JP2008120297A - Heater for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To promote the effect of improving fuel consumption due to the stoppage of an engine while maintaining heating performance. <P>SOLUTION: The water feeding capacity of an electric hot water pump 205 is smaller than that of a mechanical hot water pump 201 when the vehicle engine 20 is running at idle. Since the water feeding capacity of the electric hot water pump 205 is suppressed smaller than that of the mechanical hot water pump, the sudden dropping of the temperature of hot water can be suppressed while suppressing the lowering of heating capacity. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a vehicle heating device that includes a mechanical hot water pump and an electric hot water pump as means for circulating hot water in a heating heat exchanger, and circulates hot water using the electric hot water pump when the vehicle engine is idling. For example, it is suitable for use in a vehicle heating device such as a hybrid vehicle or an eco-run vehicle.

Conventionally, in Patent Document 1 below, in a hybrid vehicle having both an engine and an electric motor as a vehicle driving source, the engine hot water (cooling water) is exchanged for heating by a mechanical hot water pump driven by the engine during engine operation. A vehicle air conditioner having a hot water circuit that circulates in a heater and circulates the engine hot water to a heating heat exchanger by an electric hot water pump when the engine is stopped is described.
JP 2003-34126 A

  However, conventionally, the water supply capacity of the electric hot water pump when the vehicle engine is idle stopped is equivalent to the water supply capacity of the mechanical hot water pump when the vehicle engine is idle. For this reason, after a vehicle engine stopped, there existed a problem that the temperature of warm water fell rapidly and heating capability was lost rapidly.

  Moreover, since the fall of the temperature of warm water also affects the combustion state of a vehicle engine, in order to maintain warm water temperature more than predetermined temperature, it was requested | required to restart a vehicle engine. For example, when the hot water temperature is excessively reduced, a function of interrupting the idle stop control and restarting the vehicle engine may be added to the vehicle engine control device. In such a case, there has been a problem that the effect of reducing fuel consumption by exhaust stop and the effect of reducing exhaust gas are impaired.

  Moreover, in order to ensure the water supply capability of the electric hot water pump, there is a problem that the size of the electric hot water pump is increased, the cost is increased, and the operation noise is increased.

  The present invention has been made paying attention to such problems existing in the prior art, and its purpose is to promote the effect of reducing fuel consumption by stopping the engine while maintaining the heating performance. It is in.

  Another object of the present invention is to avoid a start of the engine for recovering the hot water temperature by suppressing a rapid decrease in the temperature of the engine cooling water while suppressing a decrease in the heating capacity when the vehicle engine is stopped within an allowable range. is there.

  Still another object of the present invention is to provide a vehicle heating device that can reduce the size of an electric hot water pump.

In order to achieve the above object, the present invention employs the following technical means. That is, according to the first aspect of the present invention, the mechanical hot water pump (201) is driven by the vehicle engine (20) when the vehicle engine (20) is operated and circulates the hot water of the vehicle engine (20) to the hot water circuit (200). )When,
A heating heat exchanger (21) which is provided in the hot water circuit (200) and heats the air blown into the passenger compartment with the hot water;
In a vehicle heating apparatus comprising an electric hot water pump (205) for circulating hot water of the vehicle engine (20) to the heating heat exchanger (21) when the vehicle engine (20) is idle stopped,
The water supply capacity of the electric hot water pump (205) is smaller than the water supply capacity of the mechanical hot water pump (201) when the vehicle engine (20) is idle.

  Most of the idle stops of hybrid cars and eco-run cars are waiting for traffic lights and crossings. According to the study by the inventors, the waiting time that can be estimated is about 120 seconds, which is a value that matches the conventional threshold used in the design of the automobile and its parts.

  On the other hand, the inventors confirmed the duration of the heating performance by changing the flow rate of the hot water to the heating heat exchanger when the engine was stopped in order to solve the above-described problems of the prior art. FIG. 4 is a graph showing the time required for the blowing temperature to reach the lower limit temperature (35 ° C.) with respect to the flow rate of the electric hot water pump on the driver side, and FIG. 5 shows the flow rate of the electric hot water pump on the passenger side. It is a graph which shows the arrival time until the blowing temperature with respect to falls to a minimum temperature (35 degreeC). The water supply capacity of the mechanical hot water pump when the engine is idle is 6 L / min. However, the results of the above investigation and the result of the confirmation test show that the heating performance can be satisfied even if the mechanical water pump capacity is lower than that of the mechanical hot water pump when the engine is idle, as shown in FIGS. did.

  According to the first aspect of the present invention, the water supply capacity of the electric hot water pump (205) is limited to be smaller than the water supply capacity of the mechanical hot water pump. Reduction can be suppressed.

  According to a second aspect of the present invention, in the vehicle heating device according to the first aspect, the water supply capability of the electric hot water pump (205) is provided when the vehicle engine (20) is idle stopped.

  Further, the invention according to claim 3 is characterized in that, in the vehicle heating device according to claim 1 or 2, the water supply capacity of the electric hot water pump (205) is adjustable. According to the third aspect of the present invention, the optimum water supply capacity of the electric hot water pump (205) may be varied from the actual idle stop time data and the heating state data at that time. .

  In addition, the code | symbol in the parenthesis as described in a claim and said each means is an example which shows a corresponding relationship with the specific means as described in embodiment mentioned later.

  Hereinafter, embodiments of the present invention will be described in detail with reference to FIGS. FIG. 1 is an overall system configuration diagram of a vehicle air conditioner according to an embodiment to which the present invention is applied. First, the outline of the ventilation system in which air is blown toward the vehicle interior will be described. The air conditioning case 10 forms a ventilation path for air blown toward the vehicle interior, and is the most upstream part of the ventilation path. The inside / outside air switching box 11 is arranged in the box.

  The inside / outside air switching door 12 in the inside / outside air switching box 11 switches between opening and closing the outside air introduction port 13 and the inside air introduction port 14. Thereby, outside air (vehicle compartment outside air) or inside air (vehicle compartment air) is switched and introduced into the inside / outside air switching box 11. The inside / outside air switching door 12 is driven by an electric drive device 12a such as a servo motor.

  A blower 15 is arranged on the downstream side of the inside / outside air switching box 11, and air is blown by the blower 15 through the inside of the air conditioning case 10 toward the vehicle interior. The blower 15 is provided with a centrifugal multiblade fan 16 and a drive motor 17. The applied voltage (blower voltage) to the drive motor 17 is adjusted by the motor drive circuit 17a to control the rotational speed (air flow rate) of the blower 15.

  A refrigerant evaporator 18 that constitutes a heat exchanger for cooling is disposed in the air conditioning case 10 on the downstream side of the blower 11. As is well known, the refrigerant evaporator 18 cools the air by the low-pressure refrigerant decompressed by the decompression means (not shown) of the refrigeration cycle absorbing heat from the air in the air conditioning case 10 and evaporating.

  In the air conditioning case 10, an air mix door 19 is disposed on the downstream side of the refrigerant evaporator 18. A hot water heater core (heating heat exchanger) 21 that heats air using hot water (cooling water) of the vehicle engine 20 as a heat source is installed on the downstream side of the air mix door 19. A bypass passage 22 that bypasses the heater core 21 and flows air is formed on the side (upper portion) of the heater core 21.

  The air mix door 19 is a rotatable plate-like door and is driven by an electric drive device 19a such as a servo motor. The air mix door 19 adjusts the air volume ratio between the air volume that passes through the heater core 21 and becomes warm air and the air volume of the cool air that passes through the bypass passage 22. The air temperature of the air is adjusted.

  That is, in the downstream space of the heater core 21, the hot air after passing through the heater core 21 and the cool air from the bypass passage 22 can be mixed to create air at a desired temperature. Therefore, in this example, the air mix door 19 constitutes temperature adjusting means for the air blown into the vehicle interior.

  Furthermore, a blow-out mode switching unit is configured at the most downstream portion of the ventilation path in the air conditioning case 10. That is, a defroster opening 24 for blowing air to the inner surface of the vehicle windshield 23 is formed on the upper surface of the air conditioning case 10, and the defroster opening 24 is opened and closed by a rotatable plate-like defroster door 25. In addition, a face opening 26 that blows air toward the upper body of the passenger in the passenger compartment is formed on the upper surface of the air-conditioning case 10 on the rear side of the vehicle from the defroster opening 24. The face opening 26 is rotatable. It is opened and closed by a flat plate-like face door 27.

  In the air conditioning case 10, a foot opening 28 for blowing air toward the feet of passengers in the passenger compartment is formed at a lower portion of the face opening 26, and the foot opening 28 is a rotatable plate-like foot door. 29 is opened and closed. These doors 25, 27, and 29 serving as blowout mode doors are connected by a common link mechanism (not shown), and are driven by an electric drive device 30 such as a servo motor via the link mechanism.

  Next, the hot water circuit 200 of the vehicle engine 20 in the hybrid vehicle will be described. The vehicle engine 20 constitutes a travel drive source of the hybrid vehicle together with a travel electric motor (not shown), and the mechanical hot water pump 201 is driven by the vehicle engine 20. Thereby, engine cooling water (warm water) is circulated through the warm water circuit 200.

  The mechanical hot water pump 201 is provided at a position where the engine cooling water can flow through the entire hot water circuit 200. The mechanical hot water pump 201 is provided at a position where the hot water passage passing through the radiator 202 and the hot water passage passing through the heater core 21 overlap each other, and the hot water flows to both of them.

  The mechanical hot water pump 201 is connected to a crankshaft of the vehicle engine 20 via a gear or the like. As a result, the mechanical hot water pump 201 can operate as a pump only when the vehicle engine 20 is operating. The warm water circuit 200 is connected in parallel with a radiator 202, a motor generator 203, and a heater core 21.

  The motor generator 203 functions as a starter for starting the vehicle engine 20 (motor function) and is driven by the vehicle engine 20 after the vehicle engine 20 is started to function as a generator. By circulating hot water to the motor generator 203, a cooling action of the motor generator 203 and an increase in the heating heat source by recovering waste heat from the motor generator 203 are achieved.

  The thermostat 204 is a temperature response valve that prevents the warm water from circulating to the radiator 202 at a low temperature of the warm water and promotes the rise of the warm water temperature. An electric hot water pump 205 is provided in series in a hot water circuit including the vehicle engine 20 and the heater core 21. The electric hot water pump 205 is provided in a hot water passage from the vehicle engine 20 toward the heater core 21.

  The electric hot water pump 205 can operate as a pump in response to energization from the in-vehicle battery regardless of whether the vehicle engine 20 is operated or stopped. The electric hot water pump 205 is energized and operated from a vehicle battery (not shown) when the vehicle engine 20 (mechanical hot water pump 201) is idle stopped, and circulates hot water through the motor generator 203 and the heater core 21.

  The electric hot water pump 205 is energized and exhibits a predetermined water supply capacity. The water supply capacity of the electric hot water pump 205 is smaller than the water supply capacity of the mechanical hot water pump 201 when the engine is idling. Moreover, the water supply capacity of the electric hot water pump 205 is suppressed to about 1/3 of the water supply capacity of the mechanical hot water pump 201 when the engine is in idle operation.

  The electric hot water pump 205 includes a relatively small motor and a non-volumetric pump having a relatively small flow rate. The electric hot water pump 205 has a water supply capacity when the power supply voltage of the vehicle is applied, which is smaller than the water supply capacity of the mechanical hot water pump 201 when the engine is idling.

  Next, an outline of the electric control unit in the present embodiment will be described. The air-conditioning control device 31 includes a well-known microcomputer including a CPU, a ROM, a RAM, and the like, and its peripheral circuits. Sensor signals from the sensor groups 32 to 36 and operation signals of the operation switches 38 to 42 of the air conditioning control panel 37 are input to the air conditioning control device 31.

  The sensor group is provided with well-known sensors 32 to 36 for detecting the inside air temperature Tr, the outside air temperature Tam, the solar radiation amount Ts, the hot water temperature Tw, the evaporator outlet temperature Te, and the like. The water temperature sensor 35 that detects the hot water temperature Tw is disposed at the hot water outlet of the vehicle engine 20 in the hot water circuit 200 of the vehicle engine 20. Further, the evaporator temperature sensor 36 that detects the evaporator blowing temperature Te is disposed in the air-conditioning case 10 immediately after the air blowing of the refrigerant evaporator 18.

  The air conditioning control panel 37 is installed in the vicinity of the vehicle interior instrument panel, and the operation switches 38 to 42 are manually operated by the occupant. Specifically, as the operation switches 38 to 42, a temperature setting switch 38 that generates a temperature setting signal Tset, an air volume switch 39 that generates an air volume switching signal, an air blowing mode switch 40 that generates an air blowing mode signal, and an inside / outside air switching signal. And an air conditioner switch 42 for generating an on / off signal of an air conditioning refrigerant compressor (not shown).

  Next, the operation of this embodiment in the above configuration will be described. The flowchart of FIG. 2 shows an outline of the control processing executed by the microcomputer of the air conditioning control device 31, and the control routine of FIG. 2 shows that the ignition switch of the vehicle engine 20 is turned on and power is supplied to the air conditioning control device 31. Starts when supplied.

  First, in step S1, initialization of flags and timers is performed, and in the next step S2, operation signals of the operation switches 38 to 42 of the air conditioning control panel 37 are read. In the next step S3, vehicle environmental condition detection signals are read from the sensors 32-36. Subsequently, in step S4, a target blowing temperature TAO of air blown into the vehicle interior is calculated. The target blowing temperature TAO is a blowing temperature necessary for maintaining the passenger compartment at the set temperature Tset of the temperature setting switch 38, and is calculated based on the following Equation 1.

(Equation 1) TAO = Kset * Tset-Kr * Tr-Kam * Tam-Ks *
Ts + C
However, Tr: Inside air temperature Tam detected by the inside air sensor 32: Outside air temperature Ts detected by the outside air sensor 33: Solar radiation amount Kset, Kr, Kam, Ks detected by the solar radiation sensor 34: Control gain C: For correction constant

  Next, in step S5, a target blow amount of air blown by the blower 15, specifically, a blower voltage Ve that is an applied voltage of the blower 15 (substantially the drive motor 17) is determined based on the TAO. . The method for determining the blower voltage Ve is well known. The blower voltage (target air volume) Ve is increased on the high temperature side (maximum heating side) and the low temperature side (maximum cooling side) of the TAO, and the blower voltage is increased in the intermediate temperature range of the TAO. The voltage (target air volume) Ve is reduced.

  Next, in step S6, the inside / outside air mode is determined. The inside / outside air mode is switched and set, for example, as the TAO rises from the low temperature side to the high temperature side, from the all inside air mode → the inside / outside air mixing mode → the all outside air mode. Alternatively, the inside air mode may be set when the inside temperature Tr is higher than a predetermined temperature with respect to the set temperature Tset (during cooling high load), and the outside air mode may be set at other times. When the inside / outside air mode is set manually by the inside / outside air changeover switch 41, the manually set inside / outside air mode is selected.

  Next, in step S7, the blowing mode is determined according to the TAO. As is well known, this blowing mode is switched from the face mode to the bi-level mode to the foot mode as TAO rises from the low temperature side to the high temperature side. When the blow mode is manually set by the blow mode switch 40, the blow mode of the manual setting is selected. Next, in step S8, the target opening degree SW of the air mix door 19 is calculated by the following formula 2 based on the TAO, the evaporator outlet temperature Te, and the hot water temperature Tw.

(Expression 2) SW = [(TAO−Te) / (Tw−Te)] × 100 (%)
Here, the target opening degree SW of the air mix door 19 sets the maximum cooling position of the air mix door 19 (solid line position in FIG. 1) to 0%, and the maximum heating position of the air mix door 19 (dotted line position in FIG. 1). Is expressed as a percentage with 100%.

  In the next step S9, the operation of the electric hot water pump 205 is controlled. Details of the pump control in step S9 will be described later with reference to FIG. In the next step S10, the intermittent operation (ON-OFF) of the compressor operation is determined. That is, the target evaporator temperature TEO is compared with the evaporator outlet temperature Te detected by the temperature sensor 36 to determine the voltage applied to the electromagnetic clutch (not shown) of the refrigerant compressor, and the compressor operation is intermittently turned on / off (ON-OFF). ).

  In the next step S11, control signals are output to the various actuator units (12a, 17, 19a, 30, 205) so that the control state determined in steps S5 to S10 is obtained. Then, in the next step S12, the elapse of the control cycle τ is determined, and when the control cycle τ elapses, the process returns to step S2.

  FIG. 3 is a flowchart showing the contents of the operation control (step S9) of the electric hot water pump in the flowchart of FIG. First, in step S91, it is determined whether or not the vehicle engine 20 is in an idle stop state. If the determination result is YES and the vehicle engine 20 is idlingly stopped, the electric hot water pump 205 may be operated, and the process proceeds to the next determination in step S92. When the determination result in step S91 is NO and the vehicle engine 20 is operating, the mechanical hot water pump 201 is driven and the hot water is circulated, so that the process proceeds to step S93 and the electric hot water pump 205 is This is a stop (OFF) state.

  In the next step S92, it is determined whether or not the blower 15 is operating even if the vehicle engine 20 is idlingly stopped. If this determination result is YES and the blower 15 is operating, there is a possibility that the electric hot water pump 205 may be operated, and the process proceeds to the next determination in step S94. Further, when the determination result in step S92 is NO and the blower 15 is stopped, that is, the air conditioner is stopped, the hot water circulation to the heater core 21 is unnecessary, so the process proceeds to step S93 and the electric hot water pump 205 is stopped ( OFF) state.

  In the next step S94, it is determined whether or not the air conditioning mode requires hot air even if the air conditioner is operating. That is, it is determined whether or not the air conditioning mode requires heating of the air in the heater core 21 and circulation of hot water to the heater core 21. In this case, for example, it may be determined whether the opening degree of the air mix door 19 is closer to the maximum heating position than the predetermined value.

  More specifically, this determination can be made based on the air mix door target opening degree SW calculated in step S8. Further, the actual opening degree of the air mix door 19 may be detected using position detecting means such as a potentiometer, and the determination in step S94 may be performed based on the detected opening degree.

  If the determination result is YES and the air conditioning mode requires hot air, the process proceeds to step S95 to operate the electric hot water pump 205. Further, when the determination result in step S94 is NO and the air conditioning mode does not require hot air, the hot water circulation to the heater core 21 is not necessary, so the process proceeds to step S93, and the electric hot water pump 205 is in a stopped (OFF) state. It is what.

  As described above, in the present embodiment, the electric hot water pump 205 is operated when the vehicle engine 20 is idle stopped, the air conditioner is operated, and the air conditioning mode requires hot air. ing.

  FIG. 4 is a graph showing the time required for the blowing temperature to reach the lower limit temperature (35 ° C.) with respect to the flow rate of the electric hot water pump on the driver side, and FIG. 5 shows the flow rate of the electric hot water pump on the passenger side. It is a graph which shows the arrival time until the blowing temperature with respect to falls to a minimum temperature (35 degreeC).

  The water supply capacity of the mechanical hot water pump 201 when the engine is idle is 6 L / min. The conventional electric hot water pump was set to the same water supply capacity as this, but as can be seen from the results of the confirmation tests in FIGS. 4 and 5, the water supply capacity of the mechanical hot water pump during engine idling It was found that the heating performance can be sufficiently satisfied even if it is small.

  4 and 5, 1 L / min. Over the range of the minimum air volume Lo to the maximum air volume Hi. If there is a hot water flow rate of the order, the blowing temperature can be maintained at 35 ° C. or higher for at least 120 seconds. Therefore, at least 1 L / min. It can be understood that the heating state can be maintained over a temporary engine stop period such as waiting for a signal.

  In consideration of the difference in the size of the vehicle, the difference in the outside air temperature, the difference in the engine cooling water volume, etc., 1 L / min. Or 2 L / min. If the above flow rate is ensured, an excessive decrease in heating capacity can be suppressed. Therefore, in this embodiment, the water supply capacity of the electric hot water pump 205 is about twice as large as 2 L / min. Is set.

  On the other hand, the water supply capacity of the electric hot water pump 205 is suppressed to be equal to or lower than the water supply capacity of the mechanical hot water pump 201 when the engine 20 is idling. In this embodiment, which is one of the preferred aspects, the water supply capacity of the electric hot water pump 205 is 1/3 of 2/3 or less of the water supply capacity of the mechanical hot water pump 201 when the engine 20 is idling. It is suppressed.

  As a result, after the engine 20 is stopped, 6 L / min. Compared with the case where hot water is circulated at a moderate flow rate, the temperature drop of the hot water can be moderated. As a result, the effects of reducing fuel consumption and exhaust gas, which are the purposes of idle stop control, can be ensured. Moreover, since the hot water temperature when the engine 20 is restarted can be maintained relatively high, an effect of easily improving the combustion state after the restart is expected.

  Next, features and effects of this embodiment will be described. First, the water supply capacity of the electric hot water pump 205 is made smaller than the water supply capacity of the mechanical hot water pump 201 when the vehicle engine 20 is idle. According to this, since the water supply capability in the electric hot water pump 205 can be reduced to a value that can satisfy the heating performance, the size of the electric hot water pump 205 can be reduced in size.

  Further, the electric hot water pump 205 can be easily mounted on the vehicle due to the downsizing. Further, the miniaturization of the electric hot water pump 205 also reduces the weight, and the bracket for attaching the electric hot water pump 205 to the vehicle can be made small, simple, and low cost. Further, with the miniaturization of the electric hot water pump 205, costs such as motors and material costs can be reduced. Further, along with the miniaturization of the electric hot water pump 205, it is possible to reduce the operating noise and running water noise.

  Moreover, since the heating performance deteriorates when the engine water temperature is excessively lowered in the conventional idle stop vehicle, the engine may be controlled to restart when the engine water temperature falls below a predetermined value. For this reason, when a large amount of hot water is sent to the heater core 21 while the engine 20 is stopped and the hot water temperature is lowered, the engine 20 is restarted, and the fuel consumption reduction effect may be impaired. However, lowering the flow rate of the electric hot water pump 205 also slows down the engine water temperature. For this reason, the engine stop time can be extended, and the fuel consumption of the vehicle can be improved.

(Other embodiments)
The present invention is not limited to the embodiment described above. For example, in the above-described embodiment, the water supply capacity of the electric hot water pump 205 is about twice as large as 2 L / min. However, the water supply capacity of the electric hot water pump 205 is not set to a predetermined constant value, and more optimal and minimum electric hot water is obtained from actual idle stop time data and heating state data at that time. The water supply capacity of the pump 205 may be varied. For example, the motor rotation speed of the electric hot water pump 205 can be adjusted. For example, the voltage applied to the motor and the drive frequency of the motor can be adjusted.

  Further, as the electric hot water pump 205, a large-sized pump having a capacity equivalent to or exceeding that of a mechanical hot water pump may be used. In such a case, when the engine 20 is stopped, the water supply capacity of the electric hot water pump 205 is limited to be smaller than the water supply capacity of the mechanical hot water pump 201 when the engine 20 is idling. For example, the number of rotations of the motor of the electric hot water pump 205 is limited to be lower than that at the maximum capacity. The water supply capacity of the electric hot water pump 205 may be set to about 1/2 or about 2/3 of the water supply capacity of the mechanical hot water pump 201 when the engine is idling.

  In the above-described embodiment, the air volume ratio between the warm air passing through the heater core 21 and the cool air passing through the bypass passage 22 is adjusted by the air mix door 19, and the air volume ratio of the cool / warm air is adjusted to the vehicle interior. Although the temperature of the blown air is adjusted, a warm water flow rate that circulates through the heater core 21 or a hot water valve that adjusts the temperature of the hot water is provided, and the temperature of the blown air into the vehicle compartment is adjusted by adjusting the opening of the hot water valve. The present invention can also be applied to a heating device for a house.

  In the above-described embodiment, hot water is circulated through the heater core 21 by switching between the engine-driven mechanical hot water pump 201 and the electric hot water pump 205. However, the electric hot water pump 205 constantly circulates hot water through the heater core 21. In this case, the water supply capacity of the electric hot water pump 205 may be set according to the idea of the present invention. Of course, the present invention can be applied not only to air conditioners for hybrid vehicles but also to air conditioners for eco-run vehicles that perform idling stop.

1 is an overall system configuration diagram of a vehicle air conditioner according to an embodiment to which the present invention is applied. It is a flowchart which shows the outline | summary of the air-conditioning control in the vehicle air conditioner of FIG. It is a flowchart which shows the content of the operation control (step S9) of the electric hot water pump in the flowchart of FIG. It is a graph which shows the arrival time until the blowing temperature with respect to the flow volume of the electric hot water pump at the driver's seat is lowered to the lower limit temperature (35 ° C.). It is a graph which shows the arrival time until the blowing temperature with respect to the flow volume of the electric hot water pump on the passenger seat side falls to the lower limit temperature (35 ° C.).

Explanation of symbols

20 ... Vehicle engine 21 ... Heater core (heat exchanger for heating)
DESCRIPTION OF SYMBOLS 200 ... Hot water circuit 201 ... Mechanical hot water pump 205 ... Electric hot water pump

Claims (3)

A mechanical hot water pump (201) that is driven by the vehicle engine (20) during operation of the vehicle engine (20) and circulates hot water of the vehicle engine (20) to a hot water circuit (200);
A heating heat exchanger (21) that is provided in the hot water circuit (200) and heats the air blown into the passenger compartment by the hot water;
In the vehicle heating apparatus, comprising: an electric hot water pump (205) for circulating the hot water of the vehicle engine (20) to the heating heat exchanger (21) when the vehicle engine (20) is idle stopped.
The vehicle heating device characterized in that the water supply capacity of the electric hot water pump (205) is smaller than the water supply capacity of the mechanical hot water pump (201) when the vehicle engine (20) is idle.   The vehicle heating device according to claim 1, wherein the water supply capacity of the electric hot water pump (205) is provided when the vehicle engine (20) is idle stopped.   The vehicle heating device according to claim 1 or 2, wherein the water supply capacity of the electric hot water pump (205) is adjustable.

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