supply control method by the hydraulic control apparatus according to the embodiment of the present invention.

  Embodiments of the present invention will be described below with reference to the drawings. In all the drawings of the following embodiments, the same or corresponding parts are denoted by the same reference numerals. Further, the present invention is not limited to the embodiments described below.

  First, a vehicle including a transmission hydraulic control circuit according to an embodiment of the present invention will be described. FIG. 1 shows the configuration of a vehicle Ve according to this embodiment.

  As shown in FIG. 1, the vehicle Ve includes an engine 1 as a power source, a torque converter 2, an electronic control unit (hereinafter, ECU: Electronic Control Unit) 3, a clutch mechanism 4, and a transmission 5. The torque converter 2, the clutch mechanism 4 and the transmission 5 constitute a part of the power transmission path. The engine 1 outputs power from the crankshaft 15. The torque converter 2 is connected to the engine 1. The clutch mechanism 4 constitutes a forward / reverse switching mechanism and is connected to the torque converter 2. The transmission 5 is connected to the clutch mechanism 4. The vehicle Ve also includes a hydraulic control device 13 that can supply hydraulic oil to the power transmission path.

  The torque converter 2 is a kind of fluid clutch, and transmits the power output from the engine 1 to the clutch mechanism 4 via hydraulic oil. The torque converter 2 has a lock-up mechanism, and transmits or increases the output torque from the engine 1 to the clutch mechanism 4 while maintaining or increasing the output torque.

  The ECU 3 is mainly composed of a microcomputer having a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), and the like. The ECU 3 performs calculations using the input data and data and programs stored in the ROM or RAM in advance, and outputs the calculation results as command signals.

  The ECU 3 controls, for example, the engine 1, the torque converter 2, the clutch mechanism 4, the transmission 5, and the like that are part of the power transmission path of the vehicle Ve. Specifically, the ECU 3 controls the operation of the engine 1 based on various input signals input from sensors attached to various locations of the vehicle Ve and various maps stored in the ROM. Further, the ECU 3 controls the gear ratio of the transmission 5, controls the forward / backward switching of the clutch mechanism 4, and controls the lockup of the torque converter 2. The ECU 3 is connected to the hydraulic control circuit 70, and controls the torque converter 2, the clutch mechanism 4, the transmission 5, and the like by performing hydraulic control of the hydraulic control circuit 70 and the like.

  The clutch mechanism 4 converts the rotation transmitted from the crankshaft 15 of the engine 1 into a rotation direction in which the vehicle Ve advances, or changes into a rotation direction in which the vehicle Ve moves backward. The clutch mechanism 4 is configured to be able to release power transmission from the engine 1 to the transmission 5.

  The transmission 5 is composed of, for example, a belt-type continuously variable transmission, and includes a primary shaft 55 serving as an input shaft and a secondary shaft 60 serving as an output shaft. The transmission 5 changes the rotational speed of the primary shaft 55 rotated by the power input from the clutch mechanism 4 to the desired rotational speed of the secondary shaft 60 according to the driving state of the vehicle Ve, and outputs it.

  The secondary shaft 60 is connected to the speed reducer 80 via the clutch CL <b> 2 and further coupled to the differential device 90 via the speed reducer 80. Thereby, in the vehicle Ve, the power of the engine 1 is transmitted to the drive wheels 100.

  The torque converter 2 includes a pump impeller 20, a turbine runner 21, a stator 22, a lockup clutch 23, and a facing 24 provided in the lockup clutch 23. The torque converter 2 is provided with an oil pump 25 that is operated by the power of the engine 1.

  The pump impeller 20 is connected to the front cover 26. The front cover 26 is connected to the crankshaft 15 via the drive plate 27 of the engine 1. Power from the engine 1 is transmitted to the pump impeller 20 via the crankshaft 15 and the front cover 26, and the transmitted power is transmitted to the turbine runner 21 via hydraulic oil. An oil pump 25 is connected to the pump impeller 20. The oil pump 25 operates when power from the engine 1 is transmitted through the crankshaft 15, the front cover 26, and the pump impeller 20.

  The turbine runner 21 is connected to the input shaft 38 of the clutch mechanism 4. The turbine runner 21 transmits the power of the crankshaft 15 transmitted from the pump impeller 20 via the hydraulic oil to the input shaft 38 of the clutch mechanism 4 disposed on the output side. The stator 22 is provided between the pump impeller 20 and the turbine runner 21 and is fixed to a housing (not shown) via a one-way clutch 30.

  The lockup clutch 23 is provided between the turbine runner 21 and the front cover 26 and is connected to the input shaft 38. The lock-up clutch 23 includes a hydraulic chamber defined by the pump impeller 20 and the front cover 26, an apply chamber 31 formed on the pump impeller 20 side with the lock-up clutch 23 interposed therebetween, and a drive plate with the lock-up clutch 23 interposed therebetween. It is divided into a release chamber 32 formed on the 27 side. The facing 24 is provided on the drive plate 27 side of the lock-up clutch 23 and can contact the inside of the front cover 26. Hydraulic fluid is supplied from the hydraulic control circuit 70 to the apply chamber 31 and the release chamber 32.

  The lockup clutch 23 performs a lockup fastening operation by bringing the facing 24 into contact with the front cover 26 in accordance with the supply of hydraulic oil from the hydraulic control circuit 70. When the lock-up clutch 23 performs a lock-up fastening operation, the facing 24 engages with the front cover 26 and the pump impeller 20 and the turbine runner 21 are fastened. In this specification, this state is referred to as a “lock-up on state”. In the lock-up on state, the power of the crankshaft 15 can be directly transmitted to the turbine runner 21.

  On the other hand, the lockup clutch 23 performs a lockup fastening release operation when the facing 24 is separated from the front cover 26. When the lockup clutch 23 performs the lockup engagement release operation, the engagement between the pump impeller 20 and the turbine runner 21 is released. In this specification, this state is referred to as a “lock-up off state”. In the lock-up off state, the power of the crankshaft 15 is transmitted to the turbine runner 21 via the hydraulic oil.

  On the other hand, the lockup clutch 23 is controlled to cause the facing 24 and the front cover 26 to slip each other. In this specification, this control is referred to as “flex control”, and the state in which the lock-up clutch 23 is flex-controlled is referred to as “flex control state”.

  The clutch mechanism 4 includes a planetary gear mechanism 41, a forward clutch 42, and a reverse brake 43. The planetary gear mechanism 41 includes a sun gear 44, a pinion 45, and a ring gear 46. The ring gear 46 meshes with each of the plurality of pinions 45 held by the switching carrier 47 and is connected to the reverse brake 43.

  The hydraulic control device 13 includes an oil pump 25 and a hydraulic control circuit 70 to which hydraulic oil is supplied from the oil pump 25. The ECU 3 is connected to the hydraulic control circuit 70.

  The oil pump 25 sucks and pressurizes hydraulic oil stored in an oil pan (not shown in FIG. 1), and then supplies the hydraulic oil to the hydraulic control circuit 70. The oil pump 25 is composed of, for example, a 1-port oil pump provided with a discharge port for discharging hydraulic oil at one location. As described above, the oil pump 25 can be operated by the power of the engine 1. Therefore, the oil pump 25 increases the discharge amount of the discharged hydraulic oil when the rotation speed of the engine 1 increases, while the discharge amount of the discharged hydraulic oil decreases when the rotation speed of the engine 1 decreases. The hydraulic control circuit 70 includes a plurality of hydraulic control valves including a spool valve element and an electromagnetic solenoid, and a plurality of oil passages. The ECU 3 controls the oil pressure in each oil passage by appropriately controlling the oil pressure control valve.

  Next, the hydraulic control circuit 170 in the hydraulic control device 13 devised by the present inventor will be described. FIG. 2 is a block diagram mainly showing the hydraulic control circuit 170. The hydraulic control circuit 170 shown in FIG. 2 is provided in the portion of the hydraulic control circuit 70 in FIG. As shown in FIG. 2, the hydraulic control circuit 170 includes a switching valve 171, a circulation pressure control valve 172, a primary regulator valve 173, a lockup switching valve 174, a first solenoid 175, and a second solenoid 176. The first solenoid 175 and the second solenoid 176 are on / off solenoids whose on / off is controlled by the ECU 3, respectively. A first oil passage L1 is formed from an oil passage through which hydraulic oil discharged from the oil pump 25 sequentially flows through the switching valve 171, the circulation pressure control valve 172, and the lockup switching valve 174. A second oil passage L2 is formed from an oil passage that branches off from the middle of the first oil passage L1 and sequentially flows through the primary regulator valve 173 and the lockup switching valve 174.

  Here, the switching valve 171 will be described. FIG. 3 shows a normally open type switching valve 171A that can be employed as the switching valve 171 in the hydraulic control circuit 170 shown in FIG. As shown in FIG. 3, the normally open switching valve 171 </ b> A includes a housing 710, a valve body 711, and a storage portion 712 formed by the housing 710 that stores the valve body 711. The valve body 711 has, for example, a cylindrical main shaft 711a. The valve body 711 can reciprocate in the storage portion 712 along the axial direction of the main shaft 711a. The valve body 711 has a first valve portion 711b and a second valve portion 711c that have a larger outer diameter than the main shaft 711a and have a cylindrical shape concentric with the main shaft 711a. The first valve portion 711b and the second valve portion 711c have substantially the same outer diameter, and the cut surfaces in the direction perpendicular to the axial direction have substantially the same shape. That is, the first valve part 711b and the second valve part 711c have substantially the same cross-sectional areas of their cut surfaces. The first valve portion 711b and the second valve portion 711c are arranged with a space therebetween in the axial direction, thereby forming an annular space 713 between the respective one end surfaces. A gap with a predetermined interval is formed between the first valve portion 711 b and the second valve portion 711 c and the wall surface of the housing 710 constituting the storage portion 712.

  In the normally open switching valve 171A, an inflow port 712a and an outflow port 712b for hydraulic fluid respectively connected to the storage portion 712 are formed. A first oil passage L1 as a high-pressure oil passage connected to the oil pump 25 is connected to the inflow port 712a. An oil path to the circulation pressure control valve 172 is connected from the outflow port 712b.

  In the normally open type switching valve 171A, when the second solenoid 176 is in the OFF state, the inflow port 712a and the outflow port 712b communicate with each other through the annular space 713 to be in a so-called valve open state. That is, hydraulic oil can pass through the annular space 713. On the other hand, when the second solenoid 176 is in the ON state, the inlet 712a is blocked by the first valve portion 711b and a so-called valve closing state is established. That is, when the normally open type switching valve 171A is used as the switching valve 171, the hydraulic oil discharged from the oil pump 25 can be supplied to the circulation pressure control valve 172 when the second solenoid 176 is in the OFF state.

  In the normally open switching valve 171A, an elastic chamber 714 is provided in a space on the end surface side opposite to the first valve portion 711b in the second valve portion 711c in the storage portion 712. The elastic chamber 714 is provided with an elastic member 715 such as a coiled spring that is compressed by the second valve portion 711c when the valve is closed. When the hydraulic oil passes through the annular space 713, the hydraulic oil leaks into the elastic chamber 714 through the clearance described above. In the elastic chamber 714, a drain 712c for discharging the hydraulic oil leaking from the annular space 713 to, for example, an oil pan is formed. By forming the drain 712c, the inside of the elastic chamber 714 is open to the atmosphere.

  FIG. 4 shows a normally closed switching valve 171B that can be employed as the switching valve 171 in the hydraulic control circuit 170 shown in FIG. As shown in FIG. 4, the normally closed switching valve 171B has the same members as those of the above-described normally open switching valve 171A. Therefore, the normally closed switching valve 171B is similar to the components of the normally open switching valve 171A. The same reference numerals are given to the members, and the description thereof is omitted.

  In the normally closed switching valve 171B, the formation positions of the inflow port 712a and the outflow port 712b are shifted to the second valve portion 711c side as compared with the normally open switching valve 171A. Thereby, contrary to the normally open type switching valve 171A, when the second solenoid 176 is in the OFF state, the outflow port 712b is closed by the second valve portion 711c, and a so-called valve closing state is obtained. On the other hand, when the second solenoid 176 is in the ON state, the outlet 712b is opened by the second valve portion 711c, and the inlet 712a and the outlet 712b communicate with each other through the annular space 713, so-called valve opening state. become. That is, when the normally closed type switching valve 171B is used as the switching valve 171, the hydraulic oil discharged from the oil pump 25 can be supplied to the circulation pressure control valve 172 when the second solenoid 176 is in the ON state. Other configurations are the same as the normally open switching valve 171A.

  As shown in FIG. 2, the circulation pressure control valve 172 is, for example, a circulation modulator valve and the like, and is a valve that regulates and controls the circulation pressure of the hydraulic oil to be circulated inside the torque converter 2. The primary regulator valve 173 is a valve for controlling the pressure of hydraulic oil supplied from the oil pump 25. The hydraulic oil is supplied from the circulation pressure control valve 172 to the lockup switching valve 174.

  The lockup switching valve 174 selectively switches between the passage of high-pressure line hydraulic fluid supplied from the circulation pressure control valve 172 and the passage of low-pressure secondary pressure hydraulic fluid supplied from the primary regulator valve 173. It is a valve. The lockup switching valve 174 is controlled by the first solenoid 175. Under the control of the ECU 3, the first solenoid 175 is switched on and off according to the engaged state and the released state of the lockup clutch 23. Specifically, in the lockup on state and the flex control state, the first solenoid 175 is controlled to be in the on state by the ECU 3 so that the hydraulic pressure is set to a high line pressure, and the lockup switching is performed. Through the valve 174, the torque converter 2 can be supplied with high-pressure hydraulic oil. On the other hand, in the lock-up off state, the ECU 3 controls the first solenoid 175 to the off state, and passes the second oil passage L2 in which the hydraulic pressure is set to a low secondary pressure and the lock-up switching valve 174 to the torque converter 2. Secondary pressure (low pressure) hydraulic oil is supplied.

  In addition, the switching valve 171 is a second valve branched to the primary regulator valve 173 side in the first oil passage L1 upstream of the circulation pressure control valve 172 and in the middle of the first oil passage L1 along the flow direction of the hydraulic oil. It is provided downstream of the branch position of the oil passage L2. The switching valve 171 is controlled to be turned on and off by a second solenoid 176 controlled by the ECU 3. Here, a normally open switching valve 171A is used as the switching valve 171. The second solenoid 176 is switched on and off under the control of the ECU 3 according to the state of the lockup clutch 23.

  Specifically, in the flex control state, the ECU 3 controls the second solenoid 176 to be in an off state. In this case, since the switching valve 171 is opened, the high-pressure hydraulic oil supplied from the circulation pressure control valve 172 is supplied to the torque converter 2. On the other hand, when the lockup clutch 23 is engaged and in the lockup on state, the ECU 3 controls the second solenoid 176 to be in the on state. In this case, since the switching valve 171 is closed, the supply of hydraulic oil to the torque converter 2 is stopped.

  In the hydraulic control circuit 170 devised by the present inventor described above, the switching valve 171 and the second solenoid 176 (FIG. 2) are used to cut off the supply of hydraulic oil to the torque converter 2 with respect to the conventional hydraulic control circuit. Middle, dotted line box) is added. Therefore, there is a concern about an increase in the size of the hydraulic control circuit 170 and an increase in cost.

  As shown in FIG. 5, in the hydraulic control circuit 170, the circulation flow rate is controlled in two steps. Therefore, in the flex control state, a necessary flow rate always flows under the maximum load condition. Thereby, in the hydraulic control circuit 170, the supply amount is excessive as compared with the required supply amount of hydraulic oil to the torque converter 2 in the case of a low load with a relatively small load even in the flex control state. There is a possibility. In this case, it may be difficult to reduce the pump capacity of the oil pump 25, or the subport pressure may not be reduced when a two-port oil pump is used as the oil pump 25. In the lock-up off state, the hydraulic oil at the line pressure (high pressure) is shut off by the lock-up switching valve 174, and the hydraulic oil at the secondary pressure (low pressure) is supplied to the torque converter 2.

  Therefore, in one embodiment of the present invention, without providing the switching valve 171 and the second solenoid 176 described above, the circulation pressure control valve is also used as a switching valve, and the output pressure is proportionally controlled instead of the first solenoid 175. Adopt a hydraulic control circuit using a possible solenoid. The hydraulic control circuit uses the proportionally controlled solenoid output pressure as the signal pressure for the lockup switching valve and the circulation pressure control valve, and the torque converter 2 has an output pressure higher than the output pressure at which the lockup switching valve switches. The characteristic is that the circulating pressure Pcir rises.

  FIG. 6 is a block diagram showing a hydraulic control circuit 70 according to this embodiment. As shown in FIG. 6, the hydraulic control circuit 70 according to this embodiment includes a circulation pressure control valve 72, a primary regulator valve 73, a lockup switching valve 74, a lockup control solenoid 75, and a proportional control solenoid 76.

  The circulation pressure control valve 72 is a valve that controls the pressure of the circulation pressure Pcir of the hydraulic oil to be circulated inside the torque converter 2. The circulation pressure control valve 72 is provided with valve bodies 721 and 722 that are movable in the axial direction (vertical direction in FIG. 6). A valve diameter φD2 of the valve body 721 is set larger than a valve diameter φD3 of the valve body 722. An elastic member 723 such as a coiled spring that is compressed by the valve body 722 is provided on one end side (the lower end side in FIG. 6) of the valve body 722. The circulation pressure control valve 72 is controlled by a proportional control solenoid 76 controlled by the ECU 3.

  The circulation pressure control valve 72 has an oil chamber 72a, an input port 72b, a drain port 72c, a supply port 72d, and an input port 72e. The oil chamber 72 a is provided at the end opposite to the end where the elastic member 723 is provided (upper end side in FIG. 6), and hydraulic oil of the output pressure Psol is supplied from the proportional control solenoid 76. The input port 72b is supplied with hydraulic oil having a line pressure from the oil pump 25. The drain port 72c is a port for discharging hydraulic oil to an oil pan or the like. The supply port 72d is a port for supplying hydraulic oil adjusted to the circulation pressure Pcir to the lockup switching valve 74. The operating oil discharged from the supply port 72d is supplied to the input port 72e. In the circulation pressure control valve 72, the state of the valve body 721 on the left side with respect to the center line is the initial state, the input port 72b is in the shut-off state, and the drain port 72c is in the released state. On the other hand, a state where the position of the valve body 721 is on the right side of the center line is a pressure regulation state, the drain port 72c is in a shielding state, and a release state of the input port 72b is gradually controlled.

  When the control pressure (solenoid output pressure Psol) of the hydraulic oil supplied from the proportional control solenoid 76 becomes equal to or higher than the predetermined second output pressure Psol2 in the circulation pressure control valve 72, the valve body 721 resists the reaction force of the elastic member 723. And is moved in the axial direction (downward in FIG. 6). Accordingly, the drain port 72c is shut off and the input port 72b is gradually opened, and the input port 72b and the supply port 72d communicate with each other. As a result, the hydraulic fluid that flows in through the input port 72b and flows out from the supply port 72d with the hydraulic pressure of the circulation pressure Pcir is gradually switched from the shut-off state to the lockup switching valve 74 to the supply state. As a result, the hydraulic oil having the circulation pressure Pcir can be supplied to the lockup switching valve 74. By changing the control pressure Psol of the hydraulic oil supplied from the proportional control solenoid 76 at the second output pressure Psol2 or more, the movement amount of the valve bodies 721 and 722 is changed, and the flow rate of the hydraulic oil to the lockup switching valve 74 is changed. That is, the circulation pressure Pcir can be controlled.

  The primary regulator valve 73 is a valve similar to the primary regulator valve 173 in the hydraulic control circuit 170 described above.

  The lock-up switching valve 74 selectively switches between the passage of high-pressure line hydraulic fluid supplied from the circulation pressure control valve 72 and the passage of low-pressure secondary pressure hydraulic fluid supplied from the primary regulator valve 73. It is a valve. The lockup switching valve 74 includes a plurality of valve bodies 741 that are movable in the axial direction with a valve diameter φD1. An elastic member 742 such as a coiled spring compressed by the valve body 741 is provided on one end side (the lower end side in FIG. 6) of the valve body 741. The lockup switching valve 74 is controlled by a proportional control solenoid 76 that is controlled by the ECU 3.

  The lockup switching valve 74 has an oil chamber 74a, input ports 74b, 74d, 74f, and 74i, a lockup port 74c, discharge ports 74e and 74j, a supply port 74g, a circulation port 74h, and drain ports 74k, 74l, and 74m. . The oil chamber 74a is provided at an end portion (upper end side in FIG. 6) opposite to the end portion where the elastic member 742 is provided, and hydraulic oil having an output pressure Psol is supplied from the proportional control solenoid 76.

  The input port 74b, 74d is supplied with hydraulic oil having a torque converter out pressure from the torque converter 2. The lockup port 74c supplies hydraulic oil having a control pressure for performing on / off control on the lockup clutch 23. The discharge port 74e is a port that discharges hydraulic oil to the cooler and the circulation unit. The input port 74f is supplied with hydraulic oil having a secondary pressure adjusted by the primary regulator valve 73.

  The supply port 74g is a port for supplying hydraulic oil to the torque converter 2, and the torque converter 2 is supplied with hydraulic oil having a torque converter in-pressure from the supply port 74g. The circulation port 74h is supplied with the hydraulic oil having the circulation pressure Pcir discharged from the supply port 72d of the circulation pressure control valve 72. The input port 74i is supplied with hydraulic oil having a control pressure for performing on / off control on the lockup clutch 23 from the lockup control solenoid 75. The discharge port 74j is a port for supplying hydraulic oil to the fail safe valve. The drain ports 74k, 74l, and 74m are ports for discharging hydraulic oil to an oil pan or the like.

  The lock-up control solenoid 75 is, for example, a current-controlled linear solenoid because high controllability is required for controlling the engagement pressure of the lock-up clutch 23. The proportional control solenoid 76 is, for example, a current-controlled linear solenoid or a PWM-controlled duty solenoid.

  In the lockup switching valve 74, when the position of the valve body 741 is on the left side with respect to the center line, the lockup switching valve 74 is in an off state and the lockup clutch 23 is in a lockup off state. It becomes the valve state corresponding to. On the other hand, when the position of the valve body 741 is in a state on the right side with respect to the center line, a valve state corresponding to the case where the lockup clutch 23 is in the lockup on state or the flex control state is obtained.

  In the lockup switching valve 74, the flow path of hydraulic oil when the valve state is a valve state corresponding to the lockup off state of the lockup clutch 23 will be described. A part of the hydraulic oil from the torque converter 2 is supplied to the lockup clutch 23 through the input port 74b and the lockup port 74c. The other part of the hydraulic oil from the torque converter 2 is supplied to a cooler, a lubrication part, etc. through the input port 74d and the discharge port 74e. The secondary pressure hydraulic oil, which is a drain from the primary regulator valve 73, is supplied to the torque converter 2 through the input port 74f and the supply port 74g. On the other hand, the hydraulic oil of the circulating pressure Pcir supplied from the circulating pressure control valve 72 is shut off. The hydraulic fluid supplied from the lockup control solenoid 75 is supplied to the fail-safe valve through the input port 74i and the discharge port 74j.

  In the lockup switching valve 74, when the output pressure of the proportional control solenoid 76 becomes equal to or higher than the predetermined first output pressure Psol1, the valve state becomes a valve state corresponding to the lockup on state / flex control state of the lockup clutch 23. The flow path of the hydraulic oil in this case will be described. The hydraulic oil supplied from the torque converter 2 to the input port 74b is blocked at the input port 74b. On the other hand, the hydraulic oil supplied from the lockup control solenoid 75 is supplied to the lockup clutch 23 through the input port 74i and the lockup port 74c. As a result, the lock-up clutch 23 is supplied with hydraulic oil having a lock-up on pressure, and the lock-up on state or the flex control state is set.

  Part of the hydraulic oil from the torque converter 2 is discharged to the oil pan through the input port 74d and the drain port 74l. The secondary pressure hydraulic oil, which is a drain from the primary regulator valve 73, is supplied to the cooler, the lubrication unit, and the like through the input port 74f and the discharge port 74e. The hydraulic oil having the circulation pressure Pcir supplied from the circulation pressure control valve 72 is supplied to the torque converter 2 through the circulation port 74h and the supply port 74g.

  Here, the relationship between the circulating pressure Pcir (circulating flow rate) of the hydraulic oil supplied to the torque converter 2 and the hydraulic oil output pressure Psol by the proportional control solenoid 76 will be described. FIG. 7 is a graph showing the state of the lockup switching valve 74 and the relationship between the torque converter circulation pressure (circulation flow rate) and the output pressure Psol of the proportional control solenoid 76.

First, the pressure regulation type in the lockup switching valve 74 can be expressed by the following formula (1). Fsp1 is a reaction force of the elastic member 742 in the lockup switching valve 74.

In the equation (1), the output pressure Psol of the proportional control solenoid 76 when the left side exceeds the right side is the first output pressure Psol1 that is switched. Specifically, the first output pressure Psol1 is derived from the equation (1-1) based on the equation (1). From the equation (1-1), the first output pressure Psol1 can be set to a desired pressure by adjusting the valve diameter φD1 of the valve body 741 of the lockup switching valve 74 and the reaction force Fsp1 of the elastic member 742. is there.

Moreover, the pressure regulation type in the circulation pressure control valve 72 as the circulation pressure control valve can be expressed by the following equation (2). Fsp2 is a reaction force of the elastic member 723 in the circulation pressure control valve 72.

When the output pressure of the proportional control solenoid 76 at which the circulation pressure Pcir becomes 0 (Pcir = 0) becomes larger than the second output pressure Psol2, the circulation pressure Pcir starts to increase. Specifically, the second output pressure Psol2 is derived from the equation (2-1) when the circulation pressure Pcir is set to 0 in the equation (2). From the equation (2-1), the second output pressure Psol2 can be set to a desired pressure by adjusting the valve diameter φD2 of the valve body 721 of the circulation pressure control valve 72 and the reaction force Fsp2 of the elastic member 723. is there.

  From the above equations (1-1) and (2-1), the first output pressure Psol1 and the second output pressure Psol2 can be set with a predetermined output pressure difference. Specifically, the valve diameter φD1 and reaction force Fsp1 of the lockup switching valve 74, the valve diameter φD2 and reaction force Fsp2 of the valve body 721 of the circulation pressure control valve 72, and the second output pressure Psol2 are the first output pressure. Set to be larger than Psol1. In this setting, the valve diameters φD1 and φD2 and the reaction forces Fsp1 and Fsp2 are considered, and the valve diameter is set so that the second output pressure Psol2 is larger than the first output pressure Psol1 even when these variations are maximum. φD1, φD2 and reaction forces Fsp1, Fsp2 are set. That is, the valve diameters φD1 and φD2 and the reaction forces Fsp1 and Fsp2 are set so that the second output pressure Psol2 is higher than the first output pressure Psol1 by a predetermined pressure that can be secured as a margin.

  Further, as shown in FIG. 7, the gradient of the circulation pressure with respect to the solenoid output pressure Psol, that is, the control gain of the circulation pressure is set by the ratio of the valve diameter φD2 and the valve diameter φD3 (see FIG. 6) in the circulation pressure control valve 72. it can. That is, by setting various ratios of the valve diameter ΦD2 of the valve body 721 and the valve diameter ΦD3 of the valve body 722 in the circulation pressure control valve 72, the control gain in the circulation pressure control valve 72 is set as shown in FIG. It can be arbitrarily set between the control gain and the control gain of (B). Specifically, when emphasizing controllability, it is preferable to set the control gain as shown in FIG. Conversely, when emphasizing responsiveness, it is preferable to set the control gain as shown in FIG. In addition, when the output pressure Psol in the proportional control solenoid 76 is a design upper limit value Pmax, the circulation pressure Pcir is controlled to be a required flow rate at the maximum load.

  Next, a hydraulic oil supply control method by the hydraulic control device according to the embodiment of the present invention will be described. FIG. 8 is a flowchart for explaining a hydraulic oil supply control method according to this embodiment.

  As shown in FIG. 8, in step ST <b> 1, the ECU 3 determines the state of the lockup clutch 23. When the ECU 3 determines that the lockup clutch 23 is in the lockup off state (step ST1: off), the ECU 3 proceeds to step ST2. In step ST2, the ECU 3 controls the proportional control solenoid 76 so that the output pressure Psol is in the range of 0 or more and less than the first output pressure Psol1 (0 ≦ Psol <Psol1). Here, considering the power consumption of the proportional control solenoid 76, it is desirable to control the output pressure Psol of the proportional control solenoid 76 to 0 (Psol = 0). However, considering the responsiveness when shifting from the lock-up off state to the lock-up on state or the flex control state, the output pressure Psol of the proportional control solenoid 76 is controlled to be less than the first output pressure Psol1 (Psol <Psol1). Is preferred. As a result, the hydraulic oil supply control process ends.

  On the other hand, when the ECU 3 determines in step ST1 that the lockup clutch 23 is in the lockup on state (step ST1: on), the process proceeds to step ST3. In step ST3, the ECU 3 controls the proportional control solenoid 76 so that the output pressure Psol is in the range of the first output pressure Psol1 or more and less than the second output pressure Psol2 (Psol1 ≦ Psol <Psol2). Here, considering the responsiveness of the transition from the lock-up on state to the lock-up off state and the power consumption of the proportional control solenoid 76, the output pressure Psol of the proportional control solenoid 76 is controlled to Psol1 (Psol = Psol1). Is desirable. However, considering the responsiveness when shifting from the lock-up on state to the flex control state, it is preferable to control the output pressure Psol of the proportional control solenoid 76 to a pressure close to the second output pressure Psol2. As a result, the hydraulic oil supply control process ends.

  On the other hand, when the ECU 3 determines in step ST1 that the lock-up clutch 23 is in the flex control state (step ST1: flex control), the process proceeds to step ST4. In step ST4, the ECU 3 calculates the heat generation amount of the lockup clutch 23 during flex control based on the transmission torque of the lockup clutch 23, the slip differential rotation, and the like. Thereafter, the process proceeds to step ST5.

  In step ST <b> 5, the ECU 3 calculates the circulating flow rate of the hydraulic oil in the torque converter 2 necessary for cooling the lockup clutch 23 based on the calculated heat generation amount of the lockup clutch 23. Thereafter, the process proceeds to step ST6.

  In step ST6, as shown in FIG. 7, the ECU 3 controls the proportional control solenoid 76 so that the circulating fluid flow rate of the hydraulic fluid supplied to the torque converter 2 becomes the calculated circulating fluid flow rate. Output pressure Psol. The hydraulic oil supply control process is thus completed.

  As described above, according to one embodiment of the present invention, there is no need to provide a switching valve for shutting off the supply of hydraulic oil to the torque converter 2, so that an increase in the size of the hydraulic control circuit 70 is suppressed. Cost. In addition, while maintaining the lock-up switching valve 74 in the lock-up on state / flex control state, the circulating pressure Pcir of the hydraulic oil supplied to the torque converter 2 is arbitrarily set within the range from 0 to the required flow rate at the maximum load. Can be controlled. Thereby, the pump capacity of the oil pump 25 can be reduced as compared with the two-stage control as shown in FIG. 5, and when the two-port oil pump is used as the oil pump 25, the subport pressure can be reduced.

  Further, according to the embodiment, in the proportional control solenoid 76, the second output pressure Psol2 required for switching the circulation pressure control valve 72 is set to be higher than the first output pressure Psol1 required for switching the lockup switching valve 74. The pressure is set higher than the specified pressure. As a result, robustness against manufacturing variations of components constituting the circulation pressure control valve 72 and the lockup switching valve 74 is ensured, and a region where the circulation flow rate (circulation pressure Pcir) can be controlled to 0 can be secured. Therefore, when the supply of hydraulic oil to the torque converter 2 is unnecessary, the supply of hydraulic oil can be shut off by the circulation pressure control valve 72.

  Although one embodiment of the present invention has been specifically described above, the present invention is not limited to the above-described embodiment, and various modifications based on the technical idea of the present invention are possible. For example, the numerical values given in the above-described embodiment are merely examples, and different numerical values may be used as necessary.

1 Engine 2 Torque converter 3 ECU
13 Hydraulic Control Device 23 Lockup Clutch 25 Oil Pump 70 Hydraulic Control Circuit 72 Circulating Pressure Control Valve 74 Lockup Switching Valve 75 Lockup Control Solenoid 76 Proportional Control Solenoid

Claims (1)

Hydraulic pressure for controlling hydraulic pressure of the hydraulic oil supplied to the torque converter, including a circulation pressure control valve and a lockup switching valve provided in an oil passage through which hydraulic oil is supplied from an oil pump to a torque converter having a lockup mechanism In the control device,
The output pressure of the hydraulic oil can be proportionally controlled, and the lockup switching valve can be controlled from the valve state corresponding to the lockup off state in the lockup mechanism to the lockup on state or flex in the lockup mechanism by the first output pressure. A proportional control solenoid that switches to a valve state corresponding to a control state, and switches the circulating pressure control valve from a shut-off state to a supply state of the hydraulic oil to the torque converter at a second output pressure;
The hydraulic pressure control device, wherein the second output pressure is set to an output pressure higher than a predetermined pressure with respect to the first output pressure.

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