JP2009214602A - Vehicular heating system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vehicular heating system can improve heating performance, without deteriorating fuel economy. <P>SOLUTION: This vehicular heating system has an EGR pipe 31 for recirculating a part of exhaust gas flowing in an exhaust pipe 26 of an engine 1 to an intake pipe 13, an air-cooled EGR cooler 34 arranged in a midway part of the EGR pipe 31 and cooling the exhaust gas by exchanging heat with cooling air while passing the exhaust gas and an air conditioner 2 having an evaporator 43 and a heater core 44 on the inside and taking in and sending out inside air or outside air into a cabin, and controls the air conditioner 2 so that the temperature in the cabin is approached to the target temperature, and includes an outside air introducing duct 66 for introducing the cooling air into the air conditioner 2 after exchanging heat with the exhaust gas by the air-cooled EGR cooler 34. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a vehicle heating system, and more particularly to a vehicle heating system suitable for using cooling air after cooling exhaust flowing through an exhaust gas recirculation pipe for heating control.

  In recent years, a lean combustion internal combustion engine has been put into practical use in order to improve the fuel consumption of the internal combustion engine. In this lean combustion internal combustion engine, when the oxygen concentration in the exhaust gas becomes high due to lean combustion, there is a problem that the purification efficiency of the catalyst decreases and the amount of nitrogen oxide (NOx) generated increases.

  In order to solve this problem, an exhaust gas recirculation (EGR: Exhaust Gas) that returns part of the exhaust gas from the exhaust system to the intake system and lowers the combustion temperature of the internal combustion engine to reduce the generation of nitrogen oxides (NOx). Recirculation) is being performed. In this exhaust gas recirculation, an exhaust system and an intake system of an internal combustion engine are connected by an EGR pipe as an exhaust gas recirculation pipe, and a water-cooled EGR cooler and an air-cooled EGR cooler as a cooling part are provided in the middle of the EGR pipe. The exhaust gas recirculated to the intake system via the EGR pipe is cooled to lower the combustion temperature of the internal combustion engine to reduce the generation of NOx and improve the fuel efficiency.

On the other hand, the vehicle is equipped with a vehicle heating system that controls heating in the passenger compartment. Conventionally, as this kind of heating system for vehicles, what uses the cooling water of an internal-combustion engine for heating is known (for example, refer to patent documents 1). In this vehicle heating system, a heater core is provided in a cooling water passage of an internal combustion engine, and the heater core passes through the heater core by exchanging heat between the cooling water heated through the internal combustion engine and the air blown by the blower. The later warmed air is blown into the passenger compartment. Such a vehicle heating system is naturally provided in a vehicle that performs exhaust gas recirculation.
JP-A-8-216660

  However, in such a vehicle heating system, while being mounted on a vehicle that performs exhaust gas recirculation, warmed cooling air after heat exchange with exhaust gas is discarded outside the vehicle by an air-cooled EGR cooler. It was not used effectively for heating the passenger compartment. Also, because the cooling water of the internal combustion engine is used for heating, when the outside air temperature is extremely low and high heating performance is required, the internal combustion engine must be forcibly driven, resulting in a deterioration in fuel consumption. There was a problem.

  The present invention has been made to solve the above-described conventional problems, and an object of the present invention is to provide a vehicle heating system capable of improving the heating performance without causing deterioration in fuel consumption.

  In order to achieve the above object, a vehicle heating system according to the present invention includes (1) an exhaust gas recirculation pipe that recirculates a part of exhaust gas flowing through an exhaust pipe of an internal combustion engine to an intake pipe, and an intermediate portion of the exhaust gas recirculation pipe A cooling unit that cools the exhaust gas by exchanging heat with cooling air while the exhaust gas passes, a cooling heat exchanger, and a heating heat exchanger. In the vehicle heating system, which includes an air-conditioning unit that takes in the fuel and sends it into the vehicle interior, and an air-conditioning control unit that controls the air-conditioning unit so that the temperature in the vehicle interior approaches the target temperature, heat exchange with the exhaust gas by the cooling unit It is comprised from what was provided with the introducing | transducing part which introduces the cooling air after being done in the said air-conditioning part.

With this configuration, since the cooling air after heat exchange with the exhaust gas in the cooling unit is introduced into the air conditioning unit through the introduction unit, the warm air after heat exchange can be used for heating the air conditioning unit.
Therefore, since warm air can be introduced into the air conditioning unit without forcibly driving the internal combustion engine, the heating performance can be improved without causing deterioration of fuel consumption.

  In the vehicle heating system according to the above (1), (2) an outside air introduction portion that introduces outside air from the outside of the vehicle to the introduction portion, and cooling after heat exchange with the exhaust gas from the cooling portion to the introduction portion A cooling air introduction section for introducing air; and a switching section for switching a communication state between one of the outside air introduction section and the cooling air introduction section and the introduction section. The switching unit is configured to switch the temperature so as to approach the target temperature.

With this configuration, since the switching unit switches the communication state between either the outside air introduction unit or the cooling air introduction unit and the introduction unit, for example, after the heat exchange in the case where the temperature in the passenger compartment is higher than the target temperature, etc. When there is no need to introduce cooling air into the air conditioning unit, the switching unit communicates the outside air introduction unit with the introduction unit so that the cooling air after heat exchange is not introduced from the cooling air introduction unit into the introduction unit, and heat exchange is performed. The influence of the subsequent cooling air on the air conditioning unit can be suppressed.
On the other hand, for example, when it is necessary to introduce cooling air after heat exchange into the air conditioning unit when the temperature in the passenger compartment is lower than the target temperature, the switching unit causes the cooling air introducing unit and the introducing unit to communicate with each other. The heating performance of the air conditioning unit can be improved.

  In the vehicle heating system described in (1) or (2) above, (3) a flow rate adjusting unit that adjusts the flow rate of exhaust gas that passes through the cooling unit is provided, and the air conditioning control means includes the vehicle interior. The flow rate adjusting unit is adjusted so that the temperature of the air flow approaches the target temperature.

With this configuration, by adjusting the flow rate of the exhaust gas that passes through the cooling unit, it is possible to control the temperature rise of the cooling air after heat exchange in the cooling unit. Therefore, when it is not necessary to introduce the cooling air after heat exchange into the air conditioning unit when the temperature in the passenger compartment is higher than the target temperature, the temperature of the cooling air is reduced by reducing the flow rate of the exhaust gas passing through the cooling unit. The rise can be suppressed and the influence of the cooling air after heat exchange on the air conditioning unit can be suppressed.
On the other hand, when it is necessary to introduce the cooling air after heat exchange into the air conditioning unit when the temperature in the passenger compartment is lower than the target temperature, the temperature of the cooling air is increased by increasing the flow rate of the exhaust gas passing through the cooling unit. The heating performance of the air conditioning unit can be improved.
Note that the flow rate of the exhaust gas passing through the cooling unit is preferably adjusted in a range that does not affect the operating state of the internal combustion engine.

  In the vehicle heating system described in (3) above, (4) the flow rate adjustment unit includes an annular flow rate adjustment valve that adjusts the flow rate of exhaust gas flowing through the exhaust gas recirculation pipe.

  With this configuration, the flow rate of the exhaust gas flowing through the exhaust gas recirculation pipe is adjusted by the ring flow rate adjustment valve, so that the flow rate of the exhaust gas passing through the cooling unit is adjusted, and the temperature of the cooling air rises after heat exchange in the cooling unit Can be controlled.

  Further, in the vehicle heating system according to the above (3) or (4), (5) the upstream portion and the downstream of the cooling unit of the exhaust gas recirculation pipe so that the flow rate adjusting unit bypasses the cooling unit. It comprises a bypass pipe that communicates with the side portion and a bypass valve that adjusts the flow rate of the exhaust gas flowing into the bypass pipe.

  With this configuration, the flow rate of the exhaust gas flowing into the bypass pipe is adjusted by the bypass valve, whereby the flow rate of the exhaust gas passing through the cooling unit is adjusted, and the temperature rise of the cooling air after heat exchange in the cooling unit is controlled. can do.

  Further, in the vehicle heating system described in (1) to (5) above, (6) an inside / outside air damper that closes or opens the introduction portion, and an exhaust gas to the cooling portion according to the operating state of the internal combustion engine. Determination means for determining whether or not gas is flowing, and when the determination means determines that exhaust gas is flowing into the cooling unit during cooling, the air conditioning control means is It is comprised from what closes the said introduction part.

  With this configuration, when the determination unit determines that exhaust gas is flowing into the cooling unit during cooling, the introduction unit is closed by the inside / outside air damper, so that the cooling air after heat exchange during cooling is supplied to the air conditioning unit. Since it is prevented from being introduced, the influence of the cooling air after heat exchange on the air conditioning unit can be suppressed without reducing the flow rate of the exhaust gas flowing through the exhaust gas recirculation pipe. Further, since it is not necessary to reduce the flow rate of the exhaust gas flowing through the exhaust gas recirculation pipe, NOx can be reduced and fuel consumption can be improved.

  In the vehicle heating system according to (1) to (6) above, (7) the vehicle is disposed between a rear end portion of the hood panel of the vehicle and a lower end portion of the windshield, and is arranged in the vehicle width direction. An extending cowl louver is provided, and the cooling air is configured to be introduced into the cooling unit from outside the vehicle via the cowl louver.

  With this configuration, since outside air can be introduced as cooling air through the cowl louver, the cooling unit can be simplified in comparison with a configuration in which a dedicated cooling fan is provided, and costs can be reduced. In addition, since outside air is introduced from between the rear end of the hood panel and the lower end of the windshield via the cowl louver, dust entry and odor generation can be prevented compared to a configuration in which outside air is introduced from under the floor. Can do.

  ADVANTAGE OF THE INVENTION According to this invention, the heating system for vehicles which can aim at heating performance improvement can be provided, without causing a fuel consumption deterioration.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
First, the configuration will be described.

  FIG. 1 is a schematic configuration diagram of a vehicle heating system according to a first embodiment of the present invention, and shows an example in which the vehicle heating system according to the present invention is applied to a diesel engine.

  The vehicle heating system includes a diesel engine (hereinafter simply referred to as an engine) 1 as an internal combustion engine, an air conditioner 2 as an air conditioner for air conditioning the vehicle interior, and air conditioning control for driving and controlling the engine 1 and the air conditioner 2. It includes an ECU (Electrical Control Unit) 3 as means.

  The engine 1 includes an intake device 4 that sucks air into a combustion chamber (not shown) in each cylinder, a fuel injection device 5 that injects fuel into the combustion chamber, an exhaust device 6 that exhausts exhaust gas after combustion, and an exhaust device The turbocharger 8 that supercharges the air in the intake device 4 to the combustion chamber using the exhaust energy of the exhaust gas 6, and an EGR device (Exhaust Gas Recirculation) that recirculates a part of the exhaust gas to the intake device 4 9).

  The intake device 4 includes an air intake port 11, an air cleaner 12, an intake pipe 13, and an intake manifold 14. The intake pipe 13 is provided with an air flow meter 15, an intercooler 16, and a throttle valve 17. ing.

The air intake 11 is provided at the most upstream position of the intake device 4, and takes in air from the outside and sends it into the air cleaner 12.
The air cleaner 12 has an upstream side connected to the air intake 11 and a downstream side connected to the intake pipe 13, and foreign matter such as dust or dust contained in the air taken into the air intake 11 by a filter provided therein. Is prevented, and air is fed into the intake pipe 13.

The intake manifold 14 has an upstream side connected to the intake pipe 13 and a downstream side branched into branch pipes corresponding to the number of cylinders and connected to the cylinder 24 so that air sent from the intake pipe 13 is diverted and sent to the combustion chamber. It has become.
That is, by connecting the air intake port 11, the air cleaner 12, the intake pipe 13, and the intake manifold 14, an intake passage for sending external air into the combustion chamber is configured.

The air flow meter 15 is provided in the intake pipe 13 in the vicinity of the air cleaner 12, detects the amount of intake air in the intake passage, converts it into an electrical signal, and outputs it to the ECU 3.
The intercooler 16 is provided in the intake pipe 13 on the downstream side of the turbocharger 8 and reduces the temperature of the air compressed and warmed by the turbocharger 8.
The throttle valve 17 is provided in the intake pipe 13 on the downstream side of the intercooler 16 and is connected to an accelerator pedal (not shown). The throttle valve 17 opens and closes according to the amount of depression of the accelerator pedal, thereby adjusting the amount of intake air fed into the combustion chamber. It is like that.

  The fuel injection device 5 includes a supply pump 21, a common rail 22, and a plurality of fuel injection valves 23.

The supply pump 21 uses the power of the engine 1 as a drive source, pumps up fuel from a fuel tank (not shown), pressurizes the fuel, and supplies the fuel to the common rail 22.
The common rail 22 is connected to a plurality of fuel injection valves 23, and distributes and supplies the fuel supplied from the supply pump 21 to the plurality of fuel injection valves 23 while keeping the pressure uniform.

The plurality of fuel injection valves 23 are provided corresponding to the plurality of cylinders, and are constituted by needle valves that are electromagnetically driven by commands from the ECU 3.
When the air in the combustion chamber is compressed to a high temperature by a piston (not shown), an injection command is output from the ECU 3 to the fuel injection valve 23, and the fuel injection valve 23 injects fuel into the high temperature air. The fuel is ignited and burned.

  The exhaust device 6 includes an exhaust manifold 25 and an exhaust pipe 26. The exhaust manifold 25 is provided with a fuel supply valve 27. The exhaust pipe 26 is provided with an exhaust after-treatment device 28 and an air-fuel ratio sensor 29. It has been.

  The exhaust manifold 25 has an upstream side branched into branch pipes corresponding to the number of cylinders and connected to the cylinder 24, and a downstream side joined to each branch pipe and connected to a single exhaust pipe 26. The exhaust gases discharged from the exhaust gas are combined and discharged to the outside through the exhaust pipe 26.

  The fuel supply valve 27 is connected to the common rail 22 and supplies a part of the fuel pumped up by the supply pump 21 into the exhaust manifold 25. The fuel supply valve 27 is configured by an electromagnetically driven needle valve. The fuel supply valve 27 supplies fuel as a reducing agent into the exhaust manifold 25 at a timing and supply amount corresponding to a command from the ECU 3, and supplies the fuel to the exhaust gas. It comes to mix.

The exhaust after-treatment device 28 is provided in the exhaust pipe 26 on the downstream side of the turbocharger 8 and has an oxidation catalyst such as palladium or platinum inside, and by the oxidation action of this oxidation catalyst, hydrocarbon HC and Carbon monoxide CO is oxidized to water H ₂ O or carbon dioxide CO ₂ . Further, the exhaust aftertreatment device 28 further has a NO _x storage reduction catalyst inside, and stores nitrogen oxide NO _x when the oxygen concentration of the exhaust gas is high, and when the oxygen concentration of the exhaust gas is low The stored nitrogen oxides are reduced to N ₂ by reacting with hydrocarbon HC and carbon monoxide CO.

  That is, in the exhaust aftertreatment device 28, the fuel is supplied to the exhaust gas by the fuel supply valve 27, so that the oxygen concentration in the exhaust gas is reduced and the reduction of nitrogen oxides is promoted. Yes.

  The air-fuel ratio sensor 29 is provided in the exhaust pipe 26 on the downstream side of the exhaust aftertreatment device 28, detects the air-fuel ratio of the exhaust gas discharged from the exhaust aftertreatment device 28, and outputs it to the ECU 3. The ECU 3 controls the fuel injection amount injected from the fuel injection valve 23 and the fuel supply amount supplied from the fuel supply valve 27 so that the air-fuel ratio output from the air-fuel ratio sensor 29 approaches the target air-fuel ratio. It has become.

  The turbocharger 8 has an intake air compressor 37 and an exhaust turbine 38 that are integrally connected to each other in the rotational direction, and rotates the intake air compressor 37 by rotating the exhaust turbine 38 with exhaust energy. Air can be sent in.

  The EGR device 9 has an EGR pipe 31 as an exhaust gas recirculation pipe that bypasses the combustion chamber and connects the exhaust passage in the exhaust manifold 25 and the intake passage in the intake manifold 14. An EGR valve 32 as a recirculation amount adjustment valve, which is an example of a flow rate adjustment unit that adjusts the recirculation amount of exhaust gas, a water-cooled EGR cooler 33 that cools the exhaust gas recirculating through the EGR pipe 31, and a cooling unit An air-cooled EGR cooler 34 is provided.

  The EGR valve 32 can be switched between a valve opening state in which the in-pipe passage of the EGR pipe 31 and the intake passage are in communication with each other and a valve-closed state in which communication between the in-pipe passage of the EGR pipe 31 and the intake passage is restricted or blocked. The opening degree can be controlled by a command from the ECU 3. Thus, the recirculation amount of the exhaust gas recirculated to the intake passage is adjusted by the opening degree control of the EGR valve 32.

  The EGR valve 32 is provided with an EGR valve opening sensor 35. The EGR valve opening sensor 35 detects the opening of the EGR valve 32, converts it into an electrical signal, and outputs it to the ECU 3. It has become.

  The water-cooled EGR cooler 33 is provided in the middle of the EGR pipe 31 and has a gas passage communicating with the pipe passage of the EGR pipe 31 and a cooling water passage to which a part of cooling water from the engine is supplied. ing. The water-cooled EGR cooler 33 cools the exhaust gas by exchanging heat between the cooling water flowing through the cooling water passage and the exhaust gas flowing through the gas passage.

  The air-cooled EGR cooler 34 is provided in the middle of the EGR pipe 31 downstream of the water-cooled EGR cooler 33, has a gas passage communicating with the pipe passage of the EGR pipe 31, and has a fin-like heat radiating member on the outer surface. Have. Although details will be described later, the air-cooled EGR cooler 34 is housed in a cowl 61 in front of the vehicle, and exhausts air by exchanging heat between the outside air flowing in via the cowl louver 65 and the exhaust gas flowing in the gas passage. The gas is cooled.

  The air conditioner 2 will be described with reference to FIG. FIG. 2 is a schematic configuration diagram of the air conditioner 2 according to the first embodiment of the present invention.

  The air conditioner 2 has a cylindrical case 41 connected to an outside air introduction duct 66 as an introduction portion described later, and a blower 42 that sucks air into the vehicle interior and a downstream of the blower 42 are provided in the case 41. An evaporator 43 serving as a cooling heat exchanger and a heater core 44 serving as a heating heat exchanger provided downstream of the evaporator 43 are provided.

The uppermost stream of the case 41 is formed with an outside air introduction port 41a into which outside air is introduced and an inside air introduction port 41b into which inside air is introduced. The outside air introduction port 41a is connected to the outside air introduction duct 66, and the inside air introduction port 41b is It opens toward the passenger compartment.
In addition, an inside / outside air damper 45 is rotatably provided in the vicinity of the outside air introduction port 41a and the inside air introduction port 41b in the case 41, and the inside / outside air damper 45 is driven by an actuator (not shown) according to a command from the ECU 3. The outside air inlet 41a and the inside air inlet 41b are selectively opened and closed.

  A filter 46 is provided between the outside air inlet 41a and the inside air inlet 41b and the blower 42, and foreign matters such as dust and dust contained in the air introduced from the outside air inlet 41a and the inside air inlet 41b. It is designed to prevent contamination.

  The blower 42 includes a centrifugal blower fan 51 and a blower motor 52 coupled to a rotation shaft of the blower fan 51. By rotating the blower fan 51, the outside air is introduced into the outside air inlet 41a and the inside air inlet 41b. Air is introduced into the case 41 from the side opened by the damper 45.

  The evaporator 43 constitutes a refrigeration cycle with a compressor, a condenser, a receiver, an expansion valve, and the like (not shown) so that the refrigerant 43 is cooled to low temperature and low pressure by the compressor, the condenser, the receiver, the expansion valve, and the like. It has become. The refrigerant flowing in the evaporator 43 exchanges heat with the air blown by the blower 42, whereby the air that has passed through the evaporator 43 is cooled.

  The heater core 44 forms a heating cycle with a cooling water passage or the like of the engine 1 (not shown), and cooling water heated through the engine 1 is sent into the heater core 44. The cooling water flowing in the heater core 44 exchanges heat with the air blown by the blower 42, so that the air that has passed through the heater core 44 is warmed.

  An air mix door 47 is rotatably provided between the evaporator 43 and the heater core 44, and the air mix door 47 is adjusted by an actuator (not shown) driven by an instruction from the ECU 3 to adjust the opening degree. It has become. Thus, by adjusting the opening degree of the air mix door 47, the ratio of the air passing through the heater core 44 and the air bypassing the heater core 44 is adjusted, and the temperature of the air blown into the vehicle interior is controlled. It is like that.

  In the most downstream of the case 41, a defroster outlet 41c that blows out to the inside of the windshield 63, a face outlet 41d that blows out to the upper body of the passenger, and a foot outlet 41e that blows out to the feet of the passenger are formed. Doors 53, 54, and 55 that open and close the air outlets 41c, 41d, and 41e are provided in the vicinity of the air outlets 41c, 41d, and 41e, respectively.

  The doors 53, 54, and 55 are configured to open and close the outlets 41c, 41d, and 41e by driving an actuator (not shown) according to a command from the ECU 3, and the outlet positions are selected according to various outlet modes. It is like that.

  Next, the peripheral part of the air introduction duct, which is a characteristic part of the present invention, will be described. FIG. 3 is a partial schematic view of the front portion of the vehicle according to the first embodiment of the present invention.

  As shown in FIG. 3, the front portion of the vehicle includes a hood panel 62, a windshield 63, a cowl 61 provided between a rear end portion of the hood panel 62 and a lower end portion of the windshield 63, and a cowl 61. It includes a dash panel 64 connected to the rear portion, an air conditioner 2 provided on the dash panel 64, and an outside air introduction duct 66 that connects the cowl 61 and the air conditioner 2. An engine room 67 is formed below the hood panel 62, and the engine room 67 and the vehicle compartment are partitioned by a dash panel 64.

  The cowl 61 extends in the vehicle width direction, and a cowl louver 65 is provided above the cowl 61 so as to cover the cowl 61. A slit is formed in the cowl louver 65, and outside air is introduced into the cowl 61 through the slit. A partition plate 68 extends in the vehicle width direction at the middle portion of the cowl louver 65 in the front-rear direction of the vehicle, and the cowl 61 is partitioned forward and backward by the partition plate 68.

The front portion of the cowl 61 partitioned by the partition plate 68 is a cooling air introduction portion 71 that houses the air-cooled EGR cooler 34 and introduces the cooling air that has passed through the air-cooled EGR cooler 34. Thus, outside air is introduced as cooling air for the air-cooled EGR cooler 34.
The rear portion of the cowl 61 partitioned by the partition plate 68 is an outside air introduction portion 72 for introducing outside air from the outside of the vehicle so that outside air that is not used as cooling air for the air-cooled EGR cooler 34 is introduced. It has become.

A communication passage 74 is formed in the lower portion of the cowl 61, and the communication passage 74 extends in the front-rear direction of the vehicle so as to communicate the cooling air introduction portion 71 and the outside air introduction portion 72. In addition, an opening is formed at the bottom of the cowl 61 at an intermediate position in the extending direction of the communication passage 74, and the communication passage 74 communicates with the inside of the outside air introduction duct 66 through this opening.
In addition, a communication hole 73 that connects the cooling air introduction part 71 and the engine room 67 is formed at the bottom of the cowl 61 on the cooling air introduction part 71 side, and the cooling air introduced into the air-cooled EGR cooler 34 is The outside air introduction duct 66 is introduced into the engine room 67 or the communication passage 74 through the communication hole 73.

  The communication path 74 is provided with a first switching damper 77 and a second switching damper 78 as a switching portion so as to be rotatable. According to the rotating operation of the first switching damper 77 and the second switching damper 78, Outside air is introduced into the outside air introduction duct 66 from either the cooling air introduction portion 71 or the outside air introduction portion 72.

  Specifically, the first switching damper 77 closes the communication hole 73 and connects the cooling air introduction part 71 and the outside air introduction duct 66 to each other, and the cooling air introduction part 71 and the engine room 67. At the same time, it rotates between the cooling air introduction part 71 and the shut-off position that shuts off the outside air introduction duct 66, and the cooling air introduction part 71 and the engine room 67 or the cooling air introduction part 71 and the outside air introduction duct. The communication state with 66 is selectively switched.

  Further, the second switching damper 78 rotates between a communication position where the outside air introduction part 72 and the outside air introduction duct 66 are communicated with each other and a blocking position where the outside air introduction part 72 and the outside air introduction duct 66 are blocked. Thus, the communication state between the outside air introduction portion 72 and the outside air introduction duct 66 is switched.

  Then, the first switching damper 77 rotates as indicated by an arrow A, and the second switching damper 78 rotates as indicated by an arrow C, whereby the cooling air introduction part 71 and the outside air introduction duct 66 are connected. The cooling air communicated through the passage 74 and heat-exchanged by the air-cooled EGR cooler 34 is introduced into the air conditioner 2 through the outside air introduction duct 66.

  On the other hand, the first switching damper 77 rotates as shown by arrow B and the second switching damper 78 rotates as shown by arrow D, so that the cooling air introduction unit 71 and the engine room 67 communicate with each other. The outside air introduction part 72 communicates with the inside of the outside air introduction duct 66 via the communication path 74. That is, the cooling air after the heat exchange by the air-cooled EGR cooler 34 flows into the engine room 67, and the outside air that has not been heat-exchanged by the air-cooled EGR cooler 34 is introduced into the air conditioner 2 through the outside air introduction duct 66. It has become.

  Returning to FIG. 1, the ECU 3 includes a CPU (Central Processing Unit) 84, a ROM (Read Only Memory) 85, a RAM (Random Access Memory) 86, an EEPROM (Electronically Erasable and Programmable Read Only Memory) 87, an A / D converter, An input interface circuit 88 including a buffer and the like and an output interface circuit 89 including a driving circuit are included.

  An air flow meter 15, an air-fuel ratio sensor 29, an EGR valve opening sensor 35, an inside air sensor 91, an outside air sensor 92, a solar radiation sensor 93, an evaporator temperature sensor 94, a water temperature sensor 95, and the like are connected to the input interface circuit 88 of the ECU 3. The information from these sensors 15, 29, 35, 91, 92, 93, 94, 95 is taken into the ECU 3.

The inside air sensor 91 detects the inside air temperature in the passenger compartment, converts it into an electrical signal, and outputs it to the ECU 3.
The outside air sensor 92 detects the outside air temperature outside the vehicle, converts it into an electrical signal, and outputs it to the ECU 3.
The solar radiation sensor 93 detects the amount of solar radiation incident on the passenger compartment, converts it into an electrical signal, and outputs it to the ECU 3.

The evaporator temperature sensor 94 detects the air temperature blown from the evaporator 43, converts it into an electrical signal, and outputs it to the ECU 3.
The water temperature sensor 95 detects the cooling water temperature of the engine 1 circulating through the heater core 44, converts it into an electrical signal, and outputs it to the ECU 3.

Further, an air conditioning switch 96 for switching ON / OFF of the air conditioner 2 and a mode switching switch 97 for switching the operation mode of the air conditioner 2 are connected to the input interface circuit 88 of the ECU 3.
The mode changeover switch 97 has an inside air circulation mode and an outside air introduction mode as operation modes, and can selectively switch between the two modes by the operation of the driver.

  When the mode switch 97 is operated to switch the air conditioner 2 to the inside air circulation mode, the inside / outside air damper 45 shown in FIG. 2 rotates so as to close the outside air introduction port 41a, and the inside of the air conditioner 2 and the vehicle interior Are communicated, and the introduction of outside air into the air conditioner 2 is prevented. On the other hand, when the air conditioner 2 is switched to the outside air introduction mode by operating the mode change switch 97, the inside / outside air damper 45 rotates so as to close the inside air introduction port 41b, and the inside of the outside air introduction duct 66 and the inside of the air conditioner 2 are turned on. Are communicated with each other, and outside air is introduced into the passenger compartment.

  The output interface circuit 89 of the ECU 3 includes a supply pump 21, a plurality of fuel injection valves 23, a fuel supply valve 27, an EGR valve 32, an air conditioner 2, a first switch damper 77, a second switch, via respective drive circuits not shown. A switching damper 78 is connected, and each device 21, 23, 27, 32, 2, 77, 78 is driven and controlled based on a command from the ECU 3.

Next, the operation will be described.
FIG. 4 is a flowchart showing an air conditioning control process according to the first embodiment of the present invention.

  When the air conditioning switch 96 of the air conditioner 2 is turned on (Yes in step S11), the target temperature in the passenger compartment preset by the ECU 3, the inside air sensor 91, the outside air sensor 92, the solar radiation sensor 93, the evaporator temperature sensor 94, the water temperature sensor. The rotational speed of the blower fan 51 of the blower 42 and the opening of the air mix door 47 are controlled based on the inside air temperature, the outside air temperature, the amount of solar radiation, the air temperature blown out from the evaporator 43, and the cooling water temperature obtained from 95. The vehicle interior temperature is adjusted so as to approach the target temperature.

  Next, the ECU 3 determines whether the operation mode of the air conditioner 2 is the outside air introduction mode or the inside air circulation mode (step S12). When the ECU 3 determines that the operation mode of the air conditioner 2 is the inside air circulation mode (No in step S12), the process proceeds to step S16. On the other hand, when the operation mode of the air conditioner 2 is determined to be the outside air introduction mode by the ECU 3 (Yes in step S12), the ECU 3 determines whether or not the temperature in the vehicle interior is lower than the target temperature (step S13).

  Next, when the ECU 3 determines that the temperature in the vehicle compartment is lower than the target temperature (Yes in step 13), the first switching damper 77 is rotated to a position where the cooling air introduction portion 71 and the outside air introduction duct 66 are communicated. The second switching damper 78 rotates to a position where the outside air introduction part 72 and the outside air introduction duct 66 are blocked, and the cooling air after heat exchange is performed by the air-cooled EGR cooler 34 from the cooling air introduction part 71. The air is introduced into the air conditioner 2 through the outside air introduction duct 66 (step S14).

  On the other hand, if the ECU 3 determines that the temperature in the vehicle interior is equal to or higher than the target temperature (No in step S13), the first switching damper 77 rotates to a position where the cooling air introduction part 71 and the outside air introduction duct 66 are blocked. The second switching damper 78 rotates to a position where the outside air introduction part 72 and the outside air introduction duct 66 communicate with each other, and the outside air that is not heat exchanged by the air-cooled EGR cooler 34 is air-conditioned from the outside air introduction part 72 through the outside air introduction duct 66. It is introduced into the device 2 (step S15).

  Next, when the switching operation by the switching damper is completed in step S14 and step S15, or when it is determined in step S12 that the air conditioner 2 is in the inside air circulation mode, from step S12 until the air conditioner switch 96 of the air conditioner 2 is turned off. The process up to step S15 is repeated (step S16).

  As described above, in the present embodiment, the EGR pipe 31, the air-cooled EGR cooler 34 provided in the middle part of the EGR pipe 31, the air conditioner 2 that takes in the inside air or outside air and sends it out to the vehicle interior, and the vehicle interior In the vehicle heating system including the ECU 3 that controls the air conditioner 2 so as to bring the temperature of the engine close to the target temperature, the cooling air after heat exchange with the exhaust gas is introduced into the air conditioner 2 by the air-cooled EGR cooler 34. The outside air introduction duct 66 is provided.

Therefore, since the cooling air after heat exchange with the exhaust gas in the air-cooled EGR cooler 34 is introduced into the air conditioner 2 through the outside air introduction duct 66, the warm air after heat exchange is used for heating the air conditioner 2. Can be used.
Therefore, since warm air can be introduced into the air conditioner 2 without forcibly driving the engine 1, heating performance can be improved without causing deterioration of fuel consumption.

In the present embodiment, the communication state between the cooling air introduction part 71 and the outside air introduction part 72 and the outside air introduction duct 66 is switched by the first switching damper 77 and the second switching damper 78. When it is not necessary to introduce the cooling air after heat exchange into the air conditioner 2 when the temperature is higher than the target temperature, the cooling air after heat exchange is not introduced into the outside air introduction duct 66 from the cooling air introduction part 71. As described above, the first switching damper 77 and the second switching damper 78 block the cooling air introduction portion 71 and the outside air introduction duct 66 to suppress the influence of the cooling air after heat exchange on the air conditioner 2. it can.
On the other hand, for example, when it is necessary to introduce the cooling air after heat exchange into the air conditioner 2 when the temperature in the passenger compartment is lower than the target temperature, the first switching damper 77 and the second switching damper 78 cool the cooling air. It is possible to improve the heating performance of the air conditioner 2 by communicating the air introduction part 71 and the outside air introduction duct 66.

  In the present embodiment, when the temperature in the passenger compartment is lower than the target temperature, the first switching damper 77 and the second switching damper 78 are driven and heat is exchanged by the air-cooled EGR cooler 34. The air is introduced into the air conditioner 2, but when the preset temperature lower than the target temperature is stored in the ECU 3 in advance and the temperature in the passenger compartment is lower than the preset temperature, the first switching damper 77 and the first The two-switching damper 78 may be driven. Thus, by setting the set temperature in consideration of the control error caused by the temperature in the passenger compartment exceeding the target temperature, the time until the temperature in the passenger compartment exceeds the target temperature and stabilizes can be reduced. It is possible to reduce the air conditioning control with higher accuracy.

(Second Embodiment)
The vehicle heating system according to the second embodiment of the present invention has the same configuration as the vehicle heating system according to the first embodiment described above, and is different from the first embodiment by the EGR valve 32. The only difference is that the heating control is assisted by adjusting the flow rate of the exhaust gas passing through the air-cooled EGR cooler 34. Therefore, the same configuration will be described using the same reference numerals as those in the first embodiment, and only differences will be described in detail.

  The ECU 3 estimates the operating state of the engine 1 from the temperature of the cooling water acquired from the water temperature sensor 95 and the opening degree of the EGR valve 32 based on the estimated operating state of the engine 1 and the operating state of the air conditioner 2. It comes to adjust.

  In general, the ECU 3 adjusts the opening degree of the EGR valve 32 so as to increase the flow rate of the exhaust gas passing through the EGR pipe 31 when the temperature of the cooling water on the cylinder 24 side is high, so that the water-cooled EGR cooler 33 and the air-cooling Exhaust gas cooled in the EGR cooler 34 is introduced into the combustion chamber in a large amount, and the combustion temperature is lowered in conjunction with the decrease in the oxygen concentration. However, in this embodiment, the temperature within the vehicle compartment does not exceed the target temperature. The opening degree of the EGR valve 32 is adjusted.

  That is, when the ECU 3 determines that the temperature in the vehicle interior is equal to or higher than the target temperature, the opening degree of the EGR valve 32 is adjusted so that the flow rate of the exhaust gas flowing through the EGR pipe 31 is reduced. The temperature rise of the cooling air supplied to the cooler 34 is suppressed.

As described above, in the present embodiment, the air-cooled EGR cooler 34 is used when it is not necessary to introduce the cooling air after heat exchange into the air conditioner 2 when the temperature in the passenger compartment is higher than the target temperature. The flow rate of the exhaust gas passing therethrough can be reduced to suppress the temperature rise of the cooling air, and the influence of the cooling air after heat exchange on the air conditioner 2 can be suppressed.
On the other hand, when it is necessary to introduce the cooling air after heat exchange into the air conditioner 2 when the temperature in the passenger compartment is lower than the target temperature, the flow rate of the exhaust gas passing through the air-cooled EGR cooler 34 is increased. Thus, the temperature of the cooling air can be raised and the heating performance of the air conditioner 2 can be improved.

  In the case of this configuration, by setting the operation mode of the air conditioner 2 to the inside air circulation mode, the outside air introduction port 41a is closed by the inside / outside air damper 45 and the outside air introduced into the air conditioner 2 through the outside air introduction duct 66 is used. It is also possible to prevent the influence on the air conditioning control. Thereby, the influence on the air conditioner 2 of the cooling air after heat exchange can be suppressed without reducing the flow rate of the exhaust gas flowing through the EGR pipe 31. Further, since it is not necessary to reduce the flow rate of the exhaust gas flowing through the EGR pipe 31, NOx can be reduced and fuel consumption can be improved.

  Further, the cooling air introduction part 71 and the outside air introduction duct 66 are blocked by the first switching damper 77 and the second switching damper 78, so that the cooling air heated by the air-cooled EGR cooler 34 is air-conditioned through the outside air introduction duct 66. Since it is not introduced into the device 2, it is possible to prevent the influence of outside air introduced into the air conditioner 2 on the air conditioning control. Thereby, the influence on the air conditioner 2 of the cooling air after heat exchange can be suppressed, without setting the operation mode of the air conditioner 2 to the inside air circulation mode.

(Third embodiment)
The vehicle heating system according to the third embodiment of the present invention differs from the vehicle heating system according to the first embodiment described above in that the air-cooled EGR cooler 34 is made to flow by flowing exhaust gas through the bypass pipe 98. The only difference is that the heating control is assisted by adjusting the flow rate of the exhaust gas passing therethrough. Therefore, the same configuration will be described using the same reference numerals as those in the first embodiment, and only differences will be described in detail.
FIG. 5 is a schematic configuration diagram of a vehicle heating system according to the third embodiment of the present invention.

  As shown in FIG. 5, the EGR pipe 31 has a flow rate for connecting the upstream portion and the downstream portion of the air-cooled EGR cooler 34 so as to bypass the air-cooled EGR cooler 34 downstream of the water-cooled EGR cooler 33. A bypass pipe 98 is provided as an adjustment unit, and a bypass valve 99 is provided upstream of the bypass pipe 98.

  The ECU 3 estimates the operating state of the engine 1 from the temperature of the cooling water obtained from the water temperature sensor 95, and also bypasses the bypass valve based on the estimated operating state of the engine 1, the temperature in the passenger compartment during air-conditioning control, and the target temperature. The opening degree of 99 is adjusted.

  That is, when the ECU 3 determines that the temperature in the passenger compartment is equal to or higher than the target temperature, the opening of the bypass valve 99 is adjusted so that the amount of exhaust gas flowing through the bypass pipe 98 is increased. The flow rate of the exhaust gas flowing through the air-cooling EGR cooler 34 is reduced, and the temperature rise of the cooling air supplied to the air-cooled EGR cooler 34 is suppressed. ing.

  As described above, in the present embodiment, by adjusting the flow rate of the exhaust gas flowing into the bypass pipe 98 by the bypass valve 99, the flow rate of the exhaust gas passing through the air-cooled EGR cooler 34 is adjusted, and the air-cooled type The temperature rise of the cooling air after heat exchange in the EGR cooler 34 can be controlled.

  In the case of this configuration, as in the second embodiment of the present invention, the inside / outside air damper 45, the first switching damper 77, and the second switching damper 78 are driven to be introduced into the air conditioner 2. It is also possible to prevent the influence of outside air on the air conditioning control.

(Fourth embodiment)
The vehicle heating system according to the fourth embodiment of the present invention has the same configuration as the vehicle heating system according to the first embodiment described above, and the air conditioner 2 is different from the first embodiment. The only difference is the forced shy mode. Therefore, the same configuration will be described using the same reference numerals as those in the first embodiment, and only differences will be described in detail.

In the forced inside air mode, the outside air inlet 41a is forcibly closed by the inside / outside air damper 45 based on the operating state of the engine 1 and the operating state of the air conditioner 2 regardless of the operation mode selected by the mode changeover switch 97. It has become.
Specifically, it is determined whether or not the exhaust gas is flowing into the EGR pipe 31 from the temperature of the cooling water acquired from the water temperature sensor 95 by the ECU 3 as the determining means, and the air conditioning is performed from the temperature in the passenger compartment and the target temperature. It is determined whether the device 2 is in a cooling operation or a heating operation. When the ECU 3 determines that the ECU control is to be performed and the cooling operation is determined, the operation mode of the air conditioner 2 is switched to the forced inside air mode, and the outside air introduction port 41 a is closed by the inside / outside air damper 45.

  As described above, in the present embodiment, the cooling air heat-exchanged in the air-cooled EGR cooler 34 during cooling is prevented from being introduced into the air conditioner 2, so the flow rate of the exhaust gas flowing through the EGR pipe 31 is reduced. Without reducing, the influence of the cooling air after heat exchange on the air conditioner 2 can be suppressed. Further, since it is not necessary to reduce the flow rate of the exhaust gas flowing through the EGR pipe 31, NOx can be reduced and fuel consumption can be improved.

  In the present embodiment, as shown in FIG. 6, the first switching damper 77 and the second switching damper 78 are not provided, and the air-cooled EGR cooler 34 is used as in the second and third embodiments. The air conditioning control may be assisted by adjusting the flow rate of the exhaust gas passing through the air.

  With this configuration, the air conditioner 2 is often operated in the inside air circulation mode by the cooling operation in summer, and the outside air is not introduced into the air conditioner 2 through the outside air introduction duct 66. Therefore, the flow rate of the exhaust gas flowing through the air-cooled EGR cooler 34 The frequency of suppressing the exhaust gas is often low, the heating operation is often performed in winter, the frequency of suppressing the flow rate of the exhaust gas flowing through the air-cooled EGR cooler 34 is low, and further based on the operating state of the engine 1 and the operating state of the air conditioner 2 Therefore, compared with the configuration in which the first switching damper 77 and the second switching damper 78 are provided to assist the air conditioning of the air conditioner 2, the same effect can be achieved at a low cost. Obtainable.

  Further, in each of the above-described embodiments, the cooling air introduced into the air-cooled EGR cooler 34 is introduced from the outside of the vehicle via the cowl louver 65, so that it is air-cooled compared to a configuration in which a dedicated cooling fan is provided. The EGR cooler 34 can have a simple configuration, and costs can be reduced. Further, since the outside air is introduced from between the rear end portion of the hood panel 62 and the lower end portion of the windshield 63 via the cowl louver 65, the ingress of dust and the generation of odors are reduced as compared with the configuration in which the outside air is introduced from under the floor. Can be prevented.

  The embodiment disclosed this time is illustrative in all respects and is not limited to this embodiment. The scope of the present invention is shown not by the above description of the embodiments but by the scope of the claims, and is intended to include all modifications within the meaning and scope equivalent to the scope of the claims.

  As described above, the present invention can improve the heating performance without deteriorating the fuel consumption. In particular, the cooling air after cooling the exhaust flowing through the exhaust gas recirculation pipe is used for the heating control. It is useful for a suitable vehicle heating system.

It is a schematic structure figure of the heating system for vehicles concerning a 1st embodiment of the present invention. It is a schematic block diagram of the air conditioning apparatus which concerns on the 1st Embodiment of this invention. It is a partial schematic diagram of the front portion of the vehicle according to the first embodiment of the present invention. It is a flowchart which shows the air-conditioning control process which concerns on the 1st Embodiment of this invention. It is a schematic block diagram of the heating system for vehicles which concerns on the 3rd Embodiment of this invention. It is a schematic block diagram of the modification of the heating system for vehicles which concerns on the 4th Embodiment of this invention.

Explanation of symbols

1 engine (internal combustion engine)
2 Air conditioner (air conditioner)
3 ECU (air conditioning control means, determination means)
4 Intake Device 5 Fuel Injection Device 6 Exhaust Device 8 Turbocharger 9 EGR Device 13 Intake Pipe 26 Exhaust Pipe 31 EGR Pipe (Exhaust Recirculation Pipe)
32 EGR valve (Reflux control valve)
33 Water-cooled EGR cooler 34 Air-cooled EGR cooler (cooling section)
41a Outside air inlet 41b Inside air inlet 43 Evaporator (cooling heat exchanger)
44 Heater core (heat exchanger for heating)
45 Inside / outside air damper 61 Cowl 62 Hood panel 63 Windshield 65 Cowl louver 66 Outside air introduction duct (introduction part)
71 Cooling air introduction part 72 Outside air introduction part 77 First switching damper (switching part)
78 Second switching damper (switching section)
98 Bypass pipe 99 Bypass valve

Claims (7)

An exhaust gas recirculation pipe for recirculating a part of the exhaust gas flowing through the exhaust pipe of the internal combustion engine to the intake pipe;
A cooling unit that is provided in an intermediate portion of the exhaust gas recirculation pipe, and cools the exhaust gas by exchanging heat with cooling air while the exhaust gas passes;
An air conditioning unit that includes a cooling heat exchanger and a heating heat exchanger inside, takes in the inside air or outside air, and sends it into the passenger compartment,
In a vehicle heating system comprising air conditioning control means for controlling the air conditioning unit so that the temperature in the passenger compartment approaches the target temperature,
A vehicle heating system comprising: an introduction unit that introduces cooling air after heat exchange with the exhaust gas by the cooling unit into the air conditioning unit. An outside air introduction section for introducing outside air into the introduction section from outside the vehicle;
A cooling air introduction section for introducing cooling air after heat exchange with the exhaust gas from the cooling section to the introduction section;
A switching unit that switches a communication state between the introduction unit and any one of the outside air introduction unit and the cooling air introduction unit;
2. The vehicle heating system according to claim 1, wherein the air-conditioning control unit switches the switching unit so that the temperature in the vehicle interior approaches the target temperature. A flow rate adjusting unit for adjusting the flow rate of the exhaust gas passing through the cooling unit;
3. The vehicle heating system according to claim 1, wherein the air conditioning control unit adjusts the flow rate adjusting unit so that the temperature in the vehicle interior approaches the target temperature. 4.   The vehicle heating system according to claim 3, wherein the flow rate adjustment unit includes an annular flow rate adjustment valve that adjusts a flow rate of exhaust gas flowing through the exhaust gas recirculation pipe. A bypass pipe that communicates the upstream part and the downstream part of the cooling part of the exhaust gas recirculation pipe so that the flow rate adjusting part bypasses the cooling part;
The vehicle heating system according to claim 3, further comprising a bypass valve that adjusts a flow rate of exhaust gas flowing into the bypass pipe. An inside / outside air damper that closes or opens the introduction part;
Determination means for determining whether exhaust gas is flowing into the cooling unit according to the operating state of the internal combustion engine,
The air conditioning control means closes the introduction part by the inside / outside air damper when the judgment means judges that the exhaust gas is flowing into the cooling part during cooling. The vehicle heating system according to any one of claims 5. A cowl louver disposed between the rear end of the hood panel of the vehicle and the lower end of the windshield and extending in the width direction of the vehicle;
The vehicle heating system according to any one of claims 1 to 6, wherein the cooling air is introduced into the cooling unit from outside the vehicle via the cowl louver.

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