JP2015004420A - Hydraulic pressure supplying system for power transmission device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hydraulic pressure supplying system for a power transmission device capable of improving cooling efficiency of an electric motor for operating an electric hydraulic pump.SOLUTION: A hydraulic pressure supplying system S for connecting or disconnecting a power transmission passage for transmitting power of an engine to wheels or performing gear shift by supplying hydraulic oil to hydraulic operating devices of an input clutch 114, a continuously variable transmission 118, and an output clutch 136 includes: a mechanical hydraulic pump 202 operated by the power of the engine; an electric hydraulic pump 204 operated by power of an electric motor M; a supply oil passage 210 for supplying the hydraulic oil delivered from the mechanical hydraulic pump or the electric hydraulic pump to the hydraulic operating devices; and a cooling oil passage 212 through which the hydraulic oil supplied to the hydraulic operating devices by the mechanical hydraulic pump is introduced so as to cool the electric motor by the hydraulic oil.

Description

  The present invention relates to a hydraulic pressure supply system for a power transmission device that supplies hydraulic oil to a hydraulic operation device that performs a shift by a transmission, or connects and disconnects a power transmission path.

  A general vehicle is provided with a power transmission device that constitutes a power transmission path for transmitting engine power to the vehicle. The power transmission device is provided with a clutch for connecting or disconnecting the power transmission path, and a transmission such as CVT for switching the gear ratio. Such clutches and CVTs are provided with a hydraulic actuator, and connect or cut off a power transmission path or change a gear ratio by hydraulic oil supplied to the hydraulic actuator. Therefore, the power transmission device is provided with a hydraulic pressure supply system that supplies hydraulic oil to the hydraulic actuator.

  A hydraulic pressure supply system that supplies hydraulic oil to a hydraulic actuator includes a mechanical hydraulic pump that operates with the power of an engine and an electric hydraulic pump that operates with the power of an electric motor. In recent years, in order to save energy, vehicles equipped with an idling stop function that stops the engine while driving have become widespread. In such vehicles, the necessary supply pressure can be maintained even when the engine is stopped. In addition, an electric hydraulic pump is adopted.

  However, when an electric hydraulic pump is employed, the electric motor that is the drive source generates heat, and thus it is necessary to cool the electric motor. As a method for cooling the electric motor, an air-cooling type is conceivable. However, if the electric motor is covered with mud or the like, there is a possibility that sufficient cooling performance cannot be maintained. Although a water-cooled cooling structure is also conceivable, the water-cooled type requires piping layout and an intercooler, and increases the weight of the vehicle, so that it is practically difficult to adopt.

  Therefore, for example, as shown in Patent Document 1, a configuration is proposed in which part of the hydraulic oil guided to the electric hydraulic pump is guided to the rotor or stator of the electric motor that is at the highest temperature to cool the electric motor. Has been.

JP 2009-19522 A

  However, according to the above-described electric hydraulic pump, the electric motor can be cooled during the operation, but when the operation of the electric hydraulic pump is stopped, the cooling function is also stopped at the same time. It cannot be cooled. Generally, when the electric motor generates heat and the temperature exceeds a predetermined temperature, the driving of the electric motor, that is, the electric hydraulic pump is stopped from the viewpoint of safety. During this time, the hydraulic oil required in the power transmission device can be secured by supplying from a mechanical hydraulic pump provided separately from the electric hydraulic pump, but as the electric hydraulic pump is stopped as described above. Since the cooling function is also stopped, it takes a long time to cool the electric motor.

  Therefore, an object of the present invention is to provide a hydraulic pressure supply system for a power transmission device that can improve the cooling performance of an electric motor that operates an electric hydraulic pump.

  In order to solve the above-mentioned problems, a hydraulic pressure supply system for a power transmission device according to the present invention supplies a hydraulic oil to a hydraulic actuator, thereby changing speed by the transmission or transmitting a power of an engine to wheels. Is a hydraulic supply system for a power transmission device that connects and disconnects, a mechanical hydraulic pump that operates with the power of the engine, an electric hydraulic pump that operates with the power of an electric motor, and the mechanical hydraulic pump or the electric A supply oil path for supplying hydraulic oil discharged from the hydraulic pump to the hydraulic actuator, and the hydraulic oil supplied to the hydraulic actuator by the mechanical hydraulic pump is guided, and the electric motor is cooled by the hydraulic oil. And a cooling oil passage.

  The mechanical hydraulic pump and the electric hydraulic pump may be connected in series by a connection oil passage.

  The cooling oil passage may be provided so as to bypass the electric hydraulic pump.

  The first switching valve is provided on the upstream side of the electric hydraulic pump and switches the flow path of the hydraulic oil to either the cooling oil path side or the electric hydraulic pump side. When the electric hydraulic pump is stopped, the hydraulic oil flow path may be switched to the cooling oil path side, and when the electric hydraulic pump is operated, the hydraulic oil flow path may be switched to the electric hydraulic pump side.

  Further, a bypass passage that bypasses the mechanical hydraulic pump and an upstream side of the mechanical hydraulic pump are provided, and the hydraulic fluid passage is switched to either the bypass passage side or the mechanical hydraulic pump side. A second switching valve, and when the electric hydraulic pump is stopped, the second switching valve switches the flow path of the hydraulic oil to the mechanical hydraulic pump side, and when the electric hydraulic pump is operated, The hydraulic oil flow path may be switched to the bypass flow path side.

  Further, the mechanical hydraulic pump is provided on the upstream side of the electric hydraulic pump, and the cooling oil passage is connected to the connection oil passage connecting the mechanical hydraulic pump and the electric hydraulic pump on the upstream side, and downstream The side may be connected to the supply oil passage that connects the electric hydraulic pump and the hydraulic actuator.

  Further, the hydraulic oil is provided on the downstream side of the electric hydraulic pump and upstream of the connection portion between the cooling oil passage and the supply oil passage, and the working oil flows from the supply oil passage side to the electric hydraulic pump side. And a pilot line having one end connected between the check valve and the electric hydraulic pump and the other end connected to the second switching valve, the second switching valve The hydraulic oil flow path may be switched to the bypass flow path side by a pilot pressure acting via the pilot line when the electric hydraulic pump is operated.

  According to the present invention, the cooling performance of the electric motor that operates the electric hydraulic pump can be improved.

It is a figure which shows the structure of the drive system of a motor vehicle. It is the schematic which shows the structure of a hydraulic pressure supply system. It is a figure explaining the supply path | route of hydraulic fluid when the estimated temperature of an electric motor is less than a threshold value. It is a figure explaining the supply path | route of hydraulic fluid when the estimated temperature of an electric motor is more than a threshold value.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. The dimensions, materials, and other specific numerical values shown in the embodiments are merely examples for facilitating understanding of the invention, and do not limit the present invention unless otherwise specified. In the present specification and drawings, elements having substantially the same function and configuration are denoted by the same reference numerals, and redundant description is omitted, and elements not directly related to the present invention are not illustrated. To do.

  FIG. 1 is a diagram illustrating a configuration of a drive system of the automobile 100. As shown in FIG. 1, the automobile 100 includes an engine 102 and a motor 104 as drive sources.

  The engine 102 is provided with a crankshaft 102a so as to penetrate the inside thereof, and reciprocates a piston with an explosion pressure in the combustion chamber to rotate the crankshaft 102a. The crankshaft 102a has a gear 102b and a pulley 102c fixed to one end side.

  The automobile 100 is provided with an ISG (Integrated Starter Generator) motor 106 and a compressor 108 in the vicinity of the engine 102. The ISG motor 106 functions as a starter that starts the engine 102, and also functions as an alternator that generates electric power by driving the engine 102. In the ISG motor 106, the gear 106b is fixed to the rotating shaft 106a protruding from the inside, and the gear 106b is engaged with the gear 102b, whereby the rotating shaft 106a and the crankshaft 102a transmit power.

  When the ISG motor 106 functions as a starter, the ISG motor 106 is rotationally driven by electric power supplied from a battery (not shown), and the driving force is transmitted to the crankshaft 102a via the rotating shaft 106a, the gear 106b, and the gear 102b. The engine 102 is started. Further, when the ISG motor 106 functions as an alternator, the driving force of the engine 102 is transmitted to the rotating shaft 106a via the crankshaft 102a, the gear 102b, and the gear 106b to generate electric power. The ISG motor 106 charges the battery with electric power obtained by generating electricity.

  The compressor 108 forms a part of an air conditioner device (not shown) mounted on the automobile 100 and compresses the refrigerant. In the compressor 108, a pulley 108b is provided on a rotating shaft 108a protruding from the inside, and a belt 108c is hung on the pulley 108b and the pulley 102c, whereby power is transmitted between the rotating shaft 108a and the crankshaft 102a. The compressor 108 is activated and deactivated according to the on / off control of the electromagnetic switch 108d.

  The motor 104 is, for example, a three-phase brushless DC motor having a U phase, a V phase, and a W phase, and the rotating shaft 104a is fixed to the rotor 104b. The motor 104 is connected to a battery (not shown), is driven to rotate by the electric power supplied from the battery, generates electric power by rotating the rotating shaft 104a, and charges the battery with the generated electric power. .

  Between the crankshaft 102a of the engine 102 and the rotating shaft 104a of the motor 104, a torque converter 110, an input clutch 114, and a continuously variable transmission 118 are provided from the engine 102 side.

  The torque converter 110 includes a front cover 110a connected to the other end of the crankshaft 102a, and a pump impeller 110b fixed to the front cover 110a. In the torque converter 110, a turbine runner 110c is disposed opposite to a pump impeller 110b in a front cover 110a, and a turbine shaft 110d is connected to the turbine runner 110c. Further, in the torque converter 110, a stator 110e is disposed on the inner peripheral side between the pump impeller 110b and the turbine runner 110c, and a working fluid is sealed therein. The stator 110e is fixed to a transmission case (housing) 120 that houses the torque converter 110, the input clutch 114, the continuously variable transmission 118, and the like.

  The pump impeller 110b and the turbine runner 110c are provided with a large number of blades. When the pump impeller 110b rotates, the working fluid is sent to the outer peripheral side, and the working fluid is sent to the turbine runner 110c to rotate the turbine runner 110c. Let As a result, power is transmitted from the crankshaft 102a to the turbine runner 110c.

  The stator 110e changes the flow direction of the working fluid sent from the turbine runner 110c and returns it to the pump impeller 110b, thereby promoting the rotation of the pump impeller 110b. Therefore, torque converter 110 can amplify the transmission torque.

  In the torque converter 110, a clutch plate 110f fixed to the turbine shaft 110d is disposed to face the inner surface of the front cover 110a. The clutch plate 110f is pressed against the front cover 110a by hydraulic pressure, whereby power is transmitted from the crankshaft 102a to the turbine shaft 110d. Further, the power transmitted from the crankshaft 102a to the turbine shaft 110d can be adjusted by controlling the hydraulic pressure so that the clutch plate 110f contacts the front cover 110a while sliding.

  In the input clutch 114, a fixed case 114a fixed to the turbine shaft 110d and a moving member 114b fixed to the rotating shaft 104a are arranged to face each other, and are supplied from a mechanical hydraulic pump 202 or an electric hydraulic pump 204 described later. The moving member 114b moves toward the fixed case 114a by the hydraulic pressure of the hydraulic oil.

  The input clutch 114 cuts off the transmission of power between the turbine shaft 110d and the rotating shaft 104a in the cut-off state where the fixed case 114a and the moving member 114b are separated from each other, and the moving member 114b is pressed against the fixed case 114a by hydraulic pressure. In the connected state, power is transmitted between the turbine shaft 110d and the rotating shaft 104a. The input clutch 114 can adjust the power transmitted between the turbine shaft 110d and the rotating shaft 104a by the hydraulic pressure of the hydraulic oil supplied from the mechanical hydraulic pump 202 or the electric hydraulic pump 204.

  The continuously variable transmission 118 includes a primary pulley 126, a secondary pulley 128, and a belt 130. The primary pulley 126 is provided on the rotating shaft 104a of the motor 104, and the secondary pulley 128 is provided on a parallel shaft 132 disposed in parallel to the rotating shaft 104a. The belt 130 is formed of a chain belt in which link plates are connected by pins, is stretched between the primary pulley 126 and the secondary pulley 128, and transmits power between the primary pulley 126 and the secondary pulley 128. Here, the case where the belt 130 is configured by a chain belt has been described, but the belt 130 may be configured by, for example, a metal belt configured by sandwiching a plurality of frames (elements) by two rings.

  The primary pulley 126 includes a pair of sheaves 126a and 126b. The pair of sheaves 126a and 126b are provided to face each other in the axial direction of the rotation shaft 104a. The opposing surfaces of the pair of sheaves 126a and 126b are substantially conical cone surfaces 126c, and a groove on which the belt 130 is stretched is formed by the cone surfaces 126c.

  Similarly, the secondary pulley 128 includes a pair of sheaves 128a and 128b. The pair of sheaves 128 a and 128 b are provided to face each other in the axial direction of the parallel shaft 132. The opposing surfaces of the pair of sheaves 128a and 128b form a substantially conical cone surface 128c, and a groove on which the belt 130 is stretched is formed by the cone surface 128c.

  The sheave 126b of the primary pulley 126 is configured such that the axial position of the rotating shaft 104a is variable by the hydraulic pressure of the hydraulic oil supplied from the mechanical hydraulic pump 202 or the electric hydraulic pump 204. Further, the sheave 128a of the secondary pulley 128 is configured such that the axial position of the parallel shaft 132 is variable by the hydraulic pressure supplied from the mechanical hydraulic pump 202 or the electric hydraulic pump 204.

  As described above, in the primary pulley 126 and the secondary pulley 128, the facing distance between the pair of sheaves 126a and 126b and the pair of sheaves 128a and 128b is variable. The groove on which the belt 130 is stretched has a narrow inner diameter in the pair of sheaves 126a and 126b and a pair of sheaves 128a and 128b, and a larger outer diameter in the radial direction. Therefore, when the gap between the cone surfaces 126c and 128c is changed and the width of the groove on which the belt 130 is stretched is changed, the position on which the belt 130 is stretched is changed.

  Taking the primary pulley 126 as an example, when the facing distance of the cone surface 126c is widened and the width of the groove on which the belt 130 is stretched is widened, the position where the belt 130 is stretched on the cone surface 126c is the inner diameter side. Thus, the winding diameter of the belt 130 is reduced. On the other hand, when the facing distance between the cone surfaces 126c is narrowed and the width of the groove on which the belt 130 is stretched is narrowed, the position where the belt 130 is stretched on the cone surface 126c is on the outer diameter side, and the winding diameter is large. Become. Thus, the continuously variable transmission 118 continuously shifts the transmission power between the rotating shaft 104a and the parallel shaft 132.

  The parallel shaft 132 is connected to the fixed case 136 a of the output clutch 136 via the gear mechanism 134. In the output clutch 136, a fixed case 136a and a moving member 136b fixed to the axle shaft 138 are arranged to face each other, and the moving member 136b is fixed by hydraulic pressure of hydraulic oil supplied from the mechanical hydraulic pump 202 or the electric hydraulic pump 204. It moves toward the case 136a.

  The output clutch 136 cuts off the transmission of power between the parallel shaft 132 and the axle 138 when the fixed case 136a and the moving member 136b are separated, and the moving member 136b is pressed against the fixed case 136a by hydraulic pressure. In the coupled state, power is transmitted between the parallel shaft 132 and the axle 138, and the power is output to the wheels 140 connected to the axle 138. The output clutch 136 can adjust the torque capacity transmitted between the parallel shaft 132 and the axle 138 according to the hydraulic pressure of the hydraulic oil supplied from the mechanical hydraulic pump 202 or the electric hydraulic pump 204.

  The output clutch 136 is set to a torque capacity smaller than the torque capacity of the continuously variable transmission 118, and transmits the torque from the continuously variable transmission 118 to the axle 138. On the other hand, when a torque (disturbance) larger than its own torque capacity is input from the axle 138, the output clutch 136 slips on the fixed case 136a and the transmission of the torque is limited to the torque capacity or less. Thus, torque larger than the torque capacity of the continuously variable transmission 118 is not transmitted to the continuously variable transmission 118. That is, the output clutch 136 functions as a torque fuse.

  The automobile 100 having such a configuration travels by one or both of the engine 102 and the motor 104 by switching the connection state of the input clutch 114. Specifically, the automobile 100 stops the driving of the engine 102 (idle stop), puts the input clutch 114 in a disengaged state, drives the motor traveling only by the motor 104, and connects the input clutch 114 to the connected state. By causing the motor 104 to run idle or function as a generator, the engine running that runs only by the engine 102 and the input clutch 114 are connected, and the engine 102 and the motor 104 are driven. It is possible to switch between hybrid traveling that travels in both directions.

  Here, as described above, the input clutch 114, the continuously variable transmission 118, and the output clutch 136 are all provided with a hydraulic operation device, and the hydraulic oil is supplied to the hydraulic operation device. Is connected to, disconnected from, or shifted from the power transmission path. Therefore, the automobile 100 of this embodiment includes a hydraulic pressure supply system S that supplies hydraulic oil to the hydraulic actuators of the input clutch 114, the continuously variable transmission 118, and the output clutch 136.

  The hydraulic pressure supply system S includes a mechanical hydraulic pump 202 and an electric hydraulic pump 204 connected in series to the mechanical hydraulic pump 202 in order to supply hydraulic oil to each hydraulic actuator. The mechanical hydraulic pump 202 is connected to the crankshaft 102a via the front cover 110a and the pump impeller 110b of the torque converter 110, and is driven by the power of the engine 102, and the electric hydraulic pump 204 is driven by the power of the electric motor M. .

  In the present embodiment, there may be a case where required hydraulic pressure is required for the continuously variable transmission 118 or the output clutch 136 even when the driving of the engine 102 is stopped, for example, during motor running. However, when the driving of the engine 102 is stopped, the operation of the mechanical hydraulic pump 202 using the engine 102 as a power source is also stopped. Hydraulic oil cannot be supplied to the hydraulic actuator. Therefore, the hydraulic pressure supply system S basically drives the electric motor M to operate the electric hydraulic pump 204 and supplies the hydraulic oil to each hydraulic actuator.

  On the other hand, the electric motor M, which is the drive source of the electric hydraulic pump 204, generates heat when driven. Since the electric motor M and the electric hydraulic pump 204 are integrally formed and are disposed close to each other, while the electric motor M is being driven, the electric oil is sucked and discharged by the hydraulic oil sucked and discharged. The motor M is cooled. However, when the electric motor M is continuously driven in a high load state for a long time, the cooling by the hydraulic oil does not catch up, and the heat generation amount of the electric motor M increases. Thus, when the temperature of the electric motor M becomes equal to or higher than the predetermined temperature, the driving of the electric motor M, that is, the electric hydraulic pump 204 must be stopped from the viewpoint of safety. As described above, while the drive of the electric motor M is stopped, the engine 102 is driven, the hydraulic oil is supplied from the mechanical hydraulic pump 202 to each hydraulic actuator, the input clutch 114, the continuously variable transmission 118, The hydraulic pressure required by the output clutch 136 is ensured.

  However, when the drive of the electric motor M is stopped, the suction and discharge of the hydraulic oil to the electric hydraulic pump 204 are also stopped, so that the cooling function of the electric motor M is also stopped at the same time, and it takes a long time to cool the electric motor M. It takes time. Therefore, in the hydraulic pressure supply system S of the present embodiment, when the electric motor M that is a drive source of the electric hydraulic pump 204 becomes high temperature and the drive is stopped, in order to cool the electric motor M at an early stage, the following is performed. It is configured. Hereinafter, the configuration of the hydraulic pressure supply system S will be described in detail.

  FIG. 2 is a schematic diagram illustrating the configuration of the hydraulic pressure supply system S. The hydraulic pressure supply system S includes a tank T in which hydraulic oil is stored, and a suction port of a mechanical hydraulic pump 202 is connected to the tank T via an introduction oil path 206. In addition, one end of a connection oil path 208 is connected to the discharge port of the mechanical hydraulic pump 202, and the suction port of the electric hydraulic pump 204 is connected to the other end of the connection oil path 208. Therefore, the mechanical hydraulic pump 202 and the electric hydraulic pump 204 are connected in series via the connection oil path 208. Further, hydraulic oil discharged from the mechanical hydraulic pump 202 or the electric hydraulic pump 204 is supplied to the hydraulic actuators of the input clutch 114, the continuously variable transmission 118, and the output clutch 136 at the discharge port of the electric hydraulic pump 204. A supply oil passage 210 is connected.

  The supply oil passage 210 is connected to the branch passages 210a, 210b, and 210c on the downstream side thereof, and the input clutch 114, the continuously variable transmission 118, the output clutch are connected through the branch passages 210a, 210b, and 210c. The hydraulic oil is supplied to each of the hydraulic actuators 136. Although not described in detail, each branch flow path 210a, 210b, 210c is provided with a pressure control valve (not shown), and the hydraulic pressure acting on each hydraulic actuator is controlled by the control of the pressure control valve. It has been adjusted.

  The hydraulic pressure supply system S includes a cooling oil passage 212 that bypasses the electric hydraulic pump 204. The cooling oil passage 212 is connected to the connection oil passage 208 that connects the mechanical hydraulic pump 202 and the electric hydraulic pump 204 via the first switching valve 214 on the upstream side, and the hydraulic oil passage 204 and the hydraulic pressure on the downstream side. It is connected to a supply oil passage 210 that connects the operating device. The electric hydraulic pump 204 and the electric motor M are disposed close to each other, and are integrally accommodated in the casing 216 as indicated by a one-dot chain line in the figure, and the cooling oil passage 212 has a particularly large amount of heat generated in the casing 216. It penetrates a large part.

  The first switching valve 214 is provided on the upstream side of the electric hydraulic pump 204 and switches the flow path of the hydraulic oil to either the cooling oil path 212 side or the electric hydraulic pump 204 side. The first switching valve 214 is composed of a solenoid valve. When the solenoid is not energized, the first switching valve 214 is stationary at the normal position shown in the figure by the spring urging force. Switch to the switching position. In the normal position, the first switching valve 214 allows the connection oil passage 208 and the electric hydraulic pump 204 to communicate with each other and blocks the communication between the connection oil passage 208 and the cooling oil passage 212. On the other hand, when the first switching valve 214 is switched to the switching position, the communication between the connection oil path 208 and the electric hydraulic pump 204 is blocked, and the connection oil path 208 and the cooling oil path 212 are communicated.

  The hydraulic pressure supply system S includes a bypass flow path 218 that bypasses the mechanical hydraulic pump 202. The bypass flow path 218 has an upstream side connected to the introduction oil path 206 and a downstream side connected to the connection oil path 208. On the upstream side of the mechanical hydraulic pump 202 and downstream of the connection point between the bypass flow path 218 and the introduction oil path 206, the hydraulic oil flow paths are on the bypass flow path 218 side and the mechanical hydraulic pump 202 side. The 2nd switching valve 220 which switches to either of these is provided.

  The second switching valve 220 is composed of a pilot valve having a spring 220a on one end side and a pilot chamber 220b on the other end side. The electric hydraulic pump is connected to the pilot chamber 220b via a pilot line 222. A discharge pressure of 204 acts. More specifically, on the downstream side of the electric hydraulic pump 204 and upstream of the connecting portion between the cooling oil passage 212 and the supply oil passage 210, the supply oil passage 210 side to the electric hydraulic pump 204 side is provided. A check valve 224 that suppresses the flow of the hydraulic oil is provided. One end of the pilot line 222 is connected between the check valve 224 and the electric hydraulic pump 204, and the other end is connected to the pilot chamber 220 b of the second switching valve 220.

  In a state where the discharge pressure of the electric hydraulic pump 204 is not acting on the pilot chamber 220b, the second switching valve 220 is stationary at the illustrated normal position by the biasing force of the spring 220a, and the electric hydraulic pump 204 is placed in the pilot chamber 220b. When the discharge pressure is applied, the switching position is switched against the urging force of the spring 220a. When the second switching valve 220 is in the normal position, the communication between the introduction oil path 206 and the mechanical hydraulic pump 202 is cut off, and when the second switching valve 220 is switched to the switching position, the introduction oil path 206 and the mechanical hydraulic pump 202 are switched. And communicate.

  Note that a cooling unit 226 that cools the hydraulic oil is connected to the connection oil passage 208, and the hydraulic oil cooled by the cooling unit 226 is guided to each hydraulic actuator. Further, a temperature sensor 228 for detecting the temperature of the electric motor M is provided in the casing 216, and a temperature detection signal is always input to the control unit 230 from the temperature sensor 228. The control unit 230 estimates the temperature of the electric motor M from the temperature detection signal input from the temperature sensor 228. When the estimated temperature exceeds a threshold value, the control unit 230 stops driving the electric motor M and the solenoid of the first switching valve 214. Is switched to switch the first switching valve 214 from the normal position to the switching position. Below, the supply path | route of hydraulic fluid is each demonstrated when the estimated temperature of the electric motor M is less than a threshold value, and when the estimated temperature of the electric motor M is more than a threshold value.

  FIG. 3 is a diagram illustrating a hydraulic oil supply path when the estimated temperature of the electric motor M is less than the threshold value. The controller 230 estimates the temperature of the electric motor M based on the temperature detection signal input from the temperature sensor 228. If the estimated temperature is less than the threshold value, the controller 230 drives the electric motor M and 1 The switching valve 214 is maintained in a non-energized state. Therefore, the first switching valve 214 is maintained in the illustrated normal position, and the electric hydraulic pump 204 and the connection oil passage 208 are in communication with each other. Thus, when the electric hydraulic pump 204 is operated, the first switching valve 214 switches the flow path of the hydraulic oil to the electric hydraulic pump 204 side, so that the hydraulic oil sucked from the suction port of the electric hydraulic pump 204 is the electric hydraulic pressure. The pressure is increased by the pump 204 and discharged from the discharge port to the supply oil passage 210.

  At this time, the pressure of the supply oil passage 210 acts on the pilot chamber 220b via the pilot line 222, and the second switching valve 220 is switched to the switching position as shown in the figure by this pressure. That is, when the electric hydraulic pump 204 is operated, the second switching valve 220 switches the hydraulic oil flow path to the bypass flow path 218 side by the pilot pressure acting via the pilot line 222. Accordingly, the hydraulic oil stored in the tank T is sucked into the electric hydraulic pump 204 via the introduction oil passage 206, the bypass passage 218, the connection oil passage 208, the cooling unit 226, and the first switching valve 214, and the electric hydraulic pump The pressure is increased at 204 and supplied to the hydraulic actuators of the input clutch 114, the continuously variable transmission 118, and the output clutch 136 via the supply oil passage 210 and the branch passages 210 a to 210 c.

  FIG. 4 is a diagram illustrating a hydraulic oil supply path when the estimated temperature of the electric motor M is equal to or higher than a threshold value. From the above state, when the estimated temperature of the electric motor M becomes equal to or higher than the threshold value, the control unit 230 stops driving the electric motor M and maintains the first switching valve 214 in the energized state. When the first switching valve 214 is energized, the first switching valve 214 switches to the illustrated switching position, the communication between the electric hydraulic pump 204 and the connection oil path 208 is cut off, and the connection oil path 208 and the cooling oil path 212 communicates. That is, the first switching valve 214 switches the hydraulic oil flow path to the cooling oil path 212 side when the electric hydraulic pump 204 is stopped.

  Further, when the driving of the electric motor M is stopped, the discharge of the hydraulic oil from the electric hydraulic pump 204 is stopped, and the pressure of the pilot line 222 decreases. When the pressure in the pilot line 222 drops in this way, the second switching valve 220 is switched to the normal position shown in the figure by the urging force of the spring 220a, and the introduction oil path 206 and the mechanical hydraulic pump 202 communicate with each other. That is, the second switching valve 220 switches the hydraulic oil flow path to the mechanical hydraulic pump 202 side when the electric hydraulic pump 204 is stopped.

  Since the mechanical hydraulic pump 202 operates using the engine 102 as a drive source, when the introduction oil path 206 and the mechanical hydraulic pump 202 communicate with each other via the second switching valve 220, the hydraulic oil stored in the tank T is stored. Is sucked into the mechanical hydraulic pump 202 through the introduction oil passage 206 and the second switching valve 220. The hydraulic oil boosted by the mechanical hydraulic pump 202 is supplied to the input clutch 114, the first switching valve 214, the cooling oil passage 212, the supply oil passage 210, and the branch passages 210a to 210c. This is supplied to the hydraulic actuators of the continuously variable transmission 118 and the output clutch 136.

  Thus, when the hydraulic oil supplied to each hydraulic actuator by the mechanical hydraulic pump 202 is guided to the cooling oil passage 212, the electric motor M is cooled by the hydraulic oil flowing through the cooling oil passage 212. That is, while the drive of the electric motor M is stopped, the hydraulic oil is supplied from the mechanical hydraulic pump 202 to each hydraulic actuator, and at this time, the hydraulic oil supplied to each hydraulic actuator is used as cooling oil. The electric motor M can be cooled by detouring to the path 212. Thereby, even if the electric motor M becomes high temperature due to heat generation, if the driving of the electric motor M is stopped, the electric motor M is cooled while the driving is stopped, and the electric motor M, that is, the electric hydraulic pump 204 is turned off. It can be redriven early.

  As mentioned above, although preferred embodiment of this invention was described referring an accompanying drawing, it cannot be overemphasized that this invention is not limited to this embodiment. It will be apparent to those skilled in the art that various changes and modifications can be made within the scope of the claims, and these are naturally within the technical scope of the present invention. Is done.

  For example, in the above embodiment, the mechanical hydraulic pump 202 and the electric hydraulic pump 204 are connected in series. However, the mechanical hydraulic pump 202 and the electric hydraulic pump 204 may be connected in parallel. Even in this case, the cooling oil passage 212 for cooling the electric motor M is provided, and the hydraulic oil supplied to the hydraulic actuator by the mechanical hydraulic pump 202 is guided to the cooling oil passage 212, so that the same effect as the above-described embodiment can be obtained. Can be realized. In the above embodiment, the cooling oil passage 212 is provided on the downstream side of the mechanical hydraulic pump 202. However, the cooling oil passage 212 may be provided on the upstream side of the mechanical hydraulic pump 202. In the above embodiment, the electric hydraulic pump 204 is connected in series to the downstream side of the mechanical hydraulic pump 202. Conversely, the mechanical hydraulic pump 202 is connected to the downstream side of the electric hydraulic pump 204. You may connect in series.

  Further, in the above embodiment, the hydraulic supply system S supplies hydraulic oil from the mechanical hydraulic pump 202 or the electric hydraulic pump 204 to the hydraulic actuators of the input clutch 114, the continuously variable transmission 118, and the output clutch 136. It was. However, the supply destination to which the hydraulic supply system S supplies hydraulic oil may be a part of the input clutch 114, the continuously variable transmission 118, and the output clutch 136, or may be any hydraulic actuator provided separately from these. May be. In any case, the hydraulic pressure supply system S can operate hydraulically by supplying hydraulic oil to a hydraulic actuator that performs shifting by the transmission, or connection / disconnection of a power transmission path for transmitting the power of the engine 102 to the wheels 140. The specific configuration of the apparatus is not particularly limited.

  In the above-described embodiment, the automobile 100 may travel using the engine 102 as a drive source and may travel using the motor 104 as a drive source. The motor 104 is not an essential component.

  The present invention can be used in a hydraulic pressure supply system of a power transmission device that supplies hydraulic oil to a hydraulic pressure operation device that performs a shift by a transmission, or connects and disconnects a power transmission path.

102 Engine 114 Input clutch (hydraulic actuator)
118 continuously variable transmission (hydraulic actuator)
136 Output clutch (hydraulic actuator)
140 Wheel 202 Mechanical hydraulic pump 204 Electric hydraulic pump 208 Connection oil path 210 Supply oil path 212 Cooling oil path 214 First switching valve 218 Bypass path 220 Second switching valve 222 Pilot line 224 Check valve M Electric motor S Hydraulic supply system

Claims (7)

A hydraulic power supply system for a power transmission device that connects and shuts off a power transmission path for transmitting engine power to wheels by supplying hydraulic oil to the hydraulic actuator,
A mechanical hydraulic pump that operates with the power of the engine;
An electric hydraulic pump that operates with the power of the electric motor;
A supply oil passage for supplying hydraulic oil discharged from the mechanical hydraulic pump or the electric hydraulic pump to the hydraulic actuator;
Hydraulic oil supplied to the hydraulic actuator by the mechanical hydraulic pump is guided, and a cooling oil passage for cooling the electric motor by the hydraulic oil;
A hydraulic pressure supply system for a power transmission device.   2. The hydraulic pressure supply system for a power transmission device according to claim 1, wherein the mechanical hydraulic pump and the electric hydraulic pump are connected in series by a connecting oil passage.   The hydraulic supply system for a power transmission device according to claim 2, wherein the cooling oil passage is provided to bypass the electric hydraulic pump. A first switching valve provided on the upstream side of the electric hydraulic pump, for switching the flow path of the hydraulic oil to either the cooling oil path side or the electric hydraulic pump side;
The first switching valve is
When the electric hydraulic pump is stopped, the hydraulic oil flow path is switched to the cooling oil path side, and when the electric hydraulic pump is operated, the hydraulic oil flow path is switched to the electric hydraulic pump side. The hydraulic pressure supply system of the power transmission device according to claim 3. A bypass passage for bypassing the mechanical hydraulic pump;
A second switching valve provided on the upstream side of the mechanical hydraulic pump, for switching the flow path of the hydraulic oil to either the bypass flow path side or the mechanical hydraulic pump side;
With
The second switching valve is
When the electric hydraulic pump is stopped, the hydraulic oil flow path is switched to the mechanical hydraulic pump side, and when the electric hydraulic pump is operated, the hydraulic oil flow path is switched to the bypass flow path side. The hydraulic pressure supply system for a power transmission device according to claim 4. The mechanical hydraulic pump is provided upstream of the electric hydraulic pump;
The cooling oil passage has an upstream side connected to the connection oil passage connecting the mechanical hydraulic pump and the electric hydraulic pump, and a downstream side connected to the supply oil passage connecting the electric hydraulic pump and the hydraulic actuator. The hydraulic pressure supply system for a power transmission device according to claim 5, wherein the hydraulic pressure supply system is connected. Provided on the downstream side of the electric hydraulic pump and upstream of the connection between the cooling oil passage and the supply oil passage, the flow of hydraulic oil from the supply oil passage side to the electric hydraulic pump side is suppressed. A check valve that
A pilot line having one end connected between the check valve and the electric hydraulic pump and the other end connected to the second switching valve;
With
The second switching valve is
7. The hydraulic pressure supply system for a power transmission device according to claim 6, wherein when the electric hydraulic pump is operated, the hydraulic oil flow path is switched to the bypass flow path side by a pilot pressure acting via the pilot line. .

Images