JP2008274972A - Hydraulic control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To simplify a mechanism for controlling the engagement/disengagement of a lock-up clutch and a mechanism for controlling a forward-reverse travel change-over device. <P>SOLUTION: The hydraulic control device comprises the lock-up clutch provided in parallel to a fluid transmission device, an engaging hydraulic pressure chamber 14 and a disengaging hydraulic pressure chamber 15 for controlling the lock-up clutch, a transmission torque control mechanism, a lock-up control mechanism 48 for controlling hydraulic pressure in the engaging hydraulic pressure chamber 14 and the disengaging hydraulic pressure chamber 15, a first solenoid mechanism 57 for generating signal hydraulic pressure to control the lock-up control mechanism 48, and a change-over mechanism 62 for controlling the hydraulic pressure of pressure oil to be supplied to the transmission torque control mechanism. Herein, a high pressure oil path 61 and a low pressure oil path 47 are provided. The change-over mechanism 62 selects the high pressure oil path 61 or the low pressure oil path 47 for supplying the pressure oil to the transmission torque control mechanism. The change-over mechanism 62 can be controlled by the signal hydraulic pressure generated by the first solenoid mechanism 68. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a hydraulic control device having a fluid transmission device that transmits power by the kinetic energy of a fluid and a lock-up clutch provided in parallel with the fluid transmission device.

  Generally, a clutch mechanism may be provided in a power transmission path from a power source of a vehicle to wheels. As this clutch mechanism, a fluid clutch, a friction clutch, and the like are known, and this fluid clutch has an advantage that torque fluctuations of a power source are hardly transmitted to wheels. On the other hand, since the fluid clutch is a device that transmits power by the kinetic energy of the fluid, it has a characteristic that the power loss is larger than that of the friction clutch. Therefore, when this fluid clutch is used, a decrease in power loss can be suppressed by using a friction clutch together. As described above, a fluid clutch and a friction clutch are provided in parallel in a power transmission path from the power source of the vehicle to the wheels, and an example of a hydraulic control device that controls these clutches is described in Patent Document 1. ing.

  The vehicle described in Patent Document 1 is configured such that engine torque is transmitted to an axle shaft via a torque converter, a forward / reverse switching device, a belt-type continuously variable transmission, a reduction gear device, and a differential gear device. Has been. The torque converter has a pump impeller, a turbine runner, a stator, and a lock-up clutch. The lockup clutch is configured such that when the back side hydraulic pressure is increased and the front cover is engaged, the torque of the engine crankshaft is transmitted to the output shaft of the torque converter via the lockup clutch. ing. On the other hand, when the oil pressure on the front side of the lockup clutch is increased, the lockup clutch is released away from the front cover, and torque is transmitted by the kinetic energy of the fluid. Thus, when the lockup clutch is released, the transmission torque is amplified by the stator. Further, the forward / reverse switching device is configured as a double planetary gear type, and is provided with a forward clutch and a reverse brake for switching the rotation direction of the input shaft of the belt type continuously variable transmission.

  These lock-up clutches, forward clutches and reverse clutches are all hydraulically controlled mechanisms, and their hydraulic control devices are provided. This hydraulic control device is configured such that the pressure oil discharged from the oil pump is supplied to the front side and the back side of the lockup clutch via the lockup relay valve. In addition, the pressure oil is supplied to the torque converter and the lubrication system via the lockup relay valve. And the 1st solenoid valve which selectively switches engagement / release of a lockup clutch by controlling a lockup relay valve is provided. Furthermore, a control valve for controlling the hydraulic pressure of the pressure oil supplied from the oil pump to the input side of the lockup relay valve is provided. Further, a second electromagnetic valve for controlling the output hydraulic pressure of the control valve is provided. On the other hand, a manual valve is provided for selectively supplying the pressure oil discharged from the oil pump to the forward clutch or the reverse brake. Furthermore, a clutch pressure control valve for controlling the hydraulic pressure of the pressure oil supplied from the oil pump to the manual valve is provided. Furthermore, this clutch pressure control valve is configured such that its output hydraulic pressure is controlled by the signal hydraulic pressure of the linear solenoid. An example of a vehicle having a torque converter, a hydraulically controlled lockup clutch, and a hydraulically controlled forward / reverse switching device is also described in Patent Document 2.

JP-A-11-182626 JP-A-10-325458

  However, in the hydraulic control device described in Patent Document 1, a solenoid valve that generates a signal hydraulic pressure that controls engagement / release of the lockup clutch and a signal hydraulic pressure that controls the clutch and brake of the forward / reverse switching device are generated. Since the solenoid valves to be operated are provided exclusively for each, there is a problem that the manufacturing cost of the hydraulic control device increases.

  The present invention has been made against the background of the above circumstances, and it is possible to suppress simplification of the mechanism for controlling the engagement / release of the lock-up clutch and the mechanism for controlling the clutch and brake of the forward / reverse switching device. An object of the present invention is to provide a hydraulic control device.

  The present invention provides a fluid transmission device that is provided on the output side of a power source and transmits power by the kinetic energy of hydraulic oil, a lock-up clutch provided in parallel with the fluid transmission device, and an output from the power source A transmission torque control mechanism that is provided in a transmission path of power to be transmitted and that controls transmission torque by hydraulic control, an engagement hydraulic chamber and a release hydraulic chamber that control engagement / release of the lock-up clutch, A lockup control mechanism for controlling the hydraulic pressure of the pressure oil supplied from the pressure oil supply source to the engagement hydraulic chamber and the release hydraulic chamber, and a first solenoid mechanism for generating a signal hydraulic pressure for controlling the lockup control mechanism And a switching mechanism that controls the hydraulic pressure of the pressure oil supplied from the pressure oil supply source to the transmission torque control mechanism. There is provided a high pressure oil passage in which the pressure oil supplied from the supply source is controlled to a high pressure, and a low pressure oil passage in which the pressure oil supplied from the pressure oil supply source is controlled to a pressure lower than the hydraulic pressure of the high pressure oil passage. The high-pressure oil passage and the low-pressure oil passage are connected to the switching mechanism, and the switching mechanism selectively switches the pressure oil of either the high-pressure oil passage or the low-pressure oil passage to transmit the transmission. The switching mechanism can be controlled by a signal hydraulic pressure generated by the first solenoid mechanism.

  Further, according to the present invention, when a signal hydraulic pressure for releasing the lockup clutch is generated by the first solenoid mechanism, the switching mechanism is controlled by the signal hydraulic pressure, and the pressure oil in the high-pressure oil passage is controlled by the transmission torque control. It is good also as a structure supplied to a mechanism.

  Further, according to the present invention, when a signal oil pressure for engaging the lockup clutch is generated by the first solenoid mechanism, the switching mechanism is controlled by the signal oil pressure, and the pressure oil in the low-pressure oil passage is transferred to the transmission torque. It is good also as a structure supplied to a control mechanism.

  According to the present invention, a belt-type continuously variable transmission is provided on the output side of the power source, and the belt-type continuously variable transmission is configured by winding a belt around a primary pulley and a secondary pulley. Alternatively, a pulley hydraulic chamber that controls the clamping force applied to the belt from the secondary pulley, a flow rate control mechanism that controls the flow rate of pressure oil in the pulley hydraulic chamber, and a flow rate control characteristic in the flow rate control mechanism are controlled. A second solenoid mechanism for generating a signal oil pressure, and when the lockup clutch is released, the switching mechanism is controlled by the signal oil pressure generated by the second solenoid mechanism, and the high pressure oil passage Alternatively, any pressure oil in the low pressure oil passage may be selected and supplied to the transmission torque control mechanism.

  In the present invention, when a signal oil pressure is generated in the second solenoid mechanism to increase the flow rate of the pressure oil discharged from the pulley hydraulic chamber to a predetermined amount, the signal oil pressure The switching mechanism may be controlled so that the pressure oil in the high-pressure oil passage is supplied to the transmission torque control mechanism.

  In the present invention, when a signal oil pressure is generated in the second solenoid mechanism to reduce the flow rate of the pressure oil discharged from the pulley hydraulic chamber to a predetermined amount or less, the signal oil pressure The switching mechanism may be controlled so that the pressure oil in the low-pressure oil passage is supplied to the transmission torque control mechanism.

  According to the present invention, the signal hydraulic pressure generated by the first solenoid mechanism is used to control both the lockup control mechanism that controls engagement / release of the lockup clutch and the switching mechanism that controls the transmission torque control mechanism. It is possible to eliminate the signal oil pressure generator for controlling the lock-up control mechanism and the signal oil pressure generator for controlling the switching mechanism. Can be suppressed.

  Next, an embodiment of the hydraulic control device of the present invention will be described. In the hydraulic control apparatus of the present invention, the power source is a power device that generates power to be transmitted to the wheels, and a single power source or a plurality of types of power sources having different power generation principles can be used. For example, an engine, an electric motor, a hydraulic motor, a flywheel system, or the like can be used as a plurality of types of power sources having different power generation principles. Further, the hydraulic control device is a vehicle having a power train configured such that the power of the power source is transmitted to either the front wheels or the rear wheels, that is, the two-wheel drive vehicle, or the power of the power source is the front wheels and the rear wheels. The present invention is applicable to any vehicle having a power train configured to be transmitted to both, that is, a four-wheel drive vehicle.

  Further, a lockup clutch is provided in parallel with the fluid transmission device. This lock-up clutch is a power transmission device that transmits power by frictional force. In addition, a transmission torque control mechanism is provided downstream of the fluid transmission device in the power transmission path. The transmission torque control mechanism is a device that can control transmission torque or torque capacity. Furthermore, the hydraulic control device can be applied to a vehicle in which a forward / reverse switching device and a continuously variable transmission are provided in a power transmission path. In this case, the forward / reverse switching device corresponds to a transmission torque control mechanism. This forward / reverse switching device is a device that switches the rotation direction of the output rotation member between the rotation direction of the input rotation member and the rotation direction of the output rotation member, either a device using a planetary gear mechanism or a parallel shaft gear type device. Good. When a planetary gear mechanism is used as the forward / reverse switching device, either a single pinion planetary gear mechanism or a double pinion planetary gear mechanism may be used. Further, when a forward / reverse switching device is configured using a planetary gear mechanism, a friction clutch and brake are used to control rotation / stop of the rotating elements of the planetary gear mechanism and engagement / release of the rotating elements. It is possible to use. When a parallel shaft gear type is used as the forward / reverse switching device, a meshing type clutch and brake can be used. The continuously variable transmission is a transmission capable of changing a gear ratio, which is a ratio between an input rotation speed and an output rotation speed, continuously (continuously). A toroidal type continuously variable transmission is mentioned. Further, the hydraulic control device can be applied to a vehicle in which a stepped transmission is provided in a power transmission path from a power source to wheels. This stepped transmission is a known transmission having a planetary gear mechanism and a friction engagement device, and controls the engagement / release of the friction engagement device to change the speed between the input rotation member and the output rotation member. The ratio is controlled, and the torque transmitted between the input rotating member and the output rotating member is controlled. This stepped transmission corresponds to a transmission torque control mechanism.

  Further, the transmission torque, torque capacity, engagement pressure, etc. of the transmission torque control mechanism and the lockup clutch are controlled by the hydraulic pressure in the hydraulic chamber. That is, it is configured to be controlled by a hydraulically controlled actuator. Further, the hydraulic pressure of the pressure oil in the high pressure oil passage is controlled to a high pressure, and the hydraulic pressure of the low pressure oil passage is controlled to a low pressure. Here, the high pressure and the low pressure mean a pressure relationship between the high pressure oil passage and the low pressure oil passage, and do not mean a specific pressure or a pressure range (region). Further, it does not matter whether the hydraulic pressure in the high-pressure oil passage is raised, lowered, or controlled to be substantially constant. Furthermore, it does not matter whether the oil pressure in the low-pressure oil passage is raised or lowered or controlled to be substantially constant. Furthermore, a high pressure control valve and a low pressure control valve are provided to control the oil pressure in the high pressure oil passage and the low pressure oil passage.

  Furthermore, a high-pressure solenoid valve that outputs a signal hydraulic pressure for controlling the output hydraulic pressure of the high-pressure control valve is provided. Furthermore, a low-pressure solenoid valve that outputs a signal hydraulic pressure for controlling the output hydraulic pressure of the low-pressure control valve is provided. Further, the high pressure solenoid valve and the low pressure solenoid valve are adjusted in the signal oil pressure according to the energization current value, and the energization current value is based on the data stored in advance in the electronic control device and the signal input to the electronic control device. Is configured to be controlled. In the hydraulic control device, a switching valve can be used as the switching mechanism. When the transmission torque of the lockup clutch is switched to a low torque or a high torque, the switching valve is controlled so that either the high pressure oil passage or the low pressure oil passage selectively controls the transmission torque. Supplied to the mechanism. Moreover, regardless of whether the transmission torque of the lockup clutch is low torque or high torque, the switching valve is configured to supply the pressure oil of the low pressure oil passage to the lockup clutch.

  Further, a lockup clutch, a transmission torque control device, and a belt type continuously variable transmission are arranged in the power transmission path. This belt-type continuously variable transmission is constructed by winding a belt around a primary pulley and a secondary pulley, and the gear ratio, which is the ratio between the input rotation speed and the output rotation speed, is changed steplessly (continuously). It is a possible transmission. More specifically, the second hydraulic control device has a configuration in which a lockup clutch, a transmission torque control mechanism, and a belt-type continuously variable transmission are arranged in series on a power transmission path from a power source to a wheel. It can be applied to a vehicle having a drive train. That is, in the hydraulic control device, the arrangement order of the lock-up clutch, the transmission torque control mechanism, and the belt-type continuously variable transmission is not limited in the power transmission direction from the power source to the wheels.

  Further, the forward / reverse switching device is a device that switches the rotation direction of the output rotation member between the rotation direction of the input rotation member and the rotation direction of the output rotation member, either a device using a planetary gear mechanism or a parallel shaft gear type device. May be used. In the hydraulic control device, when a planetary gear mechanism is used as the forward / reverse switching device, either a single pinion planetary gear mechanism or a double pinion planetary gear mechanism may be used. Further, when a forward / reverse switching device is configured using a planetary gear mechanism, a friction clutch and brake are used to control rotation / stop of the rotating elements of the planetary gear mechanism and engagement / release of the rotating elements. It is possible to use. On the other hand, when a parallel shaft gear type is used as the forward / reverse switching device, a meshing type clutch and brake can be used. By controlling these clutches and brakes, the transmission torque in the forward / reverse switching device is controlled.

  In the present invention, the lockup control mechanism is a mechanism for controlling the hydraulic pressure of the engagement hydraulic chamber and the release hydraulic chamber, and includes an oil passage, a passage or a port connected to the engagement hydraulic chamber and the release hydraulic chamber. In addition, a valve (pressure control valve) for controlling the hydraulic pressure of the pressure oil is included. In the present invention, both the first solenoid mechanism and the second solenoid mechanism are devices that generate a signal oil pressure, and the first solenoid mechanism and the second solenoid mechanism control the solenoid valve and the energization current value of the solenoid valve. An electronic controller that is a controller is included. In the present invention, the switching mechanism includes a switching valve that switches a connection relationship between the oil paths, an oil path and a port that are connected to the switching valve. In the present invention, the pressure oil supply source is a device that gives kinetic energy to supply pressure oil to the hydraulic circuit, and the pressure oil supply source includes an oil pump, an accumulator, and the like. The flow rate control mechanism in the present invention includes a flow rate control valve, an oil passage and a port connected to the flow rate control valve, a controller for controlling the flow area of pressure oil in the flow rate control valve, and the like. In the present invention, the predetermined amount is a value stored in the controller or a value obtained based on various conditions, and is a flow rate threshold value. Furthermore, in the present invention, the predetermined pressure is a value stored in the controller or a value obtained based on various conditions, and is a signal oil pressure threshold value.

  Next, a specific example of the hydraulic control device of the present invention will be described with reference to the drawings. First, FIG. 2 shows a vehicle power train capable of implementing the hydraulic control device and a control system of the vehicle. In the power train of the vehicle 1 shown here, a torque converter 3 which is a kind of fluid transmission device is provided on the output side of the power source 2. Further, the torque output from the torque converter 3 is transmitted to the belt type continuously variable transmission 5 via the forward / reverse switching device 4. That is, in the drive train shown in FIG. 2, the forward / reverse switching device 4 is disposed between the torque converter 3 and the belt-type continuously variable transmission 5 in the power transmission direction. As the power source 1, at least one of an engine or an electric motor can be used. This engine is a power unit that burns fuel and converts its thermal energy into kinetic energy. As the engine, an internal combustion engine, specifically, a gasoline engine, a diesel engine, an LPG engine, or the like can be used. Hereinafter, a case where a gasoline engine is used as the power source 1 will be described, and for convenience, the power source 1 will be referred to as “engine 1”. The intake pipe (not shown) of the engine 1 is provided with an electronic throttle valve (not shown), and the engine 1 has a crankshaft 6.

  A torque converter 3 is provided on the output side of the crankshaft 6. The torque converter 3 is a fluid transmission device that transmits power between the input member and the output member by the kinetic energy of hydraulic oil. The torque converter 3 is configured by providing a pump impeller 8 and a turbine runner 9 inside a casing 7, and the pump impeller 8 is connected to the crankshaft 6 by the casing 7 so that power can be transmitted. On the other hand, the turbine runner 9 is connected to the input shaft 10 so as to rotate integrally. The casing 7 is an input member, and the input shaft 10 is an output member. The pump impeller 8 and the turbine runner 9 are provided with a large number of blades (not shown), and a converter oil chamber 11 is formed between the pump impeller 8 and the turbine runner 9. The hydraulic oil is supplied via the chamber 11, and power is transmitted to the turbine runner 9 by the kinetic energy of the hydraulic oil generated by the rotation of the pump impeller 8. In addition, a stator 12 that selectively changes the flow direction of the hydraulic oil sent from the turbine runner 9 and flows into the pump impeller 8 is disposed in the inner peripheral portion of the pump impeller 8 and the turbine runner 9. Yes. The torque transmitted between the pump impeller 8 and the turbine runner 9 is amplified by the action of the stator 12.

  Furthermore, a lockup clutch 13 for selectively connecting and releasing the casing 7 and the input shaft 10 is provided. Further, the lock-up clutch 13 is a frictional transmission torque control mechanism, and is configured such that the transmission torque is controlled by pressing a friction material rotating together with the input shaft 10 against the front cover of the casing 7. In order to control the transmission torque of the lockup clutch 13, an engagement hydraulic chamber 14 and a release hydraulic chamber 15 are provided. Based on the pressure difference between the engagement hydraulic chamber 14 and the release hydraulic chamber 15, The lockup clutch 13 is engaged or released. Specifically, when the hydraulic pressure in the engagement hydraulic chamber 14 becomes higher than the hydraulic pressure in the release hydraulic chamber 15, the friction material is pressed against the front cover to increase the frictional force. In this way, the transmission torque of the lockup clutch is increased (engaged). On the other hand, when the hydraulic pressure in the engagement hydraulic chamber 14 is lower than the hydraulic pressure in the release hydraulic chamber 15, the friction material is separated from the front cover and the frictional force is reduced. In this way, the transmission torque of the lockup clutch 13 is reduced (released).

  In this embodiment, when the lockup clutch 13 is released, power transmission by the frictional force of the lockup clutch 13 is impossible. On the other hand, when the lockup clutch 13 is engaged, power transmission by the frictional force of the lockup clutch 13 is possible. In this embodiment, “engagement of the lock-up clutch 13” includes “slip of the lock-up clutch 13”. That is, even when the lockup clutch 13 is slipping, power transmission by the frictional force of the lockup clutch 13 is possible. The converter oil chamber 11 is in communication with the engagement hydraulic chamber 14, and when the oil pressure in the converter oil chamber 11 increases, the oil pressure in the engagement hydraulic chamber 14 increases and the oil pressure in the converter 11 oil chamber decreases. The hydraulic pressure in the engagement hydraulic chamber 14 is configured to decrease.

  On the other hand, the forward / reverse switching device 4 is a device that switches the rotational direction of the primary shaft 16 of the belt-type continuously variable transmission 5 with respect to the rotational direction of the input shaft 10. As the forward / reverse switching device 4, a double pinion type planetary gear mechanism is employed in the example shown in FIG. That is, a sun gear 17 that rotates integrally with the input shaft 10 and a ring gear 18 that is arranged coaxially with the sun gear 17 are provided, and a pinion gear 19 that meshes with the sun gear 17, and meshes with the pinion gear 19 and the ring gear 18. A pinion gear 20 is provided, and the two pinion gears 19 and 20 are held by a carrier 21 so as to rotate and revolve freely.

  Further, the forward / reverse switching device 4 includes a forward clutch 22 that selectively couples and releases the input shaft 10 and the carrier 21 so that power can be transmitted. Further, the forward / reverse switching device 4 includes a reverse brake 23 that selectively fixes the ring gear 18 to switch the rotation direction of the primary shaft 16 relative to the rotation direction of the input shaft 10 between forward and reverse. In this embodiment, as the forward clutch 22 and the reverse brake 23, hydraulically controlled clutches and brakes are used. That is, a clutch hydraulic chamber 24 for controlling the transmission torque of the forward clutch 22 is provided, and a brake hydraulic chamber 25 for controlling the braking force or torque capacity of the reverse brake 23 is provided. The belt type continuously variable transmission 5 includes a primary shaft 16 and a secondary shaft 26 that are arranged in parallel to each other. A primary pulley 27 that rotates integrally with the primary shaft 16 is provided, and a secondary pulley 28 that rotates integrally with the secondary shaft 26 is provided.

  The primary pulley 27 has a fixed piece (not shown) fixed in the axial direction and a movable piece (not shown) configured to be movable in the axial direction. A groove is formed between the fixed piece and the movable piece, and a primary hydraulic chamber 29 for controlling the width of the groove by operating the movable piece in the axial direction is provided. On the other hand, the secondary pulley 28 has a fixed piece (not shown) fixed in the axial direction and a movable piece (not shown) configured to be movable in the axial direction. A groove is formed between the fixed piece and the movable piece, and a secondary hydraulic chamber 30 is provided for controlling the width of the groove by operating the movable piece in the axial direction. Further, a differential 32 is connected to the secondary shaft 26 with a gear transmission 31 interposed therebetween, and wheels (front wheels) 33 are connected to the differential 32 so that power can be transmitted.

  Next, the control system of the vehicle shown in FIG. 2 will be described. First, an electronic control unit (ECU) 34 is provided. The electronic control unit 34 includes an engine speed, a speed of the primary shaft 16, a speed of the secondary shaft 26, a vehicle speed, an acceleration request, a braking request, an oil Signals indicating temperature, outside air temperature, shift position, etc. are input. The electronic control device 34 outputs a signal for controlling the engine, a signal for controlling the hydraulic control device 35, and the like. By the control of the hydraulic control device 35, the transmission torque of the lockup clutch 13 is controlled, the transmission torque of the forward clutch 22 of the forward / reverse switching device 4 and the braking force of the reverse brake 23 are controlled, and the belt type continuously variable transmission. The gear ratio and transmission torque in the machine 5 are controlled. Therefore, the electronic control unit 34 controls the lockup clutch control map for controlling the engagement / release / slip of the lockup clutch 13 and the gear ratio of the belt type continuously variable transmission 5 based on the vehicle speed and the acceleration request. A transmission ratio control map to be stored is stored.

  In the vehicle 1 configured as described above, the torque output from the engine 2 is transmitted to the wheels 33 via the torque converter 3, the forward / reverse switching device 4, and the belt type continuously variable transmission 5. The control of the lockup clutch 13 will be described. When the hydraulic pressure in the engagement hydraulic chamber 14 is increased and the lockup clutch 13 is engaged, power is transmitted by frictional force. On the other hand, when the hydraulic pressure in the release hydraulic chamber 15 is increased and the lockup clutch 13 is released, power is transmitted by the kinetic energy of the hydraulic oil. Thus, when the lockup clutch 13 is released, in the torque converter 3, when the speed ratio between the casing 7 and the input shaft 10 is in a region (torque converter range) less than 1.0, the stator 12. Torque amplification is performed by the function. On the other hand, in the region where the speed ratio between the casing 7 and the input shaft 10 is closer to 1.0 than the torque converter range, torque amplification is not performed in the (fluid coupling range).

  In this way, engine torque is transmitted to the input shaft 10. Next, the control of the forward / reverse switching device 4 will be described. When a forward position, for example, a D (drive) position is selected as the shift position, the hydraulic pressure in the clutch hydraulic chamber 24 is increased, the forward clutch 22 is engaged, and the brake hydraulic chamber 25 is engaged. And the reverse brake 23 is released. Then, the input shaft 10 and the carrier 21 rotate integrally, and the torque of the input shaft 10 is transmitted to the primary shaft 16. On the other hand, when the reverse position is selected, the hydraulic pressure in the clutch hydraulic chamber 24 is reduced, the forward clutch 22 is released, the hydraulic pressure in the brake hydraulic chamber 25 is increased, and the reverse hydraulic pressure is increased. The brake 23 is engaged. That is, the ring gear 18 is fixed. When the engine torque is transmitted to the sun gear 17, the ring gear 18 becomes a reaction force element, and the torque of the sun gear 17 is transmitted to the primary shaft 16 via the carrier 21. Here, the rotation direction of the primary shaft 16 is opposite to that in the forward position.

  Next, control of the belt type continuously variable transmission 5 will be described. As described above, the engine torque is transmitted to the primary shaft 16, and the belt type continuously variable transmission is performed based on various signals input to the electronic control unit 34 and data stored in advance in the electronic control unit 34. The gear ratio and torque capacity of the machine 5 are controlled. First, the control of the gear ratio of the belt type continuously variable transmission 5 will be described. When the groove width of the primary pulley 27 is adjusted, the winding radius of the belt 36 around the primary pulley 27 continuously changes, and the gear ratio is changed. Changes steplessly. Further, the groove width of the secondary pulley 28 is adjusted, and the clamping pressure of the secondary pulley 28 against the belt 36 is adjusted. In this manner, the torque transmitted via the belt 36 between the primary pulley 27 and the secondary pulley 28 is controlled. A specific example of the hydraulic control device 35 that controls the lockup clutch 13, the forward / reverse switching device 4, and the belt type continuously variable transmission 5 configured as described above will be described.

(Specific example 1)
FIG. 1 is a specific example 1 of the hydraulic control device 35. The hydraulic control device 35 shown in FIG. 1 corresponds to the invention of claim 1. First, an oil pump 38 for sucking oil from the oil pan 37 is provided. The oil pump 38 may have either a configuration driven by the engine 2 as a driving power source or a configuration driven by a dedicated electric motor (not shown). An oil passage 40 is connected to the discharge port 39 of the oil pump 38, and a pressure control valve 111 for controlling the oil pressure of the oil passage 40 is provided. The pressure control valve 111 has a spool 111A, an input port 113, an output port 114, a feedback port 115, a signal pressure port 116, and a spring 111B. The spool 111A is configured to reciprocate linearly. The pressure control valve 111 is configured such that the signal oil pressure of the solenoid valve 98 is input to the signal pressure port 116. Further, the pressing force according to the hydraulic pressure of the signal pressure port 116 and the pressing force of the spring 111B are configured to be applied to the spool 111A in the same direction. The feedback port 115 is connected to the oil passage 40, and the pressing force corresponding to the oil pressure of the feedback port 115 is opposite to the pressing force corresponding to the oil pressure of the signal pressure port 116 and the pressing force of the spring 111B. The spool 111A is configured to be added to the spool 111A. Furthermore, the input port 113 is connected to the oil passage 40, and the oil passage 47 is connected to the output port 44. Thus, the hydraulic pressure supplied from the oil passage 40 to the oil passage 47 can be controlled by the pressure control valve 111 and the solenoid valve 98. Specifically, the pressure control characteristic of the pressure control valve 111 is determined so that the oil pressure in the oil passage 40 increases in proportion to the increase in the signal pressure output from the solenoid valve 98. A part of the pressure oil in the oil passage 47 is supplied to the pressure control valve 41, and a part of the pressure oil in the oil passage 40 is supplied to the pressure control valve 42.

  First, one pressure control valve 41 has a function of controlling the oil pressure of the oil passage 47. The pressure control valve 41 is a known valve having an input port 43, an output port 44, a feedback port 45A, a signal pressure port 46, a spool 41A, a spring 41B, and the like. The spool 41A is configured to reciprocate linearly. The signal pressure port 46 is configured to receive the signal oil pressure of the solenoid valve 51. Further, the pressing force according to the hydraulic pressure of the signal pressure port 46 and the pressing force of the spring 41B are configured to be applied to the spool 41A in the same direction. The feedback port 45A is connected to the oil passage 47, and the pressing force according to the oil pressure of the feedback port 45A is opposite to the pressing force according to the oil pressure of the signal pressure port 46 and the pressing force of the spring 41B. The spool 41A is configured to be added to the spool 41A. Furthermore, the input port 43 is connected to the oil passage 47 and the oil passage 103 is connected to the output port 44. Thus, the oil pressure in the oil passage 47 can be controlled by the pressure control valve 41 and the solenoid valve 51. Specifically, the pressure control characteristic of the pressure control valve 41 is determined so that the oil pressure in the oil passage 47 increases in proportion to the increase in the signal pressure output from the solenoid valve 51.

  On the other hand, an engagement hydraulic chamber 14 and a release hydraulic chamber 15 are connected to the oil passage 47 through a lock-up control valve 48. The lock-up control valve 48 has two input ports 49 and 50, two output ports 52 and 53, and a signal pressure port 54. The input port 49 is connected to the oil passage 47, the oil passage 103 is connected to the input port 50, and the orifice 55 is disposed in the oil passage 103. The oil passage 103 is connected to the lubrication system 56 at a portion corresponding to the area between the orifice 55 and the input port 50. The lubrication system 56 applies lubricating oil to a portion where lubrication oil is required provided in a path for transmitting power from the engine 2 to the wheel 33, for example, a portion where heat generation, seizure, wear, sliding, etc. may occur. It is an oil passage to supply. As the lubricating oil required portion, the meshing portions of the gears constituting the forward / reverse switching device 4, the belt-type continuously variable transmission 5, the portion where the belt 36 is wound around the primary pulley 27 and the secondary pulley 28, and the gear transmission There are meshing portions of gears constituting the device 31, bearings (not shown) for supporting various rotating members, and the like. The output port 52 is connected to the converter oil chamber 11 and the engagement hydraulic chamber 14 via the engagement oil passage 101, and the output port 53 is connected to the release hydraulic chamber 15 via the release oil passage 102. Has been.

  Further, a solenoid valve 57 for controlling the lock-up control valve 48 and the switching valve 62 (described later) is provided. First, the signal pressure output from the solenoid valve 57 is input to the signal pressure port 54, and the operation of the lockup control valve 48 is switched. When the operation of the lockup control valve 48 is switched, the oil passage 47 or the oil passage 103 is selectively connected to the engagement oil passages 101 and 102. The characteristics of the solenoid valve 57 and the lockup control valve 48 in Example 1 will be described. When the condition for engaging the lockup clutch 13 is satisfied, the signal pressure output from the solenoid valve 57 is controlled to be high. The oil passage 47 and the release oil passage 102 are connected, and the oil passage 103 and the release oil passage 102 are connected. On the other hand, when the condition for releasing the lockup clutch 13 is established, the signal pressure output from the solenoid valve 57 is controlled to a low pressure, the oil passage 47 and the release oil passage 102 are connected, and The oil passage 103 and the engagement oil passage 101 are connected.

  Next, the configuration of the pressure control valve 42 will be described. The pressure control valve 42 is a known one having an input port 127, an output port 58, a feedback port 59, a signal pressure port 60, a spool 42A, a spring 42B, and the like. The signal pressure port 60 is configured to receive the signal oil pressure of the solenoid valve 51. Further, the input port 127 is connected to the oil passage 40, and the oil passage 61 is connected to the output port 58. Further, the pressing force according to the hydraulic pressure of the signal pressure port 60 and the pressing force of the spring 42B are configured to be applied to the spool 42A in the same direction. The feedback port 59 is connected to the oil passage 61, and the pressing force according to the oil pressure of the feedback port 59 is opposite to the pressing force according to the oil pressure of the signal pressure port 60 and the pressing force of the spring 42B. , And is configured to be added to the spool 42A.

  The pressure control valve 42 configured as described above controls the hydraulic pressure of the pressure oil supplied from the oil passage 40 to the oil passage 61 in accordance with the operation of the spool 42A. The pressure control valve 42 can control the hydraulic pressure of the pressure oil supplied from the oil passage 40 to the oil passage 61 by a solenoid valve 51. Specifically, the pressure control characteristic of the pressure control valve 42 is determined so that the oil pressure in the oil passage 61 increases in proportion to the increase in the signal pressure output from the solenoid valve 51. Further, in this specific example 1, the same signal pressure is input from the common solenoid valve 51 to the pressure control valves 41 and 42, but the oil pressure of the oil passage 103 and the oil pressure of the oil passage 61 are configured. Are different from each other, the pressure control characteristics of the pressure control valves 41 and 42 are determined. Specifically, the pressure control valves 41 and 42 have a pressure control characteristic in which the oil pressure in the oil passage 61 is higher than the oil pressure in the oil passage 103. Such pressure control characteristics include the pressure receiving area of the spool 41A that receives the hydraulic pressure of the feedback port 45A of the pressure control valve 41, the pressure receiving area of the spool 42 that receives the hydraulic pressure of the feedback port 59 of the pressure control valve 42, and the pressing force to the spool 41A. The spring constant of the spring 41B to be applied and the spring constant of the spring 42B to apply a pressing force to the spool 42 can be adjusted by design changes.

  Further, a switching valve 62 to which the oil passages 47 and 61 are connected is provided. The switching valve 62 has two input ports 63 and 64, one output port 65, two signal pressure ports 66 and 67, a spool 62A, and a spring 62B. The spool 62A is configured to reciprocate linearly. In addition, the signal pressure ports 66 and 67 are controlled so that the pressing force applied to the spool 62A by the signal pressure of the signal pressure port 66 and the pressing force applied to the spool 62A by the signal pressure of the signal pressure port 67 are opposite to each other. The position has been determined. Further, the pressing force of the spring 62B is configured to be applied to the spool 62A in the same direction as the pressing force corresponding to the signal pressure of the signal pressure port 66. The input port 63 is connected to the oil passage 47, and the input port 64 is connected to the oil passage 61. Further, a signal pressure of the solenoid valve 57 is input to the signal pressure port 67, and a solenoid valve 68 for inputting the signal pressure to the signal pressure port 66 is provided. When the signal pressures of the two signal pressure ports 66 and 67 are both high or low, the opposite pressing forces applied to the spool 62A are canceled by the signal pressure of the signal pressure ports 66 and 67, and the spring The spool 62A is operated by the pressing force of 62B, the input port 63 and the output port 65 are connected, and the input port 64 is shut off. In addition, when the signal pressure of the signal pressure port 66 is high and the signal pressure of the signal pressure port 67 is low, a pressing force applied to the spool 62A according to the signal pressure of the signal pressure port 66, and a spring The spool 62A is operated by the pressing force applied to the spool 62A by 62B. As a result, the input port 64 and the output port 65 are connected, while the input port 63 is blocked. Further, when the signal pressure of the signal pressure port 67 is high and the signal pressure of the signal pressure port 66 is low, the spring is applied by the pressing force applied to the spool 62A according to the signal pressure of the signal pressure port 67. The spool 62A operates against the pressing force of 62B. As a result, the operating characteristics of the switching valve 62 are determined so that the input port 63 and the output port 65 are connected while the input port 64 is blocked. As described above, the signal pressure output from the solenoid valve 57 is shared by the control of the lockup control valve 48 and the switching valve 62.

  The output port 65 of the switching valve 62 configured as described above is connected to the clutch hydraulic chamber 24 and the brake hydraulic chamber 25 via the manual valve 99. The manual valve 99 has one input port 69, two output ports 70, and one drain port 71. The input port 69 is connected to the output port 65 of the switching valve 62 via the oil passage 100, the output port 70 is connected to the clutch hydraulic chamber 24, and the output port 71 is connected to the brake hydraulic chamber 25. . The manual valve 99 is configured to operate and stop in accordance with a selected shift position and connect any of the ports at the stop position. First, when the neutral position or the parking position is selected, the output ports 70 and 71 are both connected to the drain port 72 and the input port 69 is shut off. On the other hand, when the drive position is selected, the input port 69 and the output port 70 are connected, and the output port 71 is connected to the drain port 72. Further, when the reverse position is selected, the input port 69 and the output port 71 are connected, and the output port 70 is connected to the drain port 72.

  Next, the configuration of a hydraulic circuit for controlling the gear ratio of the belt type continuously variable transmission 5 will be described. First, a speed increasing gear ratio control valve 73 is provided on the path from the oil path 40 to the primary hydraulic chamber 29. The transmission ratio control valve 73 includes a spool 74 that can linearly reciprocate, a spring 75 that presses the spool 74 in one direction, and an input port 76 and an output port 77 whose opening area is controlled by the operation of the spool 74. And a signal pressure port 78 that applies a force in the same direction as the spring 75 to the spool 74, and a signal pressure port 79 that applies a force in the direction opposite to the spring 75 to the spool 74. The signal hydraulic pressure of the solenoid 68 is input to the signal pressure port 79, the oil passage 40 is connected to the input port 76, and the output port 77 is connected to the primary hydraulic chamber 29 via the oil passage 80.

  Further, a speed reduction ratio control valve 81 for speed reduction is connected to the oil passage 80. The transmission ratio control valve 81 includes a spool 82 that can linearly reciprocate, a spring 83 that presses the spool 82 in one direction, and an input port 84 and a drain port 85 whose opening area is controlled by the operation of the spool 82. A signal pressure port 86 that applies a force in the same direction as the spring 83 to the spool 82, and a signal pressure port 87 that applies a force in the opposite direction to the spring 83 to the spool 82. The signal oil pressure of the solenoid 68 is input to the signal pressure port 86, the oil passage 80 is connected to the input port 84, and the drain port 85 is connected to the oil pan 37. Further, a solenoid valve 88 that outputs a signal pressure input to the signal pressure ports 78 and 87 is provided. The speed ratio control valves 73 and 81 configured as described above both have a function as a flow rate control valve, and the pressure oil supplied to the primary hydraulic chamber 29 is controlled by the speed ratio control valve 73. The flow rate is controlled, and the flow rate of the pressure oil discharged from the primary hydraulic chamber 29 is controlled by the control of the transmission ratio control valve 81.

  Further, a pressure control valve 89 is provided in a path from the oil path 40 to the secondary hydraulic chamber 30. The pressure control valve 89 includes a spool 90 that can linearly reciprocate, a spring 91 that presses the spool 90 in one direction, an input port 92 and an output port 93 whose opening area is controlled by the operation of the spool 90, A signal pressure port 94 that applies a force in the same direction as the spring 91 to the spool 90, a feedback port 95 that applies a force in the opposite direction to the spring 91 to the spool 90, and a drain port 96 are provided. The oil passage 40 is connected to the input port 92, the output port 93 is connected to the secondary hydraulic chamber 30 via the oil passage 97, the feedback port 95 is connected to the output port 93, and the drain port 96 is connected to the oil pan 37. It is connected to the. Further, a solenoid valve 98 for inputting a signal pressure to the signal pressure port 94 is provided. The solenoid valve 98 is controlled in signal pressure based on the transmission torque of the belt type continuously variable transmission 5. Specifically, control for increasing the signal pressure is executed in proportion to the increase in the transmission path torque. Thus, the signal pressure output from the solenoid valve 98 is shared by the pressure control valve 89 and the pressure control valve 111.

  Next, specific control of the hydraulic control device 35 will be described. Pressure oil is discharged into the oil passage 40 by driving the oil pump 38. Then, the oil pressure in the oil passage 40 is adjusted by the pressure control valve 111. In this embodiment, the hydraulic pressure of the oil passage 40 increases in proportion to the increase in the signal pressure input from the solenoid valve 98 to the signal pressure port 116 of the pressure control valve 111. The pressure control valve 111 also has a function as a relief valve. That is, the pressure control valve 111 functions as a relief valve that suppresses an increase in the oil pressure of the oil passage 40 by discharging the oil of the oil passage 40 to the oil passage 47, and the oil pressure of the oil passage 47 is greater than the oil pressure of the oil passage 40. Is also low pressure. Further, the hydraulic pressure in the oil passage 47 is controlled by the solenoid valve 51 and the pressure control valve 41. In this specific example 1, the oil pressure in the oil passage 47 increases in proportion to the increase in the signal pressure output from the solenoid valve 51. The pressure control valve 41 functions as a relief valve that suppresses an increase in oil pressure in the oil passage 47 by discharging the oil in the oil passage 47 to the oil passage 103, and the oil pressure in the oil passage 103 is greater than the oil pressure in the oil passage 47. Is also low pressure.

  In this way, the oil pressure in the oil passage 47 is controlled, and the pressure oil in the oil passage 47 passes through the lock-up control valve 48 to the converter oil chamber 11, the engagement hydraulic chamber 14, and the release hydraulic chamber 15. Supplied. Here, control of the signal pressure of the solenoid valve 57, switching operation of the lock-up control valve 48, and control for engaging and releasing the lock-up clutch 13 will be described. First, when the condition for engaging the lockup clutch 13 is established, the signal pressure output from the solenoid valve 57 is controlled to be high. Then, the pressure oil of the input port 49 is supplied to the converter oil chamber 11 and the engagement hydraulic chamber 14 and the pressure oil of the input port 50 is supplied to the release hydraulic chamber 15 by the switching operation of the lockup control valve 48. Is done. Here, the hydraulic pressure of the pressure oil that passes through the orifice 55 from the oil passage 49 and is supplied to the input port 50 is lower than the hydraulic pressure of the oil passage 49. In this way, the hydraulic pressure in the engagement hydraulic chamber 14 becomes higher than the hydraulic pressure in the release hydraulic chamber 15, and the lockup clutch 13 is engaged.

  On the other hand, when the condition for releasing the lockup clutch 13 is established, the signal pressure output from the solenoid valve 57 is controlled to a low pressure. Then, the pressure oil of the input port 49 is supplied to the release hydraulic chamber 15 and the pressure oil of the input port 50 is supplied to the converter oil chamber 11 and the engagement hydraulic chamber 14 by the switching operation of the lockup control valve 48. Is done. In this way, the hydraulic pressure in the engagement hydraulic chamber 14 is lower than the hydraulic pressure in the release hydraulic chamber 15, and the lockup clutch 13 is released. When the lockup clutch 13 is engaged, the transmission torque is determined by the hydraulic pressure of the pressure oil supplied to the engagement hydraulic chamber 14 via the oil passage 47. That is, by controlling the signal pressure of the solenoid valve 57, the transmission torque of the lockup clutch 13 is controlled. In this case, the lock-up clutch 13 can be completely engaged, or the lock-up clutch 13 can be slip-controlled (slip the friction material). A part of the pressure oil that has passed through the orifice 55 in the oil passage 103 is supplied to the lubrication system 56.

  Next, the switching operation of the switching valve 62, the switching operation of the manual valve 99, and the control of the forward / reverse switching device 4 will be described. The pressure oil in the oil passage 40 is regulated by the pressure control valve 42 and supplied to the oil passage 61. The oil pressure in the oil passage 61 is controlled to be higher than the oil pressure in the oil passage 47. This is because the pressure control characteristics of the pressure control valves 41 and 42 are different as described above. The pressure control valve 42 functions as a pressure reducing valve, and the oil pressure in the oil passage 61 is lower than the oil pressure in the oil passage 40. The switching valve 62 is switched between a case where the condition for engaging the lockup clutch 13 is satisfied and a case where the condition for releasing the lockup clutch 13 is satisfied.

  First, when the condition for engaging the lockup clutch 13 is established, the signal pressure output from the solenoid valve 57 and input to the signal pressure port 67 of the switching valve 62 decreases. Then, in the switching valve 62, the input port 64 is shut off, and the input port 63 and the output port 65 are connected. That is, the low oil pressure of the oil passage 47 is supplied to the oil passage 100 via the switching valve 62. On the other hand, when the condition for releasing the lockup clutch 13 is established, the signal pressure output from the solenoid valve 57 and input to the signal pressure port 67 of the switching valve 62 decreases. Then, the input port 63 of the switching valve 62 is shut off, and the input port 64 and the output port 65 are connected. That is, the high oil pressure in the oil passage 61 is supplied to the oil passage 100 via the switching valve 62.

  In this way, either one of the oil passage 47 or the oil passage 61 is supplied to the oil passage 100. By the way, the operation of the manual valve 99 is switched depending on the selected shift position. First, when the drive position is selected, the input port 69 and the output port 70 are connected, and the output port 71 is connected to the drain port 72. Then, the pressure oil supplied from the switching valve 62 is supplied to the clutch hydraulic chamber 24 to increase its hydraulic pressure, while the hydraulic pressure in the brake hydraulic chamber 25 decreases. As a result, the forward clutch 22 is engaged, and the reverse brake 23 is released. On the other hand, when the reverse position is selected, the input port 69 and the output port 71 are connected, and the output port 70 is connected to the drain port 72. Then, the pressure oil supplied from the switching valve 62 is supplied to the brake hydraulic chamber 25 to increase its hydraulic pressure, while the hydraulic pressure in the clutch hydraulic chamber 24 decreases. As a result, the forward clutch 22 is released and the reverse brake 23 is engaged. When the neutral position or the parking position is selected, both the output ports 70 and 71 are connected to the drain port 72 and the input port 69 is blocked. Then, both the hydraulic pressure in the clutch hydraulic chamber 24 and the brake hydraulic chamber 25 are reduced, and both the forward clutch 22 and the reverse brake 23 are released.

  By the way, in this embodiment, when the lock-up clutch 13 is released, torque is amplified by the action of the stator 12 in the torque converter 3. On the other hand, when the lockup clutch 13 is engaged, the torque converter 3 does not amplify the torque. On the other hand, in this embodiment, the forward / reverse switching device 4 is arranged downstream of the torque converter 3 in the power transmission path from the engine 2 to the wheels 33. Therefore, the torque transmitted to the forward / reverse switching device 4 when torque amplification is performed by the torque converter 3 is the torque transmitted to the forward / reverse switching device 4 when torque amplification is not performed by the torque converter 3. Higher capacity. Therefore, in this embodiment, when torque amplification is performed by the torque converter 3, the high oil pressure of the oil passage 61 is supplied to the oil passage 100. Therefore, when the lock-up clutch 13 is released and torque amplification is performed by the torque converter 3 and the torque transmitted by the forward / reverse switching device 4 is increased, the torque capacity of the forward clutch 22 or the reverse brake 23 is increased. Insufficiency and slipping can be avoided, and deterioration of durability can be suppressed.

  Next, control of the gear ratio and control of transmission torque in the belt type continuously variable transmission 5 will be described. First, the case where the condition for increasing the gear ratio of the belt type continuously variable transmission 5 is satisfied (the downshift condition is satisfied) will be described. In this case, the signal pressure of the solenoid 68 is increased, and the opening area of the output port 77 of the pressure control valve 73 is reduced. That is, the flow rate of the pressure oil supplied from the oil passage 40 to the primary hydraulic chamber 29 via the oil passage 80 is reduced. In parallel with this control, the signal pressure of the solenoid valve 88 is reduced, and the opening area of the drain port 85 is expanded. Accordingly, the pressure oil in the primary hydraulic chamber 29 is drained to the oil pump 37 via the oil passage 80 and the drain port 85, and the hydraulic pressure in the primary hydraulic chamber 29 is reduced. In this way, the clamping pressure applied from the primary pulley 27 to the belt 36 is reduced, the winding radius of the belt 36 in the primary pulley 27 is reduced, and the gear ratio of the belt type continuously variable transmission 5 is increased.

  When the signal pressure of the solenoid valve 68 is higher than a predetermined pressure, even if the signal pressure of the solenoid valve 57 is low, the operation of the switching valve 62 causes the high oil pressure of the oil passage 61 to be high. Is supplied to the oil passage 100 and the input port 63 is shut off. That is, when the control that increases the engine torque is executed, such as when the downshift of the belt-type continuously variable transmission 5 is executed when the accelerator pedal is depressed suddenly, the lockup clutch 13 is engaged. Even in this state, the torque transmitted by the forward / reverse switching device 4 increases (or the transmission torque varies). Even in such a case, in this embodiment, a shortage of torque capacity and slippage of the forward clutch 22 or the reverse brake 23 can be avoided.

  Next, a case where a condition for reducing the speed ratio of the belt type continuously variable transmission 5 is satisfied (upshift condition is satisfied) will be described. In this case, the signal pressure of the solenoid 68 is reduced, and the opening area of the output port 77 of the pressure control valve 73 is enlarged. That is, the flow rate of the pressure oil supplied from the oil passage 40 to the primary hydraulic chamber 29 via the oil passage 80 increases. In parallel with this control, the signal pressure of the solenoid valve 88 is increased and the drain port 85 is closed. In this way, the hydraulic pressure in the primary hydraulic chamber 29 increases. As a result, the clamping pressure applied from the primary pulley 27 to the belt 36 is increased, the winding radius of the belt 36 in the primary pulley 27 is increased, and the gear ratio of the belt type continuously variable transmission 5 is decreased. If a certain amount of pressure oil is held in the hydraulic chamber 29, the wrapping radius of the belt 36 in the primary pulley 27 is maintained constant, and the gear ratio becomes substantially constant.

  Further, control of the torque capacity (transmission torque) of the belt type continuously variable transmission 5 will be described. When the torque capacity of the belt type continuously variable transmission 5 is increased, the signal pressure of the solenoid valve 68 is increased, and the hydraulic pressure of the pressure oil supplied from the oil path 40 to the secondary hydraulic chamber 30 via the oil path 97 is increased. Control to increase is executed. As a result, the clamping pressure applied from the secondary pulley 28 to the belt 36 increases, and the torque capacity increases. On the other hand, when the torque capacity of the belt type continuously variable transmission 5 is reduced, the signal pressure of the solenoid valve 68 is reduced and supplied from the oil passage 40 to the secondary hydraulic chamber 30 via the oil passage 97. Control is performed to reduce the hydraulic pressure of the pressure oil. As a result, the clamping pressure applied from the secondary pulley 28 to the belt 36 decreases, and the torque capacity decreases. If the signal pressure of the solenoid valve 98 is controlled to be substantially constant, the hydraulic pressure in the secondary hydraulic chamber 30 is controlled to be substantially constant, and the torque capacity becomes substantially constant.

  As described above, according to the hydraulic control device 35 having the configuration shown in FIG. 1, the two pressure control valves 41 and 42 are shared so as to be controlled using the single solenoid valve 51. Further, by switching the operation of the switching valve 62, either the high hydraulic pressure of the oil passage 61 or the low hydraulic pressure of the oil passage 47 can be selectively supplied to the clutch hydraulic chamber 24 and the brake hydraulic chamber 25. . Even when either the high hydraulic pressure in the oil passage 61 or the low hydraulic pressure in the oil passage 47 is supplied to the clutch hydraulic chamber 24 and the brake hydraulic chamber 25, the low hydraulic pressure in the oil passage 47 is converted to the converter oil chamber 11. To be supplied. That is, high hydraulic pressure is supplied to the clutch hydraulic chamber 24 and the brake hydraulic chamber 25, but it is not necessary to supply high hydraulic pressure to the converter oil chamber 11, and an increase in the driving load of the oil pump 38 can be suppressed. The increase in power loss can be suppressed. Moreover, since the hydraulic pressure control of the pressure oil supplied to the converter oil chamber 11 and the hydraulic pressure control of the pressure oil supplied to the oil passage 100 can be performed separately, the hydraulic pressure of the pressure oil supplied to the converter oil chamber 11 is as much as possible. It can be reduced. Therefore, an increase in the amount of pressurized oil supplied to the hydraulic oil cooling device via the lubrication system 56 can be suppressed. Further, when the signal pressures of the solenoid valves 57 and 68 are both low, the low hydraulic pressure of the oil passage 47 can be supplied to the clutch hydraulic chamber 24 and the brake hydraulic chamber 25. Therefore, drag loss due to sliding resistance between the pistons forming these hydraulic chambers and the oil seal provided around the pistons can be reduced. In addition, since the number of places to which high hydraulic pressure is supplied decreases, the discharge capacity of the oil pump 98 can be reduced.

  Here, the correspondence between the configuration shown in FIGS. 1 and 2 and the configuration of the present invention will be described. The engine 2 corresponds to the power source of the present invention, and the torque converter 3 is the fluid transmission of the present invention. The forward / reverse switching device 4 corresponds to the transmission torque control mechanism of the present invention, the oil passage 61 corresponds to the high pressure oil passage of the present invention, and the oil passage 47 corresponds to the low pressure oil passage of the present invention. The lock-up control valve 48 corresponds to the lock-up control mechanism of the present invention, the solenoid valve 57 and the electronic control device 34 correspond to the first solenoid mechanism of the present invention, and the switching valve 62 corresponds to the present invention. The gear ratio control valves 73 and 81 correspond to the switching mechanism, the flow rate control mechanism in the present invention, and the solenoid valve 68 and the electronic control unit 34 correspond to the second solenoid mechanism in the present invention. And, the oil pump 38 is equivalent to the pressurized oil source of the present invention, the primary hydraulic chamber 29 corresponds to the hydraulic pressure chamber pulley of the present invention. Further, “increasing the gear ratio of the belt-type continuously variable transmission 5 (not performing downshift)” means that the flow rate of the pressure oil discharged from the primary hydraulic chamber is set to a predetermined amount. Is equivalent to “do more than”. Furthermore, “reducing the gear ratio of the belt-type continuously variable transmission 5 (when upshifting is performed) or controlling the gear ratio to be constant” refers to “pressure discharged from the pulley hydraulic chamber”. This corresponds to “reducing the oil flow rate to a predetermined amount or less”.

(Specific example 2)
Next, another specific example of the hydraulic control device 35 shown in FIG. 2 will be described with reference to FIG. 3, the same components as those in FIG. 1 are denoted by the same reference numerals as those in FIG. The hydraulic control device 35 in FIG. 3 corresponds to the second hydraulic control device. The specific example 2 is different from the specific example 1 in that the pressure control valve 42 described above is not provided. Then, the pressure oil in the oil passage 40 is directly supplied to the input port 64 of the switching valve 62. That is, the oil pressure in the oil passage 40 and the input port 64 have the same value. Further, the solenoid valve 51 described in the first specific example is not provided in the second specific example. The signal pressure of the solenoid valve 98 is input to the signal pressure port 46 of the pressure control valve 41. This pressure control valve 41 has a configuration in which the oil pressure of the oil passage 47 increases in proportion to an increase in the signal pressure input to the signal pressure port 46. The pressure control valve 41 is a relief valve that discharges the pressure oil in the oil passage 47 to the oil passage 103, and the oil pressure in the oil passage 103 is lower than the oil pressure in the oil passage 47.

  In the hydraulic control device 35 shown in FIG. 3 as well, the same functions, controls, and operational effects as those in FIG. In particular, the case where the signal pressure of the solenoid valve 68 is equal to or lower than a predetermined pressure (low pressure) in the hydraulic control device 35 of FIG. 3 will be described. First, in order to release the lockup clutch 13, when the signal pressure input from the solenoid valve 57 to the signal pressure port 67 is low and the signal pressure input to the signal pressure port 66 is low, As in the case of the specific example 1, the input port 64 and the output port 65 of the switching valve 62 are connected, and the input port 63 is blocked. Therefore, the high hydraulic pressure in the oil passage 40 is supplied to the clutch hydraulic chamber 24 or the brake hydraulic chamber 25. On the other hand, when the signal pressure of the solenoid valve 57 is increased to engage the lockup clutch 13 and the signal pressure input to the signal pressure port 66 is low, the case of the specific example 1 Similarly, the input port 63 and the output port 65 of the switching valve 62 are connected, and the input port 64 is shut off. Therefore, the low hydraulic pressure in the oil passage 47 is supplied to the clutch hydraulic chamber 24 or the brake hydraulic chamber 25. Therefore, the slip of the forward clutch 22 or the reverse brake 23 can be avoided as in the case of the specific example 1.

  Next, a case where the signal pressure of the solenoid valve 57 is high will be described. First, when control for increasing the transmission ratio of the belt type continuously variable transmission 5 is performed, the signal pressure of the solenoid valve 68 is increased to a predetermined pressure (threshold value) or more, and the primary hydraulic chamber 29 The flow rate of the discharged pressure oil becomes larger than a predetermined amount (threshold value) determined in advance. At this time, when the signal oil pressure of the solenoid valve 68 is increased to a predetermined pressure or higher, the input port 64 and the output port 65 of the switching valve 62 are connected and the input port 63 is shut off. As a result, the pressure oil in the oil passage 40 is supplied to the clutch hydraulic chamber 24 or the brake hydraulic chamber 25 through the oil passage 100.

  On the other hand, the signal pressure of the solenoid valve 68 is lowered to a predetermined pressure (threshold value) or less, the flow rate of the pressure oil discharged from the primary hydraulic chamber 29 is reduced, and the solenoid When the signal pressure of the valve 57 is lower than a predetermined pressure, the spool 62A is operated by the pressing force of the spring 62B, and the input port 63 and the output port 65 of the switching valve 62 are connected, The input port 64 is blocked. As a result, the pressure oil in the oil passage 47 is supplied to the clutch hydraulic chamber 24 or the brake hydraulic chamber 25 via the oil passage 100. Thus, in the specific example 2, the pressure oil in the oil passage 40 or the pressure oil in the oil passage 47 is selectively supplied to the oil passage 100 based on the flow rate of the pressure oil discharged from the primary hydraulic chamber 29. . When both the signal pressures of the solenoid valves 57 and 68 are increased, the pressing force due to the signal pressure at the signal pressure port 66 and the pressing force due to the signal pressure at the signal pressure port 67 are offset, and the pressing force of the spring 62B is cancelled. The spool 62A operates with pressure. As a result, the input port 64 and the output port 65 are connected, and the input port 63 is blocked. Further, when the signal pressures of the solenoid valves 57 and 68 are both low, the low hydraulic pressure of the oil passage 47 can be supplied to the clutch hydraulic chamber 24 and the brake hydraulic chamber 25. Therefore, drag loss due to sliding resistance between the oil seal that seals these hydraulic chambers and the piston that forms the hydraulic chambers can be reduced. In addition, since the number of places to which high hydraulic pressure is supplied decreases, the discharge capacity of the oil pump 98 can be reduced. Thus, also in the specific example 2, the same effect as the specific example 1 can be obtained. Further, it is possible to prevent pressure oil leakage from the seal portion of the oil passage 100. Here, the correspondence between the configuration described in the specific example 2 and the configuration of the present invention will be described. The oil passage 40 corresponds to the high-pressure oil passage of the present invention. The correspondence between the other configuration described in the second specific example and the configuration of the present invention is the same as the corresponding relationship between the configuration of the first specific example and the configuration of the present invention.

  In the specific examples 1 and 2, the switching valve 62 is switched by the signal hydraulic pressure generated by the solenoid valve 68, but the switching valve 62 is switched by the signal hydraulic pressure generated by the solenoid valve 88. A configuration is also possible. Further, the case where the forward / reverse switching device 4 and the belt-type continuously variable transmission 5 are provided in the path from the torque converter 3 to the wheel 33 has been described. However, the hydraulic control device of the present invention includes the torque converter 3. The present invention can also be applied to a vehicle having a known automatic transmission having a planetary gear mechanism and a friction engagement device in a path from the wheel to the wheel 33. In this case, the gear ratio of the automatic transmission is controlled by the engagement / release of the friction engagement device, and the input of the automatic transmission is controlled by the hydraulic control of the pressure oil supplied to the hydraulic chamber for the friction engagement device. The transmission torque between the shaft and the output shaft is controlled. The pressure oil supplied to the hydraulic chamber for the friction engagement device can be controlled to a high hydraulic pressure or a low hydraulic pressure based on the same principle as that described with reference to FIG. In such a configuration, the automatic transmission corresponds to a transmission torque control mechanism.

  The present invention is also applicable to a vehicle using a fluid coupling that does not have a torque amplification function instead of the torque converter 3. Furthermore, the present invention is applicable to a vehicle in which a lock-up clutch, a forward / reverse switching device, and a belt-type continuously variable transmission are arranged in series on the path from the engine 2 to the wheels 33, and in the direction of power transmission. An arrangement position is not ask | required. That is, a drive train having a belt-type continuously variable transmission provided between the lock-up clutch and the forward / reverse switching device, and a lock-up clutch provided between the belt-type continuously variable transmission and the forward / reverse switching device. The present invention can also be applied to drive trains with different configurations. Further, the present invention can be applied to a vehicle having another continuously variable transmission, for example, a toroidal continuously variable transmission, instead of the belt type continuously variable transmission.

It is a schematic block diagram which shows the specific example 1 of the hydraulic control apparatus of this invention. It is a figure which shows an example of the power train of the vehicle which has the hydraulic control apparatus of this invention, and its control system. It is a schematic block diagram which shows the specific example 2 of the hydraulic control apparatus of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 2 ... Engine, 3 ... Torque converter, 4 ... Forward / reverse switching device, 13 ... Lock-up clutch, 22 ... Forward clutch, 23 ... Reverse brake, 29 ... Primary hydraulic chamber, 33 ... Wheel, 34 ... Electronic control unit, 35 ... Hydraulic control device, 38 ... Oil pump, 48 ... Lock-up control valve, 41 ... Pressure control valve, 57, 68 ... Solenoid valve, 62 ... Switching valve, 101 ... Oil passage for engagement, 102 ... Oil passage for release.

Claims (6)

A fluid transmission device that is provided on the output side of the power source and transmits power by the kinetic energy of the hydraulic oil, a lock-up clutch provided in parallel with the fluid transmission device, and a power transmission output from the power source A transmission torque control mechanism which is provided in the transmission path and whose transmission torque is controlled by hydraulic control; an engagement hydraulic chamber and a release hydraulic chamber which control engagement / release of the lockup clutch; and a pressure oil supply source A lockup control mechanism for controlling the hydraulic pressure of pressure oil supplied to the engagement hydraulic chamber and the release hydraulic chamber, a first solenoid mechanism for generating a signal hydraulic pressure for controlling the lockup control mechanism, and the pressure In a hydraulic control device having a switching mechanism for controlling the hydraulic pressure of pressure oil supplied from an oil supply source to the transmission torque control mechanism,
A high pressure oil passage in which the pressure oil supplied from the pressure oil supply source is controlled to a high pressure, and a low pressure oil passage in which the pressure oil supplied from the pressure oil supply source is controlled to a pressure lower than the oil pressure of the high pressure oil passage; The high-pressure oil passage and the low-pressure oil passage are connected to the switching mechanism, and the switching mechanism selectively switches the pressure oil of either the high-pressure oil passage or the low-pressure oil passage. Having a configuration for supplying to the transmission torque control mechanism;
The hydraulic control device characterized in that the switching mechanism can be controlled by a signal hydraulic pressure generated by the first solenoid mechanism.   When a signal hydraulic pressure that releases the lock-up clutch is generated by the first solenoid mechanism, the switching mechanism is controlled by the signal hydraulic pressure, and the pressure oil in the high-pressure oil passage is supplied to the transmission torque control mechanism. The hydraulic control device according to claim 1, wherein the hydraulic control device has a configuration.   When a signal hydraulic pressure for engaging the lockup clutch is generated by the first solenoid mechanism, the switching mechanism is controlled by the signal hydraulic pressure, and the pressure oil in the low-pressure oil passage is supplied to the transmission torque control mechanism. The hydraulic control device according to claim 1, wherein the hydraulic control device is configured as follows. A belt type continuously variable transmission is provided on the output side of the power source, and this belt type continuously variable transmission is configured by winding a belt around a primary pulley and a secondary pulley,
A pulley hydraulic chamber that controls the clamping force applied to the belt from the primary pulley or the secondary pulley, a flow control mechanism that controls the flow rate of pressure oil in the pulley hydraulic chamber, and a flow control characteristic in the flow control mechanism And a second solenoid mechanism for generating a signal oil pressure for controlling
When the lock-up clutch is released, the switching mechanism is controlled by a signal oil pressure generated by the second solenoid mechanism, and either the high pressure oil passage or the low pressure oil passage is selected and the transmission is performed. The hydraulic control device according to claim 1, wherein the hydraulic control device is configured to be supplied to a torque control mechanism.   When the second solenoid mechanism generates a signal oil pressure that increases the flow rate of the pressure oil discharged from the pulley hydraulic chamber above a predetermined amount, the switching mechanism is controlled by the signal oil pressure. The hydraulic control device according to claim 4, wherein the pressure oil in the high-pressure oil passage is configured to be supplied to the transmission torque control mechanism.   When the second solenoid mechanism generates a signal oil pressure that reduces the flow rate of the pressure oil discharged from the pulley hydraulic chamber to a predetermined amount or less, the switching mechanism is controlled by the signal oil pressure. The hydraulic control device according to claim 4, wherein pressure oil in the low-pressure oil passage is configured to be supplied to the transmission torque control mechanism.

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