JP4081902B2 - Air conditioner for vehicles - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a vehicle air conditioner, and in particular, to improve air conditioning characteristics when air conditioning is forcibly interrupted by an engine load or an air conditioning load.
[0002]
[Prior art]
A so-called air conditioner cut is performed in which the operation of the air conditioner is temporarily interrupted to prevent the engine from overheating when the vehicle is operated for a long time under a high external temperature. Specifically, when the engine cooling water temperature reaches a predetermined value, the compressor is cut, reducing the engine load for driving the compressor, and suppressing the heat generation from the condenser, thereby cooling the engine by the radiator and cooling fan Raise. As a result, when the engine cooling water temperature is lowered to a predetermined value, the compressor cut is terminated and the operation of the air conditioner is resumed.
[0003]
Further, when the pressure or temperature of the refrigerant in the compression refrigeration cycle of the air conditioner exceeds a predetermined value, the air conditioner is cut.
[0004]
[Problems to be solved by the invention]
However, when the air-conditioner cut described above is performed, the compressor stops, but the blower fan continues to blow air, so the refrigerant temperature in the evaporator immediately rises, but the refrigerant temperature in the pipe before the evaporator is Does not rise so much. For this reason, when the refrigerant starts to flow again in the compression refrigeration cycle after restarting the operation of the compressor, the low-temperature refrigerant that has remained in the pipe before the evaporator passes through the evaporator. For this reason, after the air-conditioning operation is resumed, a cold wind suddenly blows out from the air outlet, which causes discomfort to the passenger. In particular, fog may blow out from the air outlet at high temperature and high humidity, giving the passenger a sense of incongruity.
[0005]
In addition, if the air conditioner cut is performed for a long time, the refrigerant flow in the compression refrigeration cycle stops, so that the refrigerant temperature in the evaporator immediately rises, and warm air blows out from the outlet, causing discomfort to the passengers.
[0006]
An object of the present invention is to improve air conditioning characteristics when air conditioning is forcibly interrupted by an engine load or an air conditioning load, and to reduce discomfort and discomfort given to passengers.
[0007]
[Means for Solving the Problems]
The present invention will be described with reference to FIG. 1 showing the configuration of an embodiment.
(1) The invention according to claim 1 is that a compressor refrigeration cycle including a compressor 1 and an air-conditioning air introduced from an intake door by a blower fan are cooled by an evaporator, and then air passing through the heater core by an air mix door and the heater core An air conditioning unit 15 that adjusts the ratio of air to bypass and blows out air-conditioning air having a target air-flow temperature and a target air-flow rate from the air outlet, and stops air from the compressor 1 when a predetermined temporary interruption condition is satisfied. It is applied to a vehicle air conditioner that temporarily interrupts.
And the control means 10 which reduces a blowing air volume gradually as air-conditioning interruption time becomes long during an air-conditioning interruption is provided, and the said objective is achieved by this.
(2) In the invention of claim 2, the air-conditioning air introduced from the intake door by the compressor refrigeration cycle including the compressor 1 and the blower fan is cooled by the evaporator, and then the air passing through the heater core by the air mix door and the heater core An air conditioning unit 15 that adjusts the ratio of air to bypass and blows out air-conditioning air having a target air-flow temperature and a target air-flow rate from the air outlet, and stops air from the compressor 1 when a predetermined temporary interruption condition is satisfied. It is applied to a vehicle air conditioner that temporarily interrupts.
And after air-conditioning resumption, it has a control means to once raise the blowing air temperature by a predetermined temperature and gradually lower it to the target temperature, thereby achieving the above object.
(3) the vehicular air conditioning apparatus according to claim 3, comprising a temperature detecting means 12 for detecting the air temperature T int after evaporator pass, the control means 10, a lower air temperature T int after evaporator passage in the air conditioning suspended The predetermined temperature is set to be larger.
(4) The vehicle air conditioner according to claim 4 is configured such that the control means 10 sets the predetermined temperature larger as the air conditioning interruption time is shorter.
[0008]
In the section of the means for solving the above-described problem, a diagram of an embodiment is used for easy understanding of the description. However, the present invention is not limited to the embodiment.
[0009]
【The invention's effect】
(1) According to the invention of claim 1, since the amount of blown air is gradually reduced as the air conditioning interruption time becomes longer during the air conditioning interruption, the warm wind blows out from the outlet during the air conditioning interruption. Therefore, the comfort of air conditioning during air conditioning interruption can be further improved.
(2) According to the invention of claim 2 , since the blowing air temperature is once increased by a predetermined temperature after the air conditioning is resumed and gradually lowered to the target temperature, a cold wind suddenly blows out from the air outlet after the air conditioning is resumed. Mist can be prevented from blowing out and the comfort of air conditioning after air conditioning is resumed can be improved.
(3) According to the invention of claim 3, since the predetermined temperature is set larger as the air temperature after passing through the evaporator during air conditioning interruption is lower, the comfort of air conditioning after resuming air conditioning can be further improved. it can.
(4) According to the invention of claim 4, since the predetermined temperature is set to be larger as the air conditioning interruption time is shorter, the same effect as in claim 3 can be obtained.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows the configuration of an embodiment.
The compressor 1 is connected to the output shaft of the engine 3 via the magnet clutch 2 and is driven by the power of the engine 3. It should be noted that compression refrigeration cycle components of an air conditioner such as a condenser other than the compressor 1, a liquid tank, an expansion valve, and an evaporator are well known and are not directly related to the present invention, and thus illustration and description thereof are omitted.
[0011]
The engine controller 4 includes a microcomputer and its peripheral components, and performs fuel injection control, ignition control, rotational speed control, torque control, and the like of the engine 3. The engine controller 4 includes an ignition switch 5 that closes when the ignition key is set to the ON position, a water temperature sensor 6 that detects the engine cooling water temperature Tw [° C.], and an opening θ [deg] of a throttle valve (not shown). A throttle sensor 7 for detecting, a rotation sensor 8 for detecting the engine rotation speed N [rpm], and the like are connected.
[0012]
The air conditioning controller 10 includes a microcomputer and its peripheral components, and performs various calculations and sequence control of the air conditioner. The air conditioning controller 10 includes an air conditioner switch (air conditioner main switch) 11, a temperature sensor 12 for detecting the air temperature Tint [° C.] after passing through the evaporator, a pressure sensor 13 for detecting the high pressure side pressure Pd [MPa] of the air conditioner refrigerant, A temperature sensor 14 for detecting the temperature Tref of the air conditioner refrigerant is connected.
[0013]
The air conditioning unit 15 is composed of an intake door (not shown), a blower fan, an evaporator, a heater core, an air mix door, various outlet doors, and the like. The ratio of the air that passes through the heater core and the air that bypasses the heater core is adjusted by the door, and the conditioned air having the target blowing air temperature and the target blowing air amount is blown out from the blowing outlet. The motor 15a is a motor that drives a blower fan, and the motor 15b is a motor that drives an air mix door. The details of the air conditioning unit 15 are not directly related to the present invention, and therefore illustration and description thereof are omitted.
[0014]
The engine controller 4 and the air conditioning controller 10 communicate with each other via the communication circuit 20. The engine controller 4 can be used for (1) a predetermined time after the throttle valve opening θ is fully opened, (2) when the engine speed N exceeds a predetermined speed, or (3) the engine coolant temperature Tw is An air conditioner cut (air conditioning temporarily interrupted) signal is sent to the air conditioning controller 10 until the temperature becomes equal to or higher than the predetermined temperature Tw1 and again decreases below the predetermined temperature Tw2 (<Tw1).
[0015]
On the other hand, the air-conditioning controller 10 (4) waits until the high-pressure side pressure Pd of the air-conditioner refrigerant becomes equal to or higher than the predetermined pressure Pd1 and again decreases below the predetermined pressure Pd2 (<Pd1), or (5) the temperature Tref of the air-conditioner refrigerant The air conditioner is cut (temporarily suspended) until the temperature becomes equal to or higher than the predetermined temperature Tref1 and again decreases below the predetermined value Tref2 (<Tref1). The air conditioner cut condition is not limited to the above conditions (1) to (5).
[0016]
FIG. 2 is a flowchart showing an air conditioning control program. The operation of the embodiment will be described with reference to this flowchart.
The air conditioning controller 10 executes this air conditioning control program when the air conditioner switch 11 is turned on. In step 1, either of the above-described air conditioner cut conditions (1) to (3) is established and an air conditioner cut signal is sent from the engine controller 4, or the above-described air conditioner cut condition (4) or (5) is established. If the air conditioner cut condition is not satisfied, the process proceeds to step 2. When all the air conditioner cut conditions are not satisfied, the magnet clutch 2 is turned on in step 2 to operate the compressor 1. In step 3, normal air conditioning control is performed.
[0017]
Here, the normal air conditioning control calculates the target blowing air temperature To based on the vehicle interior temperature set value Tptc, the vehicle interior temperature Tinc, the outside air temperature Tamb, the air temperature Tint after passing through the evaporator, the solar radiation amount Qsun, etc. The air mix door opening Xm is adjusted so that the temperature To of the conditioned air blown into the passenger compartment becomes the target temperature To *, and the blower fan is driven and adjusted to adjust the amount of blown air. Since this normal air-conditioning control is well known by many literatures, detailed description is omitted.
[0018]
If the air conditioner cut signal according to the air conditioner cut conditions (1) to (3) is received from the engine controller 4 or the air conditioner cut condition (4) or (5) is satisfied, the magnet clutch 2 is released in step 4 Stop compressor 1. In subsequent step 5, the air temperature Tint after passing through the evaporator is read from the temperature sensor 12, and it is determined whether or not the temperature is equal to or lower than a predetermined temperature Tint1. If the air temperature Tint after passing through the evaporator is equal to or lower than Tint1, the process returns to step 1 and the above-described processing is repeated.
[0019]
On the other hand, if the air temperature Tint after passing the evaporator exceeds Tint1, the process proceeds to step 6 to determine whether the speed of the blower fan motor 15a of the air conditioning unit 15 is equivalent to the first speed (Lo). The speed of the blower fan motor 15a is controlled by the duty ratio of the applied voltage, and is, for example, from a maximum of 86% to a minimum of 24%. Therefore, in step 6, it is determined whether or not the duty ratio of the voltage applied to the blower fan motor 15a is less than 24% corresponding to the first speed (Lo). In the above case, go to Step 7. In step 7, the duty ratio of the voltage applied to the blower fan motor 15a is reduced by, for example, 1/1000% in order to avoid the warm air blowing from the air outlet and giving the passenger discomfort due to the air conditioner cut. Reduce the blown air volume. As a result, while the air-conditioner cut is being performed, when one cycle that goes from step 6 to step 8 is 1 ms, for example, the duty ratio applied to the blower fan motor 15a is decreased by 1% per second.
Thereafter, when the duty ratio applied to the blower fan motor 15a becomes less than 24%, it is determined as YES in Step 6 and the process proceeds to return, and while the air conditioner cut is being performed, the air volume is 24%, that is, the first speed (Lo). A considerable air volume is secured.
[0020]
FIG. 3 is a time chart showing an example of a control pattern of the blown air temperature To after the air conditioner is restarted. .
After restarting the air conditioner, the blowout air temperature To is gradually reduced to the target temperature To * according to the elapsed time t according to the control pattern shown in FIG.
[0021]
The lower the air temperature Tint after passing the evaporator during the air conditioner cut, the colder the air blows out from the outlet after the air conditioner restarts. Therefore, as shown in (b), the blowout air temperature ToS immediately after the resumption of the air conditioner is set higher as the air temperature Tint after passing the evaporator during the air conditioner cut is lower.
[0022]
In addition, the shorter the air conditioner cut time Tcut, the colder the air blows from the outlet after the air conditioner restarts. Therefore, as shown in (c), the blowout air temperature ToS immediately after the restart of the air conditioner is set higher as the air conditioner cut time Tcut is shorter.
[0023]
After setting the control pattern of the blowing air temperature To after air conditioner resumes at step 9, driving the compressor 1 by introducing a magnetic clutch 2 in step 1 0, resumes the air-conditioning. In step 1 1, gradually reducing the blowoff air temperature To according to the control pattern set to its target temperature To *.
[0024]
In step 8 , it is confirmed whether any of the air conditioner cut conditions 1 to 5 is satisfied. If any of the conditions is satisfied, the process returns to step 7 to further decelerate the blower fan motor 15a. If none of the air conditioner cut conditions is satisfied, the process proceeds to step 9 and, as described above, the control pattern after restarting the air conditioner is set, the air conditioning is resumed, and the blowing air temperature To is gradually increased to the target temperature To *. To reduce.
[0025]
In this way, during air conditioner cut, the higher the air temperature Tint after passing the evaporator, the more the blowout air volume is reduced, so it is possible to prevent warm air from blowing out from the air outlet during air conditioner cut, and during air conditioner cut The comfort of the air conditioner can be improved.
[0026]
In addition, the lower the air temperature Tint after passing the evaporator during the air conditioner cut, the higher the blowout air temperature ToS immediately after the air conditioner restarts. The blowout air temperature To is set from the ToS to the target temperature To * according to the elapsed time t after the air conditioner restarts. Therefore, it is possible to prevent a cold wind from being suddenly blown out from the air outlet or the mist from the air outlet after restarting the air conditioner, and to improve the comfort of the air conditioner after restarting the air conditioner.
[0027]
<< Modification of Embodiment >>
The air temperature Tint after passing the evaporator during the air conditioner cut increases as the air conditioner cut time becomes longer. Therefore, instead of the air temperature Tint after passing through the evaporator, it is possible to control the blown air temperature and the blown air amount after restarting the air conditioner based on the air conditioner cut time.
[0028]
FIG. 4 is a flowchart showing an air conditioning control program according to a modification. Note that steps that perform the same processing as in FIG. 2 are assigned the same step numbers, and differences will be mainly described. Further, in the configuration of this modification, the temperature sensor 12 that detects the air temperature Tint after passing through the evaporator is omitted from the configuration shown in FIG.
[0029]
In step 5A after the compressor 1 is stopped and the air conditioner is cut, it is determined whether or not the air conditioner cut time Tcut measured by the timer of the air conditioning controller 10 is equal to or shorter than the predetermined time Tcut1. If the air conditioner cut time Tcut is equal to or shorter than Tcut1, it is determined that the air temperature Tint after passing through the evaporator is still sufficiently low, and the process returns to step 1 to repeat the above processing. On the other hand, if the air conditioner cut time Tcut exceeds Tcut1, it is determined that the air temperature Tint after passing through the evaporator is warm, and the process proceeds to step 6, and warm air is blown out from the outlet through the air conditioner cut. In order to avoid discomfort to the occupant, the blower fan motor 15a is decelerated to reduce the blown air volume.
[0030]
In Step 7A, it is determined whether the air conditioner cut time Tcut is equal to or shorter than a predetermined time Tcut2 (> Tcut1). If the air conditioner cut time Tcut is equal to or shorter than Tcut2, the process proceeds to step 10 to check whether any of the air conditioner cut conditions (1) to (5) is satisfied. If any of the air conditioner cut conditions (1) to (5) is satisfied, the process returns to step 6 to repeat the above-described processing. On the other hand, if none of the air conditioner cut conditions {circle around (1)} to {circle around (5)} is satisfied, the process proceeds to step 11 to set the control pattern of the target blown air temperature To after the air conditioner restarts as described above.
[0031]
After setting the control pattern of the blown air temperature To after the air conditioner restarts, the magnet clutch 2 is turned on in step 9 to operate the compressor 1 and the air conditioning is restarted. In the subsequent step 10, the blowout air temperature To is gradually reduced to the target temperature To * according to the set control pattern.
[0032]
Thus, during the air conditioner cut, the longer the air conditioner cut time Tcut is, the more the blowout air volume is reduced. Therefore, it is possible to prevent the warm air from being blown out from the air outlet during the air conditioner cut. Comfort can be improved.
[0033]
Also, as the air conditioner cut time is shorter, the blown air temperature ToS immediately after the air conditioner restarts is set higher, and the blown air temperature To is gradually decreased from ToS to the target temperature To * according to the elapsed time t after the air conditioner restarts. Therefore, it is possible to prevent a cold wind from suddenly blowing out from the air outlet or the mist from the air outlet after restarting the air conditioner, and to improve the comfort of the air conditioner after restarting the air conditioner.
[Brief description of the drawings]
FIG. 1 is a diagram showing a configuration of an embodiment.
FIG. 2 is a flowchart showing an air conditioning control program according to one embodiment.
FIG. 3 is a diagram showing an example of a control pattern of a target blown air temperature To after air conditioning is resumed.
FIG. 4 is a flowchart showing an air conditioning control program of a modified example.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Compressor 2 Magnet clutch 3 Engine 4 Engine controller 5 Ignition switch 6 Water temperature sensor 7 Throttle sensor 8 Rotation sensor 10 Air conditioning controller 11 Air conditioner switch 12 Temperature sensor 13 Pressure sensor 14 Temperature sensor 15 Air conditioning unit 15a Blower fan motor 15b Air mix door motor

Claims (4)

A compression refrigeration cycle including a compressor;
After the conditioned air introduced from the intake door by the blower fan is cooled by the evaporator, the ratio of the air passing through the heater core and the air bypassing the heater core is adjusted by the air mix door, and the target blowout air temperature and target from the blowout port are adjusted. An air-conditioning unit that blows out the air-conditioning air of the blowing air volume,
In a vehicle air conditioner that temporarily stops air conditioning by stopping the compressor when a predetermined temporary interruption condition is satisfied,
A vehicle air conditioner comprising control means for gradually reducing the amount of blown air as the air conditioning interruption time becomes longer during the air conditioning interruption . A compression refrigeration cycle including a compressor;
After the conditioned air introduced from the intake door by the blower fan is cooled by the evaporator, the ratio of the air passing through the heater core and the air bypassing the heater core is adjusted by the air mix door, and the target blowout air temperature and target from the blowout port are adjusted. An air-conditioning unit that blows out the air-conditioning air of the blowing air volume,
In a vehicle air conditioner that temporarily stops air conditioning by stopping the compressor when a predetermined temporary interruption condition is satisfied,
A vehicle air conditioner comprising control means for once increasing the blown air temperature by a predetermined temperature after resuming air conditioning and gradually decreasing it to a target temperature . In the vehicle air conditioner according to claim 2,
Equipped with temperature detection means for detecting the air temperature after passing through the evaporator,
The said control means sets the said predetermined temperature large, so that the air temperature after the evaporator during an air conditioning interruption is low, The air conditioner for vehicles characterized by the above-mentioned . In the vehicle air conditioner according to claim 2,
The said control means sets the said predetermined temperature large, so that air conditioning interruption time is short, The vehicle air conditioner characterized by the above-mentioned .

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