JP4661538B2 - Air conditioner for vehicles - Google Patents

Description

  The present invention relates to an air-mix type vehicle air conditioner provided with a constant temperature heating element as an auxiliary heat source, and more particularly to a device that prevents a sudden change in temperature due to operation switching of the constant temperature heating element.

  As an air mix type vehicle air conditioner equipped with a PTC heater, which is a constant temperature heating element, as an auxiliary heat source, for example, one described in Patent Document 1 is known. This PTC heater is equipped with a hybrid vehicle, diesel vehicle, or gasoline vehicle that has high efficiency and is difficult to increase the engine water temperature, and a cold region specification vehicle. It is suitable as an auxiliary heat source.

At the start of heating, a large gap is likely to occur between the passenger compartment temperature set by the passenger and the actual passenger compartment temperature, resulting in a heating capacity that exceeds the heating capacity of the heater core (heating heat exchanger) that is the main heat source. Therefore, in such a case, the PTC heater is turned on in a state where the opening position of the air mix door is set to the maximum heating position where the blow-out temperature is maximum. As a result, heat exchange is performed by the PTC heater in addition to the heater core, and the vehicle interior temperature can be brought close to the set temperature as quickly as possible.
JP 2003-34114 A

  By the way, in this type of apparatus, when the required heating capacity can be supplemented only by the heater core, the operation of the PTC heater is stopped to reduce the heating capacity, and then the air mix door as necessary. It is conceivable to adjust the temperature of the air blown into the passenger compartment by changing the opening position of the air.

  However, when the PTC heater is switched to the OFF state, the blowing temperature is rapidly lowered by the amount of the heating capacity, so that the occupant feels uncomfortable with the blown air.

  This invention is made | formed in view of the said situation, The objective is to provide the vehicle air conditioner which can prevent the rapid fluctuation | variation of the blowing temperature resulting from the operation switching of PTC.

A heating heat exchanger that heats the air sucked into the air conditioning case, a constant temperature heating element that supplementarily heats the air sucked when the energized state is on, a heating heat exchanger, and the constant temperature heating element are arranged A bypass passage that bypasses the heating passage, the heating heat exchanger and the constant temperature heating element, and an air mix door that distributes the sucked air to the air passing through the heating passage and the air passing through the bypass passage, The opening position of the air mix door and the ON / OFF of the constant temperature heating element are set so that the mixed air obtained by mixing the air that has passed through the heating passage and the air that has passed through the bypass passage has a blowing temperature corresponding to the set cabin temperature. a moving vehicle air-conditioning apparatus provided with a control means for controlling the off switch, the control means opening position of the temporary air mix door such that the air temperature only heating capacity of the heating heat exchanger Calculated, if the temporary opening position is greater than the maximum heating position is opening position to allocate all heating passage air sucked in, the constant temperature heating element in the on state, constant temperature heating element in the on state Sometimes the opening position of the air mix door is controlled so that the opening position of the air mix door is the opening position obtained by subtracting the opening width corresponding to the heating capacity of the constant temperature heating element from the temporary opening position. When the constant temperature heating element is in the ON state, the constant temperature heating element is turned off on the condition that the opening position of the air mix door reaches the offset opening position that offsets the heating capacity of the constant temperature heating element from the maximum heating position. At the same time, the opening position is returned to the maximum heating position .

According to the invention of claim 1, the constant temperature heating element is turned off at the same time as the constant temperature heating element is turned off on condition that the opening position of the air mix door has reached the offset opening position from the maximum heating position when the constant temperature heating element is on. Since the opening position of the mix door is returned to the reference position, the blowing temperature is substantially the same between immediately before turning off the constant temperature heating element and immediately after turning it off. The offset opening position includes the air blowing temperature of the mixed air when the constant temperature heating element is turned on, and the air blowing temperature of the mixed air when the constant temperature heating element is off and the air mix door is at the maximum heating position. Are the opening positions where the two are substantially the same. By doing in this way, since the rapid change of the blowing temperature resulting from switching the constant temperature heating element to the OFF state is prevented, a natural air conditioning feeling can be given to the occupant.
Further, according to the present invention, when the constant temperature heating element is in the on state and the opening position is set between the maximum heating position and the offset opening position, the heating capacity of the heat exchanger for heating exceeds the maximum heating capacity. The heating capacity can be demonstrated. Therefore, this configuration is suitable when a large amount of heating capacity is required, such as when the air conditioner is started.

The invention according to claim 2 is characterized in that the control means corrects the offset opening position in accordance with the outside temperature of the passenger compartment. According to a third aspect of the present invention, the control means corrects the offset opening position in accordance with the amount of air blown into the passenger compartment. According to a fourth aspect of the present invention, the control means corrects the offset opening position according to the blowing temperature.

According to this, even if the heating capacity of the constant temperature heating element changes due to a change in the outside air temperature, the blowout air volume, or the blowing temperature, the offset opening position is corrected according to the variation in the heating capacity of the constant temperature heating element, The blowing temperature control can be more reliably performed.

<First Embodiment>
An embodiment of a vehicle air conditioner according to the present invention will be described with reference to FIGS. As shown in FIG. 1, an air introduction port 14 communicating with the outside air introduction port 12 and the inside air introduction port 13 by switching of the inside / outside air switching door 11 is provided at one end of the air conditioning case 1. A blower fan 16 such as a centrifugal multiblade fan driven by a blower motor 15 is disposed so as to communicate with the fan 14. Further, in the air conditioning case 1, in addition to the blower fan 16, an evaporator 17 that exchanges heat of the sucked air to cool air and heats the sucked air in addition to the blower fan 16. Heater cores 18 of hot water heaters for making wind are sequentially arranged.

  On the upstream side of the heater core 18, the air sucked into the air conditioning case 1 by the blower fan 16 includes a heating passage Ph in which the heater core 18 (heating heat exchanger) is disposed, and a bypass passage Pb that bypasses the heater core 18. An air mix door 19 is provided for distribution to each other. The air mix door 19 distributes all the sucked air to the bypass passage Pb and the maximum heating position Sa for distributing all the sucked air to the heating passage Ph by the driving means 34 that operates based on a command from the air conditioner ECU 30 described later. The opening position is changed between the maximum cooling position Sb. In the following description, the opening when the air mix door 19 is at the maximum heating position Sa is 100%, and the opening when the air mix door 19 is at the maximum cooling position Sb is 0%.

  A PTC heater 20 (constant temperature heating element), which is an auxiliary heat source, is disposed on the downstream side of the heater core 18 in the heating passage Ph to supplementarily heat the air that has passed through the heater core 18. The PTC heater 20 is provided as an auxiliary heater and has an immediate effect, so that it is used as an auxiliary heat source particularly at the start of heating. The PTC heater 20 is an electric heater, and the energized state of the PTC heater 20 is switched to an on state or an off state based on a control signal from an air conditioner ECU 30 to be described later. Heat the air with a certain amount of heat.

  On the downstream side of the PTC heater 20, an air mix unit M configured to mix cold air and hot air to a predetermined temperature is configured, and a defroster outlet 21 is provided at the other end of the air conditioning case 1 located on the downstream side. A face air outlet 22 and a foot air outlet 23 are formed. A defroster door 21 a is disposed at the defroster outlet 21, a face door 22 a is disposed at the face outlet 22, and a foot door 23 a is disposed at the foot outlet 23.

  A post-evaporation sensor 24 that detects the temperature of the air that has passed through the evaporator 17 (evaporator temperature Te) is disposed downstream of the evaporator 17, and the engine cooling water that flows inside the heater core 18 is disposed in the heater core 18. A water temperature sensor 25 for detecting temperature (heater core temperature Th) is attached. On the other hand, each part of the vehicle is provided with an inside air temperature sensor 31 that detects the vehicle interior temperature Tr, an outside air temperature sensor 32 that detects the outside air temperature Tam (outside air temperature Tam), and a solar radiation sensor 33 that detects the amount of solar radiation Ts. Each sensor 24, 25, 31 to 33 outputs a detection signal corresponding to the detection state. In addition, an operation panel 40 for setting the set temperature Tset, the air volume, the air outlet, and the like is arranged at a predetermined position in the passenger compartment, and a setting signal corresponding to the setting operation of the occupant is output. Yes.

  The air conditioner ECU 30 performs the following control based on the detection signals of the sensors 24, 25, 31 to 33 and the setting signal from the operation panel 40. That is, the intake means control for selecting the introduction of the inside air or the outside air by driving the driving means 35 and switching the inside / outside air switching door 11 and the amount of air blown from the outlets 21 to 23 by controlling the operation of the blower motor 15. The air volume control for adjusting the air flow, the air outlet control for driving the driving means 36 to open and close the air outlets 21 to 23, and the air temperature control for adjusting the temperature of the air blown from the air outlets 21 to 23 are executed.

  Among these, the blowout temperature control adjusts the target blowout temperature TAO necessary for setting the passenger compartment temperature Tr to the set temperature Tset by controlling the opening position of the air mix door 19 and switching the on / off state of the PTC heater 20. To do. The target blowing temperature TAO is determined based on the outside air temperature Tam, the passenger compartment temperature Tr, the solar radiation amount Ts, and the set temperature Tset. Moreover, the opening degree of the air mix door 19 is determined by the target blowing temperature TAO, the evaporator temperature Te, and the heater core temperature Th.

  Hereinafter, the opening position control of the air mix door 19 will be described. As shown in FIG. 2, first, based on the detection signals of the sensors 24, 25, 31 to 33 and the setting signal of the operation panel 40, the temporary setting opening SWA (temporary opening SWA) of the air mix door 19 is set. It calculates based on the following numerical formula 1 (step S10).

(Equation 1)
SWA = {(TAO−Te) / (Th−Te)} × 100 (%)
The temporary opening degree SWA described above has a value of 100% or more when the cooling water temperature Te is not sufficiently raised and the cooling water temperature Th is lower than the target blowing temperature TAO. However, since the upper limit of the opening degree of the air mix door 19 is 100%, a true set opening degree SW (actual opening degree SW) (0 (%) ≦ SW ≦ 100 (%) actually set in the processing described later. )) Is calculated. For this reason, the opening calculated by the above formula is set as a temporary opening SWA.

  Subsequently, the opening width ΔSW of the air mix door corresponding to the heating capacity of the PTC heater 20 is calculated (step S20). The heating capacity of the PTC heater 20 is calculated by a predetermined calculation formula, and is the amount of heat that can be exchanged for the air passing through the heating passage Ph by the PTC heater 20.

  The opening width ΔSW of the air mix door 19 corresponding to the heating capacity is substantially the same as the blowing temperature when the PTC heater 20 is turned off and the blowing temperature when the PTC heater 20 is turned on. Thus, it is obtained from the difference in opening of the air mix door 19 set in each case.

  Here, since the heating capacity is added when the PTC heater 20 is turned on, the opening degree of the air mix door 19 set at this time is set when the PTC heater 20 is turned off. Is set to an opening obtained by subtracting the opening width ΔSW corresponding to the heating capacity from the opening of the air mix door 19 set to.

  That is, the opening degree of the air mix door 19 set when the PTC heater 20 is in the on state is calculated from the opening degree (reference position) of the air mix door 19 set when the PTC heater 20 is in the off state. This is the opening (cancellation opening position) that offsets the heating capacity of the PTC heater 20. In the present embodiment, the actual opening degree SW is set to 100% as the reference position, and “100−ΔSW”% is set as the offset opening position.

  Further, since the heating capacity of the PTC heater 20 varies depending on the outside air temperature Tam, the opening width ΔSW may be corrected based on the outside air temperature Tam. That is, as shown in FIG. 4, the opening degree width ΔSW is corrected to be small as the outside air temperature Tam increases.

  In addition to the outside air temperature Tam, the heating capacity ΔSW may be corrected based on the blown air volume (operating state of the blower motor 15) and the target blowing temperature TAO. The correction of the opening width ΔSW based on the blown air volume is performed so that the opening width ΔSW decreases as the air volume increases. The correction of the opening degree width ΔSW based on the target blowing temperature TAO is performed so that the opening degree width ΔSW decreases as the target blowing temperature increases.

  Next, it is determined whether or not the calculated temporary opening degree SWA is larger than 100% (step S30). If the temporary opening degree SWA is larger than 100% (Yes in step S30), the required heating capacity is equal to or higher than the heating capacity of the heater core 18, and therefore the PTC heater 20 as an auxiliary heat source is turned on. To do. In addition, since the heating capacity is increased by turning on the PTC heater 20, the actual opening is obtained by subtracting the opening width ΔSW corresponding to the heating capacity of the PTC heater 20 from the temporary opening SWA. SW is set (step S40).

  The actual opening SW obtained by subtracting the opening width ΔSW from the temporary opening SWA may be a value larger than 100%, but the actual opening SW of the air mix door 19 has an upper limit of 100%. When the actual opening SW obtained by subtracting the opening width ΔSW from the temporary opening SWA is larger than 100%, the actual opening SW is uniformly set to 100%.

  Conversely, if the temporary opening degree SWA is 100% or less (No in step S30), the required heating capacity can be compensated only by the heater core 18, so the PTC heater 20 is turned off and the temporary opening degree SWA is left as it is. The actual opening degree SW is set (step S50).

  Accordingly, there is a large gap between the set temperature Tset set by the occupant and the actual vehicle interior temperature Tr, and this requires heating capacity exceeding the heating capacity of the heater core 18 that is the main heat source. When the temporary opening degree SWA is larger than 100% (Yes in step S30), the PTC heater 20 is turned on, and the actual opening degree SW of the air mix door 19 is 100% (reference position). It is set between “100−ΔSW”% (cancellation opening position) obtained by subtracting the opening width ΔSW corresponding to the heating capacity ΔSW of the PTC heater 20 (step S40).

  On the other hand, when the required heating capacity decreases and the heating capacity can be supplemented only by the heater core 18, switching between the actual opening SW and the on / off state of the PTC heater 20 is controlled as follows. The First, when the temporary opening degree SWA is larger than 100% (when Yes in step S30 continues), the air mix door 19 is actually operated in accordance with a decrease in the heating capacity required while the PTC heater 20 is kept on. The opening degree SW is decreased (step S40 is continuously executed). When the temporary opening degree SWA reaches 100%, that is, when the required heating capacity can be compensated only by the heater core 18 (No in step S30), the PTC heater 20 is turned off (step S50). Then, the actual opening degree SW of the air mix door 19 is returned from “100−ΔSW”% (cancellation opening position) to 100% (reference position) (after step S40 is executed, step S50 is executed). Thereafter, the actual opening degree SW of the air mix door 19 is decreased in accordance with a decrease in the heating capacity required while the PTC heater 20 is in the off state (step S50).

  As described above, since the actual opening SW of the air mix door returns from “100−ΔSW”% (cancellation opening position) to 100% (reference position) at the moment when the PTC heater 20 is switched to the OFF state, The blowing temperature immediately before turning off the PTC heater 20 and the blowing temperature immediately after turning off the PTC heater 20 are substantially the same. As a result, the variation in the blowing temperature due to the switching of the PTC heater 20 to the off state is eliminated, and the blowing temperature decreases linearly (see FIG. 3).

  In this embodiment, when the PTC heater 20 is in the ON state, the actual opening degree SWA of the air mix door 19 is subtracted from the opening degree width ΔSW corresponding to the heating capacity of the PTC heater 20 from 100% (reference position). On the condition that the “100−ΔSW”% (cancellation opening position) has been reached, the PTC heater 20 is turned off and the actual opening SW is returned to 100%. Thereby, since the blowing temperature is substantially the same immediately before turning off the PTC heater 20 and immediately after turning it off, even if the PTC heater 20 is turned off, it is prevented that the blowing temperature fluctuates rapidly. A natural air conditioning feeling can be given.

  When the temporary opening degree SWA is larger than 100%, the PTC heater 20 is turned on and the actual opening degree SW is set between 100% and “100−ΔSW”%. As a result, a heating capacity higher than the maximum heating capacity of the heater core 18 can be exhibited. Therefore, this configuration is suitable when a large heating capacity is required at the time of starting the apparatus.

  Further, in the present embodiment, the opening degree width ΔSW corresponding to the heating capacity of the PTC heater 20 is corrected based on the change in the outside air temperature Tam, the blown air volume (the operating state of the fan motor 15), or the target blowing temperature TAO. I have to. Therefore, even if the heating capacity of the PTC heater 20 changes due to a change in the outside air temperature Tam, the blowing air volume, or the target blowing temperature TAO, the opening degree width ΔSW matches the heating capacity. Can be done.

<Other embodiments>
The present invention is not limited to the embodiments described with reference to the above description and drawings. For example, the following embodiments are also included in the technical scope of the present invention, and further, within the scope not departing from the gist of the invention other than the following. Various modifications can be made.

  In the above embodiment, the PTC heater 20 is turned on when the temporary opening degree SWA is 100% or more, and the PTC heater 20 is turned off when the temporary opening degree SWA is 100% or less. The temporary opening degree SWA for switching the on / off state of the PTC heater 20 may be set to other than 100%.

It is the schematic diagram which showed the whole structure of the vehicle air conditioner which concerns on this invention. Opening position control of air mix door when PTC heater is turned off It is the graph which showed the change of the air mix door opening degree and blowing temperature at the time of PTC heater OFF. (A) is the graph which showed the correction value of the heating capability of the PTC heater with respect to external temperature. (B) is the graph which showed the correction value of the heating capability of the PTC heater with respect to target blowing temperature. (C) is the graph which showed the correction value of the heating capability of the PTC heater with respect to a blower fan air volume.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Air conditioning case 18 ... Heater core 19 ... Air mix door 20 ... PTC heater Ph ... Heating passage Pb ... Bypass passage TAO ... Target blowing temperature Te ... Evaporator temperature Th ... Heater core temperature Tam ... External temperature SWA ... Temporary opening degree SW ... Actual opening Degree ΔSW: Opening width

Claims (4)

A heat exchanger for heating that heats the air drawn into the air conditioning case;
A constant temperature heating element that supplementarily heats the inhaled air when the energized state is on;
A heating passage in which the heat exchanger for heating and the constant temperature heating element are disposed;
A bypass passage for bypassing the heating heat exchanger and the constant temperature heating element;
An air mix door that distributes the sucked air to the air passing through the heating passage and the air passing through the bypass passage;
The opening position of the air mix door and the constant temperature heating element so that the mixed air obtained by mixing the air that has passed through the heating passage and the air that has passed through the bypass passage has a blowing temperature according to a set cabin temperature. In a vehicle air conditioner provided with a control means for controlling on / off switching of
The control means includes
Calculate the provisional opening position of the air mix door such that the temperature is just the heating temperature of the heating heat exchanger,
When the temporary opening position is larger than the maximum heating position, which is the opening position that distributes all the sucked air to the heating passage, the constant temperature heating element is turned on,
When the constant temperature heating element is in the ON state, the opening position of the air mix door is the opening position obtained by subtracting the opening width corresponding to the heating capacity of the constant temperature heating element from the temporary opening position. Control the opening position of the air mix door,
The constant temperature heating element is on the condition that the opening position of the air mix door reaches the offset opening position that offsets the heating capacity of the constant temperature heating element from the maximum heating position when the constant temperature heating element is in the on state. The vehicle air conditioner is characterized in that the opening position is returned to the maximum heating position simultaneously with turning off the heating element. The vehicle air conditioner according to claim 1, wherein the control unit corrects the offset opening position in accordance with a passenger compartment outside temperature. 2. The vehicle air conditioner according to claim 1, wherein the control unit corrects the offset opening position according to an amount of air blown into the vehicle interior. The vehicle air conditioner according to claim 1, wherein the control unit corrects the offset opening position according to the blowing temperature.

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