JP4192811B2 - Multiple engine cooling system - Google Patents

Description

  The present invention relates to a cooling system for a plurality of engines.

  In a vehicle equipped with an auxiliary engine that is equipped with an auxiliary engine for air conditioning, power generation, etc. in addition to the main engine for vehicle travel, there is a cooling device that is configured to share one radiator for the main engine and the auxiliary engine. (For example, refer to Patent Document 1).

According to this cooling device, when the vehicle air conditioner is in operation, the cooling water that is the cooling medium flowing out from the main engine and / or the auxiliary engine is branched and supplied to the radiator and the heat exchanger for air conditioning. Is done.
Japanese Utility Model Publication No. 61-157013 (page 4-15, FIG. 1)

  In the configuration in which the cooling water flowing out from the main engine and / or the auxiliary engine flows directly into the heat exchanger for air conditioning, the temperature of the cooling water flowing into the heat exchanger for air conditioning is the operating state of the main engine and / or the auxiliary engine. Fluctuates depending on. For this reason, it is difficult to stabilize the temperature of the air ejected from the heat exchanger for air conditioning.

  The present invention has been made to solve the above problems, and can stabilize the temperature of air ejected from a heat exchanger for air conditioning regardless of the operating state of the main engine and the auxiliary engine. An object is to provide a cooling device for an engine.

  An engine cooling apparatus according to the present invention includes a main engine for driving a vehicle, an auxiliary engine for driving a vehicle auxiliary machine, a heat exchanger for releasing heat of a cooling medium flowing out from the main engine to the atmosphere, and an auxiliary engine. In a cooling device for a plurality of engines in a vehicle provided with a heat exchanger for air conditioning that discharges heat of the cooling medium flowing out from the vehicle compartment, the cooling medium discharged from the main engine is transferred to the auxiliary engine via the heat exchanger. A first cooling medium passage that flows into the engine, a second cooling medium passage through which the cooling medium that has flowed out of the main engine flows into the auxiliary engine without passing through the heat exchanger, and the first cooling medium according to the temperature of the cooling medium Passage switching means for switching between the passage and the second cooling medium passage and circulating the cooling medium; and the cooling medium flowing out from the auxiliary engine is returned to the main engine via the air conditioner heat exchanger. 3 characterized in that it comprises a cooling medium passage.

  According to the engine cooling device of the present invention, according to the temperature of the cooling medium, the cooling medium is circulated without passing through the first cooling medium passage through which the cooling medium is circulated through the heat exchanger and the heat exchanger. The second cooling medium passage is switched by the switching means. By switching the passage through which the cooling medium flows, the amount of heat released from the heat exchanger is adjusted according to the temperature of the cooling medium, and the temperature of the cooling medium is adjusted to a predetermined range. The cooling medium adjusted to a predetermined range by the heat exchanger and the passage switching means flows into the auxiliary engine and is heated by the heat of the auxiliary engine. Here, the auxiliary engine for driving the vehicle auxiliary machine has a smaller output fluctuation and a smaller amount of heat generation than the main engine for driving the vehicle. Therefore, there is little fluctuation in the amount of heat released from the auxiliary engine to the cooling medium, and even if it fluctuates, the influence on the temperature of the cooling medium is small. Therefore, the temperature fluctuation of the cooling medium that flows out from the auxiliary engine and flows into the air conditioning heat exchanger can be suppressed.

  Further, the main engine has a fourth cooling medium passage through which the recirculated cooling medium flows out only through the cylinder head, and a fifth cooling medium passage through which the cooling medium flows out through the cylinder head and the cylinder block. When the temperature of the second cooling medium passage is equal to or lower than a predetermined value, the fourth cooling medium passage and the second cooling medium passage are preferably communicated, and the communication between the fifth cooling medium passage and the first cooling medium passage is blocked.

  When the temperature of the cooling medium falls below a predetermined value, the fourth cooling medium passage and the second cooling medium passage are communicated, and the communication between the fifth cooling medium passage and the first cooling medium passage is blocked. Therefore, the cooling medium discharged only through the cylinder head of the main engine is circulated without passing through the heat exchanger. In this case, the amount of heat taken away from the main engine and the amount of heat released from the heat exchanger are reduced, so that the temperature increase of the main engine is promoted. As the temperature of the main engine is raised, the temperature of the cooling medium is raised again to a predetermined temperature, so that the temperature of the cooling medium can be maintained within a predetermined range.

  According to the present invention, since the fluctuation range of the cooling water temperature flowing into the air conditioning heat exchanger can be reduced regardless of the operating state of the main engine and the auxiliary engine, the air is ejected from the air conditioning heat exchanger. It becomes possible to stabilize the temperature of air.

  DESCRIPTION OF EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. In the figure, the same reference numerals are used for the same or corresponding parts.

  A multiple-engine cooling apparatus 1 according to the embodiment will be described with reference to FIGS. 1 and 2. FIG. 1 is a diagram showing a configuration of a main engine (hereinafter referred to as “main engine”) 10 and an auxiliary engine (hereinafter referred to as “sub-engine”) 20 in which the cooling device 1 is used. FIG. 2 is a diagram illustrating a configuration of the cooling device 1.

  A vehicle equipped with the cooling device 1 includes a main engine 10 that mainly drives the vehicle, and a sub-engine 20 that has a smaller displacement than the main engine 10 that mainly drives a vehicle auxiliary machine (hereinafter simply referred to as “auxiliary machine”). And.

  A transmission 18 is connected to the main engine 10. The driving force output from the main engine 10 is transmitted to the transmission 18. The driving force transmitted to the transmission 18 is transmitted to driving wheels via a differential, a drive shaft, and the like. And a vehicle drive | works by driving a driving wheel. A main crank pulley 14 is connected to the crankshaft 12 of the main engine 10 via an electromagnetic clutch 13 that can be electromagnetically released and engaged. The driving force output from the main engine 10 is transmitted to the main crank pulley 14 via the electromagnetic clutch 13.

  The main engine 10 includes a cylinder block 10b in which a cylinder is formed, and a cylinder head 10a fixed to the upper part of the cylinder block 10b. In the cylinder head 10a and the cylinder block 10b, water jackets 10c and 10d, which are cooling water passages serving as a cooling medium for cooling the main engine 10, are provided. In FIG. 2, the water jacket 10c provided in the cylinder head 10a and the water jacket 10d provided in the cylinder block 10b are schematically shown by arrows.

  In the main engine 10, air sucked from the air cleaner 100 is throttled by an electronically controlled throttle valve 130 provided in the intake pipe 120, passes through the intake manifold 140, and is sucked into each cylinder formed in the main engine 10. The Here, the amount of air taken in from the air cleaner 100 is detected by a hot wire type air flow meter 110 disposed between the air cleaner 100 and the electronically controlled throttle valve 130.

  The intake manifold 140 is provided with injectors 150 for injecting fuel, and pressurized fuel is guided to each injector 150. In each cylinder, the mixture of intake air and fuel burns, and the exhaust gas after the combustion is discharged to the exhaust pipe 170 through the exhaust manifold 160. Heat generated by the combustion of the air-fuel mixture is released to the cooling water in the water jackets 10c and 10d provided in the cylinder head 10a and the cylinder block 10b.

  The operation of the main engine 10 is controlled by a main engine electronic control unit (hereinafter referred to as “main ECU”) 50 constituted by a microprocessor, ROM, RAM, and the like.

  The main ECU 50 includes a crank position sensor 51 that detects a crank position of the main engine 10, an accelerator opening sensor 52 that detects an accelerator pedal opening, a water temperature sensor 53 that detects a cooling water temperature of the main engine 10, and a main engine 10 is connected to an air flow meter 110 for detecting the amount of air sucked. The main ECU 50 also includes an injector driver that drives the injector 150, a motor driver that drives an electric motor that opens and closes the electronically controlled throttle valve 130, an output circuit that outputs an ignition signal to a spark plug, and the like.

  The main ECU 50 calculates control values such as the fuel injection amount and the ignition timing based on the output values from the various sensors. Then, based on the calculated control value, a driver circuit or the like is driven, and the operation of the main engine 10 is comprehensively controlled.

  The sub-engine 20 is a single-cylinder engine with a displacement of about 100 to 150 cc, and is an engine whose thermal efficiency is improved by, for example, increasing the stroke or increasing the expansion ratio.

  The sub-engine 20 includes a cylinder block 20b in which a cylinder is formed, and a cylinder head 20a fixed to the upper part of the cylinder block 20b. The cylinder head 20a and the cylinder block 20b are provided with a water jacket 20c that is a passage of cooling water for cooling the sub-engine 20. In FIG. 2, the water jacket 20c provided in the cylinder head 20a and the cylinder block 20b is schematically shown by arrows.

  A sub crank pulley 34 is connected to the crankshaft 23 of the sub engine 20 via a one-way clutch 33 that transmits a driving force output from the sub engine 20 side and blocks a driving force input to the sub engine 20 side. ing. The driving force output from the sub-engine 20 is transmitted to the sub-crank pulley 34 via the one-way clutch 33. In the present embodiment, a double pulley provided with a large diameter pulley 34a and a small diameter pulley 34b having a smaller diameter than the large diameter pulley 34a is used as the sub crank pulley 34.

  A belt B1 is hung on the small-diameter pulley 34b and the main crank pulley 14, and the driving force is transmitted between the small-diameter pulley 34b and the main crank pulley 14 by the belt B1.

  A pulley 38 is attached to the auxiliary machine 36. A belt B2 is hung on the pulley 38. When the large-diameter pulley 34a is rotated, the pulley 38 is rotated and the auxiliary machine 36 is driven. As the auxiliary machine 36 driven by the belt B2, there are a water pump, an alternator, a power steering pump, an air conditioner compressor, etc., but only one auxiliary machine is shown in FIG. Is omitted.

  In the sub-engine 20, the intake air drawn from the air cleaner 200 is throttled by an electronically controlled throttle valve 230 provided in the intake pipe 220 and is drawn into a cylinder 21 formed in the sub-engine 20. Here, the amount of air taken in from the air cleaner 200 is detected by a hot wire type air flow meter 210 disposed between the air cleaner 200 and the electronically controlled throttle valve 230.

  Pressurized fuel is guided to an injector 250 provided in the intake port 26. In the cylinder 21, the mixture of the fuel injected from the injector 250 and the intake air is combusted, and the exhaust gas after the combustion is discharged to the exhaust pipe 260. The heat generated by the combustion of the air-fuel mixture is released to the cooling water in the water jacket 20c provided in the cylinder head 20a and the cylinder block 20b.

  The exhaust pipe 260 is assembled with the exhaust pipe 170 of the main engine 10 in a collecting portion 180 provided upstream of the exhaust purification catalyst 40. The exhaust gas of the sub-engine 20 discharged to the exhaust pipe 260 is collected with the exhaust gas of the main engine 10 and discharged.

  The operation of the sub-engine 20 is controlled by a sub-engine electronic control unit (hereinafter referred to as “sub-ECU”) 60 constituted by a microprocessor, ROM, RAM, and the like.

  The sub ECU 60 includes a crank position sensor 61 that detects the crank position of the sub engine 20, a water temperature sensor 62 that detects the coolant temperature of the sub engine 20, and an air flow meter 210 that detects the amount of air taken into the sub engine 20. Etc. are connected. The sub ECU 60 also includes an injector driver that drives the injector 250, an output circuit that outputs an ignition signal to the spark plug, and the like.

  The sub ECU 60 calculates control values such as fuel injection amount and ignition timing based on output values from the various sensors. Then, based on the calculated control value, a driver circuit or the like is driven, and the operation of the sub-engine 20 is comprehensively controlled.

  One end of a first coolant passage 80 is connected to an outlet (hereinafter referred to as “first outlet”) 10 f of a water jacket 10 d provided in the cylinder block 10 b of the main engine 10. The cooling water that has flowed in through the water jackets 10c and 10d provided in the cylinder head 10a and the cylinder block 10b flows into the first cooling water passage 80 from the first outlet 10f. To be discharged. The water jacket 10c and the water jacket 10d constitute a fifth coolant passage.

  The other end of the first cooling water passage 80 is connected to the upper tank 72 a of the radiator 72. The cooling water flowing out from the first outlet 10 f of the main engine 10 is guided to the radiator 72 through the first cooling water passage 80. The radiator 72 is a heat exchanger that performs heat exchange between the cooling water and the atmosphere. When the cooling water passes through the radiator core portion composed of the tubes and the fins, the heat of the cooling water is released to the atmosphere.

  One end of the second cooling water passage 82 is connected to the lower tank 72 b of the radiator 72. The other end of the second cooling water passage 82 is connected to the thermostat 70. The cooling water cooled by the radiator 72 is guided to the thermostat 70 through the second cooling water passage 82.

  On the other hand, one end of a third cooling water passage 84 is connected to an outlet (hereinafter referred to as “second outlet”) 10 e of a water jacket 10 c provided in the cylinder head 10 a of the main engine 10. Cooling water that flows in from the inlet 10g provided in the cylinder head 10a and flows only in the water jacket 10c provided in the cylinder head 10a is discharged from the second outlet 10e to the third cooling water passage 84. The water jacket 10c functions as a fourth coolant passage.

  The other end of the third cooling water passage 84 is connected to the thermostat 70. The cooling water flowing out from the second outlet 10 e of the main engine 10 is guided to the thermostat 70 through the third cooling water passage 84.

  In addition to the second cooling water passage 82 and the third cooling water passage 84, one end of a fourth cooling water passage 86 is connected to the thermostat 70. The thermostat 70 closes the water channel to the radiator 72 to promote the temperature rise of the engine when the main engine 10 and the sub-engine 20 are warmed up, and after the cooling water temperature reaches a predetermined value, cooling that flows to the radiator 72 is performed. The cooling water temperature is adjusted to a predetermined range by controlling the flow rate of water. The thermostat 70 of the present embodiment used a wax pellet mold that expands when the wax melts and pushes out a needle to open a valve. Needless to say, the thermostat 70 is not limited to the wax pellet type.

  More specifically, when the cooling water temperature is equal to or higher than a first predetermined value (for example, 82 ° C.), the valve of the thermostat 70 is in the first position shown by the solid line in FIG. The communication with the cooling water passage is made, and the communication between the third cooling water passage and the fourth cooling water passage is blocked. Thus, the thermostat 70 functions as switching means for switching the coolant flow path. Thereby, the outflow of the cooling water from the second outlet 10e is stopped, and the cooling water flowing in from the inlet 10g flows into the water jacket 10c, the water jacket 10d, the first outlet 10f, the first cooling water passage 80, Circulation is performed via the radiator 72, the second cooling water passage 82, the thermostat 70, and the fourth cooling water passage 86. Here, the first, second and fourth cooling water passages 80, 82 and 86 constitute a first cooling medium passage.

  On the other hand, when the cooling water temperature is equal to or lower than a second predetermined value (for example, 76 ° C.), the valve of the thermostat 70 is in the second position indicated by the dotted line in FIG. 2 and the third cooling water passage 84 and the fourth cooling water passage. 86 communicates with the second cooling water passage 82 and the fourth cooling water passage 86. Thereby, the outflow of the cooling water from the first outlet 10f is stopped, and the cooling water flowing in from the inlet 10g flows into the water jacket 10c, the second outlet 10e, the third cooling water passage 84, the thermostat 70, and the first. It is circulated through the four cooling water passages 86. In this case, the cooling water is circulated without passing through the water jacket 10 d and the radiator 72. Here, the third and fourth cooling water passages 84 and 86 constitute a second cooling medium passage.

  When the cooling water temperature is lower than the first predetermined value and higher than the second low value, the valve of the thermostat 70 is located between the first position and the second position according to the cooling water temperature, and the cooling water flowing to the radiator 72 is The amount is adjusted according to the cooling water temperature. In this way, the cooling water whose temperature is adjusted to a predetermined range is supplied to the sub-engine 20.

  The other end of the fourth coolant passage 86 is connected to the inlet 20 d of the sub-engine 20. The fourth cooling water passage 86 is provided with a water pump 74 that pumps the cooling water. The cooling water flowing through the fourth cooling water passage 86 is sucked into the water pump 74 and supplied to the sub-engine 20.

  The cooling water flowing in from the inflow port 20d of the sub-engine 20 passes through the water jacket 20c, is heated again, and then discharged from the outflow port 20e. One end of the fifth coolant passage 88 is connected to the outlet 20e. The other end of the fifth cooling water passage 88 is connected to the inlet 76 a of the heater core 76, and the cooling water heated by the sub-engine 20 is guided to the heater core 76 through the fifth cooling water passage 88.

  The heater core 76 is a heat dissipating device for in-vehicle air conditioning (heating) that is configured by tubes and fins and that exchanges heat when cooling water flows through the tubes. That is, the heater core 76 functions as a heat exchanger for air conditioning.

  One end of a sixth cooling water passage 90 is connected to the outlet 76 b of the heater core 76. The other end of the sixth cooling water passage 90 is connected to the inlet 10 g of the main engine 10, and the cooling water flowing out from the heater core 76 is returned to the main engine 10 through the sixth cooling water passage 90. Here, the fifth and sixth coolant passages 88 and 90 constitute a third coolant passage.

  As described above, according to the cooling device 1, the amount of heat taken from the main engine 10 and the amount of heat released from the radiator 72 are adjusted by switching the flowing water passage by the thermostat 70 in accordance with the cooling water temperature. The temperature is adjusted to a predetermined range. The cooling water adjusted to a predetermined range by the radiator 72 and the thermostat 70 flows into the sub engine 20 and is heated by the heat of the sub engine 20. Here, the auxiliary engine driving sub-engine 20 has a smaller output fluctuation and a smaller amount of heat generation than the vehicle driving main engine 10. For this reason, the amount of heat released from the sub-engine 10 to the cooling water varies little, and even if it fluctuates, the influence on the temperature of the cooling water is small. Therefore, the temperature of the cooling water flowing out from the sub-engine 20 and flowing into the heater core 76 can be raised while suppressing temperature fluctuations, so that the temperature of the air ejected from the heater core 76 is stabilized and the heating capacity is secured. It becomes possible to do.

  In the cooling device 1, all the cooling water that has flowed out of the main engine 10 flows into the heater core 76. For this reason, since the quantity of the cooling water which flows into the heater core 76 increases compared with the conventional cooling device, a heating capability can be improved.

  Although the embodiment of the present invention has been described above, the present invention is not limited to the above embodiment, and various modifications can be made. For example, instead of the thermostat 70, a valve electromagnetically driven by the main ECU 50 based on the coolant temperature detected by the water temperature sensor 53 may be used.

It is a figure which shows the structure of the main engine and auxiliary engine in which the cooling device which concerns on embodiment is used. It is a figure which shows the structure of the cooling device which concerns on embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Cooling device, 10 ... Main engine, 10a ... Cylinder head, 10b ... Cylinder block, 10c, 10d ... Water jacket, 20 ... Sub engine, 20a ... Cylinder head, 20b ... Cylinder block, 20c ... Water jacket, 36 ... Supplementary 50 ... main ECU, 53, 62 ... water temperature sensor, 60 ... sub ECU, 70 ... thermostat, 72 ... radiator, 74 ... water pump, 76 ... heater core, 80 ... first cooling water passage, 82 ... second cooling water A passage, 84 ... a third cooling water passage, 86 ... a fourth cooling water passage, 88 ... a fifth cooling water passage, 90 ... a sixth cooling water passage.

Claims (2)

A main engine for driving a vehicle, an auxiliary engine for driving an auxiliary machine for the vehicle, a heat exchanger for releasing heat of the cooling medium flowing out from the main engine to the atmosphere, and a cooling medium flowing out from the auxiliary engine In a cooling device for a plurality of engines in a vehicle provided with a heat exchanger for air conditioning that releases heat into the vehicle interior,
A first coolant passage for allowing the coolant flowing out from the main engine to flow into the auxiliary engine via the heat exchanger;
A second coolant passage for allowing the coolant flowing out from the main engine to flow into the auxiliary engine without passing through the heat exchanger;
Passage switching means for switching between the first cooling medium passage and the second cooling medium passage according to the temperature of the cooling medium, and circulating the cooling medium;
A cooling device for a plurality of engines, comprising: a third cooling medium passage for returning the cooling medium flowing out from the auxiliary engine to the main engine via the air conditioning heat exchanger. The main engine has a fourth cooling medium passage for allowing the refluxed cooling medium to flow out only through the cylinder head, and a fifth cooling medium passage for flowing out through the cylinder head and the cylinder block.
The passage switching means communicates the fourth cooling medium passage and the second cooling medium passage when the temperature of the cooling medium is equal to or lower than a predetermined value, and the fifth cooling medium passage and the first cooling medium. The cooling device for a plurality of engines according to claim 1, wherein communication with the passage is cut off.

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