Drive system

Abstract

The present invention aims to efficiently preheat and maintain the temperature of a catalyst. The present invention relates to a drive system comprising: an internal combustion engine; a catalyst unit that purifies exhaust gas from the internal combustion engine; a motor used for at least one of driving and regeneration; and a flow path formed so that an oily medium that lubricates the motor flows near the catalyst unit. The oily medium is heated by the motor and then heat is exchanged in the catalyst unit, thereby heating the catalyst unit.

Description

Technical Field

[0001] The present invention relates to a drive system, and more particularly to a drive system having a motor and an engine. Background Art

[0002] In vehicles equipped with an engine, the three-way catalyst is preheated by the high-temperature exhaust gas from the engine. On the other hand, in hybrid vehicles equipped with both an engine and a motor, the engine is used less frequently for driving, resulting in insufficient preheating of the three-way catalyst by the exhaust gas. This lowers the catalyst temperature and reduces exhaust gas purification performance.

[0003] As background technology in this technical field, there is Patent Document 1 (Japanese Patent Laid-Open No. 6-276614). Patent Document 1 describes a hybrid vehicle drive device (see Claim 1), characterized by comprising: a generator that is driven by an engine to generate electricity; a battery that converts the output of the generator into direct current and stores it; an electric motor that generates driving force using the generator and the battery as power sources; a power conversion control device that controls the electric motor; a heating unit that recovers heat generated by the power conversion control device and the electric motor to heat engine-related parts; a temperature detection unit that detects the temperature of the engine-related parts; and a refrigerant flow path switching unit that switches the flow path of the refrigerant in the heating unit based on the temperature detected by the temperature detection unit.

[0004] In addition, patent document 2 describes a temperature raising device (refer to claim 1), which is characterized in that it comprises: a retarder that applies braking force to the drive system of the vehicle when the vehicle decelerates; an exhaust pipe that circulates exhaust gas from the engine installed in the vehicle; an exhaust gas purification device that is arranged on the exhaust pipe and contains an exhaust gas purification catalyst in a cover; a refrigerant circulation pipe that includes a first heat exchange pipe portion installed on the outer periphery of the retarder, a second heat exchange pipe portion installed on the outer periphery of the cover or on the outer periphery of the exhaust pipe on the upstream side of the cover, a first connecting pipe portion connecting the outlet portion of the first heat exchange pipe portion and the inlet portion of the second heat exchange pipe portion, and a second connecting pipe portion connecting the outlet portion of the second heat exchange pipe portion and the inlet portion of the first heat exchange pipe portion, and a refrigerant is sealed in the interior thereof; and a pump that is driven when the retarder is operating to pressurize and circulate the refrigerant into the refrigerant circulation pipe.

[0005] In addition, patent document 3 describes a hybrid vehicle (refer to claim 1), which includes a self-ignition gasoline engine, an electric generator and a battery for driving the electric generator, and the output torque of the engine and the electric generator is transmitted to the drive wheels via a transmission. The hybrid vehicle is characterized in that it includes: a first chamber and a second chamber, which are arranged in series upstream of the intake passage of the engine; a unit for absorbing waste heat from at least one of the engine, the electric generator and the transmission; a unit for guiding the absorbed waste heat to the first chamber to increase the intake air temperature in the first chamber; and a unit for using the electric energy supplied from the battery to increase the intake air temperature in the second chamber.

[0006] Prior art literature

[0007] Patent Literature

[0008] Patent Document 1: Japanese Patent Application Laid-Open No. 6-276614

[0009] Patent Document 2: Japanese Patent Application Laid-Open No. 2017-227163

[0010] Patent Document 3: Japanese Patent Application Laid-Open No. 2000-265910 Summary of the Invention

[0011] Problems to be solved by the invention

[0012] In the prior art described above, engine cooling water is used for preheating. Consequently, the catalyst temperature does not rise sufficiently due to the relatively low cooling water temperature of approximately 65°C to 90°C, resulting in poor preheating and heat retention. Therefore, the industry is looking for a drive system that can more efficiently preheat and retain the catalyst.

[0013] Technical means to solve the problem

[0014] A representative example of the invention disclosed in this application is shown below. Specifically, a drive system is characterized by comprising: an internal combustion engine; a catalyst unit that purifies exhaust gas from the internal combustion engine; a motor used for at least one of driving and regeneration; and a flow path formed so that an oily medium that lubricates the motor flows near the catalyst unit; the oily medium is heated by the motor and exchanges heat in the catalyst unit, thereby heating the catalyst unit.

[0015] Effects of the Invention

[0016] According to one aspect of the present invention, it is possible to reduce the amount of fuel consumed for preheating and heat preservation of the catalyst. Other problems, configurations, and effects than those described above will become clearer through the following description of the embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a diagram showing the configuration of a vehicle drive system according to the first embodiment of the present invention.

[0018] Figure 2 It is a diagram showing the structure of the catalytic converter of this embodiment.

[0019] Figure 3 It is a diagram showing the structure of the catalytic converter of this embodiment.

[0020] Figure 4 It is a diagram showing the structure of the catalytic converter of this embodiment.

[0021] Figure 5 It is a diagram showing the structure of the catalytic converter of this embodiment.

[0022] Figure 6 This is a flowchart showing an example of control of the drive system of this embodiment.

[0023] Figure 7 Graph showing changes in catalyst temperature in the drive system of this embodiment.

[0024] Figure 8 Graph showing changes in catalyst temperature in the drive system of this embodiment.

[0025] Figure 9 A diagram showing the configuration of a vehicle drive system according to a second embodiment of the present invention.

[0026] Figure 10 A diagram showing the configuration of a vehicle drive system according to a third embodiment of the present invention. DETAILED DESCRIPTION

[0027] <Example 1>

[0028] Figure 1 It is a diagram showing the configuration of a vehicle drive system according to the first embodiment of the present invention.

[0029] The drive system of this embodiment is composed of a motor 1 , a gear assembly 3 arranged along the output direction of the motor 1 , an engine 4 , and a control device 5 .

[0030] The motor 1 is provided with a rotor 11 on the inner circumference of the stator 10, and a winding 12 is wound on the stator 10. The type of motor 1 may be a permanent magnet motor having permanent magnets, a synchronous motor having an excitation winding, an induction motor having a cage conductor, a reluctance motor formed only by a rotor core, etc. The components used to generate a magnetic field from the rotor and their shapes are not limited. The stator 10 is fixed to the inner circumference of the housing 16 by shrink fit or the like. The housing 16 is formed by low-pressure casting or die casting, etc., and includes a bracket for supporting the bearing, and its shape and size are not limited. The winding 12 is formed by distributed winding or concentrated winding. The winding 12 can be composed of square wire or round wire. The winding method and type of the winding are not limited.

[0031] Motor 1 uses the current and voltage output from inverter 2 to flow current through winding 12 and generate a rotating magnetic field, causing rotor 11 to rotate and generate torque. Rotor 11 is connected to gear assembly 3 via shaft 17, and gear output shaft 23 inside gear assembly 3 is connected to the axle, thereby driving the vehicle. In addition, motor 1 can also be used for regeneration, using the vehicle's kinetic energy to generate electrical energy, rather than for driving, converting electrical energy into vehicle kinetic energy, or for both driving and regeneration. In addition, motor 1 can be cooled by a refrigerant such as water. In this case, lubricating oil 30 should be heated to a temperature higher than that of the refrigerant.

[0032] The gear assembly 3 is configured by arranging a plurality of gears 22 inside a gear case 21 , and the gear ratio of the gears 22 is configured to reduce the rotational speed of the motor 1 . Figure 1 In the figure, gear 22 is composed of parallel-axis spur gears. However, gear 22 may also be a single planetary gear or a combination of planetary gears and spur gears. Whether it is a parallel-axis or single-axis configuration, and the gear ratio, are not limited. Furthermore, although not shown in the figure, a differential is typically provided between gear assembly 3 and the axle.

[0033] like Figure 1 Lubricating oil 30, shown in medium gray, accumulates in the lower portion of the gear assembly 3. Lubricating oil 30 communicates between the motor 1 and the gear assembly 3, lubricating and cooling the motor 1 and the gear 22. Gear 22 within the gear assembly 3 is partially immersed in lubricating oil 30. As gear 22 rotates, lubricating oil 30 spreads throughout the gear assembly 3, lubricating the gear 22.

[0034] Engine 4 is an internal combustion engine with pistons within cylinders, generating torque for driving and / or driving a generator. A catalytic converter 44 is installed in the exhaust pipe 43. The three-way catalyst within catalytic converter 44 is unable to fully purify exhaust gas at low temperatures, requiring the catalyst temperature to exceed 500°C. Furthermore, the exhaust gas temperature of engine 4 ranges widely, from approximately 200°C at idle to approximately 800°C at full load. Therefore, the catalyst cannot fully purify the exhaust gas during low-temperature startup.

[0035] Therefore, in the drive system of this embodiment, an oil passage is provided for circulating the lubricating oil 30 between the gear assembly 3 and the catalytic converter 44 .

[0036] The oil circuit in this embodiment consists of an oil circuit 51 and an oil circuit 52. The oil circuit 51 directs the lubricating oil 30 from the gear assembly 3 to the catalytic converter 44, while the oil circuit 52 returns the lubricating oil 30 from the catalytic converter 44 to the motor 1. The oil circuit 52 is preferably arranged to extend downward from the catalytic converter 44, allowing the lubricating oil 30 within the catalytic converter 44 to escape under gravity. A pump 59 is provided in the oil circuit 52 to circulate the lubricating oil 30. The pump 59 preferably operates when the temperature of the catalytic converter 44 is lower than the oil temperature. Details of its operating conditions will be described later. The pump 59 is preferably located downstream of the catalytic converter 44 to pump any lubricating oil 30 accumulated within the catalytic converter 44. Furthermore, since the lubricating oil 30 cooled by the catalytic converter 44 flows to the pump 59, hot lubricating oil 30 does not flow into the pump 59, allowing the pump 59 to be operated with minimal thermal load. The lubricating oil 30 returning to the motor 1 from the oil passage 52 can be directly applied to the windings 12 of the motor 1. Alternatively, the lubricating oil 30 ejected from the oil passage 52 can be accumulated within the motor 1 to cool the windings 12. Furthermore, the windings 12 that come into contact with the lubricating oil 30 are preferably positioned toward a position extending from the outer periphery of the stator 10 (the coil end). The lubricating oil 30 that cools the motor 1 is heated by the windings 12, then flows through the communication passage between the motor 1 and the gear assembly 3 and accumulates in the lower portion of the gear assembly 3.

[0037] In this embodiment, the lubricating oil 30 cools the coil of the motor 1, lubricates the gear 22, and is then directed to the catalytic converter 44. Therefore, the gear 22 is lubricated by the high-temperature (i.e., low-viscosity) lubricating oil 30. The high-temperature lubricating oil 30 then supplies heat to the catalyst.

[0038] Three temperature sensors 61 to 63 are provided in the drive system of this embodiment. The temperature sensor 61 is provided in the motor 1 to measure the temperature of the winding 12. The temperature sensor 62 is provided in the gear assembly 3 to measure the temperature (oil temperature) of the lubricating oil 30. The temperature sensor 63 is provided in the catalytic converter 44 to measure the temperature of the catalyst. In this embodiment, the pump 59 is switched on / off according to the temperature of each part measured by the sensors 61 to 63 to operate. In addition, in other embodiments described later, in addition to the on / off of the pump 59, the opening and closing of the valve are also controlled according to the temperature of each part measured by the sensors 61 to 63.

[0039] The control device 5 is composed of a computer (microcomputer) including a calculation device, a memory, and an input / output device. The control device 5 may be provided separately from the inverter 2 or provided within the inverter 2 that controls the motor 1.

[0040] The computing device includes a processor that executes the program stored in the memory. Part of the processing performed by the computing device executing the program can also be performed by other computing devices (such as hardware such as FPGA (Field Programmable Gate Array) and ASIC (Application Specific Integrated Circuit)).

[0041] The memory includes ROM and RAM, which are non-volatile storage elements. ROM stores unchanging programs (such as BIOS). RAM, which is a high-speed, volatile storage element such as DRAM (Dynamic Random Access Memory) and a non-volatile storage element such as SRAM (Static Random Access Memory), stores programs executed by the computing device and data used during program execution. Programs executed by the computing device are stored in the non-volatile storage device of the control device 5, which serves as a non-transitory storage medium.

[0042] The input / output device is an interface that sends processing content to the outside or receives data from the outside according to a prescribed protocol.

[0043] Figures 2 to 5 3 is a diagram showing the structure of the catalytic converter 44 of this embodiment.

[0044] Figure 2 In the illustrated catalytic converter 44, the sidewalls of a housing 441, which houses a catalyst 442 and allows exhaust gas to pass through, have a double-layer structure. An oil passage 443 for lubricating oil 30 is provided within the housing 441. The oil passage 443 has an inlet 445 for lubricating oil 30 to flow in the direction of exhaust gas inflow (indicated by arrow 440), and an outlet 446 for lubricating oil 30 to flow out in the direction of exhaust gas outflow. An air layer 444 is provided between the housing 441 and the catalyst 442. The air layer 444 acts as a thermal insulator to prevent the catalyst 442 from rapidly increasing in temperature due to the high-temperature lubricating oil 30 or from becoming overheated due to the high-temperature exhaust gas.

[0045] Figure 3In the catalytic converter 44 shown, the sidewalls of the housing 441, which houses the catalyst 442 and allows exhaust gas to pass through, have a double-layer structure. An oil channel 443 for the lubricating oil 30 is provided within the housing 441. Arrow 440 in the figure indicates the direction of exhaust gas flow. The housing 441 is provided with an inlet 445 for the lubricating oil 30 to flow in radially, and an outlet 446 for the lubricating oil 30 to flow out radially. An air layer 444 is provided between the housing 441 and the catalyst 442. The air layer 444 functions as a thermal insulator to prevent the catalyst 442 from rapidly increasing in temperature due to the high temperature of the lubricating oil 30, or to prevent the lubricating oil 30 from becoming too hot due to the high temperature of the exhaust gas.

[0046] Figure 4 In the illustrated catalytic converter 44, an oil passage 443 for lubricating oil 30 is provided along the inner surface of a sidewall of a housing 441 that houses a catalyst 442 and allows exhaust gas to pass through. Oil passage 443 is provided with an inlet 445 for allowing lubricating oil 30 to flow in the direction of exhaust gas inflow (indicated by arrow 440), and an outlet 446 for allowing lubricating oil 30 to flow out in the direction of exhaust gas outflow. Figure 4 The illustrated catalytic converter 44 does not have an air layer, but is controlled so that a sufficient amount of lubricating oil 30 flows, thereby preventing the lubricating oil 30 from being heated to a high temperature even without providing an air layer.

[0047] Figure 5 In the illustrated catalytic converter 44, a spirally structured oil passage 443 is provided within a housing 441. The oil passage 443 may be provided on the inner or outer side of the housing 441. An inlet 445 for the lubricating oil 30 to flow in and an outlet 446 for the lubricating oil 30 to flow out are provided at the ends of the oil passage 443. Figure 5 The catalytic converter 44 shown may or may not have an air layer. Furthermore, arrows 440 in the figure indicate the flow direction of the exhaust gas.

[0048] Figure 6 This is a flowchart showing an example of control of the drive system of this embodiment.

[0049] When the ignition switch is detected to be turned on, the control of the drive system in this flowchart starts (101).

[0050] Thereafter, the control device 5 determines whether the engine 4 is stopped (102). Furthermore, in step 102, the time elapsed from the most recent start of the engine 4 until the catalyst 442 is sufficiently heated may be determined. If the engine 4 is operating, it is inferred that the catalyst 442 is being heated by exhaust gas, and thus this process is terminated.

[0051] On the other hand, if the engine 4 is stopped, it is estimated that the catalyst 442 is cooling, so it is determined whether the temperature of the catalyst 442 is below a predetermined threshold value (e.g., 550° C.) (103). If the temperature of the catalyst 442 is higher than the predetermined threshold value, it is not necessary to heat the catalyst 442, so the process ends.

[0052] On the other hand, if the temperature of the catalyst 442 is below the predetermined threshold, it is necessary to heat the catalyst 442, so it is determined whether the temperature of the lubricating oil 30 is above the predetermined threshold (104). If the temperature of the lubricating oil 30 is below the predetermined threshold, it is impossible to heat the catalyst 442, so the process ends. Alternatively, instead of comparing the temperature of the catalyst 442 and the oil temperature with the predetermined thresholds in steps 103 and 104, it is possible to determine whether the temperature of the lubricating oil 30 is higher than the temperature of the catalyst 442. If the temperature of the lubricating oil 30 is higher than the temperature of the catalyst 442, the process proceeds to step 105.

[0053] On the other hand, if the temperature of the lubricating oil 30 is higher than the predetermined threshold, the catalyst 442 can be heated, so it is determined whether the temperature of the winding 12 is higher than the predetermined threshold (105). If the temperature of the winding 12 is lower than the predetermined threshold, the lubricating oil 30 cannot be heated, and thus the catalyst 442 cannot be heated, so this process ends.

[0054] On the other hand, if the temperature of the winding 12 is above the specified threshold, the lubricating oil 30 can be heated, so the pump 59 is operated to circulate the lubricating oil 30 in the oil circuit (106), and the motor 1 is cooled by the lubricating oil 30 after being cooled by the catalytic converter 44 (107), and the gear 22 is lubricated by the lubricating oil 30 after being heated by the motor 1 (108), and the lubricating oil 30 after being heated by the motor 1 is circulated to the catalytic converter 44, heating the catalyst 442 and raising the temperature (109).

[0055] Specifically, pump 59 is controlled to operate before catalyst 442 is heated up. After catalyst 442 is preheated, pump 59 is controlled to operate when the coil temperature reaches a level sufficient to preheat catalyst 442. Furthermore, if insufficiently cooled high-temperature lubricating oil 30 is circulated after catalyst 442 has heated up, the winding 12 may reach a high temperature, potentially burning the winding 12. Therefore, if the temperature of lubricating oil 30 is high, control must be performed to circulate a large amount of lubricating oil 30 to lower the temperatures of the lubricating oil 30 and winding 12.

[0056] Figure 7 、 Figure 8 Graph showing temperature changes of the catalyst 442 in the drive system of this embodiment.

[0057] like Figure 7As shown, when engine 4 is running, catalyst 442 is preheated to over 550°C by the exhaust gas from engine 4. However, when engine 4 is stopped, the temperature of catalyst 442 drops. Subsequently, as engine 4 is repeatedly started and stopped, the temperature of catalyst 442 fluctuates. However, in this embodiment, if motor 1 is running even when engine 4 is stopped, the heat generated by winding 12 preheats catalyst 442, maintaining the temperature of catalyst 442 at approximately 100°C. Therefore, compared to conventional catalyst temperature control, as shown by the dashed line, the time it takes for catalyst 442 to rise in temperature during engine 4 startup can be shortened.

[0058] In addition, if Figure 8 As shown, when the engine 4 is stopped and the temperature of the catalyst 442 drops to a predetermined threshold value (circulation determination temperature), the pump 59 can be operated to preheat the catalyst 442. By preheating the catalyst 442 in such a manner as to prevent the temperature of the catalyst 442 from dropping to room temperature and maintaining the temperature of the catalyst 442 at approximately 100°C, the time it takes for the temperature of the catalyst 442 to rise can be shortened when the engine 4 is started.

[0059] As described above, in the first embodiment, during extended EV driving (when the engine 4 is stopped), the lubricating oil 30 of the gear assembly 3, heated by the motor 1, can be flowed to the catalytic converter 44 to preheat and maintain the temperature of the catalyst 442. Therefore, the operation of the pump 59 is switched based on the temperature of the catalyst 442, the temperature of the lubricating oil 30, and the temperature of the winding 12, thereby circulating the lubricating oil 30.

[0060] Furthermore, the motor 1 can be cooled without providing a heat exchanger for cooling the lubricating oil 30 heated by the motor 1 .

[0061] Furthermore, the time it takes for the temperature of catalyst 442 to rise can be shortened, eliminating the need for preheating the catalytic converter 44, thereby reducing fuel and power consumption. In particular, in electric vehicles equipped with an internal combustion engine, such as PHEVs, if the internal combustion engine is stopped for a long time, the exhaust gas will not be able to increase the temperature of catalyst 442, causing the temperature of catalyst 442 to drop. However, in this embodiment, catalyst 442 can be maintained at a temperature higher than normal, even if the engine 4 is stopped for a long time or a large number of times.

[0062] <Example 2>

[0063] Figure 9 A diagram showing the configuration of a vehicle drive system according to a second embodiment of the present invention.

[0064] The drive system of the second embodiment is provided with a bypass oil passage 53 and a radiator 55 in the oil passage.

[0065] In the second embodiment, the configuration different from the first embodiment described above will be mainly described, and the description of the configuration having the same function as the first embodiment will be omitted.

[0066] The drive system of this embodiment is composed of a motor 1 , a gear assembly 3 , an engine 4 and a control device 5 .

[0067] The oil circuit in this embodiment consists of an oil circuit 51, an oil circuit 52, and a bypass oil circuit 53. The oil circuit 51 directs the lubricating oil 30 from the gear assembly 3 to the catalytic converter 44. The oil circuit 52 returns the lubricating oil 30 from the catalytic converter 44 to the motor 1. The bypass oil circuit 53 bypasses the catalytic converter 44 and connects the oil circuit 51 and the oil circuit 52. A valve 56 is provided at the junction of the oil circuit 51 and the bypass oil circuit 53. When the valve 56 is open, the lubricating oil 30 from the gear assembly 3 flows into the catalytic converter 44. When the valve 56 is closed, the lubricating oil 30 from the gear assembly 3 flows into the bypass oil circuit 53 without flowing into the catalytic converter 44.

[0068] The oil passage 52 is preferably arranged to extend downward from the catalytic converter 44, allowing the lubricating oil 30 within the catalytic converter 44 to escape under gravity. A radiator 55 is provided in the oil passage 52 to cool the lubricating oil 30 heated by the motor 1. Furthermore, a pump 59 is provided downstream of the radiator 55 in the oil passage 52 to circulate the lubricating oil 30. As described above in Example 1, the pump 59 is preferably operated when the temperature of the catalytic converter 44 is lower than the oil temperature. The pump 59 is preferably provided downstream of the catalytic converter 44 to pump the lubricating oil 30 accumulated within the catalytic converter 44. The lubricating oil 30 returning from the oil passage 52 to the motor 1 can be directly poured onto the windings 12 of the motor 1, or the lubricating oil 30 ejected from the oil passage 52 can be accumulated within the motor 1 to cool the windings 12. Furthermore, the windings 12 that come into contact with the lubricating oil 30 are preferably arranged toward a position (coil end) extending from the outer periphery of the stator 10. The lubricating oil 30 that has cooled the motor 1 is heated by the winding 12 , passes through the communication passage between the motor 1 and the gear assembly 3 , and accumulates in the lower portion of the gear assembly 3 .

[0069] In this embodiment, the lubricating oil 30 cools the coils of the motor 1, then lubricates the gear 22 and is directed to the catalytic converter 44. Therefore, the gear 22 is lubricated by the high-temperature (i.e., low-viscosity) lubricating oil 30. The high-temperature lubricating oil 30 then provides heat to the catalyst. Furthermore, when the catalytic converter 44 reaches a high temperature, the valve 56 is closed, allowing the lubricating oil 30 from the gear assembly 3 to bypass the catalytic converter 44 and flow to the bypass oil passage 53. This prevents the lubricating oil 30 from contacting the high-temperature catalyst 442, thus suppressing degradation of the lubricating oil 30.

[0070] Furthermore, since the radiator 55 is provided downstream of the catalytic converter 44, the lubricating oil 30, which has been heated by the motor 1, can transfer heat to the catalytic converter 44 before dissipating the heat in the radiator 55. Furthermore, the lubricating oil 30, having been cooled by the catalytic converter 44, is further cooled in the radiator 55, thereby improving the cooling efficiency of the motor 1.

[0071] Furthermore, since the pump 59 is provided downstream of the radiator 55 , the lubricating oil 30 cooled by the radiator 55 flows to the pump 59 , and the high-temperature lubricating oil 30 does not flow to the pump 59 , thereby enabling the pump 59 to be driven with a low temperature load.

[0072] <Example 3>

[0073] Figure 10 A diagram showing the configuration of a vehicle drive system according to a third embodiment of the present invention.

[0074] The drive system of embodiment 3 is provided with a circulating oil passage 54 and a radiator 55 in the oil passage. In embodiment 3, the configurations different from those of embodiments 1 and 2 described above are mainly described, and the description of configurations having the same functions as embodiments 1 and 2 is omitted.

[0075] The oil circuit in this embodiment consists of an oil circuit 51, an oil circuit 52, and a circulating oil circuit 54. The oil circuit 51 directs the lubricating oil 30 from the gear assembly 3 to the catalytic converter 44. The oil circuit 52 returns the lubricating oil 30 from the catalytic converter 44 to the motor 1. The circulating oil circuit 54 circulates the lubricating oil 30 to a radiator 55. A valve 57 is provided upstream of the catalytic converter 44. When the valve 57 is open, the lubricating oil 30 from the gear assembly 3 flows into the catalytic converter 44. When the valve 57 is closed, the lubricating oil 30 from the gear assembly 3 does not flow into the catalytic converter 44.

[0076] The oil passage 52 is preferably arranged to extend downward from the catalytic converter 44, allowing the lubricating oil 30 within the catalytic converter 44 to escape under gravity. A radiator 55 is provided in the oil passage 52 to cool the lubricating oil 30 heated by the motor 1. Furthermore, a pump 59 is provided downstream of the radiator 55 in the oil passage 52 to circulate the lubricating oil 30. As described above in Example 1, the pump 59 is preferably operated when the temperature of the catalytic converter 44 is lower than the oil temperature. The pump 59 is preferably provided downstream of the catalytic converter 44 to pump the lubricating oil 30 accumulated within the catalytic converter 44. The lubricating oil 30 returning from the oil passage 52 to the motor 1 can be directly poured onto the windings 12 of the motor 1, or the lubricating oil 30 ejected from the oil passage 52 can be accumulated within the motor 1 to cool the windings 12. Furthermore, the windings 12 that come into contact with the lubricating oil 30 are preferably arranged toward a position (coil end) extending from the outer periphery of the stator 10. The lubricating oil 30 that has returned to the motor 1 is heated by the winding 12 , passes through the communication passage between the motor 1 and the gear assembly 3 , and is retained in the lower portion of the gear assembly 3 .

[0077] The circulating oil circuit 54 is configured to connect the oil circuit 52 near the outlet of the lubricating oil 30 of the catalytic converter 44 with the outlet of the lubricating oil 30 of the radiator 55. A valve 58 is provided midway along the circulating oil circuit 54. A circulation pump may also be provided midway along the circulating oil circuit 54. Normally, when the lubricating oil 30 is circulating, the valve 58 is closed. However, when the catalytic converter 44 reaches a high temperature and the lubricating oil 30 has already reached a high temperature, the valve 57 is closed and the valve 58 is opened. This allows the radiator 55 to efficiently cool the heated lubricating oil 30. Meanwhile, when the temperature of the lubricating oil 30 drops, the valve 57 is opened and the valve 58 is closed. This allows the lubricating oil 30 to circulate through the catalytic converter 44 and the radiator 55, cooling the lubricating oil 30 heated by the motor 1.

[0078] In this embodiment, the lubricating oil 30 cools the coils of the motor 1, then lubricates the gear 22 and is directed to the catalytic converter 44. Therefore, the gear 22 is lubricated by the high-temperature (i.e., low-viscosity) lubricating oil 30. The high-temperature lubricating oil 30 then supplies heat to the catalyst. Furthermore, when the catalytic converter 44 reaches a high temperature, the lubricating oil 30 is circulated to the radiator 55 via the circulating oil passage 54, effectively cooling the lubricating oil 30 and preventing degradation of the lubricating oil 30.

[0079] Furthermore, since the radiator 55 is provided downstream of the catalytic converter 44, the lubricating oil 30, which has been heated by the motor 1, can transfer heat to the catalytic converter 44 before dissipating the heat in the radiator 55. Furthermore, the lubricating oil 30, having been cooled by the catalytic converter 44, is further cooled in the radiator 55, thereby improving the cooling efficiency of the motor 1.

[0080] Furthermore, since the pump 59 is provided downstream of the radiator 55 , the lubricating oil 30 cooled by the radiator 55 flows to the pump 59 , and the high-temperature lubricating oil 30 does not flow to the pump 59 , thereby enabling the pump 59 to be driven with a low temperature load.

[0081] As described above, the drive system according to an embodiment of the present invention includes an internal combustion engine (engine 4), a catalyst unit (catalytic converter 44), a motor 1, and flow paths (oil paths 51, 52, 53). The catalyst unit (catalytic converter 44) purifies exhaust gas from the internal combustion engine. The motor 1 is used for at least one of driving and regeneration. The flow paths (oil paths 51, 52, 53) are formed to allow an oily medium (lubricating oil 30) that lubricates the motor 1 to flow near the catalyst unit (catalyst 442). The oily medium 30 is heated by the motor 1 and heat is exchanged in the catalytic converter 44, thereby heating the catalyst 442. Therefore, by using the oily medium 30, which is hotter than water, the preheating efficiency of the catalytic converter 44 can be improved, allowing the catalytic converter 44 to be quickly preheated to a high temperature and then maintained, compared to preheating and maintaining the temperature at 65°C to 90°C or less using a water-cooled refrigerant. This reduces fuel consumption for preheating and maintaining the temperature of the catalytic converter 44.

[0082] Furthermore, the gear assembly 3 is provided, which transmits the output of the motor 1 via the gears 22. Lubricating oil 30, which lubricates the gears 22, serves as the oily medium. Specifically, by circulating transmission oil through the catalytic converter 44, the catalytic converter 44 is preheated and its temperature is raised. After cooling the windings 12 of the motor 1, the lubricating oil 30 is supplied to the transmission and then introduced into the catalytic converter 44. This allows the lubricating oil 30 to maintain a high temperature while preheating the catalytic converter 44. Compared to direct introduction of lubricating oil 30 from the motor 1 into the catalytic converter 44, the gear assembly 3 can be lubricated using the high-temperature, low-viscosity lubricating oil 30, thereby reducing lubrication resistance within the gear assembly 3.

[0083] Furthermore, the oil medium 30 contacts the winding 12 of the motor 1 and is heated by cooling the winding 12 , thereby increasing the temperature of the oil medium 30 . This reduces the lubrication resistance of the gear assembly 3 and uses the heat to preheat the catalyst 442 .

[0084] Furthermore, the motor 1 is cooled by the refrigerant, and the oily medium 30 is heated to a temperature higher than that of the refrigerant. Therefore, compared with the case where the catalytic converter 44 is preheated using a water-cooled refrigerant, the catalytic converter 44 can be preheated to a high temperature and kept warm by using the oily medium 30.

[0085] In addition, valves 56 and 57 are provided, and the valves 56 and 57 are controlled in such a manner that the oily medium 30 does not flow to the vicinity of the catalyst 442 when the temperature of the catalyst 442 is higher than a predetermined threshold value. Therefore, the lubricating oil 30 can be prevented from becoming hot without the need for preheating, thereby suppressing the deterioration of the lubricating oil 30.

[0086] Furthermore, a pump 59 is provided for circulating the oily medium 30. The pump 59 is controlled so as not to flow the oily medium 30 near the catalyst 442 when the temperature of the motor 1 is lower than a predetermined threshold value. This reduces energy consumption caused by the pump 59 when preheating is not possible.

[0087] Furthermore, the present invention encompasses various variations and equivalent configurations within the spirit of the appended claims and is not limited to the aforementioned embodiments. For example, the aforementioned embodiments are provided for the purpose of providing a detailed description of the present invention in an easily understandable manner, and the present invention is not necessarily limited to all of the configurations described. Furthermore, a portion of the configuration of one embodiment may be replaced with a configuration of another embodiment. Furthermore, a configuration of another embodiment may be added to a configuration of one embodiment. Furthermore, a portion of the configuration of each embodiment may be supplemented with, deleted from, or replaced with another configuration.

[0088] In addition, the various structures, functions, processing units, processing methods, etc. described above can be partially or entirely implemented in hardware, for example, by designing using integrated circuits, or can be implemented in software by having a processor interpret and execute programs that implement various functions.

[0089] Information such as programs, tables, and files that implement various functions can be stored in storage devices such as memories, hard disks, and SSDs (Solid State Drives), or recording media such as IC cards, SD cards, and DVDs.

[0090] Furthermore, the control lines and information lines shown are those considered necessary for explanation, and do not necessarily show all the control lines and information lines required for installation. In reality, it is assumed that almost all components are connected to each other.

[0091] Explanation of symbols

[0092] 1…Motor

[0093] 3…Gear assembly

[0094] 4…Engine

[0095] 5…Control device

[0096] 10…stator

[0097] 11…Rotor

[0098] 12…Winding

[0099] 16…Case

[0100] 17…Rotary shaft

[0101] 21…Gearbox

[0102] 22…Gear

[0103] 23…Gear output shaft

[0104] 30…lubricating oil

[0105] 43…Exhaust pipe

[0106] 44…Catalytic converter

[0107] 51, 52, 53…Oil lines

[0108] 53…Circular oil route

[0109] 54… Oil circulation circuit

[0110] 55…Radiator

[0111] 56, 57, 58… valves

[0112] 59…Pump

[0113] 61, 62, 63…temperature sensors.

Claims

1. A drive system, characterized in that: have: internal combustion engine; a catalyst unit for purifying exhaust gas from the internal combustion engine; a motor for at least one of driving and regeneration; as well as a flow path formed so that the oil medium for lubricating the motor flows to the vicinity of the catalyst portion, The catalyst unit includes: a housing for accommodating the catalyst and allowing exhaust gas to pass through; and an oil channel provided in the housing, wherein the oil channel is for the oil medium to flow. The oily medium is heated by the motor and exchanges heat in the catalyst portion, thereby heating the catalyst portion. An air layer is provided between the housing and the catalyst.

2. The drive system according to claim 1, characterized in that A gear assembly is provided for transmitting the output of the motor using gears, The oily medium is lubricating oil for lubricating the gears.

3. The drive system according to claim 1, characterized in that The oil medium contacts the windings of the motor and is heated by cooling the windings.

4. The drive system according to claim 1, characterized in that The motor is cooled by means of a refrigerant, The oil medium is heated to a temperature higher than that of the refrigerant.

5. The drive system according to claim 1, characterized in that: A valve is provided that is controlled so as not to allow the oily medium to flow near the catalyst portion when the temperature of the catalyst portion is higher than a predetermined threshold value.

6. The drive system according to claim 1, characterized in that: A pump is provided for circulating the oily medium in the flow path. The pump is controlled so as not to allow the oily medium to flow to the vicinity of the catalyst portion when the temperature of the motor is lower than a predetermined threshold value.

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