JP3982064B2 - Air conditioner for vehicles - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a vehicle air conditioner including a front seat air conditioning unit and a rear seat air conditioning unit. In addition to a heating heat exchanger that uses hot water or the like as a heat source for each of the front and rear air conditioning units, a plurality of auxiliary heating heat sources are provided. The present invention relates to a control device that includes an electric heating element and automatically controls the number of energizations of the electric heating element.
[0002]
[Prior art]
In recent years, with the increase in efficiency of vehicle engines, the temperature of cooling water (warm water) of vehicle engines tends to be lower than before even after engine warm-up. Therefore, in the hot water type air conditioner that heats the passenger compartment by using the waste heat from the engine cooling water, a lack of heating capacity is a problem.
[0003]
Therefore, as seen in Japanese Patent Application Laid-Open No. 9-20129, an electric heating element is combined with a hot water heating heat exchanger, and when the hot water temperature is low, the electric heating element is energized and the electric heating element generates heat. The thing which eliminates the lack of heating capability by heating air is proposed.
By the way, in a vehicle having a long cabin space in the front-rear direction, such as a one-box vehicle or a minivan vehicle, an air conditioning unit is arranged on each of the front seat side and the rear seat side, and the heat that passengers want on both the front and rear sides in the vehicle interior. The air conditioning feeling is improved so that a feeling can be obtained.
[0004]
[Problems to be solved by the invention]
As described above, in a vehicle in which air conditioning units are arranged on the front seat side and the rear seat side, respectively, if a large-capacity electric heating element is arranged only on the front seat air conditioning unit in order to improve the heating capacity, the rear seat air conditioning unit Since the foot blowing air temperature of the vehicle is significantly lower than the foot blowing air temperature of the front seat air conditioning unit, the room temperature difference between the front and rear of the vehicle interior increases. Therefore, the comfort on the rear seat side is impaired during heating.
[0005]
In addition, since the room temperature rises slowly on the rear seat side, the maximum airflow level continues for a long period of time after the start of heating compared to the front seat side, so the blowing noise is harsh and quiet. Damaged.
The present invention has been made in view of the above points. In a vehicle air conditioner including a front seat air conditioning unit and a rear seat air conditioning unit, the air conditioning feeling during heating on both the front seat side and the rear seat side is improved. For the purpose.
[0006]
Another object of the present invention is to suppress power consumption by the electric heating elements of the front and rear air conditioning units when a plurality of electric heating elements are provided as auxiliary heating heat sources in the front and rear air conditioning units, respectively. .
[0007]
[Means for Solving the Problems]
  In order to achieve the above object, according to the first aspect of the present invention, a plurality of electric heating elements (which are provided in the front seat air conditioning unit (20) and the rear seat air conditioning unit (40), respectively) and function as auxiliary heating heat sources ( 68a-68c, 69a-69c),
  Determination means (S220) for determining a difference between the heating load on the front seat side and the heating load on the rear seat side in the vehicle interior;
  Difference in heating load between the number of energized electric heating elements (68a to 68c) in the front seat air conditioning unit (20) and the number of energized electric heating elements (69a to 69c) in the rear seat air conditioning unit (40) Provided with heating element control means (S300) to switch according toe,
  When the heating load on the front seat side is larger than the heating load on the rear seat side, the number of energizations of the electric heating elements (68a to 68c) in the front seat air conditioning unit (20) is reduced by the heating element control means (S300). The number of electric heating elements (69a to 69c) in the seat-side air conditioning unit (40) is larger than the number of energizations, and the electric heating element in the front seat-side air conditioning unit (20) is increased in accordance with the increase in the heating load difference. (68a-68c) while increasing the number of energization and reducing the number of energization of the electric heating elements (69a-69c) in the rear seat air conditioning unit (40),
  On the other hand, when the heating load on the rear seat side is larger than the heating load on the front seat side, the number of energizations of the electric heating elements (69a to 69c) in the rear seat air conditioning unit (40) is controlled by the heating element control means (S300). More than the number of energized electric heating elements (68a to 68c) in the front seat air conditioning unit (20), and the electric heating in the rear seat air conditioning unit (40) according to the increase in the difference in heating load. The number of energizations of the bodies (69a to 69c) is increased and the number of energizations of the electric heating elements (68a to 68c) in the front seat air conditioning unit (20) is reduced.It is characterized by that.
[0008]
According to this, since the number of energizations of the electric heating elements in the front and rear air conditioning units (20, 40) is determined according to the difference between the heating loads before and after the passenger compartment, the front and rear regions of the passenger compartment are simultaneously heated. In addition, the auxiliary heating capacity by the front and rear electric heating elements can be appropriately controlled according to the heating load. Accordingly, both the front and rear regions of the passenger compartment can be heated satisfactorily with a uniform thermal feeling using the electric heating element.
[0009]
  Further, since the auxiliary heating capacity by the front and rear electric heating elements is controlled corresponding to the heating load, the front and rear air conditioning units are controlled when the air volume level of the front and rear air conditioning units (20, 40) is controlled corresponding to the heating load. The air volume level of (20, 40) changes similarly. Therefore, there is no problem that the maximum airflow level is maintained for a long period of time only by one unit on the front and rear sides of the passenger compartment, and the quietness is not impaired.
  Furthermore, among the front and rear electric heating elements, the number of energizations of the electric heating element on the side with the larger heating load is increased in accordance with the increase in the difference in heating load, while the number of energizations of the electric heating element on the side with the smaller heating load is increased. Since the number is reduced, the total number of energizations of the front and rear electric heating elements can be suppressed, and the power consumption of the entire electric heating element can be reduced.
[0010]
Specifically, the difference between the heating loads described above is the target air temperature (TAO (Fr)) on the front seat side and the target air temperature (TAO (Rr)) on the rear seat side as described in claim 2. Based on the difference (ΔTAO).
Further, based on the difference (ΔTr) between the room temperature (Tr (Fr)) on the front seat side in the vehicle interior and the room temperature (Tr (Rr)) on the rear seat side in the vehicle interior as described in claim 3. The difference may be determined.
[0011]
In the invention according to claim 4, the total number of installed electric heating elements (68a to 68c, 69a to 69c) in both the air conditioning units (20, 40) is N in both air conditioning units (20, 40). The total number n of electric heating elements of
It is characterized in that the number of energizations of the electric heating elements in both air conditioning units (20, 40) is switched stepwise so that n = 1 / 2N.
[0012]
  According to this, the total number of energizations n of the electric heating elements in both air conditioning units (20, 40) is always ½ of the total number N of electric heating elements installed, and the maximum power consumption of the entire electric heating elements is determined on one side. It can be suppressed within the maximum value of the electric heating element in the air conditioning unit, which is advantageous for preventing over-discharge of the in-vehicle battery.
  In the fifth aspect of the present invention, the front seat air conditioning unit (20) and the rear seat air conditioning unit (40) are respectively provided, and the amount of heating by the heating heat exchanger (28, 47) is adjusted to the vehicle interior. Temperature adjusting means (27, 49) for adjusting the blown air temperature of
  When only one of the front seat side air conditioning unit (20) and the rear seat side air conditioning unit (40) operates, the operating position of the temperature adjusting means (27, 49) in the one operating air conditioning unit is set. And control means (S320, S330) for determining the number of energized electrical heating elements (68a-68c, 69a-69c) in response.e,
  This control means (S320, S330) is the number of energized electric heating elements (68a to 68c, 69a to 69c) as the operating position of the temperature adjusting means (27, 49) shifts to the high temperature side position of the blown air temperature. To increaseIt is characterized by that.
[0013]
  According to this, even when only one of the air conditioning units is operated, the number of energized electric heating elements is appropriately set according to the operating position of the temperature adjusting means (27, 49) in the air conditioning unit on the one operating side. Can be determined.
[0014]
In addition, the code | symbol in the bracket | parenthesis of each said means shows a corresponding relationship with the specific means of embodiment description later mentioned.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings.
(First embodiment)
1 and 2 exemplify an arrangement layout in which a front seat air conditioning unit 20 and a rear seat air conditioning unit 40 are arranged in a one-box type RV vehicle 10. The vehicle 10 has three rows of seats 12 in the front-rear direction in the passenger compartment 11, and forms a long passenger compartment space in the front-rear direction.
[0016]
The front seat side air conditioning unit 20 is disposed on the inner side of the frontmost instrument panel 13 in the vehicle interior and air-conditions the area on the front seat side of the vehicle interior, and has a configuration as shown in FIG. Yes. In FIG. 3, the front seat air conditioning unit 20 is roughly divided into a blower unit 21 and a heat exchanger unit 22. In addition, the air blower part 21 is arrange | positioned in the passenger seat front side of the inner side part of the instrument panel 13, and the heat exchanger part 22 is arrange | positioned in the inner part of the instrument panel 13, and the approximate center position of the vehicle left-right direction.
[0017]
The blower unit 21 includes an inside / outside air switching box 23 that switches between introduction of inside air and outside air, and a centrifugal blowing fan 24, and the blowing fan 24 is rotationally driven by a motor 24a. In the heat exchanger section 22, an evaporator 25 of a refrigeration cycle is disposed in a case 26 as a cooling heat exchanger that cools conditioned air. Here, the refrigeration cycle has a well-known configuration (not shown), and stores a compressor driven by a vehicle engine, a condenser that condenses the refrigerant discharged from the compressor, and a refrigerant condensed by the condenser. Thus, a liquid receiver for separating the gas and liquid of the refrigerant and a temperature type expansion valve (pressure reducing means) for reducing the pressure of the liquid refrigerant from the liquid receiver are provided.
[0018]
In the refrigeration cycle described above, an evaporator (cooling heat exchanger) 46 of a rear seat side air conditioning unit 40 shown in FIG. 4 to be described later is connected in parallel with the evaporator 25 of the front seat side air conditioning unit 20 described above. ing.
Next, in the heat exchanger section 22, an air mix door 27 and a heater core 28 are disposed on the air downstream side of the evaporator 25. Here, the heater core 28 is a hot water heating heat exchanger that heats the conditioned air with hot water (cooling water) from the vehicle engine, and cool air that has passed through the evaporator 25 flows to the side of the heater core 28. Bypass paths 29 are formed in parallel.
[0019]
A plate-like air mix door (temperature adjusting means) 27 is rotatably disposed at a portion upstream of the heater core 28, and passes through the heater core 28 by selecting the rotation position (opening) of the air mix door 27. Then, the blown air temperature is adjusted by adjusting the air volume ratio between the heated hot air and the cold air passing through the bypass passage 29. Reference numeral 27 ′ shows a maximum heating state (opening SW = 100% of the air mix door 27) in which the air mix door 27 fully closes the bypass path 29 and fully opens the air path to the heater core 28. On the downstream side of the heater core 28, a cold / hot air mixing chamber 30 for mixing the hot air and the cold air is disposed.
[0020]
And the defroster blowing opening part 31, the face blowing opening part 32, and the foot blowing opening part 33 are opening in the downstream end of case 26, These opening parts 31-33 are three blowing mode doors 34-36. Is switched to open or close. In addition, the conditioned air that has passed through each of the openings 31 to 33 is directed from an unshown defroster outlet, face outlet, and foot outlet toward the inner surface of the vehicle window glass, the head of the front seat occupant, and the feet, respectively. Blown out.
[0021]
Next, as shown in FIGS. 1 and 2, the rear seat side air conditioning unit 40 is disposed on the rear seat (second and third seats 12) side of the vehicle interior and air-conditions the rear seat area. More specifically, according to this example, the rear seat air conditioning unit 40 is disposed on the right side of the seat 12 in the rearmost row of the passenger compartment.
The specific configuration of the rear seat side air conditioning unit 40 is, for example, as shown in FIG. 4. The rear seat side air conditioning unit 40 is roughly divided into a blower unit 41 disposed on the front side of the vehicle and a rear side of the vehicle. The heat exchanger section 42 is configured. The blower unit 41 includes a centrifugal blower fan 43 that sucks and blows only air in the passenger compartment 11 (inside air), and a scroll casing 44. The blower fan 43 is driven to rotate by a fan drive motor 43a. Is done. Then, as the fan 43 rotates, the intake air is blown from the scroll casing 44 toward the heat exchanger section 42.
[0022]
The case 45 of the heat exchanger unit 42 described above is connected to the air flow downstream side of the blower unit 41, and the lower part of the case 45 of the heat exchanger unit 42 has a front side air conditioning unit 20. An evaporator (cooling heat exchanger) 46 for evaporating the refrigerant branched from the refrigeration cycle is accommodated. The evaporator 46 has a substantially rectangular thin shape and is disposed in a substantially horizontal direction, and air passes through the heat exchange portion from below to above.
[0023]
A heater core 47 is disposed on the downstream side of the air flow of the evaporator 46, that is, on the upper side of the evaporator 46. The heater core 47 is also a hot water heating heat exchanger that heats air using hot water from the vehicle engine, and is disposed horizontally above the evaporator 46. The heat exchange section of the heater core 47 also allows air to pass from below to above. The heater cores 28 and 47 of the front and rear air conditioning units 20 and 40 basically have the same configuration, and will be described in detail with reference to FIG.
[0024]
A bypass path 48 for bypassing the heater core 47 and flowing cool air is formed on the side of the heater core 47, and a slide type air mix door (temperature adjusting means) 49 is disposed below the heater core 47. It is. The air mix door 49 has a flat plate shape and is slidable in a substantially horizontal direction A. As the air mix door 49 slides in the substantially horizontal direction A, the air volume ratio between the hot air heated through the heater core 47 and the cold air passing through the bypass 48 is adjusted to adjust the blown air temperature.
[0025]
On the upper side of the heater core 47, a face blowing opening 50 on the rear seat side and a foot blowing opening 51 on the rear seat are opened. The face blowout opening 50 blows air to the upper part on the rear seat side through a rear seat side face duct (not shown), and the foot blowout opening 51 passes through the rear seat side foot duct (not shown). The air is blown out to the passenger's foot on the side.
[0026]
A sliding blowout mode door 52 is disposed below the openings 50 and 51. The blowing mode door 52 is slid in a substantially horizontal direction B, so that both openings 50 and 51 are switched open and closed.
FIG. 5 is a front view of the heater cores (heat exchangers for heating the vehicle) 28 and 47 of the front and rear air conditioning units 20 and 40 described above. The heater cores 28 and 47 include the hot water inlet side tank 60 and the hot water outlet side. A tank 61 and a heat exchanging core 62 provided between the tanks 60 and 61 are provided.
[0027]
The hot water inlet side tank 60 is provided with an inlet pipe 63 into which hot water (engine cooling water) from a water-cooled vehicle engine 70 shown in FIG. 7 which will be described later flows, and the hot water outlet side tank 61 flows out the hot water to the outside. In addition, an outlet pipe 64 is provided for returning to the engine 70 side.
Each of the tanks 60 and 61 has a well-known tank structure including tank main body portions 60a and 61a and sheet metals 60b and 61b that close the opening end surfaces of the tank main body portions 60a and 61a. A large number of flat tube insertion holes (not shown) are formed in the sheet metals 60b and 61b side by side in the left-right direction in FIG. The heat exchanging core section 62 has a plurality of flat tubes 65 formed in a flat shape parallel to the flow direction of the heating air (perpendicular to the plane of FIG. 5) and arranged in parallel in the left-right direction of FIG. Hot water flows in one direction from the lower side to the upper side in FIG. Then, corrugated fins (fin members) 66 formed in a wave shape are disposed and joined between the multiple flat tubes 65.
[0028]
Openings at both ends of the flat tube 65 are inserted into the tube insertion holes of the sheet metals 60b and 61b, respectively, and joined. Further, side plates 67 and 67 are disposed on the outer side of the corrugated fins 66 on the outermost side of the core part 62 (both left and right ends in FIG. 5). The side plates 67 and 67 are arranged on the outermost corrugated fins 66 and the tank. 60, 61.
[0029]
Further, in place of the flat tube 65, three electric heating elements 68a, 68b, 68c (69a, 69b, 69c) are installed in a part of the heat exchanging core portion 62. This electric heating element plays a role as an auxiliary heating heat source when the temperature of the hot water is low. Reference numerals 68a, 68b and 68c denote electric heating elements of the front seat side heater core 28, and reference numerals 69a, 69b and 69c denote The electric heating element of the rear seat side heater core 47 is shown.
[0030]
In the example of FIG. 5, the electric heating elements are installed at three positions of the heat exchanging core portion 62 at equal intervals and at symmetrical positions. A specific configuration of the electric heating elements 68a to 68c (69a to 69c) will be described with reference to FIG. 6. In the heat exchange core portion 62, the electric heating elements 68 a to 68 c (69 a to 69 c) are installed. The metal holding plate 100 is joined to the bent top portion of the adjacent corrugated fin 66. This holding plate 100 is bent and formed into a U-shape with a predetermined interval, and is arranged so that its closed end is located upstream in the air blowing direction C to the heater core.
[0031]
The electric heating elements 68a to 68c (69a to 69c) are assembled within a predetermined interval between the two flat plate portions 101 and 102 of the holding plate 100.
Each component of the heater cores 28 and 47 and the holding plate 100 are made of aluminum, and are joined by integral brazing. After this brazing, each electric heating element is assembled into the metal holding plate 100.
[0032]
The electric heating elements 68a to 68c (69a to 69c) are three-layer sandwiches of a plate-like heating element 103 and elongated plate-like electrode plates 104 and 105 disposed on both front and back surfaces of the heating element 103. The structure is covered with an electrical insulating material 106, and the heating element 103 is electrically connected to an external circuit through the electrode plates 104 and 105. The heating element 103 is a PTC heater element made of a resistor material (for example, barium titanate) having a positive resistance temperature characteristic in which the resistance value rapidly increases at a predetermined set temperature (curie point). Further, a total of six electric heating elements 68a to 68c (69a to 69c) of the front and rear heater cores 28 and 47 are electrically connected in parallel to the in-vehicle power supply (battery 79 shown in FIG. 7).
[0033]
FIG. 7 shows a schematic block diagram of a vehicle hot water circuit and an electric control unit including both hot water type heater cores 28 and 47 in which electric heaters are integrated. The hot water circuit 71 of the water-cooled vehicle engine 70 is provided with a hot water pump 72 that is rotationally driven by the vehicle engine 70, and the hot water (engine cooling water) circulates through the hot water circuit 71 by the operation of the hot water pump 72.
[0034]
In the hot water circuit 71, the hot water heated by the vehicle engine 70 flows into the front seat side heater core 28 via the front seat side hot water valve 73. Here, the hot water valve 73 is controlled to be opened and closed by an electric actuator such as a servo motor. In the hot water circuit 71, the rear seat side hot water valve 74 and the rear seat side heater core 47 are provided in parallel with the front seat side hot water valve 73 and the front seat side heater core 28.
[0035]
Next, the electric control system of the air conditioner will be described. The air conditioning electronic control device 75 is composed of a microcomputer or the like, and performs predetermined arithmetic processing based on a preset program to thereby generate the electric heating element 68a. The energization to .about.68c, 69a.about.69c, etc. is controlled. The output signal of the electronic control unit 75 is applied to the relays 76a to 76c and the relays 77a to 77c, and the relays 76a to 76c and the relays 77a to 77c are intermittently connected to the electric heating elements 68a to 68c and 69a to 69c. It has come to be.
[0036]
In addition, power is supplied to the electronic control unit 75 from the in-vehicle battery 79 via an ignition switch 78 that intermittently operates the vehicle engine 70.
On the other hand, the following various sensors and signals from the air conditioning operation panel are input to the electronic control unit 75. That is, the sensors include an outside air temperature sensor 80 that detects the outside air temperature Tam, a front air side inside air temperature sensor 81 that detects an inside air temperature Tr (Fr) on the front side of the vehicle interior, and an inside air temperature Tr on the rear side of the vehicle interior. (Rr) is detected in the rear seat side air temperature sensor 82, the solar radiation sensor 83 detects the amount of solar radiation Ts entering the vehicle interior, the water temperature sensor 84 detects the temperature of the water-cooled vehicle engine 70, the front seat side evaporator. 25 (specifically, the evaporator blown air temperature) Te (Fr) for detecting the front seat side evaporator temperature sensor 85 and the cooling temperature of the rear seat side evaporator 46 (specifically, the evaporator A rear-seat evaporator temperature sensor 86 for detecting the blown air temperature (Te (Rr)) is provided. The solar radiation sensor 83 may be provided independently of each other without being common to the front seat side and the rear seat side.
[0037]
The front seat air conditioning operation panel 87 is provided with a manually operated front seat temperature setting device 88, and the rear seat air conditioning operation panel 89 is provided with a manually operated rear seat temperature setting device 90, The front seat side set temperature Tset (Fr) and the rear seat side set temperature Tset (Rr) set by the occupant are input to the electronic control unit 75, respectively. In addition to the set temperature, manual operation signals such as switching of introduction of inside / outside air, switching of air volume, switching of blowing mode, and the like are input to the electronic control unit 75 from both the operation panels 87 and 89, as is well known.
[0038]
In addition to the above-described relays 76a to 77c, the electronic control unit 75 includes front and rear fan drive motors 24a and 43a, a front seat side air mix door 27 drive actuator 27a, and a rear seat side air mix door 49 drive actuator. 49a controls the actuators for driving the front and rear hot water valves 73 and 74.
Next, the operation in the above configuration will be described. Before describing energization control of the electric heating elements 68a to 68c and 69a to 69c, first, an outline of the air conditioning operation by each functional component will be described. When heating the front and rear of the passenger compartment, the blower fans 24 and 43 of the front and rear air conditioning units 20 and 40 are operated, and the hot water valves 73 and 74 are opened. The air for heating passes through the space between the flat tubes 65 and the corrugated fins 66 of the front and rear heater cores 28 and 47 by the operation of the blower fans 24 and 43.
[0039]
On the other hand, by the operation of the hot water pump 72 of the vehicle engine 70, the hot water from the engine 70 flows into the hot water inlet side tank 60 through the hot water valves 73, 74 through the inlet pipes 63 of the front and rear heater cores 28, 47. The hot water is distributed to a large number of flat tubes 65 in the inlet side tank 60, and radiates heat to the heating air via the corrugated fins 66 while flowing in the flat tubes 65 in parallel. The hot water that has passed through the multiple flat tubes 65 flows into the hot water outlet side tank 61 and is gathered here, and the hot water flows out from the outlet pipe 64 to the outside of the heater core and returns to the engine 70 side.
[0040]
On the other hand, when heating, the temperature of the hot water is low and an auxiliary heat source is required due to the heat generated by the electric heating elements 68a to 68c and 69a to 69c, the relay 76a to 77c corresponds to the electric heating element that needs to generate heat. The relay is turned on, and the voltage of the in-vehicle battery 79 is applied to the electric heating element. As a result, an electric heating element that requires heat generation is energized through the relay to generate heat.
[0041]
The heat generated by the electric heating element is conducted to the corrugated fins 66 on both sides, and is radiated from the corrugated fins 66 to the heating air. Therefore, even when the hot water is at a low temperature, the heating air can be quickly heated to perform immediate heating.
Here, the heating element 103 of the electric heating elements 68a to 68c and 69a to 69c is a PTC element having a positive resistance temperature characteristic in which the resistance value rapidly increases at a predetermined curie point (for example, 150 ° C.). As is well known, a self-temperature control function that self-controls the heat generation temperature at a curie point is provided.
[0042]
Next, a specific example of energization control of the electric heating element, which is a feature of the present invention, will be described based on the flowchart of FIG. The control routine of FIG. 8 starts when the ignition switch 78 of the vehicle engine 70 is turned on, and reads signals from various sensors and switches in step S200. In the next step S210, it is necessary to maintain the front seat side region and the rear seat side region in the vehicle interior at the front seat side set temperature Tset (Fr) and the rear seat side set temperature Tset (Rr), respectively. The front seat side target air temperature TAO (Fr) and the rear seat side target air temperature TAO (Rr) are calculated. The target blown air temperatures TAO (Fr) and TAO (Rr) before and after this are calculated based on the following formulas 1 and 2 stored in advance in the ROM.
[0043]
[Expression 1]
TAO (Fr) = Kset (Fr) × Tset (Fr) −Kr (Fr) × Tr (Fr) −Kam (Fr) × Tam
−Ks (Fr) × Ts + C (Fr) −Tc (Fr) + fFr (ΔTset) −Kw × Tw
[0044]
[Expression 2]
TAO (Rr) = Kset (Rr) × Tset (Rr) −Kr (Rr) × Tr (Rr) −Kam (Rr) × Tam
-Ks (Rr) * Ts + C (Rr) -Tc (Rr) + fRr ([Delta] Tset)
In Formulas 1 and 2 above, Fr represents the front seat side, and Rr represents the rear seat side. The same reference numerals as those in FIG. 7 represent the same contents. Further, Tc is a correction coefficient for correcting when the compressor of the refrigeration cycle is turned on and off, and ΔTset is a temperature between the front seat side set temperature Tset (Fr) and the rear seat side set temperature Tset (Rr). It is a difference. Further, Kset, Kr, Kam, Ks, Kw are all gains, and C is a correction constant.
[0045]
Next, the process proceeds to step S220, and the temperature difference ΔTAO (= TAO (Fr) −TAO (Rr)) between the target blown air temperatures TAO (Fr) and TAO (Rr) before and after the above is calculated. Next, in step S230, the front and rear air mix doors 27 and 49 are expressed by the following formulas 3 and 4 stored in advance in the ROM based on the front and rear target blown air temperatures TAO (Fr) and TAO (Rr). The opening degree SW (Fr) and SW (Rr) are calculated.
[0046]
[Equation 3]
SW (Fr) = [(TAO (Fr) −Te (Fr)) / (Tw−Te (Fr))] × 100
[0047]
[Expression 4]
SW (Rr) = [(TAO (Rr) −Te (Rr)) / (Tw−Te (Rr))] × 100
In the above mathematical expressions 3 and 4, the same reference numerals as those in FIG. 7 represent the same contents.
Next, the process proceeds to step S240, and it is determined whether or not the determination reference value f (Tw) = 1 for the hot water temperature Tw. Here, as shown in FIG. 9A, the judgment reference value f (Tw) is 1 when the hot water temperature Tw is equal to or lower than a predetermined temperature (in the example shown, 70 ° C. or 80 ° C. having a hysteresis width). When the temperature exceeds a predetermined temperature, it becomes 0. This determination reference value f (Tw) is 1 in the hot water low temperature region where the heating capacity by the heater cores 28 and 47 of the hot water heat source is insufficient, and is 0 in the hot water high temperature region where the heating capacity by the heater cores 28 and 47 is sufficient. The predetermined temperature is set.
[0048]
Accordingly, when the hot water temperature Tw is higher than the predetermined temperature, the determination in step S240 is NO and the process returns to step S200. On the other hand, when the hot water temperature Tw is not more than the predetermined temperature, the process proceeds to the next step S250, where it is determined whether or not the judgment reference value f (Tam) = 1 for the outside air temperature Tam. As shown in FIG. 9B, the determination reference value f (Tam) is 1 when the outside air temperature Tam is equal to or lower than a predetermined temperature (in the illustrated example, 10 ° C. or 15 ° C. having a hysteresis width). 0 when the temperature is exceeded. This predetermined reference value f (Tam) is 1 in the low temperature outside temperature range where an auxiliary heat source using an electric heating element is required, and 0 in the high temperature range outside the room where an auxiliary heat source using an electric heating element is not required. The temperature is set.
[0049]
Therefore, when the outside air temperature Tam is higher than the predetermined temperature, the determination in step S250 is NO and the process returns to step S200. On the other hand, when the outside air temperature Tam is equal to or lower than the predetermined temperature, the process proceeds to the next step S260, and it is determined whether the blower fan 24 of the front seat air conditioning unit 20 is operating (ON).
When the front seat fan 24 is operating (ON), the process proceeds to the next step S270, and it is determined whether the fan 43 of the rear seat air conditioning unit 40 is operating (ON). When the rear seat side blower fan 43 is operating (ON), the process proceeds to the next step S280, and a determination reference value f (SW (Fr)) of the opening degree SW (Fr) of the front seat side air mix door 27 = It is determined whether it is 1. Similarly, in the next step S290, it is determined whether or not the determination reference value f (SW (Rr)) = 1 of the opening degree SW (Rr) of the rear seat side air mix door 49.
[0050]
As shown in FIG. 9C, the determination reference values f (SW (Fr)) and f (SW (Rr)) indicate that the air mix door opening SW is a predetermined opening (in the illustrated example, the hysteresis width is It is 0 when it is less than 80% or 90%), and is 1 when the predetermined opening is exceeded. Here, the determination reference value f (SW) is 1 when the air mix door opening SW is close to the maximum heating state (opening SW = 100%), and the air mix door opening SW is near the maximum heating. The predetermined opening is set so as to be 0 when not in a state.
[0051]
In both of steps S280 and S290, when the determination reference value is 1, that is, when both the front and rear air conditioning units 20 and 40 are in the vicinity of the maximum heating, the process proceeds to the next step S300, and the front and rear air conditioning units The number of energizations of the electric heating elements 68a to 68c and 69a to 69c of the 20 and 40 heater cores 28 and 47 is determined.
[0052]
That is, in step S300, based on the temperature difference ΔTAO (= TAO (Fr) −TAO (Rr)) between the front and rear target blown air temperatures calculated in step S220 described above, as shown in FIG. The number of energizations of the heating elements 68a to 68c and 69a to 69c is determined. That is, when the temperature difference ΔTAO is larger than 10 ° C, the three electric heating elements having the higher target blowing air temperature are energized at the same time, and the air conditioning unit having the higher target blowing air temperature Aim to secure the heating capacity by maximizing the auxiliary heating capacity by the electric heating element.
[0053]
On the other hand, in the air conditioning unit on the side where the target blown air temperature is lower by 10 ° C. or more, the electrical heating element is energized to zero.
When 10 ° C> ΔTAO> 0 ° C, the number of energizations of the electric heating element on the side with the higher target blowing air temperature is two, and the electric heating element on the side of the lower target blowing air temperature is energized with one. And
[0054]
As described above, the front and rear room temperatures in the passenger compartment are set by the occupant even when the temperature of the hot water is low by switching and controlling the number of energizations of the front and rear electric heating elements in accordance with the target front and rear air temperature difference ΔTAO. It can be controlled well so as to be close to the set temperature. Moreover, the switching control of the number of energizations is advantageous for preventing over-discharge of the in-vehicle power supply battery 79. That is, the total number of energizations n of the electrical heating elements in the front and rear air conditioning units 20 and 40 is always equal to the total number N (six in this example) of the front and rear electrical heating elements 68a to 68c and 69a to 69c. Since the number of energizations of the electric heating elements is switched so as to be 1 / 2N (3 in this example), when the temperature difference ΔTAO is greater than 10 ° C, the limited power capacity of the in-vehicle power supply battery 79 is reduced. It is possible to effectively prevent over-discharge of the in-vehicle power supply battery 79 by intensively and effectively using the auxiliary heating heat source of the air conditioning unit on the higher target blown air temperature side.
[0055]
Incidentally, assuming that the power consumption per electric heating element is 300 W, according to the control of this example, the electric power consumption of the entire electric heating element can always be suppressed to 900 W.
It should be noted that even with the air conditioning unit on the side where the target blown air temperature is lower by 10 ° C or more, heating with the hot water as the heat source is possible even if the electric heating element is energized to zero, and Since the areas are connected as a single space, there is no possibility that the room temperature is extremely lowered in the area where the target blown air temperature is low.
[0056]
Here, in order to prevent overdischarge of the in-vehicle power supply battery 79 more reliably, the state of charge of the battery 79 (for example, the charge voltage of the battery 79) is detected, the state of charge of the battery 79 is determined, and the electric heating element You may make it define the upper limit of the total energization number.
Next, in step S260 described above, when the front seat side blower fan 24 is not operating, the process proceeds to step S310, and it is determined whether the rear seat side blower fan 43 is operating (ON). When the rear seat side fan 43 is not activated (ON), the process returns to step S200. On the contrary, when the rear seat side blower fan 43 is operating (ON), the process proceeds to the next step S320, and the rear seat side electric heating element according to the opening degree SW (Rr) of the rear seat side air mix door 49. The number of energizations 69a to 69c is determined as shown in FIG.
[0057]
That is, when the opening degree SW (Rr) of the rear seat side air mix door 49 is smaller than 80%, it is a region (temperature control region) that does not require an auxiliary heat source by the electric heating element. The number of energizations 69a to 69c is always zero. On the other hand, when the opening degree SW (Rr) of the rear seat side air mix door 49 is larger than 110%, it is a necessary area to maximize the auxiliary heat source by the electric heating element, and therefore the rear seat side electric heating element 69a. The energized number of .about.69c is the maximum number (three). As the door opening SW (Rr) increases or decreases between 80% and 110%, the number of energizations of the rear seat side electric heating elements 69a to 69c is increased or decreased between 0 and 3. Yes.
[0058]
Thus, when only the rear seat air conditioning unit 40 is operated, the number of energizations of the rear seat side electric heating elements 69a to 69c is changed to the necessary auxiliary heating based on the change in the rear seat air mix door opening degree SW (Rr). It can be determined appropriately according to ability.
In step S270 described above, when the rear seat side blower fan 43 is not operating, the process proceeds to step S330, and the front seat side electric heating element 68a is operated according to the opening degree SW (Fr) of the front seat side air mix door 27. The number of energized lines of -68c is determined as shown in FIG. The specific method of determining the number of energized wires is the same as that in the case of the above-described rear seat side electric heating elements 69a to 69c, and thus the description thereof is omitted.
[0059]
Thereby, even when only the front seat side air conditioning unit 20 is operated, the number of energizations of the front seat side electric heating elements 68a to 68c is required based on the change in the front seat side air mix door opening SW (Fr). It can be determined appropriately according to the auxiliary heating capacity.
When the determination reference value is not 1 in steps S280 and S290 described above (when the front and rear air conditioning units 20 and 40 are not in the vicinity of maximum heating), the process returns to step S200.
[0060]
Here, the correspondence between each step of FIG. 8 and the function realizing means in each claim will be described. Front seat side calculating means for calculating the front seat side target blowing air temperature TAO (Fr), and rear seat side target blowing. The rear seat side calculating means for calculating the air temperature TAO (Rr) is configured by step S210.
The determining means for determining the difference between the heating loads before and after the passenger compartment based on the difference ΔTAO between the target air temperature TAO (Fr) on the front seat side and the target air temperature TAO (Rr) on the rear seat side is step. S220 is comprised.
[0061]
Further, the number of energizations of the electric heating elements 68a to 68c in the front seat air conditioning unit 20 and the number of energizations of the electric heating elements 69a to 69c in the rear seat air conditioning unit 40 are determined in accordance with the difference in heating load before and after the vehicle interior. The heating element control means for switching is configured by step S300.
When only one of the front and rear air conditioning units 20 and 40 is activated, the electric heating element is energized in accordance with the air mix door opening SW (Fr) and SW (Rr) in the air conditioning unit on the one operating side. The control means for determining the number is composed of steps S320 and S330.
[0062]
Next, FIG. 10 shows the control characteristics of the air volume of the blower fans 24 and 43 of the front and rear air conditioning units 20 and 40 and the water temperature (Tw) in this embodiment, and the vertical axis in FIG. 43 is a voltage level applied to the drive motors 24a and 43a. In the figure, the vertical axis “31” indicates the maximum value of the applied voltage level, that is, the maximum level of the motor rotation speed (air flow). In the figure, “1” on the vertical axis is the lowest value of the applied voltage level, which is the lowest level of the motor rotation speed (air volume).
[0063]
According to the control characteristics of FIG. 10, as the number of energizations of the front seat side electric heating elements 68a to 68c or the rear seat side electric heating elements 69a to 69c increases from 0 to 1, 2, and 3, the auxiliary heating by the electric heating elements is performed. Focusing on the fact that the capacity can be increased, the water temperature Tw when the motor applied voltage level of the front and rear blower fans 24 and 43 is shifted from 0 to 1, that is, when the blower fans 24 and 43 are started, is determined by the number of energized electric heating elements. The price has been lowered with the increase. Specifically, when the number of electric heating element energization = 0, the fan starting water temperature Tw = 35 ° C. → when the number of electric heating element energization = 3, the fan starting water temperature Tw = 26 ° C. .
[0064]
Similarly, the water temperature Tw at which the motor applied voltage level of the front and rear blower fans 24 and 43 reaches the maximum 31 is also lowered with an increase in the number of energized electrical heating elements. Specifically, when the number of electrified heating elements energized = 0, the fan maximum speed water temperature Tw = 65 ° C. → When the number of electrified heating elements energized = 3, the fan maximum speed water temperature Tw = 56 ° C. ing.
[0065]
In this way, the operation of the blower fans 24 and 43 from the lower temperature side in the process of increasing the water temperature after starting the engine by lowering the water temperature at the start of the fan and the water temperature at the maximum fan speed as the number of electric heating elements energized increases. Can start. As a result, a comfortable temperature can be reached in the passenger compartment in a short time after the engine is started, and the air conditioning feeling can be improved.
[0066]
(Second Embodiment)
FIG. 11 shows the second embodiment. In the example of the air flow control of FIG. 10 according to the first embodiment, the blower fans 24 and 43 are stopped until the water temperature Tw rises to a predetermined temperature, for example, 35 ° C. In the second embodiment, as shown in FIG. 11, the air conditioning unit on the front seat side is used until the water temperature Tw rises to a predetermined temperature, for example, 35 ° C. 20, the motor applied voltage level of the blower fan 24 is fixed to the lowest level “1”, the blower outlet mode is fixed to the defroster mode, and the minimum amount of wind from the blower fan 24 is blown out only from the defroster blower outlet. At this time, the number of energizations of the front seat-side electric heating elements 68a to 68c in the front-seat-side air conditioning unit 20 is determined in step S330 of FIG.
[0067]
(Third embodiment)
FIG. 12 shows a third embodiment. When the outside air mode is selected as the inside / outside air intake mode in the front seat side air conditioning unit 20, if the vehicle speed increases, the vehicle running dynamic pressure ( The outside air flows into the passage in the case 26 due to the ram pressure. Accordingly, as shown in FIG. 10, when outside air flows in due to ram pressure at a low water temperature until the water temperature Tw rises to a predetermined temperature, for example, 35 ° C., there is a problem that low-temperature air is blown out into the vehicle interior. .
[0068]
Therefore, in the third embodiment, in view of the above points, when the blower fan 24 of the front seat air conditioning unit 20 is stopped due to a low water temperature, the inside / outside air suction mode is the outside air mode, and the vehicle speed Is a predetermined speed (for example, 40 km / h) or more, the front seat side electric heating elements 68a to 68c in the front seat side air conditioning unit 20 are forcibly energized to blow out low-temperature air into the vehicle interior. You may make it prevent reliably.
[0069]
(Other embodiments)
In the above embodiment, the difference between the front and rear heating loads is determined based on the difference ΔTAO between the target air temperature TAO (Fr) on the front seat side and the target air temperature TAO (Rr) on the rear seat side. However, since the room temperature (inside temperature) is an environmental factor that greatly affects the heating load, the difference ΔTr between the room temperature Tr (Fr) on the front seat side and the room temperature Tr (Rr) on the rear seat side in the vehicle interior Based on this, the difference in heating load may be determined.
[0070]
In addition, the front seat heating load (TAO (Fr), Tr (Fr), etc.) and the rear seat heating load (TAO (Rr), Tr (Rr), etc.) in the passenger compartment are calculated respectively. The number of energizations of the electric heating elements 68a to 68c in the side air conditioning unit 20 is determined according to the heating load on the front seat side, and the number of energizations of the electric heating elements 69a to 69c in the rear seat side air conditioning unit 40 is determined on the rear seat side It may be determined according to the heating load.
[0071]
Of course, the heat source fluid circulating in the heater cores 28 and 47 is not limited to warm water, but may be oils such as engine oil.
Further, when the electric heating elements 68a to 68c and 69a to 69c are integrated with the heater cores 28 and 47, the installation form of the electric heating elements is not limited to that shown in FIG. Of course, various modifications can be made.
[0072]
In the above-described embodiment, the case where the plurality of electric heating elements 68a to 68c and 69a to 69c are integrated with the heater cores 28 and 47 has been described. The electric heating element may be installed separately.
Further, the air volume control of the blower fans 24 and 43 is not limited to the method of changing the applied voltage level of the drive motors 24a and 43a, and the pulse width that modulates the pulse width of the pulse output voltage applied to the drive motors 24a and 43a. A modulation (PWM) method can also be used.
[0073]
Moreover, although the case where the air mix doors 27 and 49 for adjusting the blown air temperature by adjusting the air volume ratio between the hot air and the cold air has been described as the temperature adjusting means for adjusting the temperature of the air blown into the passenger compartment, The valves 73 and 74 may be of a type that can continuously adjust the hot water flow rate to the heater cores 28 and 47, and the temperature of the blown air may be adjusted by adjusting the hot water flow rate by the hot water valves 73 and 74.
[Brief description of the drawings]
FIG. 1 is a schematic plan view of a vehicle in which a front seat side air conditioning unit and a rear seat side air conditioning unit to which the present invention is applied are arranged.
FIG. 2 is a schematic side view of the vehicle shown in FIG.
3 is a schematic cross-sectional view illustrating a ventilation system of the front seat air conditioning unit of FIG. 1;
4 is a schematic cross-sectional view illustrating the ventilation system of the rear seat side air conditioning unit of FIG. 1;
FIG. 5 is a front view of a heater core integrated with an electric heating element according to the present invention.
6 is an enlarged perspective view of an electric heating element portion in the heater core of FIG.
FIG. 7 is an overall system diagram including a hot water circuit including a heater core and an electric control system in the first embodiment of the present invention.
FIG. 8 is a flowchart of electric control in the first embodiment of the present invention.
FIG. 9 is an electric control characteristic diagram according to the first embodiment of the present invention.
FIG. 10 is a control characteristic diagram showing the relationship between water temperature and air volume in the first embodiment of the present invention.
FIG. 11 is an air flow control characteristic diagram in the second embodiment of the present invention.
FIG. 12 is a flowchart of electric heating element energization control in a third embodiment of the present invention.
[Explanation of symbols]
20 ... Front seat air conditioning unit, 40 ... Rear seat air conditioning unit,
27, 49 ... air mix door, 28, 47 ... heater core,
68a-68c, 69a-69c ... Electric heating element.

Claims (5)

A front-seat-side air conditioning unit (20) that is disposed on the front-seat side in the passenger compartment and that includes at least a heat exchanger (28) for heating and that air-conditions the front-seat side;
In a vehicle air conditioner that is disposed on the rear seat side of the vehicle interior and includes at least a heating heat exchanger (47) and includes a rear seat air conditioning unit (40) that air-conditions the rear seat side,
A plurality of electric heating elements (68a to 68c, 69a to 69c) that are provided in the front seat air conditioning unit (20) and the rear seat air conditioning unit (40), respectively, and act as auxiliary heating heat sources;
Determining means (S220) for determining the difference between the heating load on the front seat side and the heating load on the rear seat side in the vehicle interior, and the number of energizations of the electric heating elements (68a to 68c) in the front seat air conditioning unit (20) and Bei example a heating element control means (S300) for switching in accordance with current number to the difference of the heating load of the electric heating elements of the rear seat side air-conditioning unit (40) (69a to 69c),
When the heating load on the front seat side is larger than the heating load on the rear seat side, the heating element control means (S300) causes the electric heating elements (68a to 68c) in the front seat side air conditioning unit (20). The number of energizations is made larger than the number of energizations of the electric heating elements (69a to 69c) in the rear seat air conditioning unit (40), and the front seat air conditioning unit (20 ) And increasing the number of energizations of the electric heating elements (68a to 68c) in the rear seat side air conditioning unit (40), and reducing the number of energizations of the electric heating elements (69a to 69c) in the rear seat air conditioning unit (40),
On the other hand, when the heating load on the rear seat side is larger than the heating load on the front seat side, the heating element control means (S300) controls the electric heating elements (69a to 69c) in the rear seat air conditioning unit (40). ) More than the number of energizations of the electric heating elements (68a to 68c) in the front seat air conditioning unit (20), and the rear seat air conditioning unit according to the increase in the difference in heating load. A vehicle characterized by increasing the number of energizations of the electric heating elements (69a to 69c) in (40) and decreasing the number of energizations of the electric heating elements (68a to 68c) in the front seat air conditioning unit (20). Air conditioner. Front seat side calculating means (S210) for calculating a target blown air temperature (TAO (Fr)) of blown air blown out from the front seat air conditioning unit (20) to the front seat side in the vehicle compartment;
Rear seat side calculation means (S210) for calculating a target blown air temperature (TAO (Rr)) of blown air blown out from the rear seat side air conditioning unit (40) to the rear seat side of the vehicle interior;
The difference in the heating load is determined based on a difference (ΔTAO) between the target air temperature on the front seat side (TAO (Fr)) and the target air temperature on the rear seat side (TAO (Rr)). The vehicle air conditioner according to claim 1. Front seat side room temperature detecting means (81) for detecting the room temperature (Tr (Fr)) of the front seat side in the passenger compartment;
A rear seat side room temperature detecting means (82) for detecting a room temperature (Tr (Rr)) on the rear seat side of the vehicle interior;
The heating load difference is determined based on a difference (ΔTr) between a room temperature (Tr (Fr)) on the front seat side and a room temperature (Tr (Rr)) on the rear seat side. The vehicle air conditioner according to 1.   The total number of energized electric heating elements in the air conditioning units (20, 40) relative to the total number N of electric heating elements (68a to 68c, 69a to 69c) installed in the air conditioning units (20, 40). 4. The number of energizations of the electric heating elements in the air conditioning units (20, 40) is switched in stages so that n has a relationship of n = 1 / 2N. The vehicle air conditioner described in 1. It is provided in each of the front seat air conditioning unit (20) and the rear seat air conditioning unit (40), and adjusts the amount of heating by the heating heat exchanger (28, 47) to control the temperature of air blown into the vehicle interior. Temperature adjusting means (27, 49) to adjust;
When only one of the front seat side air conditioning unit (20) and the rear seat side air conditioning unit (40) operates, the temperature adjusting means (27, 49) in the one operating side air conditioning unit said electric heating element in accordance with the operating position (68a to 68c, 69a to 69c) control means (S320, S330) for determining the current number of the Bei give a,
The control means (S320, S330) are arranged so that the electric heating elements (68a-68c, 69a-69c) correspond to the operating position of the temperature adjusting means (27, 49) being shifted to the high temperature side position of the blown air temperature. The vehicle air conditioner according to any one of claims 1 to 4, wherein the number of energizations is increased.

Images