JP2007321744A - Electric pump control method and vehicle heating device - Google Patents

Abstract

When an engine cooling water is circulated to an engine, an engine radiator and a heater core using one electric pump, proper heating can be achieved while saving power.
An air conditioner ECU that controls the operation of an electric pump sets a flow rate of cooling water to an engine radiator based on a water temperature and the like, and also sets a flow rate of cooling water to a heater core based on a heating load such as an outside air temperature. Set (steps 100 and 102). Thereafter, the flow rate of cooling water required for the electric pump is set from the sum of the respective flow rates, and rotation control of the electric pump is performed based on the set flow rate (steps 104 to 108). With this simple process, the air conditioner ECU can heat the air conditioning air accurately with the heater core while suppressing the excess or deficiency in the flow rate of the cooling water and saving power when driving the electric pump. It is said.
[Selection] Figure 1

Description

  The present invention relates to a method for controlling an electric pump that circulates cooling water when air-conditioning the inside of the vehicle interior using cooling water of an internal combustion engine such as an engine, and the interior of the vehicle interior by engine cooling water supplied to a heater core by the electric pump. The present invention relates to a vehicle heating apparatus for heating.

  In a vehicle using an engine as a driving source, the engine coolant is circulated between the engine and the engine radiator, and the coolant is circulated between the engine and a heater core of an air conditioner (hereinafter referred to as an air conditioner). A circuit is provided to heat the conditioned air blown out into the passenger compartment using engine cooling water.

  Conventionally, the water pump is driven by the driving force of the engine to circulate the engine cooling water to each of the engine radiator and the heater core, and the flow rate of the cooling water circulated to the engine radiator is controlled using a thermostat. In recent years, however, there are vehicles in which a water pump is driven by the driving force of the electric motor (hereinafter referred to as an electric pump) to circulate engine cooling water.

  In general, in an air conditioner, the temperature of a target blowing air (target blowing temperature) is set based on a set temperature, a cabin temperature, an outside temperature, and an amount of solar radiation. The flow rate of hot water supplied from the engine side to the heater core and the target mixing ratio of the cold water cooled by the heater core are determined, and the rotational speed of the electric pump is set based on this target mixing ratio, whereby the hot water flow rate It is proposed to adjust properly.

  By the way, when using an electric pump for circulation of engine cooling water, in order to save power, it is necessary to appropriately control the number of rotations of the electric pump and circulate the engine cooling water efficiently.

  In contrast to this electric pump control, in Patent Document 2, a target cooling water temperature is set based on the cooling water temperature, the engine speed, and the like, and the electric pump rotation is performed based on the actual cooling water temperature and the target cooling water temperature. Proposals have been made so that the cooling water temperature converges to the target cooling water temperature while controlling the number of electric pumps while suppressing the power consumption of the electric pump.

  Further, in Patent Document 3, the flow rate control valve that controls the flow rate of the cooling water to the engine radiator is fully closed, and the electric pump is driven so that the flow rate becomes maximum when the cooling water temperature becomes higher than the heater inlet side air temperature. By setting the heater performance promotion mode so that the heating operation can be obtained before the warm-up operation of the internal combustion engine is completed, the rotational speed of the internal combustion engine, the load, the cooling water temperature, the vehicle speed, the heater of the air conditioner It has been proposed to suppress the electric power consumption of the electric pump by setting the number of rotations of the electric pump based on the demand.

  On the other hand, in Patent Document 4, in the range where the Reynolds number Re is 1800 to 6000, the fan motor for cooling the engine radiator and the electric pump are driven to improve the cooling efficiency by the engine radiator to save power. Proposals have been made.

In Patent Document 4, for example, when the outside air temperature is 10 ° C. or lower and the cooling water temperature is 105 ° C. or lower, or when the cooling water temperature is 80 ° C. or lower and the room temperature does not exceed the target temperature. The electric pump is driven at the minimum flow rate (for example, 10 l / min), but when the cooling water temperature exceeds 105 ° C, the electric pump is driven so that the Reynolds number Re becomes 2600, thereby saving power. It has been proposed to enable heating of air-conditioning air using a heater core while trying to make it easier.
Japanese Patent No. 2595508 JP 2001-32714 A JP 2004-360509 A JP 2002-332842 A

  However, the heating temperature when the cooling water is circulated through the heater core to heat the air-conditioning air is determined by the temperature of the cooling water and the circulation amount of the cooling water. When idling in an environment where the outside air temperature is low, the flow rate of the cooling water circulated through the heater core may become insufficient, while when the outside air temperature is not so low, the flow rate of the cooling water may be excessive.

  That is, when considering the heating efficiency, it is preferable that the flow rate of the cooling water circulated to the heater core can be continuously changed according to the heating load, and thereby the flow rate of the cooling water (the number of rotations of the electric pump). Therefore, it is possible to save power while suppressing the occurrence of excess or deficiency.

  Specifically, it is preferable to increase the flow rate of the cooling water to the heater core as the outside air temperature is lower, and to increase the flow rate of the cooling water to the heater core as the room temperature is lower than the target temperature. In order to do this, it is necessary to divide a large number of conditions and combinations, which causes a problem that the control program becomes complicated.

  The present invention has been made in view of the above-mentioned facts, and when heating the air conditioning air together with the cooling of the engine cooling water by circulating the engine cooling water, an appropriate heating capacity can be obtained with a simple control. It is an object of the present invention to provide an electric pump control method that can save power while making it possible, and a vehicle heating device that enables efficient heating while saving power.

  In order to achieve the above object, an electric pump control method according to the present invention includes: an engine radiator that cools engine cooling water; and a control of the electric pump that sends engine cooling water to each of a heater core that heats conditioned air using engine cooling water. The method sets the flow rate of engine cooling water to be sent to the engine radiator based on the water temperature of the engine cooling water, and sends the flow rate to the heater core based on a heating load when air-conditioning a vehicle interior with the conditioned air. A flow rate of engine cooling water is set, and based on the sum of the flow rate to the engine radiator and the flow rate to the heater core, the required flow rate of the engine cooling water sent out by the electric pump is set, and the set required flow rate is The electric pump is driven so as to be obtained.

  According to the present invention, the engine cooling water is sent to the engine radiator and the heater core by the electric pump, thereby cooling the engine (engine cooling water) and heating using the engine cooling water.

  Here, the engine radiator is provided with a thermostat that opens and closes the flow path in accordance with the temperature of the engine cooling water. When the temperature of the engine cooling water is low, the flow rate of the engine cooling water is suppressed.

  Further, when heating is performed with the engine cooling water sent to the heater core, it is necessary to increase the flow rate of the engine cooling water if the heating load is large. However, if the heating load is small, it is preferable to decrease the flow rate of the engine cooling water. An appropriate flow rate of engine cooling water from the heating load to the heater core can be determined.

  In the present invention, when the engine coolant is sent to the engine radiator and the heater core with one electric pump, the electric pump is driven so that the sum of the flow rate to the engine radiator and the flow rate to the heater core is obtained.

  As a result, it is possible to suppress an excess or deficiency in the flow rate of the engine coolant, and to save power when the electric pump is driven.

  The invention according to claim 2 is characterized in that an outside air temperature that is an environmental condition outside the vehicle is detected as the heating load, and a flow rate of the engine cooling water to be sent to the heater core is set based on the detected outside air temperature.

  According to the present invention, the outside air temperature is detected as the heating load. When the outside air temperature is low, the heating load is large. Therefore, the flow rate of the cooling water to the heater core is set to be large. Since it is small, set the flow rate to the heater core small.

  According to a third aspect of the present invention, the target flow temperature of the conditioned air blown into the passenger compartment is used as the heating load, and the flow rate of the engine cooling water to be sent to the heater core is set based on the target blow temperature. Features.

  According to this invention, since the target blowing temperature varies depending on the heating load, when the target blowing temperature is high, it is determined that the heating load is large, and the flow rate to the heater core is set so that the target blowing temperature is increased. When it is low, it is determined that the heating load is small, and the flow rate to the heater core is set low.

  Thereby, the electric pump can be driven so that the flow rate of the engine cooling water to the heater core becomes appropriate.

  The invention according to claim 4 is characterized in that the flow rate to the engine radiator is set including the outside air temperature or the engine speed in the water temperature of the engine cooling water.

  According to this invention, when the outside air temperature is low or when the engine speed is low, the water temperature of the engine cooling water tends to be low, and when the outside air temperature is high or when the engine speed is high, the water temperature of the engine cooling water becomes high. Cheap.

  From this point, when the water temperature of the engine cooling water tends to be low, the flow rate to the engine radiator is decreased, and when the water temperature of the engine cooling water tends to be high, the flow rate to the engine radiator is increased.

  Thereby, the electric pump can be driven so that the flow rate to the engine radiator becomes appropriate.

  Such a vehicle heating apparatus according to the present invention is a cooling water circuit provided with a thermostat for connecting an engine and an engine radiator and opening and closing a flow path of the engine cooling water to the engine radiator based on the temperature of the engine cooling water. And a heater core and a circulation circuit that connects the engine to the engine so that the engine coolant can circulate, and an electric pump that sends the engine coolant from the engine to the coolant circuit and the circulation circuit. A vehicle heating apparatus that heats conditioned air for air-conditioning a vehicle interior with the engine cooling water circulated to the heater core, the water temperature detecting means for detecting the water temperature of the engine cooling water, and the detection result of the water temperature detecting means A first flow rate setting means for setting a first flow rate of the engine coolant to be sent to the engine radiator based on And second flow rate setting means for setting a second flow rate of the engine cooling water to be sent to the heater core based on a heating load when heating the vehicle interior, the first flow rate and the second flow rate Drive means for setting the required flow rate of the electric pump from the sum and driving the electric pump so as to obtain the set required flow rate.

  According to this invention, the first flow rate set by the first flow rate setting means based on the coolant temperature of the engine cooling water and the second flow rate set by the second flow rate setting means based on the heating load. The electric pump is driven so that a sum flow rate is obtained.

  Thereby, it is possible to prevent the heating capacity from being excessive or insufficient due to excessive or insufficient engine cooling water to the heater core while saving power.

  The invention according to claim 6 includes an outside air temperature detecting unit that detects an outside air temperature as the heating load, and the second flow rate setting unit sets the second flow rate from the outside air temperature. .

  According to the present invention, when the outside air temperature is high, the heating load is small. When the outside air temperature is low, the heating load is large. Therefore, when the outside air temperature is low, the second flow rate is increased. Set the flow rate of 2 low. Thereby, an appropriate heating capacity can be obtained while saving power.

  Note that the target blowing temperature when heating the passenger compartment is generally calculated including the outside air temperature, and when the heating load is large, the target blowing temperature is also high. From here, when the target blowing temperature is high, the second flow rate may be increased, and when the target blowing temperature is low, the second flow rate may be set small.

  As described above, according to the electric pump control method of the present invention, it is possible to efficiently drive the electric pump while suppressing the excess or deficiency in the flow rate of the engine cooling water. By using this, it is possible to save power for engine cooling water.

  At the same time, the present invention can set the flow rate of the electric pump by a simple process, so that an excellent effect that the development cost of the processing program can be suppressed can be obtained.

  In the vehicle heating device of the present invention, the electric pump can be efficiently driven to obtain an appropriate heating capacity.

  Embodiments of the present invention will be described below with reference to the drawings. FIG. 2 shows a schematic configuration of a vehicle air conditioner (hereinafter referred to as an air conditioner 10) applied as a vehicle heating device to the present embodiment.

  In the air conditioner 10, a compressor 12, a condenser 14, an expansion valve 16, and an evaporator 18 form a refrigeration cycle that circulates refrigerant.

  The compressor 12 is driven by the compressor motor 20 to compress the refrigerant and send out the high-temperature and high-pressure refrigerant. This refrigerant is cooled and liquefied by the condenser 14, and the evaporator 18 cools the air passing through the evaporator 18 when the liquefied refrigerant is vaporized.

  At this time, moisture in the air is condensed in the evaporator 18, thereby dehumidifying the air passing through the evaporator 18. The expansion valve 16 is liquefied and abruptly depressurizing the refrigerant so as to be atomized to be supplied to the evaporator 18. The refrigerant evaporating efficiency in the evaporator 18, that is, the air passing through the evaporator 18 is supplied. The cooling efficiency is improved.

  The air conditioner 10 includes an air conditioning duct 22, and the evaporator 18 is disposed in the air conditioning duct 22. A plurality of air intakes 24 are formed on one end side of the air conditioning duct 22. As the air intake 24, an air intake 24 </ b> A that opens toward a vehicle interior (not shown) that is air-conditioned by the air conditioner 10 and an air intake 24 </ b> B that communicates with the outside (outside of the vehicle) of the vehicle are provided.

  Further, the air conditioning duct 22 is provided with a mode switching damper 26 that opens and closes the air intakes 24A and 24B and a blower fan 28. The blower fan 28 is rotationally driven by the blower motor 30, so that the air intake 24A. Alternatively, air in the vehicle interior or air outside the vehicle is sucked into the air conditioning duct 22 from the air intake 54 </ b> B and sent out toward the evaporator 18.

  The air conditioner 10 is selectable between an inside air circulation mode and an outside air introduction mode. When the inside air circulation mode is selected, the air intake port 24B is closed by the mode switching damper 26, and the air intake port 24A closes the interior of the vehicle interior. Air (inside air) is introduced. In the air conditioner 10, when the outside air introduction mode is selected, the air intake 24 </ b> A is blocked by the mode switching damper 26, and air outside the vehicle (outside air) is introduced into the air conditioning duct 22 from the air intake 24 </ b> B.

  On the other hand, a plurality of air outlets 32 are formed on the other end side of the air conditioning duct 22. The air outlet 32 includes a center defroster outlet 32A that opens toward the windshield glass of the vehicle, a defroster outlet 32A such as a side defroster outlet, a center register outlet that opens toward the passenger in the vehicle compartment, and a side register. It includes a register outlet 32B, such as an outlet, and a foot outlet 32C that opens toward the feet of the front and rear passengers.

  The air conditioning duct 22 is provided with a switching damper 34, and the air blowing port 32 is selectively opened and closed by the switching damper 34.

  In the air conditioner 10, as the air-conditioning air blowing mode, the DEF mode blowing from the defroster outlet 32A, the FACE mode blowing from the register outlet 32B, the FOOT mode blowing from the foot outlet 32C, and the DEF blowing from the register outlet 32A and the foot outlet 32C. The / FOOT mode and the BI-LEVEL mode for blowing out from the register outlet 32B and the foot outlet 32C can be selected.

  In the air conditioner 10, the switching damper 34 is operated based on the selected air-conditioning air blowing mode, and the air-conditioning air is blown out from the air outlet 32 based on the selected air-blowing mode.

  In the air conditioner 10, a heater core 36 and an air mix damper 38 are provided in the air conditioning duct 22. The air mix damper 38 guides the air that has passed through the evaporator 18 to the heater core 36 at a ratio corresponding to the opening degree. Further, on the downstream side of the heater core 36, the air that has passed through the heater core 36 and the air that has bypassed the heater core 36 are mixed, and conditioned air that blows out into the passenger compartment is generated.

  In the air conditioner 10, the air cooled by the evaporator 18 is heated by the heater core 36, and the temperature of the air that has passed through the evaporator 18 (post-evaporator temperature), the temperature of the air that has passed through the heater core 36, and the mixing ratio. The conditioned air having a predetermined temperature (target blowing temperature) is generated, and the generated conditioned air is blown into the vehicle interior from the air outlet 32 so that the temperature in the vehicle interior becomes the set temperature.

  On the other hand, as shown in FIG. 3, the vehicle provided with the air conditioner 10 includes an engine 40 as a driving source for traveling, and can travel by the driving force of the engine 40.

  The engine 40 is a water-cooled internal combustion engine having a general configuration in which a water jacket (both not shown) serving as a circulation path for engine cooling water (hereinafter referred to as cooling water) is formed in a cylinder block and a cylinder head. ing.

  The vehicle is provided with an engine radiator 42, and a cooling water circuit 44 through which cooling water is circulated is formed between the engine (water jacket) 40 and the engine radiator 42.

  The cooling water circuit 44 is provided with a water pump 48 (hereinafter collectively referred to as an electric pump 50) that is rotationally driven by the driving force of the electric motor 46. Thus, when the electric pump 50 is operated, the cooling water flows to the engine radiator 42 through the cylinder block and the cylinder head of the engine 40, and the cooling water of the engine radiator 42 passes to the cylinder block of the engine 40 through the electric pump 50. It is sent.

  In the engine radiator 42, air on the vehicle front side is guided as cooling air by a vehicle running or a cooling fan (not shown), and cooling water circulated between the engine 40 is cooled by the cooling air. The cooling water is circulated to the engine 40, whereby the engine 40 is cooled.

  The cooling water circuit 44 is provided with a thermostat 52 and a bypass circuit 54 that bypasses the engine radiator 42. The thermostat 52 opens and closes the cooling water flow path to the engine radiator 42 according to the temperature of the cooling water.

For example, the thermostat 52 is fully opened when the cooling water temperature (water temperature Tw) is equal to or higher than the temperature T ₁ (for example, 88 ° C.), and when the temperature is lower than the temperature T ₁ , the thermostat 52 gradually narrows the flow path to the temperature T ₂ ( For example, when the temperature is lowered to 82 ° C., the valve is fully closed. When the flow path to the engine radiator 42 is narrowed by the thermostat 52, the bypass circuit 54 returns the cooling water sent out from the engine 40 to the electric pump 50 side. Thereby, cooling of the cooling water by the engine radiator 42 is suppressed.

That is, the water temperature Tw of the cooling water is returned to the engine 40, when the lower temperature T ₁ of the cooling water by the engine radiator 42 cooling is suppressed, the coolant temperature Tw is higher target temperature Tt more temperatures T ₁ (T _The temperature is adjusted so that ₁ <Tt).

  On the other hand, in the air conditioner 10, the cooling air of the engine 40 is used to heat the conditioned air, and a circulation circuit 56 that circulates the cooling water to the heater core 36 is formed between the heater core 36 and the engine 40. ing.

  Thus, when the electric pump 50 is driven, cooling water is sent from the engine 40 to the heater core 36, and the cooling water that has passed through the heater core 36 is returned to the engine 40 via the electric pump 50. In the air conditioner 10, the air passing through the heater core 36 is heated by the cooling water.

  Thereby, in this embodiment, the cooling water of the engine 40 is circulated to each of the heater core 36 and the engine radiator 42 by one electric pump 50.

  The air conditioner 10 is provided with an air conditioner ECU 58 that controls the operation of the air conditioner 10. A compressor motor 20 and a blower motor 30 are connected to the air conditioner ECU 58 via drive circuits 60 and 62. The air conditioner ECU 58 controls the rotation speed of the compressor motor 20 and turns the evaporator 18 on and off. The temperature of the passing air is controlled. At the same time, the air conditioner ECU 58 controls the amount of conditioned air blown out from the outlet 32 into the passenger compartment by controlling the drive of the blower motor 30.

  The air conditioner ECU 58 is connected to actuators 64A, 64B, 64C for operating the mode switching damper 26, the switching damper 34, and the air mix damper 38, and the air conditioner ECU 58 controls the operation of the actuators 64A to 64C. Thus, switching between the inside air circulation mode and the outside air introduction mode, switching of the air outlet 32, and temperature control of the conditioned air are performed.

  Furthermore, the air conditioner ECU 58 includes a room temperature sensor 66 for detecting the indoor temperature, an outside air temperature sensor 68 for detecting the outside air temperature, a solar radiation sensor 70 for detecting the amount of solar radiation, and the temperature of the air that has passed through the evaporator 18 (post-evaporator temperature Te). The post-evaporator temperature sensor 72 and the like to be detected are connected to detect environmental conditions and the like when performing the air conditioning operation.

Thus, for example, when the air conditioner ECU 58 sets the temperature by operating an operation panel (not shown), the target blowout temperature T for setting the vehicle interior to the set temperature T _SET based on the set temperature and the environmental conditions at this time. _AO is calculated. Thereafter, in the air-conditioner ECU 58, on the basis of the target outlet air temperature T _AO, blowing air flow rate (blower volume) and sets the opening degree of the air mix damper 38 controls the operation based on these settings.

The target blowing temperature T _AO is obtained from the set temperature T _SET , the outside air temperature To, the room temperature Tr, and the solar radiation amount ST.

T _AO = K ₁・ T _SET −K ₂・ To−K ₃・ Tr−K ₄・ ST + C
(K ₁ , K ₂ , K ₃ , K ₄ and C are constants set in advance)
In general, the blower air volume can be set from the target blowing temperature T _AO , and FIG. 4 shows an example of the blower air volume with respect to the target blowing temperature T _AO . The air-conditioner ECU 58, for example, based on the set temperature _{T SET,} large difference between the set temperature _{T SET} and the room temperature Tr, when the target outlet air temperature _{T AO} is lower than the high or the set temperature _{T SET} is so blower air amount increases, When the target blowout temperature T _AO is in the vicinity of the set temperature T _SET , the blower air volume is reduced.

Further, in the air-conditioner 10, the air passing through the heater core 36, by mixing the bypass air with the heater core 36, and as conditioned air becomes the target outlet air temperature T _AO is obtained, the air mixing damper 38 opening S is obtained from the mixing ratio r. That is, assuming that the ratio of the air volume passing through the heater core 36 to the total air volume is the mixing ratio r, the mixing ratio r is the temperature of the air that has passed through the evaporator 18 (post-evaporator temperature Te) and the temperature of the air that has passed through the heater core 36 ( Obtained from the temperature after the heater core (Th),
_{r = (T AO -Te) /} (Th-Te)
It can be. Moreover, the opening degree S of the air mix damper 38 can be calculated as a function (increasing function) that increases as the mixing ratio r increases.

S = f (r)
Here, the post-evaporator temperature Te can be detected by the post-evaporator temperature sensor 72. The post-heater temperature Th can also be detected by providing a temperature sensor downstream of the heater core 36, but can be obtained from the coolant temperature Tw, the flow rate of the coolant, and the temperature efficiency η of the heater core 36.

When the air-conditioner ECU 58 calculates the mixing ratio r, the opening degree S of the air mix damper 38 is calculated based on the mixing ratio r, the actuator 64C is operated so as to obtain the calculated opening degree, and the target blowing temperature is set. T blower air amount set on the basis of the _AO operates the blower motor 30 so as to obtain.

As a result, the air conditioning operation of the air conditioner 10 is performed so that the passenger compartment becomes the set temperature T _SET . A known general configuration can be applied to the basic air conditioning operation control of the air conditioner 10.

  Incidentally, the air conditioner ECU 58 applied to the present embodiment performs cooling control of the cooling water by the engine radiator 42 and heating control by the heater core 36 by controlling the operation of the electric pump 50.

  That is, as shown in FIG. 3, a water temperature sensor 74 that detects the coolant temperature Tw is connected to the air conditioner ECU 58. The air conditioner ECU 58 is connected to a drive circuit 76 that drives the electric pump 50 (electric motor 48) and an engine speed sensor 78 that detects the speed of the engine 40.

  The air conditioner ECU 58 forms a flow rate control device that controls the flow rate of the circulated cooling water by controlling the rotational speed of the electric pump 50 via the drive circuit 76.

  The engine speed sensor 78 may be a sensor that detects the rotational speed of the drive shaft of the engine 40, and acquires an engine speed detected by an engine ECU that controls the driving of the engine 40. Also good.

  The drive circuit 76 performs amplification control based on a control signal that is a duty ratio input from the air conditioner ECU 58 when electric power of a predetermined voltage (for example, DC12v) is supplied to the electric pump 50 from a battery (not shown) of the vehicle. The electric pump 50 is rotationally driven at a rotational speed corresponding to the duty ratio, and sends out coolant at a flow rate corresponding to the rotational speed.

  Thus, the air conditioner ECU 58 can control the flow rate of the cooling water using the electric pump 50 by controlling the duty ratio of the electric power output from the drive circuit 76.

  That is, as shown in FIG. 5, the flow rate F of the cooling water by the electric pump 50 increases as the rotational speed R of the electric pump 50 increases, and decreases as the rotational speed R decreases.

  The upper limit (rotation speed Rmax) of the rotation speed R of the electric pump 50 is determined by the supply voltage (here, the voltage of the battery, for example, DC12v), and the flow rate F of the cooling water at this time becomes the maximum flow rate (flow rate Fmax). Further, when the rotational speed R of the electric pump 50 is low, the rotation of the water pump 46 may become unstable. From here, the air conditioner 58 has a minimum rotational speed when controlling the rotational speed R of the electric pump 50. (Rotation speed Rmin) and the minimum flow rate (flow rate Fmin) at that time are set.

  The air conditioner ECU 58 appropriately controls the cooling capacity of the engine radiator 42 and the heating capacity of the heater core 36 while saving power by controlling the rotational speed R of the electric pump 50.

  In general, when the outside temperature Tr is high, such as in summer, the temperature of the cooling water is high and the thermostat 52 is often open. Thereby, the cooling water is circulated from the engine 40 to the engine radiator 42 to be cooled.

Here, the target temperature Tt of the cooling water is set higher than the temperature T ₁ of the thermostat 52 is fully opened, the cooling water circulated in the engine radiator 42 flow rate (hereinafter referred to as the flow rate Fr) to more than necessary If the amount is large, the coolant temperature Tw is lowered, the flow path is narrowed by the thermostat 52, and the flow rate Fr of the coolant circulated to the engine radiator 42 is suppressed. At this time, the rotational speed R of the electric pump 50 is increased more than necessary.

  Further, in the winter season when the outside temperature Tr is low, the thermostat 52 may be closed even when the engine 40 is in a driving state. In such a case, the cooling of the cooling water using the engine radiator 42 is intended. The operation of the electric pump 50 is unnecessary power consumption.

  That is, when the cooling water is efficiently cooled using the engine radiator 42, it is only necessary to circulate the minimum amount of cooling water with the thermostat 52 fully open. From here, the first flow rate Fr is the cooling flow rate Fr. It can set based on the water temperature Tw of water.

  FIG. 6A shows an outline of the characteristics of the flow rate Fr of the cooling water with respect to the cooling water temperature Tw at this time. When only cooling of the cooling water by the engine radiator 42 is performed, the cooling water temperature Tw is By increasing, the required flow rate Fr increases, and when the cooling water temperature Tw decreases, the required flow rate Fr can be reduced. In the present embodiment, hysteresis is provided when the electric pump 50 is turned on or off.

  The coolant temperature Tw tends to increase as the rotational speed N of the engine 40 increases. From here, as shown in FIG. 6B, the flow rate Fr of the cooling water with respect to the cooling water temperature Tw can be set with the engine speed N as a parameter.

That is, when the engine speed N is low, the flow rate Fr with respect to the coolant temperature Tw is suppressed more than when the engine speed N is high. In FIG. 6 (B), the engine speed _N 1 to N _5, is set to _{N 1 <N 2 <N 3} <N 4 <N 5.

  The coolant temperature Tw is difficult to be cooled when the outside air temperature Tr is high, and is easily cooled when the outside air temperature Tr is low. From this point, as shown in FIG. 6C, the flow rate Fr with respect to the coolant temperature Tw can be set using the outside temperature Tr as a parameter.

That is, when the outside air temperature Tr is low, the flow rate Fr with respect to the coolant temperature Tw is made larger than when the outside air temperature Tr is high. In FIG. 6C, the outside air temperatures Tr ₁ to Tr ₅ are Tr ₁ <Tr ₂ <Tr ₃ <Tr ₄ <Tr ₅ .

  Furthermore, the flow rate Fr may be set from the coolant temperature Tw using the outside air temperature Tr and the engine speed N as parameters, thereby making it possible to set the coolant flow rate Fr more appropriately.

On the other hand, in the air-conditioner 10 has set the opening degree of the air mix damper 38 on the basis of the target outlet air temperature T _AO. The opening degree S of the air mix damper 38 is calculated based on the air volume passing through the heater core 30 and the air volume bypassing the heater core 36. As described above, the target blowout temperature T _AO , the post-evaporator temperature Te, and the post-heater core temperature It can be set based on the mixing ratio r calculated from Th.

_{r = (T AO -Te) /} (Th-Te)
Here, the heater core post-temperature Th can be measured using a temperature sensor, but can be obtained by calculation from the temperature efficiency η of the heater core 36 and the coolant temperature Tw detected by the coolant temperature sensor 74.

Th = η · Tw + (1−η) · Te
The opening degree S of the air mix damper 38 can be obtained from the mixing ratio r.

S = f (r)
FIG. 7 shows an outline of the temperature efficiency η of the heater core 36. The temperature efficiency η varies according to the flow rate of cooling water supplied to the heater core 36 (hereinafter referred to as flow rate Fh), and the temperature efficiency η increases as the flow rate Fh increases. Further, it also changes depending on the air volume of the air passing through the heater core 36, that is, the blower air volume B, and the temperature efficiency η is higher when the blower air volume B is large than when the blower air volume B is large. In FIG. 7, the blower air volumes B _{1 to} B ₅ are set as B ₁ <B ₂ <B ₃ <B ₄ <B ₅ .

  In the air conditioner 10, the heater core post-temperature Th is increased by increasing the flow rate Fh of the cooling water in the heater core 36. Along with this, the mixing ratio r decreases, and the mixing ratio r decreases, whereby the air mix damper 38 is operated in the closing direction. Therefore, when the flow rate Fh of the cooling water increases, there is a margin in the heating capacity by the heater core 36, and power saving can be achieved by suppressing this heating capacity margin.

  That is, as shown in FIG. 8A, the flow rate Fh of the cooling water flowing through the heater core 36 is set as the second flow rate based on the heating load, thereby improving the efficiency of the operation of the electric pump 50 and saving. Motorization becomes possible.

Here, FIG. 8A conceptually shows the setting of the flow rate Fr of the cooling water in the heater core 36 based on the heating load. Specifically, the target blowout temperature _TAO and the outside air temperature Tr Based on this, the flow rate Fh of the cooling water of the heater core 36 can be set.

When the heating load is large, the target outlet air temperature T _AO is high. From here, it is possible, as shown in FIG. 8 (B), set the flow rate Fh of the cooling water on the basis of the target outlet air temperature T _AO.

  Further, since the heating load increases as the outside air temperature Tr decreases, the flow rate Fh of the cooling water with respect to the outside air temperature Tr is set and detected by the outside air temperature sensor 68 as shown in FIG. The flow rate Fh of the cooling water may be calculated from the outside air temperature Tr.

The flow rate Fh of the cooling water with respect to the heating load is preferably small, and the heating capacity of the heater core 36 varies depending on the cooling water temperature Tw. The flow rate Fh of the cooling water of the heater core 36 may be set from _AO or the outside air temperature Tr.

  On the other hand, the electric pump 50 circulates cooling water between the engine radiator 42 and the engine 40 and between the heater core 36 and the engine 40. From here, the total flow rate of the cooling water required (the above-described flow rate). F) is the sum of the flow rate Fr to the engine radiator 42 and the flow rate Fh to the heater core 36 (F = Fr + Fh).

  From here, the air conditioner ECU 58 calculates the flow rate F of the cooling water of the electric pump 50 from the flow rate Fr of the cooling water to the engine radiator 42 and the flow rate Fh of the cooling water to the heater core 36, and the calculated flow rate F is obtained. The rotational speed R is set, and the electric pump 50 is driven based on the setting.

  FIG. 1 shows an outline of processing when the air conditioner ECU 58 controls the flow rate F of the cooling water by driving the electric pump 50 in the above configuration. In the air conditioner ECU 58, for example, when an ignition switch (not shown) is turned on so that the vehicle can run, the control is repeated at predetermined time intervals to execute the flow control of the cooling water, and the ignition switch is turned off. This completes the flow control.

  In this flowchart, in a first step 100, a flow rate Fr, which is a required flow rate when circulating cooling water to and from the engine radiator 42, is calculated. The flow rate Fr can be calculated by using the coolant temperature Tw, the coolant temperature Tw, the engine speed N, or the outside temperature Tr (see FIGS. 6A to 6C).

  At the same time, in the next step 102, a flow rate Fh, which is a required flow rate when circulating cooling water to and from the heater core 36, is calculated. The flow rate Fh at this time can be set based on the heating load on the air conditioner 10, and the heating load may be calculated from the target blowing temperature TAO or may be calculated from the outside air temperature Tr. (See FIGS. 8A to 8C).

  Thereafter, in step 104, the flow rate F required for the electric pump 50 is calculated based on the flow rate Fr of cooling water flowing to the engine radiator 42 and the flow rate Fh of cooling water flowing to the heater core 36. At this time, since the cooling water circulation circuit is parallel between the heater core 36 and the engine radiator 42, the flow rate F is equal to the flow rate Fr of the cooling water circuit 44 in which the engine radiator 42 is provided, and the heater core 36. Is the sum of the flow rates Fh of the circulation circuit 56 provided.

  When the flow rate F of the cooling water required for the electric pump 50 is calculated, in the next step 106, the rotational speed R of the electric pump 50 at which the calculated flow rate F is obtained is set. The rotational speed R at this time can be obtained from the flow rate F with respect to the rotational speed R of the electric pump 50 shown in FIG.

  Thus, when the rotation speed of the electric pump 50 is set, in step 108, the electric pump 50 is driven so that the set rotation speed R is obtained.

  FIG. 9 shows an example of specific processing for controlling the rotational speed of the electric pump 50. Here, the flow rate Fr for the engine radiator 42 is set based on the engine speed N and the coolant temperature Tw (see FIG. 6B), and the flow rate Fh for the heater core 36 is set based on the outside temperature Tw. (See FIG. 8C).

  In this flowchart, the engine speed N detected by the engine speed sensor 78 is read in the first step 110, and the coolant temperature Tw detected by the water temperature sensor 74 is read in step 112.

  Thereafter, in step 114, based on the engine speed N and the coolant temperature Tw, the coolant flow rate Fr required when the coolant is cooled by the engine radiator 42 is set.

  In step 116, the outside air temperature Tr detected by the outside air temperature sensor 68 is read. In step 118, the flow rate Fh of cooling water used for heating in the heater core 36 is set based on the outside air temperature Tr.

  Thereafter, in step 120, the flow rate F of the cooling water required by the electric pump 50 is calculated based on the flow rate Fh to the heater core 36 and the flow rate Fr to the engine radiator 42. The rotational speed R is set (step 122).

  Here, the electric pump 50 is driven in the range of the rotational speed R from the rotational speed Rmin to the rotational speed Rmax, and thereby the flow rate F in the range of the flow rate Fmin to the flow rate Fmax is obtained. For this reason, when the sum of the flow rate Fr and the flow rate Fh exceeds the flow rate Fmax, the rotational speed R is set to the rotational speed Rmax, and the sum of the flow rate Fr and the flow rate Fh is not “0” but less than the flow rate Fmin. (0 <F ≦ Fmin), the rotational speed R is set to the rotational speed Rmin.

  When the rotational speed R of the electric pump 50 is set in this way, in step 124, the electric pump 50 is driven at the set rotational speed R.

  In this way, by driving the electric pump 50, the cooling water of a necessary flow rate flows through the heater core 36 and the engine radiator 42, respectively, and the cooling water cooled to the target temperature Tt by the engine radiator 42 The heater core 36 is used for heating the conditioned air.

  At this time, since the electric pump 50 is configured to circulate cooling water at a flow rate necessary for each of the heater core 36 and the engine radiator 42, while preventing the circulation amount of the cooling water from being insufficient, And it can suppress circulating the cooling water more than necessary, and can attain power saving when circulating the cooling water using the electric pump 50.

  The rotational speed R of the electric pump 50 is set based on the sum of the flow rate Fr of cooling water sent to the engine radiator 42 and the flow rate Fh of cooling water sent to the heater core 36, so that the outside temperature Tr is reduced from a low temperature. It can be executed with a simple program without dividing complicated cases up to high temperatures.

  Therefore, it is possible to reduce the cost of a processing program that operates accurately. That is, the development period of the processing program can be shortened, and the development cost can be suppressed. In addition, since a simple program can be provided, the memory capacity for storing can be reduced, and the occurrence of bugs and the like can be suppressed, and the cost and period for collecting bugs and the like are not required.

  The present embodiment described above does not limit the configuration of the present invention. The present invention circulates cooling water for the engine 40 to each of the engine radiator 42 and the heater core 36 by one electric pump 50. Any configuration provided with a path can be applied.

  In addition, the present invention can be applied to a vehicle air conditioner or a vehicle heating device having an arbitrary configuration that generates air-conditioned air by being heated by the heater core 36.

It is a flowchart which shows the outline of control of the electric pump in air-conditioner ECU which concerns on this invention. It is a schematic block diagram of the air conditioner applied to this Embodiment. It is the schematic which shows the connection to the flow path of the cooling water which concerns on this Embodiment, and air-conditioner ECU. It is a diagram which shows the outline of the air volume with respect to the target blowing temperature used for the setting of a blower air volume. It is a diagram which shows the outline of the change of the flow volume of the cooling water with respect to the rotation speed of an electric pump. (A) is a diagram showing the outline of setting the flow rate to the engine radiator with respect to the water temperature, (B) is a diagram showing the outline of setting the flow rate to the engine radiator with respect to the water temperature with the engine speed as a parameter, (C) These are the diagrams which show the outline of the setting of the flow volume to an engine radiator with respect to the water temperature which made external temperature a parameter. It is a diagram which shows an example of the temperature efficiency with respect to the flow volume of the cooling water in a heater core. (A) is a diagram conceptually showing a change in the flow rate of cooling water in the heater core with respect to the heating load, (B) is a diagram showing an outline of the flow rate to the heater core with respect to the target blowing temperature, and (C) is a heater core with respect to the outside air temperature. It is a diagram which shows the outline of the flow volume to. It is a flowchart which shows an example of the flow control of an electric pump.

Explanation of symbols

10 Air conditioner (vehicle heating system)
18 Evaporator 22 Air Conditioning Duct 36 Heater Core 40 Engine 42 Engine Radiator 44 Cooling Circuit 50 Electric Pump 52 Thermostat 56 Circulation Circuit 58 Air Conditioner ECU (First and Second Flow Rate Setting Means, Driving Means)
68 Outside temperature sensor (outside temperature detection means)
74 Water temperature sensor (Water temperature detection means)
76 Drive circuit (drive means)

Claims (6)

An engine radiator that cools engine cooling water and a control method for an electric pump that sends engine cooling water to each of a heater core that heats conditioned air with engine cooling water,
While setting the flow rate of the engine cooling water sent to the engine radiator based on the water temperature of the engine cooling water,
Setting the flow rate of the engine coolant to be sent to the heater core based on the heating load when air-conditioning the passenger compartment with the conditioned air,
Based on the sum of the flow rate to the engine radiator and the flow rate to the heater core, the required flow rate of the engine cooling water sent out by the electric pump is set,
Driving the electric pump so as to obtain the set required flow rate;
A method for controlling an electric pump.   2. The electric pump control according to claim 1, wherein an outside air temperature that is an environmental condition outside the vehicle is detected as the heating load, and a flow rate of the engine cooling water to be sent to the heater core is set based on the detected outside air temperature. Method.   2. The flow rate of the engine cooling water to be sent to the heater core is set based on the target blowing temperature using the target blowing temperature of the conditioned air blown into the passenger compartment as the heating load. Control method for electric pump.   The electric pump according to any one of claims 1 to 3, wherein the flow rate to the engine radiator is set to a water temperature of the engine cooling water including an outside air temperature or an engine speed. Control method. A cooling water circuit provided with a thermostat for connecting the engine and the engine radiator and opening and closing a flow path of the engine cooling water to the engine radiator based on the temperature of the engine cooling water;
A circulation circuit that connects the heater core and the engine so that the engine coolant can circulate;
An electric pump for sending the engine coolant from the engine to the coolant circuit and the circulation circuit;
A vehicle heating device that heats conditioned air to air-condition a vehicle interior with the engine coolant circulated to the heater core,
Water temperature detecting means for detecting the temperature of the engine cooling water;
First flow rate setting means for setting a first flow rate of the engine cooling water to be sent to the engine radiator based on the detection result of the water temperature detection means;
Second flow rate setting means for setting a second flow rate of the engine coolant to be sent to the heater core based on a heating load when heating the vehicle interior;
Drive means for setting the required flow rate of the electric pump from the sum of the first flow rate and the second flow rate, and driving the electric pump so as to obtain the set required flow rate;
The vehicle heating device characterized by including.   The vehicle according to claim 5, further comprising an outside air temperature detecting unit that detects an outside air temperature as the heating load, wherein the second flow rate setting unit sets the second flow rate from the outside air temperature. Heating device.

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