JP2005180261A - Cooling structure of power unit for hybrid vehicles - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cooling structure of a power unit for a hybrid vehicle provided with an internal combustion engine and a motor capable of effectively cooling a stator of the motor. <P>SOLUTION: In the power unit for the hybrid vehicle having the motor 3 put between the internal combustion engine 2 and a transmission 5 and generating power by either of the internal combustion engine 2 or the motor 3, the stator 30 of the motor 3 is combined with a main body 10 of the internal combustion engine 2. A downstream end of an oil return passage 28 in the internal combustion engine main body 10 opens toward the motor stator 30. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a cooling structure for a hybrid vehicle power unit including an electric motor and an internal combustion engine that can effectively cool a stator of the electric motor.

In Patent Document 1, in a hybrid vehicle power unit in which an electric motor is interposed between an internal combustion engine and a transmission, the internal combustion engine and the electric motor are cooled with cooling water cooled by a radiator.
JP 2001-73765 A

In the one described in Patent Document 1, a cooling system for cooling the electric motor is required in addition to the cooling system for cooling the internal combustion engine, and the motor cooling system requires high water tightness. There are many and the structure is complicated.

  The present invention aims to overcome the above-mentioned difficulties.

  According to a first aspect of the present invention, in the hybrid vehicle power unit in which an electric motor is interposed between the internal combustion engine and the transmission, and the motive power is generated by at least one of the internal combustion engine and the electric motor, the stator of the electric motor includes: The oil return passage is integrally connected to the main body of the internal combustion engine, and the downstream end of the oil return passage in the main body of the internal combustion engine is open toward the motor stator.

  According to a second aspect of the present invention, there is provided a hybrid vehicle power unit in which an electric motor is interposed between an internal combustion engine and a transmission, and power is generated by at least one of the internal combustion engine and the electric motor. The cooling water passage of the internal combustion engine is formed integrally with the main body of the internal combustion engine and extends into the motor housing.

  In the first aspect of the present invention, the oil after the lubrication of each lubrication portion of the internal combustion engine flows from the downstream end of the oil return passage toward the motor stator, and the motor stator is cooled by the oil. No special parts for guiding the motor to the motor stator are required, the structure is simplified, and the cost can be greatly reduced.

  Further, since the electric motor is not air-cooled but liquid-cooled with oil, the cooling effect is high, and since the cooling fluid is not water but oil, there is no fear of electric leakage in the electric system.

  In the invention described in claim 2, since the cooling water passage of the internal combustion engine is formed to extend in the motor housing integrally formed with the internal combustion engine body, there is no possibility that the cooling water leaks into the motor. The motor housing is cooled efficiently and reliably with cooling water.

  Further, there is no need for special parts for cooling the motor housing, the structure is simplified, and the cost can be reduced.

  Hereinafter, an embodiment of a cooling structure for a hybrid vehicle power unit according to the first aspect of the present invention will be described with reference to FIGS. 1 and 2.

  The hybrid vehicle power unit 1 includes a four-stroke cycle overhead valve type three-cylinder internal combustion engine 2 having an ignition plug, an electric motor 3 that also serves as a generator in which a rotor 31 is directly connected to a crankshaft 16 of the internal combustion engine 2, an internal combustion engine The clutch 4 transmits the power of the engine 2 and the electric motor 3 to the transmission 5 in a freely detachable manner, and the transmission 5 in which an input shaft 50 is coupled to a boss portion 48 of the clutch 4.

  In the internal combustion engine 2, the cylinder head 11 and the head cover 12 are overlaid on the upper surface of the cylinder block 10, and the oil pan 13 is applied to the lower surface of the cylinder block 10, and these cylinder block 10, cylinder head 11, head cover 12, and oil The pans 13 are joined together by bolts (not shown).

  Further, three cylinder holes 14 are formed in series in the cylinder block 10 in parallel with each other, and a piston 15 is slidably fitted in the cylinder hole 14 so as to be positioned immediately below the cylinder hole 14. A journal 16a of the crankshaft 16 is pivotally supported on the cylinder block 10 by a crankshaft holder 17, and is connected to a crankpin (not shown) of the crankshaft 16 and a piston pin (not shown) fitted to the piston 15. Both ends of 18 are rotatably connected, and the piston 15 is driven up and down by combustion of the air-fuel mixture sucked into the combustion chamber 19, so that the crankshaft 16 is rotationally driven.

  Further, the cylinder head 11 is formed with an intake port and an exhaust port (not shown), and an intake valve and an exhaust valve (not shown) for closing the open end of the intake port and the exhaust port on the combustion chamber 19 side so as to be openable and closable. A valve operating mechanism (not shown) such as a camshaft, a rocker arm, and the like that is provided to open and close the intake valve and the exhaust valve is disposed in a space surrounded by the head cover 12 on the cylinder head 11, and one end of the crankshaft 16 (see FIG. An endless chain 23 is placed between a drive sprocket 21 fitted to the left end (1) and a driven sprocket 22 fitted to one end of the shaft 20 connected to the camshaft, and the crankshaft 16 rotates. When driven, every time the crankshaft 16 makes two revolutions, the intake and exhaust valves are opened and closed at the required timing, and gas exchange in the combustion chamber 19 is performed appropriately. So that the crack.

  The cylinder block 10 and the cylinder head 11 are formed with a cooling water passage 24 (partially shown) for cooling the internal combustion engine body, particularly a portion surrounding the combustion chamber 19, and the cooling water cooled by a radiator (not shown). However, after passing through the coolant passage 24 by a water pump (not shown), the cylinder block 10 and the cylinder head 11 are cooled by returning to the radiator again.

The cylinder head 11 is detachably mounted with a spark plug 25 having an electrode portion 25a exposed in the combustion chamber 19.

  In addition, an oil passage (not shown) is formed in the cylinder block 10 and the cylinder head 11, and oil stored in the bottom of the oil pan 13 is sent to the oil filter 26 through an oil passage by an oil pump (not shown). The oil filtered in the oil filter 26 is supplied to lubrication parts such as the crankshaft 16, the cam and the rocker arm through another oil passage, and these lubrication parts are lubricated with oil. ing.

Further, an oil return passage 27 is formed in the cylinder block 10 and the cylinder head 11 to return the oil that has fallen on the upper surface of the cylinder head 11 by lubricating a valve mechanism such as a camshaft or a rocker arm, into the oil pan 13. An opening end of the oil discharge passage 28 communicating with the return passage 27 opens toward the stator 30 of the electric motor 3.
Note that all of the oil that has been lubricated and dropped onto the upper surface of the cylinder head 11 may be guided to the oil discharge passage 28.

  The stator 30 of the electric motor 3 is integrally mounted on the side wall of the cylinder block 10 of the internal combustion engine 2 by a bolt 33 via a bracket 32 that is integrally fixed to the stator 30. In the stator 30, a plurality of metal plates are laminated. In the core 34, notches (not shown) are formed at equal intervals in the circumferential direction from the central part toward the outer peripheral part, and a large number of electrode parts (not shown) directed from the outer peripheral part to the central direction are configured. A coil 36 is wound through a guide portion 35 having a U-shaped cross section.

  In addition, the rotor 31 disposed at the center of the stator 30 is integrally coupled to one end (right end in FIG. 2) of the crankshaft 16 by bolts 37, and the outer periphery of the rotor 31 has a core 34 of the stator 30. Permanent magnets 38 are integrally mounted at equal intervals in the circumferential direction relative to the tip, and by supplying an alternating current to the coil 36, power is generated from the motor 3 or power of the internal combustion engine 2 Thus, electric power is generated from the electric motor 3 by rotating the rotor 31.

  Further, a flywheel 40 is integrally attached to one end surface (right end surface in FIG. 2) of the rotor 31 by a bolt 41, and a pin 42 is provided to one end surface circular hole of the rotor 31 and the other end surface circular hole of the flywheel 40. The flywheel 40 is integrally connected to the rotor 31.

A ring gear 43 formed on the outer periphery of the flywheel 40 meshes with a drive gear integral with a rotation shaft of a starter motor (not shown), and the crankshaft 16 is connected to the crankshaft 16 via the rotor 31 with the power of the starter motor. The internal combustion engine 2 is started by rotating it.

  Furthermore, in the clutch 4 interposed between the flywheel 40 and the input shaft 50 of the transmission 5, two friction plates 44, a pressure plate 45, and a diamond frame spring 46 are adjacent to one end surface of the flywheel 40. The friction plate 44 on the side adjacent to the diamond frame spring 46 is connected to a boss portion 48 via a spring 47, and this boss portion 48 is splined to the input shaft 50 of the transmission 5. The hydraulic piston 49 is disposed on one end side of the diaphragm spring 46. When the hydraulic piston 49 protrudes, the pressure plate 45 is urged to approach the flywheel 40, and the two friction plates 44 are The clutch 4 is clutch-engaged by being strongly sandwiched between the flywheel 40 and the pressure plate 45.

  The embodiment shown in FIGS. 1 and 2 is configured as described above, and therefore, when the internal combustion engine 2 is in an operating state, an oil pump (not shown) is in an operating state and the oil accumulated in the bottom of the oil pan 13 is retained. Is supplied to the lubrication part of the internal combustion engine 2 by this oil pump, and these lubrication parts are lubricated by oil.

  Of this lubricating portion, part or all of the oil that has fallen on the upper surface of the cylinder head 11 by lubricating a valve operating mechanism including a camshaft provided on the cylinder head 11 and a rocker arm (not shown) is passed through the oil discharge passage 28. Then, it falls on the upper upper surface of the stator 30 of the electric motor 3 and flows downward along the peripheral surface of the stator 30, so that the stator 30 heated by the heat generated in the electric motor 3 is cooled by this oil.

  Since the stator 30 is not air-cooled but liquid-cooled with oil, the stator 30 is sufficiently cooled without the need for radiating fins or the like.

  Further, since the stator 30 of the electric motor 3 is adjacent to one end of the cylinder block 10 and is integrally attached to the cylinder block 10 via the bracket 32, the axial dimension of the hybrid vehicle power unit 1 is significantly shortened. Compact size is possible.

  Furthermore, since the stator 30 of the motor 3 can be sufficiently cooled only by forming the oil discharge passage 28 directed downward from the upper surface at one end of the cylinder block 10, no special parts are required and the structure As a result, the cost can be greatly reduced.

  Next, a cooling structure for a hybrid vehicle power unit according to the second aspect of the present invention will be described with reference to FIG.

  In the embodiment shown in FIGS. 1 and 2, the stator 30 and the cylinder block 10 of the electric motor 3 are separate structures, and the oil discharge passage 28 is formed in the cylinder block 10. In the embodiment, the housing 51 of the electric motor 3 is configured integrally with the cylinder block 10, and the stator cooling cooling water passage 52 communicating with the cooling water passage 24 of the cylinder block 10 is provided in the entire circumference of the stator 30. It is formed over.

Parts that are not changed in structure are given the same reference numerals as those used in the respective embodiments shown in FIGS.

  In the embodiment shown in FIG. 3, since the cooling water cooled by a radiator (not shown) passes through the cooling water passage 52, the stator 30 is uniformly and sufficiently cooled over the entire circumference.

  Also in this embodiment, since no special parts are required, the assemblability is good and the cost is low.

  In the embodiment of FIG. 3, the cooling water passage 24 provided in the cylinder block 10 and the cooling water passage 52 for stator cooling communicate with each other (not shown), but the cooling provided in the cylinder head 11. A structure in which the water passage 24 and the cooling water passage 52 for cooling the stator communicate with each other may be employed.

It is a side view of the hybrid vehicle power unit provided with the cooling structure of the invention of claim 1. It is a vertical side view of FIG. FIG. 5 is a longitudinal side view of a hybrid vehicle power unit equipped with a cooling structure according to a second aspect of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Hybrid vehicle power unit, 2 ... Internal combustion engine, 3 ... Electric motor, 4 ... Clutch, 5 ... Transmission,
10 ... Cylinder block, 11 ... Cylinder head, 12 ... Head cover, 13 ... Oil pan, 14 ... Cylinder hole, 15 ... Piston, 16 ... Crankshaft, 17 ... Crankshaft holder, 18 ... Connecting rod, 19 ... Combustion chamber,
20 ... shaft, 21 ... drive sprocket, 22 ... driven sprocket, 23 ... endless chain, 24 ... cooling water passage, 25 ... ignition plug, 26 ... oil filter, 27 ... oil return passage, 28 ... oil discharge passage,
30 ... Stator, 31 ... Rotor, 32 ... Bracket, 33 ... Bolt, 34 ... Core, 35 ... Guide, 36 ... Coil, 37 ... Bolt, 38 ... Permanent magnet, 40 ... Flywheel, 41 ... Bolt, 42 ... Pin , 43 ... Ring gear, 44 ... Friction plate, 45 ... Pressure plate, 46 ... Diamond frame spring, 47 ... Spring, 48 ... Boss, 49 ... Hydraulic piston, 50 ... Input shaft, 51 ... Housing, 52 ... Cooling for cooling the stator Water passage.

Claims (2)

In the hybrid vehicle power unit, wherein an electric motor is interposed between the internal combustion engine and the transmission, and power is generated by at least one of the internal combustion engine and the electric motor.
The stator of the electric motor is integrally coupled to the main body of the internal combustion engine,
The cooling structure for a hybrid vehicle power unit, wherein a downstream end of an oil return passage in the main body of the internal combustion engine opens toward the motor stator. In the hybrid vehicle power unit, wherein an electric motor is interposed between the internal combustion engine and the transmission, and power is generated by at least one of the internal combustion engine and the electric motor.
The electric motor housing is configured integrally with the internal combustion engine body,
A cooling structure for a hybrid vehicle power unit, wherein a cooling water passage of the internal combustion engine is formed extending into the motor housing.

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