JPH0569328U - Hybrid engine cooling system - Google Patents

Abstract

(57) [Abstract] [Purpose] In a hybrid engine in which an engine and an electric motor are combined, the cooling systems of the engine and the electric motor are integrated to optimize each cooling and improve the exhaust gas emission of the engine. [Structure] As a hybrid engine 1, an engine 2
The electric motor 3 is connected to the drive system so that the electric motor 3 can be driven independently.
Is a closed water-cooling type, and the cooling system of the engine 2 and the cooling system of the electric motor are integrally configured by a single forced circulation path 20. Then, only the electric motor 3 is driven in the cold state, and at this time, the engine 2 is warmed up via the cooling water due to the heat generation of the electric motor 3, and the engine 2 is controlled after being warmed up.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a cooling system for a hybrid engine in which an engine and an electric motor are combined, and more particularly, to a cooling system for the engine and the electric motor.

[0002]

[Prior Art]

 As a vehicle engine, a hybrid engine that combines an engine and an electric motor is already known, and there are expectations for improvements in engine fuel efficiency and exhaust gas emissions. Conventionally, in this type of hybrid engine, the cooling system of the engine is a water cooling type, and the cooling system of the electric motor is an air cooling type. For this reason, in an electric motor, heat generation is cooled by air cooling, which makes it difficult to provide a sealed structure for waterproofing and soundproofing. Further, in the engine, the temperature of each part of the engine and the cooling water are low when the engine is cold, so that the warm-up time becomes long, and in this case, there are problems such as deterioration in running performance and exhaust gas emission. Therefore, it is desirable to optimize the cooling system for these engines and electric motors.

Conventionally, as for the above-mentioned hybrid engine cooling device, for example, there is a prior art in Japanese Examined Patent Publication No. 63-25166, and a liquid for recovering heat generated during the operation of the retarder is supplied to a forced circulation path for cooling the engine. It has been shown to introduce and integrate the engine and retarder cooling systems.

[0004]

[Problems to be solved by the device]

 By the way, in the above-mentioned prior art, since it is a system in which a retarder having a function of electrically braking the engine is combined, it is different from the system in which the engine and the electric motor which are the subject of the present invention are combined. Further, the heat energy of the retarder is intermittently collected only when the vehicle is electrically braked when the vehicle is decelerated, so that it cannot effectively act on the rise of engine cooling water in the cold state.

The present invention has been made in view of this point, and in a hybrid engine in which an engine and an electric motor are combined, the cooling systems of the engine and the electric motor are integrated to optimize each cooling. The purpose is to improve engine exhaust gas emissions.

[0006]

[Means for Solving the Problems]

 In order to achieve the above object, the present invention is a hybrid engine in which an electric motor can be independently driven to be connected to an engine drive system, and the electric motor is configured as a water-cooled type, and the engine cooling system and the electric motor cooling system are combined into a single unit. It is composed of a forced circulation route.

[0007]

[Action]

 Based on the above configuration, the engine and the electric motor of the hybrid engine are always cooled by the cooling water in the forced circulation path to be the same. Therefore, if it is controlled to drive only the electric motor in the cold state, it is warmed up to raise the engine temperature of the engine by the cooling water that has cooled the heat generated by the electric motor, and the engine is driven after this warming up. By controlling it, the exhaust gas emission of the engine is improved.

[0008]

【Example】

 Embodiments of the present invention will be described below with reference to the drawings. Referring to FIG. 1, the overall structure of the hybrid engine of the present invention applied to a vehicle engine will be described. The hybrid engine 1 includes an internal combustion engine 2 and an electric motor 3. The output shaft 4 of the engine 2 is connected to the electric motor 3 via the one-way clutch 5, and the output shaft 6 of the electric motor 3 is connected to the transmission 8 via the clutch 7. The output shaft 9 of the transmission 8 is configured to be transmitted to the drive wheels 12 via the differential device 10 and the axle 11, and can be driven by the electric motor 3 alone or by the engine 2 and the electric motor 3.

The cooling system of the engine 2 and the electric motor 3 will be described. The cooling passage 21 of the engine 2 is communicated with the radiator 23 via the thermostat 22. The electric motor 3 has a water-cooled closed structure, and a cooling passage 24 of its heat generating portion is connected to a cooling passage 21 of the engine 2 by a hose 25. An electric pump 27 having a motor 26 is provided in the middle of the hose 25 to form a forced circulation path 20 in which the engine 2 and the electric motor 3 are integrated.

Next, the control system of the hybrid engine 1 and the like will be described. First, it has a motor control unit 40 to which signals from the key switch 30, the accelerator opening sensor 31, etc. are input, and when the key switch 30 is turned on, the exciting current Im can be supplied from the battery 41 to the electric motor 3 and the accelerator opening is adjusted according to the accelerator opening. The output of the electric motor 3 is variably controlled by the exciting current Im. Further, it has an engine drive determination unit 42 to which the signals of the key switch 30 and the water temperature sensor 32 are input, and when the water temperature Tw becomes a set value b or more after a predetermined time a has passed after the key switch 30 was turned on, the motor drive is continued. On the other hand, the engine drive is determined and a drive signal is output to the engine control unit 43. When the drive signal is input, the engine control unit 43 drives the engine 2 by outputting a starter signal, an ignition signal, and a fuel injection signal in response to signals from the engine speed sensor 33, the accelerator opening sensor 31, etc. It can be driven by the output. The electric motor control unit 40 checks the charge amount B of the battery 41, controls the exciting current Im of the electric motor 3 when the charge amount B is less than the predetermined charge amount Bo, and switches to the generator operation as described above when a brake is detected. Further, signals from the key switch 30, the accelerator opening sensor 31, etc. are input to the pump control section 44 so that the current of the pump motor 26 is controlled when the key switch 30 is turned on.

Next, the operation of this embodiment will be described with reference to the flowchart of FIG. First, when the operation of the key switch 30 is checked and turned on in step S1, the process proceeds to step S2, in which the pump controller 44 supplies a current to the motor 26 to drive the pump 27. Therefore, the forced circulation path 20 allows the cooling water to flow between both the engine 2 and the electric motor 3 for common cooling, and at the same temperature. After that, the time t is checked in step S3, and if it is within the predetermined time a, the process proceeds to step S4. When the predetermined time a has elapsed, the process proceeds to step S5 to check the water temperature Tw, and if the temperature is lower than the set value b, the process similarly proceeds to step S4.

Immediately after turning on the key switch 30 or in the cold state, the process proceeds to step S4, and the exciting current Im is supplied to the electric motor 3 by the electric motor control unit 40. In this way, only the electric motor 3 of the hybrid engine 1 is first supplied. To drive. At this time, the one-way clutch 5 of the drive system becomes free, so that the engine 2 is held in a stopped state and only the electric motor 3 is rotationally driven independently. Therefore, when the clutch 7 is connected in this electric motor driven state, the electric power of the electric motor is changed by the transmission 8 and transmitted to the drive wheels 12 to drive the vehicle. In this case, the electric motor control unit 40 is controlled so as to change the exciting current Im of the electric motor 3 to change the power of the electric motor 3 according to the accelerator opening degree, and thereby the output characteristic according to the accelerator operation is generated. Run.

In the cold state, the electric motor runs and the engine 2 is held in a stopped state. Therefore, the engine 2 does not need to be warmed up with a rich air-fuel mixture and does not emit harmful HC and CO at all. On the other hand, when the motor is running, heat is generated in the motor 3 due to copper loss, iron loss, etc., but this heat generation is effectively absorbed by the cooling water in a sealed state. Then, in this case, the cooling water whose temperature has risen by cooling the electric motor 3 flows into the cooling passage 21 of the engine 2 by the integrated forced circulation path 20 to increase the engine temperature, and thus the electric motor 3 is cooled. The engine 2 is automatically warmed up by utilizing the heat generation.

Thereafter, even if a predetermined time a has passed and the water temperature Tw becomes equal to or higher than the set value b, the electric motor drive is continued in step S6, the engine drive is determined in step S7, and the process proceeds from step S7 to step S8. The engine operating state is checked in step S8, and if the engine 2 has not been started, the process proceeds to step S8, in which the engine control unit 43 outputs a starter signal, an ignition signal, and a fuel injection signal to start the engine 2. Since the engine has already been warmed up at the start of the engine, it can be satisfactorily burned with a lean air-fuel mixture from the beginning, which improves fuel efficiency and exhaust gas emissions. Then, after that, the engine 2 and the electric motor 3 of the hybrid engine 1 are both driven (step S9), the one-way clutch 5 is locked and the motive power of both is output, and the clutch 7 is connected to the vehicle by the engine power and the electric motor power. To run. In step S10, the charge amount of the battery 41 is checked, and if the predetermined value is not reached, the electric motor is switched to the generator in step S11. If this is not the case, engine braking determination is made from the running state in step S12, and when engine braking is in progress, the process proceeds to step S11 and the electric motor is switched to the generator.

When the vehicle is driven by the engine power and the electric motor power, a part of the output characteristic is borne by the power of the electric motor 3, so that the engine power can be reduced by that much. Exhaust gas emissions are reduced. Further, the same cooling water is circulated in the engine 2 and the electric motor 3 by the forced circulation path 20 to be cooled in common, and the heat is radiated by the thermostat 22 and the radiator 23, so that the engine 2 and the electric motor 3 are simultaneously brought to a predetermined temperature. Controlled to prevent overheating.

Although the embodiment of the present invention has been described above, the invention can be similarly applied to a system in which the combination of the engine and the electric motor of the hybrid engine is different.

[0017]

[Effect of the device]

 As described above, according to the present invention, in the hybrid engine in which the engine and the electric motor are combined, the cooling system for the engine and the electric motor is integrated, so that the engine is automatically generated by utilizing the heat generated by the electric motor. It can be warmed up. Therefore, the engine can always be warmed up and then started and operated, which eliminates the need for warm-up operation with a rich air-fuel mixture, and can significantly reduce fuel consumption and exhaust gas emissions. .. Since the electric motor is water-cooled and controlled to a specified temperature, durability and efficiency can be improved. In addition, the electric motor can be hermetically sealed to ensure effective soundproofing and waterproofing.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing a drive system, a cooling system, and a control system of an embodiment of a hybrid engine cooling device according to the present invention.

FIG. 2 is a flowchart explaining the operation of the hybrid engine.

[Explanation of symbols]

 1 Hybrid Engine 2 Engine 3 Electric Motor 20 Forced Circulation Route 21, 24 Cooling Passage 22 Thermostat 23 Radiator 25 Hose 27 Pump

Claims (2)

[Scope of utility model registration request] 1. A hybrid engine in which an electric motor is connected to a drive system of the engine so that the electric motor can be independently driven. The electric motor is a water-cooled type, and the engine cooling system and the electric motor cooling system are integrated by a single forced circulation path. A cooling device for a hybrid engine, which is characterized by being configured. 2. The hybrid engine according to claim 1, wherein only the cooling system and the electric motor are driven at the time of starting or in a cold state, and the engine is controlled to operate after being warmed up. Hybrid engine cooling system.