Vehicle air conditioning system

Abstract

To provide a vehicle air conditioning system that can improve the comfort of air conditioning in automatic air conditioning control without requiring an increase in costs. [Solution] The vehicle air conditioning system 1 comprises an air conditioning device 10 that sends conditioned air into the vehicle's interior, a solar radiation detection unit 33 that detects the amount of solar radiation in the interior, a control device 20 that can perform automatic air conditioning control to maintain a constant temperature for occupants in the interior by controlling the operation of the air conditioning device using the amount of solar radiation, and a storage unit 22 that stores a reference time ts until the amount of air conditioning air corresponding to the amount of solar radiation reaches a predetermined value BLt. The control device sets a correction value Cv for the amount of solar radiation used in automatic air conditioning control based on the difference time Δt, which is the difference between the reference time and the measured time tm until the amount of air conditioning air reaches a predetermined value.

Description

[Technical Field]

[0001] The present disclosure relates to an air conditioning system for a vehicle. [Background Art]

[0002] Conventionally, in a vehicle solar radiation detection device, there is known a technology that determines the incident direction of solar radiation entering a vehicle based on solar position information and road information, and further determines the amount of solar radiation entering the vehicle based on vehicle-specific information including the vehicle height, the color of the vehicle body, the position of seats, the positional relationship between seats and window glass, and the position, size, angle and transmission characteristics of the window glass. [Prior Art Literature] [Patent Literature]

[0003] [Patent Literature 1] Japanese Unexamined Patent Application Publication No. 2002-362129 [Summary of the Invention] [Problem to be Solved by the Invention]

[0004] By the way, the conventional configuration adopts a structure in which the amount of solar radiation entering the vehicle is obtained by using an additional device for acquiring solar position information and road information, thus incurring costs related to the installation of the additional device, which causes the problem that solar radiation amount cannot be detected with high accuracy at low cost.

[0005] The present disclosure has been made in view of the above problems, and an object thereof is to provide an air conditioning system for a vehicle that can improve the comfort of air conditioning in automatic air conditioning control without requiring increased cost. [Means for Solving the Problem]

[0006] To achieve the above objective, one embodiment of a vehicle air conditioning system (1) includes an air conditioning device (10) that sends conditioned air into the passenger compartment of a vehicle, a solar radiation detection unit (33) that detects the amount of solar radiation in the passenger compartment, a control device (20) that can perform automatic air conditioning control to maintain a constant temperature for the passengers in the passenger compartment by controlling the operation of the air conditioning device using the amount of solar radiation, and a storage unit (22) that stores a reference time (ts) until the amount of air conditioning corresponding to the amount of solar radiation reaches a predetermined value (BLt), wherein the control device sets a correction value (Cv) for the amount of solar radiation used in the automatic air conditioning control based on a difference time (Δt), which is the difference between the reference time and the measured time (tm) until the amount of air conditioning reaches the predetermined value.

[0007] According to this, the comfort level of air conditioning in automatic air conditioning control can be improved without incurring increased costs. [Brief explanation of the drawing]

[0008] [Figure 1] This figure schematically shows an example of the configuration of a vehicle air conditioning system according to one embodiment. [Figure 2] This figure shows an example of blower level information stored in the memory unit of a vehicle air conditioning system according to one embodiment. [Figure 3] This figure shows an example of the difference between the theoretical blower level progression and the measured blower level progression in automatic air conditioning control for a vehicle air conditioning system according to one embodiment. [Figure 4] This figure shows an example of correction value information stored in the memory unit of a vehicle air conditioning system according to one embodiment. [Figure 5] A flowchart (Part 1) showing an example of the control content related to the correction of the target outlet temperature (TAO) performed by the air conditioning ECU in a vehicle air conditioning system according to one embodiment. [Figure 6] A flowchart (part 2) showing an example of the control content related to the correction of the target outlet temperature (TAO) performed by the air conditioning ECU in a vehicle air conditioning system according to one embodiment. [Modes for carrying out the invention]

[0009] The following describes one embodiment of a vehicle air conditioning system with reference to the drawings. The vehicle air conditioning system 1 shown in Figure 1 is mounted on a vehicle (not shown) and controls the air conditioning inside the vehicle's cabin. The vehicle air conditioning system 1 comprises an air conditioning unit 10 and an air conditioning ECU 20. The vehicle air conditioning system 1 can also be configured to include, for example, a radiant heater for radiating heat to the vehicle's occupants. The air conditioning unit 10 sends temperature-controlled air into the vehicle's cabin. The air conditioning unit 10 is located below an instrument panel (not shown) positioned at the front of the vehicle in the direction of travel inside the cabin.

[0010] The air conditioning unit 10 includes a case member 11, a blower 12, an evaporator 13, a heater core 14, an air mix door 15, an interior / exterior air switching door 16, and outlet switching doors 171 and 172. The case member 11 constitutes the outer shell of the air conditioning unit 10. Inside the case member 11, an air passage is formed to guide the amount of air generated by the blower 12 toward the passenger compartment.

[0011] The case member 11 has an internal air inlet 111, an external air inlet 112, a defroster outlet 113, a face outlet 114, and a foot outlet 115. The internal air inlet 111 and the external air inlet 112 are located on the upstream side of the case member 11. The defroster outlet 113, the face outlet 114, and the foot outlet 115 are located on the downstream side of the case member 11. Upstream means upstream in the direction in which air flows within the case member 11, and downstream means downstream in the direction in which air flows within the case member 11.

[0012] The interior air intake 111 is the part that introduces interior air, which is the air inside the vehicle cabin. The exterior air intake 112 is the part that introduces outside air from outside the vehicle cabin. The defroster outlet 113, face outlet 114, and foot outlet 115 are opening into the vehicle cabin and are the parts that blow conditioned air into the vehicle cabin. The defroster outlet 113 blows conditioned air towards the vehicle's windshield, for example. The face outlet 114 blows conditioned air towards the upper body of an occupant seated in the vehicle cabin, for example. The foot outlet 115 blows conditioned air towards the lower body of an occupant seated in the vehicle cabin, for example.

[0013] The blower 12 comprises an impeller 121 and a blower motor 122. The impeller 121 is located inside the case member 11. The impeller 121 is rotationally driven by the blower motor 122 and has the function of sending air introduced from the interior air inlet 111 or the exterior air inlet 112 into the vehicle interior. In this specification, the airflow rate of the conditioned air from the blower 12 may be referred to as the blower level. The evaporator 13 is located downstream of the blower 12 and cools the air blown by the blower 12. The evaporator 13, together with a compressor, condenser, and expansion valve (not shown), constitutes a well-known refrigeration cycle.

[0014] The heater core 14 is located downstream of the evaporator 13. The heater core 14 heats the air that has passed through the evaporator 13 by utilizing the temperature of the coolant heated, for example, by the vehicle's engine. A bypass channel 18 is also provided downstream of the evaporator 13 to guide the air that has passed through the evaporator 13, bypassing the heater core 14.

[0015] The air mix door 15 is rotatably mounted on the inlet side of the heater core 14 and the bypass channel 18. The air mix door 15 adjusts the ratio of the airflow volume passing through the heater core 14 to the airflow volume passing through the bypass channel 18 of the total airflow volume flowing through the evaporator 13. The temperature of the conditioned air flowing downstream of the heater core 14 and the bypass channel 18 changes according to the ratio of the airflow volume passing through the heater core 14 to the airflow volume passing through the bypass channel 18, as determined by the operation of the air mix door 15.

[0016] The interior / exterior air switching door 16 opens and closes at least one of the interior air inlet 111 and the exterior air inlet 112. In other words, the interior / exterior air switching door 16 can switch the air introduced into the case member 11 between interior and exterior air. The air outlet switching doors 171 and 172 are for selectively switching the state of air being blown into the vehicle interior. The air outlet switching door 171 opens and closes the defroster air outlet 113 and the face air outlet 114. The air outlet switching door 172 opens and closes the foot air outlet 115.

[0017] The air conditioning ECU 20 is mainly composed of a microcomputer having a CPU, ROM, RAM, and rewritable flash memory, and controls the operation of the entire air conditioning system 10. The air conditioning ECU 20 functions as a control device. As shown in Figure 1, the air conditioning ECU 20 is electrically connected to a timing unit 21 and a storage unit 22. The timing unit 21 has the function of acquiring the time at any given point in time. Time refers to an absolute time, such as hours, minutes, and seconds, or a relative time based on a certain point in time. The timing unit 21 may also have the function of measuring the elapsed time from a reference point. Time refers to the length of time from one point in time to another. The storage unit 22 can be composed of well-known storage media such as ROM, HDD, semiconductor memory, and magnetic disk.

[0018] Furthermore, detection signals from the outside temperature detection unit 31, the inside temperature detection unit 32, and the solar radiation detection unit 33 are input to the air conditioning ECU 20. The outside temperature detection unit 31 detects the outside temperature, which is the temperature outside the vehicle cabin. The inside temperature detection unit 32 detects the inside temperature, which is the temperature inside the vehicle cabin. The solar radiation detection unit 33 detects the amount of solar radiation irradiating into the vehicle cabin. The solar radiation detection unit 33 is located, for example, at the top of the instrument panel. For example, the blower motor 122 is electrically connected to the air conditioning ECU 20 and operates under control from the air conditioning ECU 20. The memory area of ​​the air conditioning ECU 20 stores a control program for controlling the air conditioning system 10 to perform air conditioning in the vehicle cabin. Each process of the air conditioning ECU 20 is realized by the CPU executing the control program.

[0019] An air-conditioning ECU 20 receives detection signals from an outside air temperature detection unit 31, an inside air temperature detection unit 32, a solar radiation detection unit 33, and the like, controls the operation of a blower motor 122 and the like based on a control program, and performs air conditioning in a vehicle compartment. The air-conditioning ECU 20 can control the operation of an air conditioner 10 based on the well-known target outlet temperature TAO calculated using various types of information including the outside air temperature detected by the outside air temperature detection unit 31, the inside air temperature detected by the inside air temperature detection unit 32, and the solar radiation amount detected by the solar radiation detection unit 33, so as to execute automatic air conditioning control that keeps the temperature feeling of occupants in the vehicle compartment constant. The target outlet temperature TAO is the temperature of air that needs to be blown out from each of outlets 113, 114, and 115 in order to keep the air temperature in the vehicle compartment at a set temperature.

[0020] The target outlet temperature TAO can be obtained by the following formula. TAO=Kset×Tset-Kam×Tam-Kr×Tr-Ks×Ts+C Here, Kset is a correction coefficient for the set temperature, Tset is the set temperature, Kam is a correction coefficient for the outside air temperature, Tam is a detection value of the outside air temperature detection unit 31, Kr is a correction coefficient for the inside air temperature, Tr is a detection value of the inside air temperature detection unit 32, Ks is a correction coefficient for the solar radiation amount, Ts is a detection value of the solar radiation detection unit 33, and C is a correction constant.

[0021] Further, a storage unit 22 can store, for example, blower level information. As shown in Fig. 2, the blower level information is information that associates a solar radiation amount section Sr, which is a section of the solar radiation amount detected by the solar radiation detection unit 33 during execution of automatic air conditioning control, with a reference time ts from when automatic air conditioning control is started until the blower level reaches a predetermined value BLt.

[0022] The reference time ts is the theoretical time it takes for the airflow rate of the air conditioning system, corresponding to the amount of solar radiation, to reach a predetermined value BLt. The predetermined value BLt represents, for example, the airflow rate at which the temperature feels comfortable to the occupants inside the vehicle. Furthermore, the solar radiation classification Sr and reference time ts in the blower level information may be specific numerical values ​​or information indicating a certain range. The reference time ts is set to a larger value as the amount of solar radiation increases. For example, in Figure 4, the value of the corresponding reference time ts is set to a larger value according to the order of solar radiation classification Sr: Sr1, Sr2, Sr3, Sr4, Sr5. The number of solar radiation classifications Sr can be set arbitrarily.

[0023] Here, for example, in order to suppress solar radiation entering the vehicle interior, a film that reduces the transmission of sunlight may be applied to the vehicle's windows. In this case, the amount of solar radiation detected by the solar radiation detection unit 33 may be lower than the actual amount of solar radiation. On the other hand, for example, due to the influence of reflected light from the surface of an object surrounding the solar radiation detection unit 33, the amount of solar radiation detected by the solar radiation detection unit 33 may be higher than the actual amount of solar radiation.

[0024] Thus, the amount of solar radiation detected by the solar radiation detection unit 33 is affected by changes in the environment in which the solar radiation detection unit 33 is located. Furthermore, if automatic air conditioning control is performed using the amount of solar radiation detected in an environment with low detection accuracy, it may impair the comfort of the air conditioning. In addition, attempting to correct the amount of solar radiation based on information obtained, for example, from an additional device is undesirable because it incurs the cost of installing such an additional device.

[0025] The inventors of this application noticed that when the detection accuracy of the solar radiation detection unit 33 is affected, there is a difference between the theoretical change in the blower level shown by the dotted line A1 in Figure 3 and the measured change in the blower level shown by the solid line A2 in Figure 3. They then found a method to estimate the actual amount of solar radiation based on the difference time Δt, which is the absolute value of the difference between the reference time ts of the blower level information stored in the memory unit 22 and the measured time tm until the blower level reaches a predetermined value BLt during the execution of the current automatic air conditioning control. Furthermore, it is believed that by correcting the solar radiation value Ts used to calculate the target outlet temperature TAO based on the difference time Δt, automatic air conditioning control corresponding to the estimated actual amount of solar radiation can be executed.

[0026] Therefore, in automatic air conditioning control, the air conditioning ECU 20 calculates the target outlet temperature TAO by correcting the amount of solar radiation detected by the solar radiation detection unit 33 based on the difference time Δt, and controls the operation of the air conditioning unit 10. In other words, the air conditioning ECU 20 estimates the actual amount of solar radiation based on the difference time Δt and corrects the amount of solar radiation detected by the solar radiation detection unit 33. This ensures comfortable air conditioning in response to changes in the environment in which the solar radiation detection unit 33 is located, without requiring additional costs such as the installation of additional equipment. The air conditioning ECU 20 can perform the correction of the amount of solar radiation based on the difference time Δt for each period from when the occupants get into the vehicle until when they get out. The period from getting in to getting out means, for example, the period from when the ignition switch is turned on until the ignition switch is turned off.

[0027] In this embodiment, the air conditioning ECU 20 extracts a correction value Cv corresponding to the difference time Δt from the correction value information stored in the storage unit 22, in relation to the correction of the amount of solar radiation detected by the solar radiation detection unit 33 based on the difference time Δt. As shown in Figure 4, the correction value information is information that associates a difference time category, which is a category of the difference time Δt between a reference time ts and an actual measured time tm, with a correction value Cv as a preset value. The difference time category may be a specific numerical value or information indicating a certain range. The correction value Cv is set to a larger value as the difference time Δt increases. For example, in Figure 4, the corresponding correction value Cv is set to a larger value according to the difference time categories in the order of Δt1, Δt2, Δt3, Δt4, and Δt5. The number of difference time categories can be set arbitrarily.

[0028] The air conditioning ECU 20 can then perform automatic air conditioning control using a corrected solar radiation amount obtained by adding a correction value Cv extracted from correction value information to the solar radiation amount detected by the solar radiation detection unit 33 when the actual measurement time tm is measured. The corrected solar radiation amount can be calculated, for example, by multiplying the solar radiation amount detected by the solar radiation detection unit 33 by the correction value Cv. However, it is not limited to this, and the corrected solar radiation amount may also be calculated by adding the correction value Cv to the solar radiation amount. In the execution of automatic air conditioning control, the air conditioning ECU 20 controls the operation of the air conditioning device 10 using the target outlet temperature TAO calculated using the corrected solar radiation amount instead of the detected value Ts from the solar radiation detection unit 33. The memory unit 22 can also store the correction value Cv used to calculate the target outlet temperature TAO as a set value.

[0029] Here, the correction value Cv can be set in accordance with the difference time division in the correction value information. However, if the difference time Δt is calculated based on solar radiation due to, for example, a false detection by the solar radiation detection unit 33, it may not be possible to properly ensure the comfort level of the air conditioning. Therefore, when the difference correction value ΔCv, which is the difference between the correction value Cvp set in the past and the correction value Cvc extracted based on the difference time Δt calculated this time, is greater than or equal to a threshold, the air conditioning ECU 20 updates the setting value of the correction value Cv used to calculate the target outlet temperature TAO to the correction value Cvc. In other words, when the difference between the difference time Δtp calculated in the past and the difference time Δtc calculated this time is greater than or equal to a threshold, the air conditioning ECU 20 considers that the installation environment of the solar radiation detection unit 33 has changed and can perform automatic air conditioning control using the corrected solar radiation amount obtained by incorporating the correction value Cvc corresponding to the difference time Δtc calculated this time.

[0030] Specifically, for example, if the previously set correction value Cvp is Cv2 as shown in Figure 4, the air conditioning ECU 20 will not update the setting value of the correction value Cv if the difference time Δt calculated this time corresponds to difference time category Δt3, but will update the setting value of the correction value Cv4 if the difference time Δt calculated this time corresponds to difference time category Δt4.

[0031] Next, with reference to Figures 5 and 6, an example of the control content related to the correction of the target outlet temperature TAO performed by the air conditioning ECU 20 will be explained. When the air conditioning ECU 20 starts control (start in Figure 5), it performs correction value processing in step S11. In the correction value processing, the air conditioning ECU 20 determines whether the ignition switch has been turned on or not in step S21 in Figure 6. If the ignition switch has not been turned on (NO in step S21), the air conditioning ECU 20 proceeds to step S12 in Figure 5. On the other hand, if the ignition switch has been turned on (YES in step S21), the air conditioning ECU 20 determines whether automatic air conditioning control is being performed or not in step S22.

[0032] If automatic air conditioning control is not being performed (NO in step S22), the air conditioning ECU 20 proceeds to step S12 in Figure 5. On the other hand, if automatic air conditioning control is being performed (YES in step S22), the air conditioning ECU 20 starts measuring time using the timing unit 21 in step S23. Next, in step S24, the air conditioning ECU 20 determines whether the blower level has reached a predetermined value BLt.

[0033] If the blower level reaches a predetermined value BLt (YES in step S24), the air conditioning ECU 20, in step S25, obtains the measured time tm until the blower level reaches the predetermined value BLt and ends the time measurement. Next, in step S26, the air conditioning ECU 20 extracts a reference time ts corresponding to the amount of solar radiation detected by the solar radiation detection unit 33 from the blower level information stored in the memory unit 22. Then, in step S27, the air conditioning ECU 20 calculates the difference time Δt, which is the difference between the reference time ts and the measured time tm.

[0034] Next, in step S28, the air conditioning ECU 20 extracts a correction value Cvc corresponding to the difference time Δt calculated from the correction value information stored in the memory unit 22. In step S29, the air conditioning ECU 20 calculates a differential correction value ΔCv, which is the difference between the previously set correction value Cvp and the correction value Cvc extracted based on the difference time Δt calculated this time. Then, in step S30, the air conditioning ECU 20 determines whether the differential correction value ΔCv is greater than or equal to a threshold.

[0035] If the differential correction value ΔCv is less than the threshold (NO in step S30), the air conditioning ECU 20 proceeds to step S12 in Figure 5. On the other hand, if the differential correction value ΔCv is greater than or equal to the threshold (YES in step S30), the air conditioning ECU 20 updates the set value of the correction value Cv to the correction value Cvc in step S31 and proceeds to step S12 in Figure 5.

[0036] In step S12, the air conditioning ECU 20 determines whether the set value of the correction value Cv has been updated. If the set value of the correction value Cv has not been updated (NO in step S12), the air conditioning ECU 20 terminates the series of controls (end).

[0037] On the other hand, if the set value of the correction value Cv is updated (YES in step S12), the air conditioning ECU 20 calculates the corrected solar radiation amount in step S13 by multiplying the updated correction value Cv by the solar radiation amount detected by the solar radiation detection unit 33. Next, in step S14, the air conditioning ECU 20 calculates the target outlet temperature TAO using the corrected solar radiation amount and ends the series of control operations (end).

[0038] According to the embodiment described above, the vehicle air conditioning system 1 comprises an air conditioning device 10, a solar radiation detection unit 33, an air conditioning ECU 20, and a storage unit 22. The air conditioning device 10 sends conditioned air into the vehicle's interior. The solar radiation detection unit 33 detects the amount of solar radiation inside the vehicle. The air conditioning ECU 20 controls the operation of the air conditioning device 10 using the amount of solar radiation to perform automatic air conditioning control that maintains a constant temperature for the occupants inside the vehicle. The storage unit 22 stores a reference time ts until the amount of conditioned air reaches a predetermined value BLt, corresponding to the amount of solar radiation. The air conditioning ECU 20 then sets a correction value Cv for the amount of solar radiation used in automatic air conditioning control based on the difference time Δt, which is the difference between the reference time ts and the measured time tm until the amount of conditioned air reaches the predetermined value BLt.

[0039] According to this, if the installation environment of the solar radiation detection unit 33 changes, the correction to the amount of solar radiation used for automatic air conditioning control can be performed using only the amount of solar radiation detected by the solar radiation detection unit 33. Therefore, it is not dependent on the vehicle and does not require the installation of additional equipment. As a result, the comfort of the air conditioning in automatic air conditioning control can be improved without increasing costs.

[0040] The air conditioning ECU 20 performs automatic air conditioning control using the corrected solar radiation amount obtained by incorporating a correction value Cvc corresponding to the currently calculated differential time Δtc if the difference between the previously calculated differential time Δtp and the currently calculated differential time Δtc is greater than or equal to a threshold. This allows for appropriate estimation of changes in the installation environment of the solar radiation detection unit 33. As a result, the comfort level of the air conditioning in automatic air conditioning control can be further improved.

[0041] Furthermore, the air conditioning ECU 20 sets a correction value Cv for each period from when the occupant gets into the vehicle until when they get out. This allows for appropriate monitoring of fluctuations in the installation environment of the solar radiation detection unit 33. As a result, the comfort level of the air conditioning can be improved by adapting to fluctuations in the installation environment of the solar radiation detection unit 33.

[0042] While this disclosure is written in accordance with embodiments, it is understood that this disclosure is not limited to such embodiments or structures. This disclosure also includes various modifications and variations within the scope of equivalents. In addition, various combinations and forms, as well as other combinations and forms that include only one, more, or fewer of those elements, fall within the scope and concept of this disclosure. [Explanation of symbols]

[0043] 1...Vehicle air conditioning system, 10...Air conditioning unit, 20...Air conditioning ECU (control unit), 22...Memory unit, 33...Solar radiation detection unit

Claims

1. An air conditioning system (10) that sends conditioned air into the passenger compartment of the vehicle, A solar radiation detection unit (33) for detecting the amount of solar radiation inside the vehicle interior, A control device (20) capable of performing automatic air conditioning control to maintain a constant temperature for occupants inside the vehicle by controlling the operation of the air conditioning system using the amount of solar radiation, The system includes a storage unit (22) that stores a reference time (ts) for the amount of air conditioning wind corresponding to the amount of solar radiation to reach a predetermined value (BLt), The control device sets a correction value (Cv) for the amount of solar radiation used in the automatic air conditioning control based on the difference time (Δt), which is the difference between the reference time and the measured time (tm) until the amount of air conditioning air reaches the predetermined value. Vehicle air conditioning system.

2. The control device executes the automatic air conditioning control using the corrected solar radiation obtained by adding a correction value (Cvc) corresponding to the currently calculated difference time (Δtp) if the difference between the difference time calculated in the past and the difference time calculated this time (Δtc) is greater than or equal to a threshold. The vehicle air conditioning system according to claim 1.

3. The control device sets the correction value for each period from when the occupant boards the vehicle until when they disembark. The vehicle air conditioning system according to claim 1 or 2.

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