JP4356889B2 - Air conditioner for vehicles - Google Patents

Description

  The present invention relates to a vehicle air conditioner, and more particularly to a vehicle air conditioner including a control device that controls a water valve.

  A conventional vehicle air conditioner includes a heater circuit that circulates cooling water between an engine and a radiator by a water pump to take out hot water from a cooling circuit that cools the engine and returns it to the water pump via a water valve and a heater core.

In the vehicle air conditioner as described above, conventionally, a water valve provided in the heater circuit is closed at the time of maximum cooling and is opened at other times (for example, see Patent Document 1).
JP-A-6-171339

  In the conventional vehicle air conditioner, the water valve is fully opened at once when the maximum cooling time is exceeded, so that more cooling water flows through the heater circuit in a region where the heating requirement is small. In addition, when the coolant temperature rises due to the engine running at a high load with the water valve fully open, etc., when the coolant temperature is lowered with the radiator, the radiator is compared to when the water valve is closed. It takes a lot of time to lower the cooling water temperature because less cooling water flows. Thus, there is a problem that the control of the water valve in the prior art cannot satisfy both the heating request and the cooling request.

  In view of the above problems, an object of the present invention is to provide a vehicle air conditioner that controls a water valve so that both a heating request and a cooling request can be satisfied.

  The vehicle air conditioner according to the present invention is configured as follows in order to achieve the above object.

A vehicle air conditioner (corresponding to claim 1) according to the present invention is provided with a heater core and a water valve provided in a heater circuit branched from an engine cooling circuit, and a controller for controlling the opening degree of the water valve, and the heater core. and the air conditioning duct, the vehicle air-conditioning apparatus and an air mixing door to air flowing in the air conditioning duct is distributed to the bypass side to bypass the heater core and the heater core side passing through the heater core, the control device targets and control to control the opening side of the opening of the water valve in response to an increase in air temperature, the air mixing with cooling water temperature when the predetermined value or more, controls the opening of the water valve to the closed side The opening degree of the door is shifted to the bypass side by a predetermined amount, and this predetermined amount becomes smaller as the opening degree of the water valve increases. And wherein the door.

According to the present invention, the heater circuit branched from the engine cooling circuit is provided with a heater core and a water valve and the opening degree of the water valve is controlled , the air conditioning duct in which the heater core is disposed, and the air flow in the air conditioning duct. In a vehicle air conditioner that includes an air mix door that distributes air to a heater core side through which the heater core passes and a bypass side that bypasses the heater core , the control device sets the opening degree of the water valve in response to an increase in the target blowing temperature. When the cooling water temperature is higher than a predetermined value, it is controlled to the closing side, so that the cooling water can be supplied to the heater circuit according to the heating requirement and the cooling circuit is in accordance with the cooling requirement. Since cooling water can flow, the control of the water valve should be compatible with both heating and cooling requirements. It is possible. Further, according to the present invention, the air-conditioning duct in which the heater core is disposed, and the air mix door that distributes the air flowing in the air-conditioning duct to the heater core side and the side bypassing the heater core, the control device has a cooling water temperature of a predetermined value. In the above case, since the opening degree of the air mix door is shifted by a predetermined amount to the bypass side, it is possible to compensate for the deterioration of the heating performance associated with the water valve closing side control . Also, according to the present invention, a predetermined amount due to the smaller in accordance with increase of the degree of opening of the water valve, it is possible to perform the temperature increase correction commensurate with the magnitude of the reduction in heating performance.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments (examples) of the invention will be described with reference to the accompanying drawings.

  FIG. 1 schematically shows a configuration viewed from the side of the front half of an automobile equipped with a vehicle air conditioner according to the present invention. In FIG. 1, a compartment 12 part and an engine room 13 part of the automobile 11 are shown. A driver 15 seated on a seat 14 is shown in the passenger compartment 12. An engine 16 is disposed in the engine room 13. A driving force transmission mechanism that transmits power output from the engine 16 is not shown.

  A configuration related to the air conditioner 17 will be described. A radiator 18 is disposed on the front side (left side in FIG. 1) of the engine 16. The radiator 18, the water pump 19 and the engine 16 are connected by a pipe 20 to form a cooling circuit 21, and the water pump 19, the engine 16, the water valve 22 and the heater core 23 are connected in a ring shape by a pipe 24 to form a heater. A circuit 25 is formed.

  The water pump 19 is driven by the engine 16. The water pump 19 circulates cooling water in the water jacket of the engine 16 and feeds the heated cooling water to the radiator 18.

  The radiator 18 cools the high-temperature cooling water sent from the water pump 19 and returns it to the engine 16.

  The air conditioner 17 forms a circulation path (heater circuit) of hot water via the heater core 23 by the pipe 24 and the pipe 26. The heater core 23 is a heat exchanger. A water valve 22 is provided in the heater core pipe 24 in the circulation channel. The heater core 23 is disposed in the air conditioning duct 27.

  Cooling water heated by the engine 16 is taken out to the heater circuit 25, passed through the heater core 23, and sent to the water pump 19 side. A water valve 22 is provided at the entrance of the heater core 23 to send a necessary amount of cooling water when necessary. In this embodiment, the opening degree of the water valve 22 is controlled to the open side according to the increase of the target blowing temperature, and is controlled to the closed side when the cooling water temperature is a predetermined value or more.

  The air conditioning duct 27 includes a blower fan 28, an evaporator (indoor heat exchanger) 29, an openable / closable air mix door 30, the heater core 23, and air outlets 31 and 32 from the upstream side located on the engine room 13 side. Is provided. The evaporator 29 cools the air sent from the blower fan (blower) 28. The outlet 31 is a vent outlet, and the outlet 32 is a foot outlet.

  In the air conditioning duct 27, the air mix door 30 causes the air passing through the air conditioning duct 27 to pass through the heater core 23 (hot air, the air portion 33 in FIG. 2) and the portion bypassing the heater core 23 (non-hot). The side air is distributed to the air portion 34) in FIG. Thus, according to the configuration of the air conditioning duct 27, the temperature-adjusted air can be supplied into the passenger compartment 12. In FIG. 1, reference numeral 35 denotes a partition wall that separates the vehicle compartment 12 and the engine compartment 13.

  According to the air conditioner 17, the air passing through the heater core 23 of the heater circuit can be warmed, and warm air can be supplied to the vehicle compartment 12.

  FIG. 2 is a diagram showing a configuration including a control system of the vehicle air conditioner 17 according to the present invention. The structure of the air conditioner 17 is as described above, and the same elements as those described in FIG.

  The control device 40 includes a water valve control unit 41 that sends a valve opening signal to the water valve 22, an air mix door control unit 42 that sends an air mix door opening signal to the air mix door 30, and a water valve control unit 41. A target blowing temperature setting unit 43 for sending a command signal is provided. The control device 40 is realized by a computer mounted on an automobile.

  The control device 40 includes, as input signals, Tr from the indoor temperature sensor 44 (signal related to the vehicle interior air temperature), Tsun from the solar radiation amount sensor 45 (signal related to the amount of solar radiation incident on the vehicle interior), and an outside air temperature sensor. 46 (Tam (signal related to the air temperature outside the passenger compartment)) from 46, Tset (signal related to the air temperature inside the vehicle interior) from the temperature setting unit 47, and Tw (cooling water temperature) from the cooling water temperature sensor 48 are input. . Tset is a set temperature set by the driver, and Tr, Tsun, Tam, and Tw are detection signals output from the corresponding sensors.

  The control device 40 to which the above various signals are input controls the opening degree of the water valve 22 and the opening degree of the air mix door 30 based on the control flow and the relational expression shown in FIG.

  In the first step S101, various input signals are read. Here, the input signals to be read are the aforementioned Tr, Tsun, Tam, Tset, and Tw.

  A target blowing temperature (TAO) is calculated using the input signal read in step S101 and based on the following equation (Equation 1) (step S102).

(Equation 1)
TAO = Kset * Tset-Kr * Tr-Kam * Tam-Ksun * Tsun + C
Tset: Car interior air temperature setting Tr: Car interior air temperature Tam: Car interior air temperature Tsun: Solar radiation incident on the vehicle interior Kset, Kr, Kam, Ksun, C: Control constant *: Multiplication symbol

  It is determined whether the TAO calculated in step S102 is equal to or smaller than a predetermined value X (step S103).

  If TAO is less than or equal to the predetermined value X in step S103, the water valve control unit 41 controls the valve opening degree of the water valve 22 to 0% (step S104). At this time, the valve is closed and the cooling water does not flow into the heater core 23. Then return.

  If TAO is larger than the predetermined value X in step S103, it is determined whether TAO is equal to or smaller than a predetermined value Y (X <Y) (step S105).

  If TAO is less than or equal to the predetermined value Y in step S105, the water valve control unit 41 controls the valve opening of the water valve 22 to 30% (step S106). Then, Step S107 is executed.

  In step S107, it is determined whether or not the cooling water temperature Tw is equal to or higher than a predetermined value F (eg, 110 ° C.) (step S107).

  Here, the predetermined value F is increased as TAO increases. FIG. 4 is a graph showing the relationship between TAO and the predetermined value F. The horizontal axis is TAO, and the vertical axis is the predetermined value F. A straight line L10 is a graph showing the relationship of the predetermined value F with respect to TAO. The predetermined value F is made higher as the target blowing temperature TAO increases. This graph is stored as a map in the storage unit of the control device 40, and a predetermined value F corresponding to TAO is set.

  If the cooling water temperature is equal to or higher than the predetermined value F in step S107, the air mix door control unit 42 shifts the opening of the air mix door 30 to the hot side by a predetermined amount G (step S108), and executes step S104. Return the water valve 22 to 0% and return.

  Here, the predetermined amount G is made smaller as the opening degree of the water valve 22 increases. FIG. 5 is a graph showing the relationship of the predetermined amount G with respect to the opening degree of the water valve 22. The horizontal axis indicates the opening degree of the water valve 22, and the vertical axis indicates the predetermined amount G. A curve C11 is a graph showing the relationship of the predetermined amount G to the opening degree of the water valve 22. The predetermined amount G is made smaller as the opening degree of the water valve 22 increases. This graph is stored as a map in the storage unit of the control device 40, and a predetermined amount G corresponding to the opening degree of the water valve 22 is set.

  When the cooling water temperature Tw is smaller than the predetermined value F in step S107, the process returns.

  If TAO is larger than the predetermined value Y in step S105, it is determined whether TAO is equal to or smaller than a predetermined value Z (Y <Z) (step S109).

  If TAO is equal to or less than the predetermined value Z, the water valve control unit 41 sets the valve opening of the water valve 22 to 50% (step S110), and determines whether the coolant temperature Tw is equal to or higher than the predetermined value F (step S110). S111). At this time, the predetermined value F corresponding to TAO is set by the map shown in FIG.

  If the coolant temperature Tw is not less than the predetermined value F in step S111, the water valve control unit 41 sets the valve opening of the water valve 22 to 30% (step S112), and the air mix door control unit 42 sets the air mix door 30. Is shifted to the hot side by a predetermined amount G (step S113), and the process returns. As the predetermined amount G at this time, the predetermined amount G corresponding to the opening degree of the water valve 22 is set according to the map shown in FIG.

  When the cooling water temperature Tw is lower than the predetermined value F in step S111, the process returns.

  When TAO is larger than the predetermined value Z in step S109, the water valve control unit 41 controls the valve opening degree of the water valve 22 to 100% (step S114), and determines whether or not the cooling water temperature Tw is equal to or higher than the predetermined value F. (Step S115). The predetermined value F here is a value set corresponding to TAO by the map shown in FIG.

  When the coolant temperature Tw is equal to or higher than the predetermined value F in step S115, the water valve control unit 41 controls the valve opening of the water valve 22 to 50% (step S116), and the air mix door control unit 42 controls the air mix door. The opening degree of 30 is shifted to the hot side by a predetermined amount G (step S117), and the process returns. The predetermined amount G here is set to a value corresponding to the opening degree of the water valve 22 in accordance with the map shown in FIG.

  When the cooling water temperature Tw is lower than the predetermined value F in step S115, the process returns.

  By performing the control as described above, it is possible to flow the cooling water according to the heating request to the heater circuit and to flow the cooling water according to the cooling request to the cooling circuit. The heating request and the cooling request can be made compatible. Moreover, the fall of the heating performance accompanying the closing side control of a water valve can be compensated. Furthermore, it is possible to suppress a decrease in heating performance regardless of the size of the heating request. Further, it is possible to perform temperature rise correction commensurate with the magnitude of the decrease in heating performance.

  The present invention is used as a vehicle air conditioner that can satisfy both a heating request and a cooling request.

It is the schematic of the structure seen from the side surface of the front half part of a motor vehicle provided with the vehicle air conditioner which concerns on this invention. It is a figure which shows the structure including the control system of the vehicle air conditioner which concerns on this invention. It is a flowchart of control of a water valve opening degree and an air mix door opening degree. It is a map which sets predetermined value F from TAO. It is a map which sets predetermined amount G from the opening degree of a water valve.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Car 12 Car compartment 13 Engine room 14 Seat 15 Driver 16 Engine 17 Air conditioner 18 Radiator 19 Water pump 20 Piping 21 Cooling circuit 22 Water valve 23 Heater core 24 Piping 25 Heater circuit 26 Piping 27 Air conditioning duct 28 Blower fan 29 Evaporator 30 Air Mix door 31 Outlet 32 Outlet 40 Control device 41 Water valve control unit 42 Air mix door control unit 43 Target outlet temperature setting unit

Claims (1)

A heater circuit and a water valve are provided in a heater circuit branched from an engine cooling circuit, and the controller for controlling the opening degree of the water valve, an air conditioning duct in which the heater core is disposed, and air flowing in the air conditioning duct passes through the heater core. In a vehicle air conditioner provided with a heater core side to be distributed and an air mix door that is distributed to a bypass side that bypasses the heater core ,
Wherein the control device,
And Gosei to side to open the opening of the water valve in response to an increase in targets air temperature,
When cooling water temperature is equal to or higher than a predetermined value, the opening degree of the air mix door by a predetermined amount shifted to the bypass side to control the opening of the water valve to the closing side,
The vehicle air conditioner is characterized in that the predetermined amount decreases as the opening of the water valve increases .

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