JP6413993B2 - Motor cooling device - Google Patents

Description

  The present invention relates to a motor cooling device.

  In Patent Document 1, in a hybrid vehicle including an internal combustion engine and two electric motors, an oil cooler is connected to a pump unit including a mechanical oil pump and an electric oil pump driven by the internal combustion engine, and is cooled by the oil cooler. A cooling device is described in which the oil after cooling is supplied to two electric motors to cool the electric motors.

JP 2013-220771 A

  However, in the cooling device of Patent Document 1, there is one flow path from the oil cooler to the inside of the case, and the two electric motors accommodated in the case are collectively cooled. Therefore, there is a possibility that two motors having different physiques and output characteristics cannot be properly cooled. Moreover, although patent document 1 is disclosing the structure of the cooling device which has one oil cooler, it does not disclose the cooling device which has two oil coolers from which the cooling characteristic differs, an air cooling cooler and a water cooling cooler.

  The present invention has been made in view of the above, and an object of the present invention is to provide an electric motor cooling device capable of improving the cooling performance of two electric motors that are power sources of a vehicle in the case of having an air cooling cooler and a water cooling cooler. And

  The present invention is an electric motor cooling device mounted on a vehicle including an internal combustion engine, a first electric motor, and a second electric motor, driven by the internal combustion engine, a refrigerant source that stores refrigerant for cooling each electric motor, And a mechanical oil pump that sucks the refrigerant from the refrigerant source and discharges it from the discharge port, and is connected to the discharge port of the mechanical oil pump and supplies the refrigerant discharged by the mechanical oil pump to the first electric motor. An air cooling cooler that is connected to the mechanical oil pump via a first branch path branched from the first flow path and that cools the refrigerant discharged from the mechanical oil pump, and the air cooling A second flow path for supplying the first electric motor with a refrigerant connected to a cooler and air-cooled by the air-cooled cooler; and branched from the second flow path and cooled by the air-cooled cooler. A third flow path for supplying the second refrigerant to the second electric motor, and the refrigerant source connected in parallel with the mechanical oil pump, and sucking the refrigerant from the refrigerant source and An electric oil pump that discharges, a water-cooled cooler that water-cools the refrigerant discharged from the electric oil pump, and a water-cooled cooler that is connected to the water-cooled cooler and accommodates the first motor and the second motor. And a first check valve provided on the mechanical oil pump side with respect to a branch point that branches from the first flow path to the first branch path. A second branch path branched from a flow path between an oil pump and the water-cooled cooler and connected to the first branch path; a second check valve provided in the second branch path; and the mechanical oil Pump and electric oil Switching means for switching a flow path through which the refrigerant discharged from the electric oil pump is pumped when the pump is driven and when the mechanical oil pump is stopped and the electric oil pump is driven. The air cooling cooler is connected to the electric oil pump via the first branch path and the second branch path, and cools the refrigerant discharged from the electric oil pump, and the mechanical oil pump and the electric oil When the pump is driven, the switching unit causes the refrigerant discharged from the electric oil pump to be pumped to the path reaching the inside of the case via the water-cooled cooler, the mechanical oil pump is stopped, and the electric When the oil pump is driven, the switching unit causes the refrigerant discharged from the electric oil pump to pass through the air-cooled cooler. It is characterized by being pumped to a route leading to one electric motor and the second electric motor.

  In the present invention, in a cooling device including an air-cooled cooler and a water-cooled cooler, the flow path for pumping the refrigerant discharged from the electric oil pump can be switched by the switching means. Thus, when the mechanical oil pump and the electric oil pump are driven, the refrigerant can be air-cooled with the air-cooled cooler, and the refrigerant can be water-cooled with the water-cooled cooler. Further, when the mechanical oil pump is stopped and the electric oil pump is driven, the refrigerant discharged from the electric oil pump can be supplied to the two electric motors after being cooled by the air cooling cooler. Therefore, the cooling performance of the cooling device for the two electric motors can be improved. Furthermore, since it is possible to supply the refrigerant after being cooled by the air-cooled cooler and the water-cooled cooler having different cooling characteristics according to the traveling state of the vehicle, it is possible to appropriately perform the cooling required for each electric motor.

FIG. 1 is a skeleton diagram showing an example of a vehicle equipped with a motor cooling device. FIG. 2 is a schematic diagram showing a schematic configuration of the cooling device and a cooling circuit. FIG. 3 is a flowchart showing an example of the cooling control flow. FIG. 4 is a schematic diagram showing a schematic configuration of a cooling device and a cooling circuit in a modified example. FIG. 5 is a flowchart showing a cooling control flow in the modification.

  Hereinafter, with reference to drawings, the cooling device of the electric motor in the embodiment of the present invention is explained concretely.

  FIG. 1 is a skeleton diagram showing an example of a vehicle Ve equipped with a motor cooling device according to this embodiment. The vehicle Ve is a hybrid vehicle including an engine 1, a first motor (MG1) 2, and a second motor (MG2) 3 as power sources. The engine 1 is a known internal combustion engine. Each of the motors 2 and 3 is a known motor / generator having a motor function and a power generation function, and is electrically connected to a battery (both not shown) via an inverter.

  In the vehicle Ve, the power output from the engine 1 can be divided into the first motor 2 side and the drive wheel 4 side by a power split mechanism 5 provided in the power transmission path from the engine 1 to the drive wheels 4. At that time, the first motor 2 generates power using the power output from the engine 1, and the electric power is stored in the battery or supplied to the second motor 3.

  On the same axis as the crankshaft 1a of the engine 1, an input shaft 6, a power split mechanism 5 and a first motor 2 are arranged. The crankshaft 1a is connected to the input shaft 6 via the clutch C. When the clutch C is engaged, the engine 1 and the input shaft 6 are connected so that power can be transmitted. When the clutch C is released, power is transmitted between the engine 1 and the input shaft 6. It is blocked so that it cannot. That is, when the clutch C is engaged, the crankshaft 1a and the input shaft 6 rotate integrally, and when the clutch C is released, the engine 1 is disconnected from the power transmission system. The first motor 2 is adjacent to the power split mechanism 5 and is disposed on the opposite side of the engine 1 in the axial direction. The first motor 2 includes a stator 2a around which a coil is wound, a rotor 2b, and a rotating shaft (rotor shaft) 2c attached so that the rotor 2b rotates integrally.

  The power split mechanism 5 is a differential mechanism having a plurality of rotating elements. In the example shown in FIG. 1, the power split mechanism 5 is constituted by a single pinion type planetary gear mechanism (planetary gear). The power split mechanism 5 meshes with an external gear sun gear 5S, an internal gear ring gear 5R arranged concentrically with the sun gear 5S, and the sun gear 5S and the ring gear 5R as three rotating elements. And a carrier 5C that holds the pinion gear so that it can rotate and revolve.

  The rotor shaft 2c of the first motor 2 is connected to the sun gear 5S so as to rotate integrally. The input shaft 6 is connected to the carrier 5C so as to rotate integrally, and the engine 1 is connected to the carrier 5C via the input shaft 6. An output gear 7 that outputs torque from the power split mechanism 5 toward the drive wheels 4 is integrated with the ring gear 5R.

  The output gear 7 is an external gear that rotates integrally with the ring gear 5 </ b> R, and meshes with the counter driven gear 8 b of the counter gear mechanism 8. The counter gear mechanism 8 includes a counter shaft 8 a disposed in parallel with the input shaft 6, a counter driven gear 8 b, and a counter drive gear 8 c that meshes with the ring gear 9 a of the differential gear mechanism 9. A counter driven gear 8b and a counter drive gear 8c are attached to the counter shaft 8a so as to rotate integrally. Drive wheels 4 are connected to the differential gear mechanism 9 via left and right drive shafts 10.

  The vehicle Ve is configured so that the torque output from the second motor 3 can be added to the torque transmitted from the engine 1 to the drive wheels 4. The second motor 3 includes a stator 3a around which a coil is wound, a rotor 3b, and a rotating shaft (rotor shaft) 3c attached so that the rotor 3b rotates integrally. The rotor shaft 3c is disposed so as to be parallel to the counter shaft 8a, and is attached so that the reduction gear 11 engaged with the counter driven gear 8b rotates integrally.

  Further, the vehicle Ve is provided with a mechanical oil pump (MOP) 101 that is driven by the engine 1. The mechanical oil pump 101 is provided on the same axis as the crankshaft 1 a of the engine 1 and includes a pump rotor (not shown) that rotates integrally with the input shaft 6. When the vehicle Ve travels by the power of the engine 1, the pump rotor of the mechanical oil pump 101 rotates in the forward direction by the torque of the input shaft 6, and the mechanical oil pump 101 discharges oil from the discharge port. The oil discharged from the mechanical oil pump 101 is supplied to the lubrication-required parts such as the power split mechanism 5 through the supply oil passage and functions as the lubrication oil, and also supplied to the cooling-required parts such as the motors 2 and 3. And function as a refrigerant. The vehicle Ve is configured such that oil discharged from the mechanical oil pump 101 is supplied to the motors 2 and 3 as a refrigerant to cool the motors 2 and 3. The mechanical oil pump 101 is not limited to a structure and arrangement that rotate integrally with the input shaft 6, and may be provided at a position offset from the input shaft 6. In this case, the mechanical oil pump 101 and the input shaft 6 are connected to be able to transmit torque via a transmission mechanism such as a gear mechanism or a belt mechanism.

  FIG. 2 is a schematic diagram showing a schematic configuration of the cooling device 100 for each of the motors 2 and 3 and a cooling circuit 200. The planetary gear shown in FIG. 2 is the power split mechanism 5, and the gear is the differential gear mechanism 9.

  The motors 2 and 3 are accommodated in the case 30 and are cooled by oil (refrigerant) supplied from the cooling device 100. The cooling device 100 has a cooling circuit 200 through which oil circulates, and is formed across the inside and outside of the case 30.

  The case 30 is formed between a case main body 31 accommodating the two motors 2 and 3 and the power split mechanism 5, a rear cover 32 attached to the case main body 31, and the case main body 31 and the rear cover 32. A pump body 33 and a housing 34 that houses the differential gear mechanism 9 below the case body 31. The pump body 33 forms part of the mechanical oil pump 101 and accommodates the pump rotor inside. The differential gear mechanism 9 can scoop up oil in the housing 34. The scraped oil moves from the housing 34 into the case body 31 and is supplied to the first motor 2.

  The cooling device 100 includes a mechanical oil pump 101, an electric oil pump (EOP) 102, an air-cooled oil cooler (hereinafter referred to as “air-cooled cooler”) 103, a water-cooled oil cooler (hereinafter referred to as “water-cooled cooler”) 104, , A first check valve 105, a second check valve 106, and a switching valve 107 are provided.

  Oil (refrigerant) is stored in an oil reservoir 108 serving as a refrigerant source. The oil pumps 101 and 102 are connected in parallel to the strainer 109, and when in operation, the oil in the oil reservoir 108 is sucked through the strainer 109 and discharged from the discharge port. The oil reservoir 108 is configured by a structure capable of storing oil at the bottom in the case main body 31, an oil pan, or the like.

  The electric oil pump 102 is configured to be driven by an electric motor (M) 111 and to be driven and controlled by a control device 112. A rotor shaft 111a of the electric motor 111 is connected to rotate integrally with a pump rotor (not shown) of the electric oil pump 102, and functions as a drive shaft of the electric oil pump 102. The control device 112 is a well-known electronic control device that can control the electric oil pump 102, and is configured to drive and control the electric oil pump 102 by controlling the electric motor 111. The control device 112 controls the electric motor 111 so that the rotor shaft 111a rotates forward, and executes drive control for driving the electric oil pump 102. When the electric oil pump 102 is driven, oil is discharged from the discharge port. The forward rotation is the direction of rotation of the pump rotor (rotor shaft 111a) when the electric oil pump 102 sucks the refrigerant from the oil reservoir 108 and discharges the refrigerant from the discharge port.

  The air-cooled cooler 103 is a heat exchanger that performs heat exchange between oil discharged from the oil pumps 101 and 102 and air (for example, outside air of the vehicle Ve), and has higher cooling performance than the water-cooled cooler 104. . The air cooling cooler 103 may cool the oil discharged from the mechanical oil pump 101 or may cool the oil discharged from the electric oil pump 102. The oil (refrigerant) after being air-cooled by the air-cooling cooler 103 is discharged from the MG cooling pipe to the motors 2 and 3 (stators 2a and 3a) to cool the motors 2 and 3. The MG cooling pipe includes an MG1 cooling pipe for cooling the first motor 2 and an MG2 cooling pipe for cooling the second motor 3. In the cooling device 100, one MG2 cooling pipe is provided.

  The water cooling cooler 104 is a heat exchanger that performs heat exchange between the oil discharged from the electric oil pump 102 and cooling water (for example, engine cooling water or hybrid cooling water). The hybrid cooling water cools the inverter and the like, and is cooler than the temperature of the engine cooling water.

  The first check valve 105 is configured to be opened by the discharge pressure of the mechanical oil pump 101, and prevents the oil from flowing back toward the discharge port side of the mechanical oil pump 101. The first check valve 105 is provided inside the pump body 33. In the cooling circuit 200, a first check valve 105 is provided between the mechanical oil pump 101 and the air cooling cooler 103.

  The second check valve 106 is configured to open by the discharge pressure of the electric oil pump 102, and is for preventing the oil from flowing back toward the discharge port side of the electric oil pump 102. The second check valve 106 is provided inside the pump body 33. In the cooling circuit 200, a second check valve 106 is provided between the electric oil pump 102 and the air cooling cooler 103.

  The switching valve 107 is switching means for switching a flow path through which oil discharged from the electric oil pump 102 is pumped. The switching valve 107 is controlled to be switched by the control device 112, and is configured to switch between a flow path from the electric oil pump 102 to the water cooling cooler 104 and a flow path from the electric oil pump 102 to the air cooling cooler 103. . For example, the switching valve 107 is a linear solenoid valve, and switches the flow path when a switching signal is input from the control device 112. Note that the switching valve 107 is not limited to an electromagnetic valve, and may be configured to operate by an actuator other than an electromagnetic type.

  The cooling circuit 200 includes a plurality of distribution paths, a first path 210, a second path 220, a third path 230 starting from the mechanical oil pump 101, and a fourth path 240 starting from the electric oil pump 102. A fifth path 250 and a sixth path 260.

  The first path 210 is a path from the mechanical oil pump 101 to the first motor 2 without passing through the coolers 103 and 104. The first path 210 is formed by a flow path that supplies oil discharged from the mechanical oil pump 101 to the first motor 2 (rotor 2 b) and the power split mechanism 5.

  As shown in FIG. 2, the first path 210 includes a discharge passage 210 a connected to the discharge port of the mechanical oil pump 101, a first check valve 105, and a first downstream of the first check valve 105. It is comprised by the supply flow path 210b. The first check valve 105 prevents the oil in the first path 210 from flowing back toward the discharge port side of the mechanical oil pump 101. An orifice 113 is provided in the first supply channel 210b. The orifice 113 controls the flow rate of oil flowing from the mechanical oil pump 101 into the first supply flow path 210b.

  When the mechanical oil pump 101 is driven, the first check valve 105 is opened by the discharge pressure of the mechanical oil pump 101, and the oil discharged from the mechanical oil pump 101 is pumped to the first supply flow path 210b. The first supply flow path 210 b includes a shaft core side flow path formed inside the input shaft 6, and supplies oil as a refrigerant to the first motor 2 (rotor 2 b) and the power split mechanism 5 in the case body 31. . The refrigerant in the first supply flow path 210b is discharged into the case main body 31 from the discharge hole of the input shaft 6, and the inside of the case main body 31 is caused by the hydraulic pressure of the first supply flow path 210b or the centrifugal force or gravity by the rotating member. Move from the center of rotation toward the outside in the radial direction. Note that a flow path including the discharge flow path 210a, the first check valve 105, and the first supply flow path 210b can be referred to as a first flow path.

  The second path 220 is a path branched from the first path 210 at the first branch point, and is a path from the mechanical oil pump 101 to the first motor 2 via the air cooling cooler 103. The first branch point is a portion where the flow path of the oil discharged from the mechanical oil pump 101 branches to the air cooling cooler 103 side and the rotor 2b side of the first motor 2. The second path 220 is formed by a flow path that supplies the oil discharged from the mechanical oil pump 101 to the first motor 2 (stator 2a) after air cooling by the air cooling cooler 103.

  As shown in FIG. 2, the second passage 220 includes a discharge passage 210a, a first check valve 105, a first branch passage 220a that branches from the first supply passage 210b at the first check valve 105, The air-cooled cooler 103, the air-cooled flow path 220b connected to the discharge port of the air-cooled cooler 103, the second air-cooled flow path 220b connected to the air-cooled flow path 220b, and the second air-cooled refrigerant discharged to the first motor 2 (stator 2a). It is comprised by the supply flow path 220c. In the example shown in FIG. 2, the first check valve 105 is the first branch point.

  The first branch passage 220 a is formed so as to communicate the air cooling side outflow port of the first check valve 105 and the supply port of the air cooling cooler 103. The post-air-cooling flow path 220 b is formed so that the upstream side is provided outside the case 30 and the downstream side reaches the inside of the case body 31. The second supply flow path 220c is a flow path formed inside the case 30, and is formed by, for example, an MG1 cooling pipe provided inside the case main body 31. The MG1 cooling pipe has a discharge hole for discharging refrigerant to the stator 2a of the first motor 2. In the second path 220, a flow path including the first branch path 220a, the air cooling cooler 103, the post-air cooling flow path 220b, and the second supply flow path 220c can be referred to as a second flow path.

  When the oil discharged from the mechanical oil pump 101 is pumped from the first branch point to the rotor 2b of the first motor 2 and the power split mechanism 5 side (first path 210 side), it does not pass through the air cooling cooler 103. Then, the oil is supplied to the first motor 2 (rotor 2b) and the power split mechanism 5 from the oil hole of the input shaft 6 (the discharge hole of the flow path on the shaft core side). On the other hand, the oil pressure-fed from the first branch point to the air cooling cooler 103 side (second path 220) flows into the air cooling cooler 103. Further, since the air cooling cooler 103 is provided outside the case 30, the oil pumped in the second path 220 once circulates outside the case 30 and then returns to the inside of the case 30 again.

  In addition, two relief valves 114A and 114B for adjusting the hydraulic pressure in the first branch path 220a are connected to the first branch path 220a. In each of the relief valves 114A and 114B, the supply port is connected to the first branch passage 220a, and the discharge port is opened toward the inside of the case body 31. For example, the relief pressure of the first relief valve 114A and the relief pressure of the second relief valve 114B are set to different magnitudes. The refrigerant in the first branch passage 220a is configured to be supplied into the case body 31 from the relief valves 114A and 114B.

  The third path 230 is a path branched from the second path 220 at the branch point P after air cooling, and is a path from the mechanical oil pump 101 to the second motor 3 via the air cooling cooler 103. The third flow path 230 is formed by a flow path for supplying the refrigerant after air cooling by the air cooling cooler 103 to the second motor 3 (stator 3a).

  As shown in FIG. 2, the third path 230 includes a discharge flow path 210a, a first check valve 105, a first branch path 220a, an air cooling cooler 103, a post-air cooling path 220b, and a post-air cooling branch point. The second supply flow path 220c branches at P, and the third supply flow path 230a discharges the air-cooled refrigerant to the second motor 3 (stator 3a).

  The third supply flow path 230a is a flow path formed inside the case 30, and is formed by, for example, an MG2 cooling pipe provided inside the case main body 31. The MG2 cooling pipe has a discharge hole for discharging the air-cooled refrigerant to the stator 3a of the second motor 3. In the third path 230, the third supply flow path 230a on the downstream side from the branch point P after air cooling can be referred to as a third flow path.

  The fourth path 240 is a path from the electric oil pump 102 to the oil reservoir 108 inside the case 30 via the water cooling cooler 104. The fourth path 240 is formed by a flow path for returning the oil discharged from the electric oil pump 102 to the inside of the case body 31 after water cooling by the water cooling cooler 104.

  As shown in FIG. 2, the fourth path 240 includes a discharge flow path 240 a connected to the discharge port of the electric oil pump 102, the switching valve 107, and a pre-water cooling flow path 240 b connected to the supply port of the water cooling cooler 104. And a water-cooled return flow path 240c that is connected to the discharge port of the water-cooled cooler 104 and opens toward the inside of the case body 31. In the example shown in FIG. 2, the switching valve 107 is the second branch point. The second branch point is where the flow path of the oil discharged from the electric oil pump 102 branches into the water-cooled cooler 104 side and the air-cooled cooler 103 side.

  The switching valve 107 communicates the discharge flow path 240a and the pre-water cooling flow path 240b and blocks the second branch path 250a (described later) (water cooling side open state), and the discharge flow path 240a and the second branch path. A state (air-cooling side open state) in which 250a is communicated and the pre-water-cooling flow path 240b side is blocked is selectively switched. In the example shown in FIG. 2, the switching valve 107 includes an inflow port connected to the discharge flow path 240a, a water cooling side discharge port connected to a pre-water cooling flow path 240b that is a flow path on the water cooling cooler 104 side, and will be described later. And an air cooling side discharge port connected to the second branch passage 250a on the air cooling cooler 103 side. That is, the switching valve 107 communicates the inflow port and the air cooling side discharge port, closes the water cooling side discharge port (air cooling side open state), communicates the inflow port and water cooling side discharge port, and air cooling side. The state is selectively switched between a state where the discharge port is closed (water cooling side open state).

  By connecting the discharge flow path 240a and the pre-water cooling flow path 240b by the switching valve 107, the cooling circuit 200 can pump the refrigerant from the electric oil pump 102 to the water cooling cooler 104. The coolant after being water cooled by the water cooling cooler 104 is discharged into the case body 31 from the discharge hole of the return flow path 240c after water cooling, and is returned downward to the oil reservoir 108.

  The fifth path 250 is a path branched from the fourth path 240 at the second branch point (switching valve 107), and is a path from the electric oil pump 102 to the first motor 2 via the air cooling cooler 103. The fifth path 250 is formed by a flow path that supplies the oil discharged from the electric oil pump 102 to the first motor 2 (stator 2a) after air cooling by the air cooling cooler 103.

  As shown in FIG. 2, the fifth path 250 includes a discharge flow path 240a, a switching valve 107, a second branch path 250a, a second check valve 106, a connection flow path 250b, and a first branch path 220a. And an air cooling cooler 103, a post-air cooling flow path 220b, and a second supply flow path 220c.

  The second branch passage 250a is a passage that branches off from the pre-water cooling passage 240b by the switching valve 107, and is connected to the air cooling side outflow port of the switching valve 107. The connection flow path 250b is connected to the first branch path 220a on the downstream side of the second check valve 106. By connecting the discharge flow path 240a and the second branch path 250a by the switching valve 107, the refrigerant can be pumped from the electric oil pump 102 to the air cooling cooler 103.

  The sixth path 260 is a path branched from the fifth path 250 at the branch point P after air cooling, and is a path from the electric oil pump 102 to the second motor 3 via the air cooling cooler 103. The sixth path 260 is formed by a flow path that supplies the oil discharged from the electric oil pump 102 to the second motor 3 (stator 3a) after the air cooling cooler 103 cools the oil.

  As shown in FIG. 2, the sixth path 260 includes a discharge flow path 240a, a switching valve 107, a second branch path 250a, a second check valve 106, a connection flow path 250b, and a first branch path 220a. And an air cooling cooler 103, a post-air cooling flow path 220b, and a third supply flow path 230a.

  FIG. 3 is a flowchart showing a cooling control flow. The control device 112 determines whether the travel mode of the vehicle Ve is the HV mode or the EV mode (step S1). In step S1, the control device 112 is configured to determine the HV mode and the EV mode by a known determination method.

  When it determines with it being HV mode in step S1, the control apparatus 112 determines whether the vehicle load at the time of driving | running | working is a low load or a high load (step S2). In step S2, the control device 112 is configured to determine the traveling vehicle load by a known determination method. For example, the control device 112 calculates the required driving torque based on the accelerator opening and the vehicle speed, and determines that the load is low when the required driving torque is smaller than a predetermined threshold, and the required driving torque is equal to or higher than the threshold. In some cases, it is determined that the load is high.

  When it determines with it being low load in step S2, the control apparatus 112 stops the electric oil pump 102 (step S3). When the control device 112 executes the control in step S3, the mechanical oil pump 101 is driven because it is in the HV mode from the determination result in step S1.

  When the control device 112 executes the control in step S3, the cooling device 100 air-cools the refrigerant discharged by the mechanical oil pump 101 with the air cooling cooler 103, and discharges the air-cooled refrigerant to the motors 2 and 3 from the MG cooling pipe. The first cooling state is performed (step S4). During the HV running at a low load, the cooling for each of the motors 2 and 3 is sufficient for the cooling performance driven only by the mechanical oil pump 101, so the control device 112 stops the electric oil pump 102. At that time, it is necessary to prevent the driven mechanical oil pump 101 from sucking oil or air from the stopped electric oil pump 102 side. As shown in FIG. 2, when the mechanical oil pump 101 is driven and the electric oil pump 102 is stopped, the second check valve 106 is connected to the discharge passage 240a by setting the switching valve 107 to the air cooling side open state. The internal oil is prevented from flowing back toward the discharge port side of the electric oil pump 102. As a result, it is possible to prevent air from being sucked from the discharge hole on the downstream side of the electric oil pump 102, so that it is possible to prevent deterioration in pump performance due to the mechanical oil pump 101 sucking air, and the cooling performance of the cooling device 100. Decline can be prevented. Further, it is not necessary to provide a check valve on the pre-water cooling channel 240b side. Furthermore, compared to the case where the electric oil pump 102 is always driven during HV traveling, power consumption can be suppressed, and fuel consumption is improved. Then, the control device 112 ends this control routine.

  When it is determined in step S2 that the load is high, the control device 112 executes drive control for driving the electric oil pump 102, and the switching valve 107 opens the flow path on the water-cooled cooler 104 side and the air-cooled cooler 103 side. The switching control for shutting off the flow path is executed (step S5). Moreover, when the control apparatus 112 performs control of step S5, since it is HV mode from the determination result of step S1, the mechanical oil pump 101 is driving.

  When the control device 112 executes the control in step S5, the cooling device 100 air-cools the refrigerant discharged by the mechanical oil pump 101 with the air cooling cooler 103, and discharges the air-cooled refrigerant to the motors 2 and 3 from the MG cooling pipe. In the first cooling state, the refrigerant discharged from the electric oil pump 102 is cooled by the water-cooled cooler 104, and the water-cooled refrigerant is returned to the oil reservoir 108 (step S6). That is, it is a cooling state that combines the first cooling state and the second cooling state. During HV traveling at a high load, the cooling of the second motor 3 is insufficient for the cooling performance driven only by the mechanical oil pump 101, so that it is necessary to drive the electric oil pump 102 to improve the cooling performance. Therefore, in addition to supplying the air-cooled refrigerant to the motors 2 and 3 (stators 2a and 3a) (first cooling state), returning the water-cooled refrigerant to the oil reservoir 108 (second cooling state). Thus, the cooling performance of the cooling device 100 is improved. As shown in FIG. 2, when the water-cooled oil is returned to the oil reservoir 108 from the return channel 240c after water cooling, the temperature of the oil in the oil reservoir 108 can be lowered. Thereby, the temperature of a refrigerant source can be lowered and the cooling performance of the cooling device 100 can be improved. Then, the control device 112 ends this control routine.

  When it is determined in step S1 that the EV mode is set, the control device 112 determines whether the vehicle speed is a high vehicle speed or a low vehicle speed (step S7). For example, the control device 112 compares the vehicle speed detected by the vehicle speed sensor with a predetermined threshold, and determines that the vehicle speed is high in step S7 if the vehicle speed is equal to or higher than the threshold, and the vehicle speed is lower than the threshold. In this case, the vehicle speed is determined to be low in step S7.

  When it is determined in step S7 that the vehicle speed is high, the control device 112 performs drive control for driving the electric oil pump 102, and opens the flow path on the air cooling cooler 103 side in the switching valve 107 to thereby open the water cooling cooler 104. Switching control for blocking the flow path on the side is executed (step S8). In the EV traveling mode, the engine 1 is stopped and the mechanical oil pump 101 is stopped. Therefore, the electric oil pump 102 needs to be driven in order for the cooling device 100 to exhibit the cooling performance. In step S <b> 8, the switching valve 107 switches the path through which the refrigerant discharged from the electric oil pump 102 is pumped to the path reaching the air cooling cooler 103. As shown in FIG. 2, when the electric oil pump 102 is driven and the switching valve 107 is in the air-cooling side open state, the second check valve 106 is opened by the discharge pressure of the electric oil pump 102. The oil thus sent is pumped to the first branch 220a and flows into the air cooling cooler 103.

  When the control device 112 executes the control in step S8, the cooling device 100 air-cools the refrigerant discharged by the electric oil pump 102 with the air cooling cooler 103, and discharges the air-cooled refrigerant to the motors 2 and 3 from the MG cooling pipe. A third cooling state is established (step S9). In the third cooling state, the switching valve 107 pumps the refrigerant discharged from the electric oil pump 102 to the paths (fifth path 250 and sixth path 260) to the motors 2 and 3 via the air cooling cooler 103. The Since the necessity of cooling is higher during EV traveling at a high vehicle speed than in EV traveling at a low vehicle speed, the oil discharged from the electric oil pump 102 is cooled by an air-cooled cooler 103 having a cooling performance higher than that of the water-cooled cooler 104. After that, the motors 2 and 3 are supplied and cooled. Further, the first check valve 105 prevents the electric oil pump 102 being driven from sucking oil or air from the stopped mechanical oil pump 101 side and lowering the pump performance. As a result, when the mechanical oil pump 101 is stopped and the electric oil pump 102 is driven, the electric oil pump 102 can prevent the pump performance from being reduced by sucking air, and the cooling performance of the cooling device 100 can be prevented from being reduced. it can. Then, the control device 112 ends this control routine.

  When it is determined in step S7 that the vehicle speed is low, the control device 112 performs drive control for driving the electric oil pump 102, and the switching valve 107 opens the flow path on the water-cooled cooler 104 side to the air-cooled cooler 103 side. The switching control for shutting off the flow path is executed (step S10). In step S <b> 10, the switching valve 107 switches the path through which the refrigerant discharged from the electric oil pump 102 is pumped to the path reaching the water-cooled cooler 104.

  When the control device 112 executes the control in step S10, the cooling device 100 enters the second cooling state in which the refrigerant discharged from the electric oil pump 102 is water-cooled by the water-cooled cooler 104 and the water-cooled refrigerant is returned to the oil reservoir 108. (Step S11). In the second cooling state when the mechanical oil pump 101 is stopped and the electric oil pump 102 is driven, the refrigerant discharged from the electric oil pump 102 by the switching valve 107 passes through the water-cooled cooler 104 and the case main body 31. It is pumped to the fourth path 240 leading to the inside. Then, the control device 112 ends this control routine.

  As described above, according to the present embodiment, in the cooling device 100 including the air-cooled cooler 103 and the water-cooled cooler 104, the flow path for pumping the refrigerant discharged from the electric oil pump 102 by the switching valve 107 can be switched. . Thus, when the mechanical oil pump 101 and the electric oil pump 102 are driven, the air cooling cooler 103 can cool the refrigerant, and the water cooling cooler 104 can cool the refrigerant. When the mechanical oil pump 101 is stopped and the electric oil pump 102 is driven, the refrigerant discharged from the electric oil pump 102 is cooled by the air cooling cooler 103 and then supplied to the two motors 2 and 3. it can. Therefore, the cooling performance of the cooling device 100 can be improved. Furthermore, since the refrigerant after being cooled by the air-cooled cooler 103 and the water-cooled cooler 104 having different cooling characteristics can be supplied in accordance with the traveling state of the vehicle Ve, the cooling required by the motors 2 and 3 is appropriately performed. Can be implemented.

  Further, in the cooling circuit 200 having a plurality of paths 210, 220, 230, 240, 250, 260, the first check valve 105 and the second check valve 106 are provided in the above-described flow path. When one oil pump is driven and the other oil pump is stopped, backflow of oil can be prevented. As a result, it is possible to prevent deterioration in pump performance due to air being sucked from the discharge hole (opening) formed in the flow path on the oil pump side that is stopped.

  In addition, this invention is not limited to embodiment mentioned above, In the range which does not deviate from the objective of this invention, it can change suitably.

  For example, as a modification of the above-described embodiment, the cooling device 100 in which the switching valve 107 is not provided may be used. FIG. 4 shows a schematic configuration of the cooling device 100 in the modified example. An example of the cooling control flow in the modification is shown in FIG. In addition, description is abbreviate | omitted about the structure similar to embodiment mentioned above.

  FIG. 4 is a schematic diagram showing a schematic configuration of a cooling device 100 and a cooling circuit 200 in a modification. In the cooling device 100 of the modified example, a relief valve 115 after water cooling is provided instead of the switching valve 107. As shown in FIG. 4, the fourth path 240 is a flow for returning the oil discharged from the electric oil pump 102 to the inside of the case body 31 through the relief valve 115 after water cooling after the water cooling cooler 104 cools the oil. It is formed by a road.

  Specifically, the fourth path 240 includes a discharge flow path 240a, a pre-water cooling flow path 240b communicated with the discharge flow path 240a at the second branch point Q, a post-water cooling return flow path 240c, and a return after water cooling. It is comprised by the relief valve 115 after the water cooling connected to the flow path 240c. At the second branch point Q, the discharge flow path 240a branches into a pre-water cooling flow path 240b and a second branch path 250a. That is, the discharge flow path 240a, the pre-water cooling flow path 240b, and the second branch path 250a are always in communication at the second branch point Q.

  The relief valve 115 after water cooling is configured such that the supply port is connected to the return flow path 240c after water cooling, and the discharge port opened toward the case body 31 is opened by the hydraulic pressure in the return flow path 240c after water cooling. ing. When the oil pressure in the return flow path 240c after water cooling is higher than the relief pressure of the relief valve 115 after water cooling, the outlet of the relief valve 115 after water cooling opens, and the oil pressure in the return flow path 240c after water cooling becomes the relief valve 115 after water cooling. When the pressure is below the relief pressure, the outlet of the relief valve 115 is closed after water cooling.

  A water cooling cooler 104 and an air cooling cooler 103 are connected in parallel to the electric oil pump 102. Therefore, the relief pressure of the water-cooled relief valve 115 is set higher than the air-cooled cooler pressure and lower than the discharge pressure of the electric oil pump 102. That is, the relationship of air cooling cooler pressure <relief pressure <EOP discharge pressure is established.

  The air-cooled cooler pressure is the pressure on the air-cooled cooler 103 side that branches at the second branch point Q with respect to the electric oil pump 102 (pressure that becomes resistance as a hydraulic circuit). Oil flowing through the air cooling cooler 103 causes a pressure loss in the air cooling cooler 103. The pressure loss generated in the air cooling cooler 103 is included in the air cooling cooler pressure. Further, the pressure on the water cooling cooler 104 side (water cooling cooler pressure) includes the relief pressure of the relief valve 115 after water cooling and the pressure loss generated in the water cooling cooler 104. Further, the discharge pressure of the electric oil pump 102 depends on the performance of the electric oil pump 102.

  In short, the cooling circuit 200 of this modification is configured so that the refrigerant flow path is automatically switched by the hydraulic pressure difference as the hydraulic circuit. That is, since the cooling device 100 is configured to switch the path by the relief pressure of the relief valve 115 after water cooling, the relief valve 115 after water cooling functions as switching means for switching the path. The control device 112 is configured to control the electric motor 111 to drive the electric oil pump 102, but does not perform switching control unlike the above-described embodiment.

  FIG. 5 is a flowchart showing a cooling control flow in the modification. 5 is the same as step S1 in FIG. 3, and step S22 in FIG. 5 is the same as step S2 in FIG.

  When it determines with it being low load in step S22, the control apparatus 112 stops the electric oil pump 102 (step S23). When the control device 112 executes the control in step S23, the mechanical oil pump 101 is driven because it is in the HV mode from the determination result in step S1.

  When the control device 112 executes the control in step S23, the cooling device 100 air-cools the refrigerant discharged from the mechanical oil pump 101 with the air cooling cooler 103, and discharges the air-cooled refrigerant to the motors 2 and 3 from the MG cooling pipe. The first cooling state is performed (step S24). In this case, both the second check valve 106 and the water-cooled relief valve 115 are closed in the flow path downstream of the stopped electric oil pump 102. Therefore, backflow of oil and air inhalation can be prevented. Then, the control device 112 ends this control routine.

  When it determines with it being high load in step S22, the control apparatus 112 performs the drive control which drives the electric oil pump 102 (step S25). At that time, since it is in the HV mode, the mechanical oil pump 101 is driven.

  When the control device 112 executes the control in step S25, the cooling device 100 air-cools the refrigerant discharged by the mechanical oil pump 101 with the air cooling cooler 103, and discharges the air-cooled refrigerant to the motors 2 and 3 from the MG cooling pipe. In the first cooling state, the refrigerant discharged from the electric oil pump 102 is cooled by the water cooling cooler 104, and the water-cooled refrigerant is returned to the oil reservoir 108 from the relief valve 115 after water cooling (step S26). . When the mechanical oil pump 101 is driven and the electric oil pump 102 is driven, the relief valve 115 is opened after water cooling due to the pressure difference in the cooling circuit 200, so that the oil discharged from the electric oil pump 102 passes through the water cooling cooler 104. It is returned to the inside of the case main body 31 via. In this case, depending on the magnitude relationship between the water-cooled cooler pressure and the air-cooled cooler pressure, the second check valve 106 may open and a part of the oil discharged from the electric oil pump 102 may flow into the air-cooled cooler 103. Then, the control device 112 ends this control routine.

  When it determines with it being EV mode in step S21, the control apparatus 112 performs drive control which drives the electric oil pump 102 (step S27). At that time, because of the EV mode, the mechanical oil pump 101 is stopped.

  When the control device 112 executes the control in step S27, the cooling device 100 air-cools the refrigerant discharged by the electric oil pump 102 by the air cooling cooler 103, and discharges the air-cooled refrigerant to the motors 2 and 3 from the MG cooling pipe. A third cooling state is established (step S28). When the mechanical oil pump 101 is stopped and the electric oil pump 102 is driven, the relief pressure of the relief valve 115 after water cooling is larger than the air cooling cooler pressure, so that the relief valve 115 is closed after water cooling and the second check valve 106 opens. That is, the refrigerant discharged from the electric oil pump 102 is pumped by the relief valve 115 after water cooling to the paths (fifth path 250 and sixth path 260) to the motors 2 and 3 via the air cooling cooler 103. . Thereby, the refrigerant discharged from the electric oil pump 102 and cooled by the air-cooled cooler 103 having high cooling performance during EV traveling can be supplied to the motors 2 and 3. Further, since the first check valve 105 is closed in the flow path on the downstream side of the mechanical oil pump 101 being stopped, it is possible to prevent backflow of oil and intake of air. Then, the control device 112 ends this control routine.

  As described above, according to the cooling device 100 of the modified example, when the air-cooled cooler 103 and the water-cooled cooler 104 are connected in parallel to the electric oil pump 102, the cooling circuit 200 can be used without a switching valve. The distribution route can be automatically switched depending on the hydraulic pressure difference. Thereby, the installation space of the switching valve can be reduced, and the size and weight of the cooling device can be reduced. Furthermore, the cost can be reduced because the switching valve is unnecessary. Further, since the control device 112 in the modified example may be any device for driving and controlling the electric oil pump 102, for example, an electronic control device for switching the path of the cooling circuit 200 becomes unnecessary.

1 Engine 2 First motor (MG1)
2a Stator 2b Rotor 3 Second motor (MG2)
3a Stator 3b Rotor 5 Power split mechanism (planetary gear)
9 Differential gear mechanism (gear)
100 Cooling device 101 Mechanical oil pump (MOP)
102 Electric oil pump (EOP)
103 Air-cooled oil cooler (air-cooled cooler)
104 Water-cooled oil cooler (water-cooled cooler)
105 First check valve 106 Second check valve 108 Oil reservoir (refrigerant source)
200 Cooling circuit 210 First path 210a Discharge path 210b First supply path 220 Second path 220a First branch path 220b Air-cooled path 220c Second supply path 230 Third path 230a Third supply path 240 Fourth Path 240a Discharge flow path 240b Flow path before water cooling 240c Return flow path after water cooling 250 Fifth path 250a Second branch path 250b Connection flow path 260 Sixth path P Branch point after air cooling Q Second branch point Ve Vehicle

Claims (1)

In an electric motor cooling device mounted on a vehicle including an internal combustion engine, a first electric motor, and a second electric motor,
A refrigerant source for storing a refrigerant for cooling each electric motor;
A mechanical oil pump that is driven by the internal combustion engine and sucks refrigerant from the refrigerant source and discharges it from a discharge port;
A first flow path that is connected to a discharge port of the mechanical oil pump and supplies the refrigerant discharged by the mechanical oil pump to the first electric motor;
An air-cooled cooler that is connected to the mechanical oil pump via a first branch path branched from the first flow path, and that cools the refrigerant discharged from the mechanical oil pump;
A second flow path connected to the air cooling cooler and for supplying the first electric motor with the refrigerant after being air cooled by the air cooling cooler;
A third flow path for branching from the second flow path and supplying the refrigerant after being cooled by the air cooling cooler to the second electric motor;
An electric oil pump connected in parallel to the mechanical oil pump with respect to the refrigerant source, and sucking refrigerant from the refrigerant source and discharging it from a discharge port;
A water-cooled cooler that water-cools the refrigerant discharged from the electric oil pump;
A fourth flow path that is connected to the water-cooled cooler and that discharges the refrigerant after being water-cooled by the water-cooled cooler inside the case that houses the first motor and the second motor;
A first check valve provided on the mechanical oil pump side from a branch point branched from the first flow path to the first branch path;
A second branch path branched from the flow path between the electric oil pump and the water-cooled cooler and connected to the first branch path;
A second check valve provided in the second branch path;
The refrigerant discharged from the electric oil pump is pumped between when the mechanical oil pump and the electric oil pump are driven and when the mechanical oil pump is stopped and the electric oil pump is driven. Switching means for switching the flow path,
The air cooling cooler is connected to the electric oil pump via the first branch path and the second branch path, and cools the refrigerant discharged from the electric oil pump,
When the mechanical oil pump and the electric oil pump are driven, the switching unit causes the refrigerant discharged from the electric oil pump to be pumped to a path reaching the inside of the case via the water-cooled cooler,
When the mechanical oil pump is stopped and the electric oil pump is driven, the refrigerant discharged from the electric oil pump by the switching means passes through the air cooling cooler and the first electric motor and the second electric motor. An electric motor cooling device characterized by being pumped to a route leading to the motor.

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