JPS6332644B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an improvement in an air conditioning control device employed in a vehicle, such as a large vehicle.

[Prior art]

Conventionally, in this type of air conditioning control device, air
When the mix damper is at the maximum heating position, the blower controls the amount of airflow blown into the vehicle interior to the maximum, and all of the airflow sent from the blower is derived from the internal combustion engine cooling system of the vehicle. The cooling water is heated by a heater and then blown into the passenger compartment to provide the maximum heating feeling.

[Problem that the invention seeks to solve]

However, in such a configuration, since the cooling water temperature decreases when the internal combustion engine is idling or under low load, the air flow applied to the heater cannot be sufficiently warmed, and the above-mentioned heating I tend not to feel the same way. Furthermore, this tendency becomes more pronounced as the amount of air flow from the blower increases.

In order to deal with such problems, the present invention provides a vehicle air conditioning control system in which a heating means for the air flow from the temperature regulating means such as an air mix damper is set at the maximum heating position. The aim is to reduce the amount of air flow that should be blown into the passenger compartment when the heating capacity of the vehicle is insufficient.

[Means for solving problems]

In order to solve this problem, the structural features of the present invention include a blowing means for blowing the airflow into an air passage having an outlet for blowing the airflow into the vehicle interior, and a blowing means for blowing the airflow from the blowing means. the air flow from the outlet into the vehicle interior by adjusting the heating ratio of the heating means to the cooling air flow; A vehicle air conditioner comprising: a temperature adjusting means for controlling the actual blowing temperature to a desired blowing temperature; and an air blowing amount controlling means for controlling the amount of air flow of the blowing means according to a change in the desired blowing temperature. In the control device, heating capacity detection means for detecting the actual heating capacity of the heating means;
determining means for determining whether the detected heating capacity of the heating capacity detecting means is below a reference value when the heating means is adjusted to maximize its actual heating rate; The present invention further includes air blowing amount correcting means for correcting the amount of air flow controlled by the air blowing amount control means to decrease when it is determined that the blowing air flow is less than or equal to the air blowing amount control means.

[Effect]

By configuring the present invention in this way, when the heating means is adjusted to maximize its actual heating rate under the adjustment action of the temperature adjusting means, the determining means determines whether the heating means It is determined whether the detected heating capacity is below the reference value. When the result of this determination is less than or equal to the reference value, the air flow rate correction means corrects the amount of air flow controlled by the air flow rate control means to decrease. Therefore, the amount of air flow into the passenger compartment is reduced to ensure the desired air flow temperature, and as a result, the feeling of heating for the occupants is reduced without an unnecessary increase in the air flow. can be appropriately prevented.

〔Example〕

Hereinafter, one embodiment of the present invention will be described with reference to the drawings. Fig. 1 shows an example in which the present invention is applied to a known air conditioning system for a large vehicle. , a switching door 20, a blower 30, an evaporator 40, a heater 50, and an air mix damper 60 are arranged. The switching door 20 is manually operated to introduce outside air into the air duct 10 from outside the vehicle when the inlet 11 of the air duct 10 is opened, and to introduce outside air into the vehicle interior 13 when the recirculation port 12 of the air duct 10 is opened. The air inside is returned to the air duct 10.

The blower 30 sucks air from the inlet 11 or the reflux port 12 and sends it to the evaporator 40 as an air flow having a flow rate depending on the rotation speed. The air flow from the blower 30 is cooled by a cooling medium in the evaporator 40 and applied to the air mix damper 60 as a cooling air flow, while the air inside the evaporator 40 heated by the heat of the air flow from the blower 30 is The cooling medium is sent to compressor 41. The compressor 41 is operatively connected to the internal combustion engine E via its electromagnetic clutch 42, and when energized by the electromagnetic clutch 42, the compressor 41 is operatively connected to the internal combustion engine E.
The refrigerant sent from the evaporator 40 is compressed into a high-pressure, high-temperature refrigerant, which is passed through a condenser 43, a pressure receiver 44, and an expansion valve 45 to the evaporator 40 as a low-pressure, low-temperature refrigerant.
Send again to. Note that when the electromagnetic clutch 42 is in a de-energized state, the compressor 41 is disconnected from the internal combustion engine E.

The heater 50 receives cooling water from the cooling device of the internal combustion engine E, warms the cooling air flow sent from the evaporator 40, and sends it into the vehicle interior 13 as an air flow having a predetermined temperature. air mix damper 60
is connected to the rod 62 of the electric pneumatic actuating mechanism 61, and when the electric pneumatic actuating mechanism 61 is applied with atmospheric pressure or negative pressure from the internal combustion engine E, the rod 6
When the rod 2 is moved upward or downward, the opening degree Ar is decreased or increased in accordance with the upward or downward movement of the rod 62. As a result, a part of the cooling air flow from the evaporator 40 is transferred to the heater 50 according to the opening degree Ar of the air mix damper 60.
while the remaining portion of the cooling air flow from the evaporator 40 is applied directly into the passenger compartment 13 . In this case, air mix damper 60
has a minimum opening degree when the rod 62 is at the upper moving end shown, and the entire cooling airflow from the evaporator 40 is applied directly into the passenger compartment 13.
On the other hand, when the rod 62 is at the lower moving end, the air mix damper 60 is at its maximum opening, and the entire cooling airflow from the evaporator 40 is applied to the heater 50. Note that when the electric pneumatic actuation mechanism 61 is simultaneously cut off from atmospheric pressure and the negative pressure of the internal combustion engine E to stop the rod 62, the opening degree of the air mix damper 60 changes to a value corresponding to the stop position of the rod 62. will be maintained.

The electric control circuit 70 includes an A-D converter 79a connected to various sensors 71 to 76, and a temperature setting device 77.
and a digital computer 79 connected to a control switch 78. Inside temperature sensor 71
is placed in the vehicle interior 13, detects the actual temperature Tr in the vehicle interior 13, and generates an analog signal having a level corresponding to the interior temperature Tr. The opening sensor 72 is connected to the rod 6 of the electric pneumatic actuation mechanism 61.
2, and in relation to displacement of rod 62, air mix damper 60
The actual opening degree Ar is detected, and an analog signal having a level corresponding to the detected opening degree Ar is generated.
The outside temperature sensor 73 is disposed close to the front grill of the vehicle radiator, detects the actual temperature Tam of the air outside the vehicle, and generates an analog signal having a level corresponding to this outside temperature Tam.

The water temperature sensor 74 is disposed close to the inlet of the heater 50, detects the actual temperature Tw of the cooling water from the cooling device, and generates an analog signal having a level corresponding to the detected water temperature Tw. The air temperature sensor 75 is disposed close to the outlet of the evaporator 40, detects the actual temperature T _E of the air flow from the evaporator 40, and converts this detected air temperature
Generates an analog signal having a level corresponding to T _E. The solar radiation sensor 76 is disposed near the window of the vehicle interior 13, detects the actual solar radiation amount Ts, and generates an analog signal having a level corresponding to this.

The A-D converter 79a converts each sensor 71 to 76 based on a request from the digital computer 79.
Converts the analog signal from to a digital signal,
These digital signals are converted into internal temperature Tr, opening degree Ar,
Outside temperature Tam, water temperature Tw, air temperature T _E , and solar radiation Ts
A digital computer 79 represents
granted to. The temperature setting device 77 is provided in the vehicle compartment 13, and a desired temperature setting Tset is selected by manual operation by a passenger and is generated as a temperature setting signal. Under its operation, the control switch 78
A first command signal necessary to drive the blower 30 at a predetermined rotational speed is generated. Furthermore, when the control switch 78 is not operated, it generates a second command signal necessary to place the blower 30 under automatic control.

Digital computer 79 is a single chip
The microcomputer 79 is formed of an LSI, and receives a constant voltage from a constant voltage circuit (not shown) to be ready for operation. In this case, the constant voltage circuit receives DC voltage from a DC power source in response to closing of an ignition switch (not shown) and generates the constant voltage. The microcomputer 79 is
It is equipped with a central processing unit (hereinafter referred to as CPU), memory, input/output device (hereinafter referred to as L/O), and a clock circuit.
and clock circuits are connected to each other via a bus line. The memory of the microcomputer 79 receives and temporarily stores each digital signal from the A-D converter 79a, the temperature setting signal from the temperature setting device 77, and the command signal from the control switch 78 through the L/O. Selectively give signals to the CPU. The clock circuit of the microcomputer 79 cooperates with the crystal oscillator 79b to generate a clock signal having a predetermined frequency, and allows the microcomputer 79 to execute a predetermined control program based on this clock signal.

The predetermined control program is stored in advance in the memory of the microcomputer 79 in order to execute the following arithmetic processing within the microcomputer 79.

(1) The CPU uses the set temperature Tset stored in memory,
According to the inside temperature Tr, the outside temperature Tam, and the amount of solar radiation Ts, the blowout temperature _TAO required for the air flow blown out from the air duct 10 into the passenger compartment 13 is calculated using the following formula (1).
Calculate based on.

T _AO = Kset・Tset−Kr・Tr −Kam・Tam−Ks・Ts+C ...(1) However, each coefficient Kset, Kr, Kam, and Ks is determined experimentally considering the performance of the air conditioning device. The symbol C indicates a constant, and each gain and constant are stored in the memory in advance.

(2) The CPU calculates the optimum opening degree SW of the air mix damper 60 based on the following equation (2) according to the blowout temperature T _AO and the water temperature Tw and air temperature T _E stored in the memory, and This calculation result and the actual opening degree of the air mix damper 60 stored in memory
An output signal representative of the difference from Ar is generated and applied to the electrical pneumatic actuation mechanism 61.

SW=T _AO −T _E /Tw−T _E −15×100 (%) ...(2) (3) The CPU determines the optimal opening SW based on the second command signal from the control switch 78.・Determine whether or not the opening degree of the mixer damper 60 is at its maximum, and if the optimal opening degree SW is the maximum opening degree, determine whether the water temperature Tw stored in the memory is 70°C or less. Do the following. Therefore, if the optimum opening degree SW is not the maximum opening degree, or if the water temperature Tw exceeds 70°C even if the optimum opening degree SW is the maximum opening degree, the CPU
From the characteristic curve that defines the relationship between the amount W of air flow blown into the vehicle compartment 13 from the outlet of the air outlet and the outlet temperature _TAO , the outlet temperature is obtained from equation (1).
The blown air flow rate W is calculated according to _TAO , and this is generated as an output signal and applied to the drive circuit 31. In this embodiment, the characteristic curve is determined as shown in FIG. 2 based on the performance of the air conditioner, the shape of the air outlet of the air duct 10, the volume of the vehicle compartment 13, etc., and is stored in the memory. is stored in advance. In this case, as can be easily understood from Fig. 2, the blowout air flow rate W takes a maximum value Hi at the minimum and maximum values of the blowout temperature _TAO , and a minimum value near the median value of the blowout temperature _TAO . Lo
Take.

In addition, if the water temperature Tw is below 70℃,
The CPU uses the water temperature Tw and air temperature stored in memory.
In accordance with _T
Correct the blowout air flow rate W when the air flow rate is more than Lo
When the calculated result Va is smaller than the minimum value Lo, the blown air flow rate W is set to the minimum value Lo, and the calculated result Va or the minimum value Lo is generated as an output signal and applied to the drive circuit 31.

Va=1/a {b-N/Cpγ(Tw-T _E )} ...(3) Therefore, in this example, this equation (3) is replaced by equation (5) and equation (5) in equation (4) described below. It can be obtained by substituting equation (6).

Va=Q/N...(4) However, the symbol N represents the stove ratio, and this stove ratio N is kept constant and stored in memory in advance in order to maintain the same heating feeling given to the occupants in the passenger compartment 13. has been done. In addition, the symbol Q is the modified air flow rate Va
The amount of heat dissipated is expressed by the following equation (5).

Q=φVa・Cpγ(Tw−T _E ) ……(5) However, the symbol Cp is the constant pressure specific heat of air (0.24Kcal/
Kg°C), and the symbol γ indicates the specific gravity of air (1.66Kcal/m ₃ ). Further, the symbol φ indicates the temperature efficiency of the heater 50, which can be approximated by the following equation (6) if the flow rate of the cooling water is constant.

φ=-a·Va+b (6) However, the symbols a (a>o) and b are constants determined in relation to a constant flow rate of cooling water. In addition, each value
Cp, γ, a and b are each stored in the memory in advance.

(4) The CPU sets the blowing air flow rate W to a constant value W _M based on the first command signal from the control switch 78,
An output signal representing this is generated and applied to the drive circuit 31.

The electric gas actuating mechanism 61 selects the optimum opening SW from the microcomputer 79 and the actual opening.
In response to an output signal representing the difference between the opening degree and Ar, when the optimum opening degree SW is larger than the actual opening degree, negative pressure is applied from the internal combustion engine E according to the difference between these opening degrees, and the optimum opening degree is set. When SW is smaller than the actual opening degree Ar, atmospheric pressure is applied according to the difference between these opening degrees, and when the optimum opening degree SW is equal to the actual opening degree Ar, it is cut off from negative pressure and atmospheric pressure. The drive circuit 31 also includes a microcomputer 7.
An output signal representing the blown air flow rate W is received from 9, converted into an analog signal having a level corresponding to the value of this output signal, and applied to the blower 30. This means that the blower 30
This means that the motor is driven at a rotational speed that corresponds to the level of the analog signal from the motor.

In this embodiment configured as described above, the internal combustion engine E is placed in an idling state by operating the ignition switch of the vehicle, and the microcomputer 79 receives a constant voltage from the constant voltage circuit to be in an operation ready state. Then, execution of arithmetic processing is started in step 101 according to the flowchart shown in FIG.
At this time, the temperature setting device 77 generates a temperature setting signal representing the desired temperature Tset by manual operation,
and the control switch 78 is not operated and the second
Assume that a command signal is being generated.

In this state, when the computer program proceeds to step 102, the actual temperature Tr in the passenger compartment 13 and the actual opening degree Ar of the air mix damper 60 are detected by the internal temperature sensor 71 and the opening degree sensor 72, respectively. The actual temperature Tam outside the vehicle and the actual temperature Tw of the cooling water from the cooling system are detected as analog signals by the outside air temperature sensor 73 and the water temperature sensor 74, respectively, and the evaporator 40
The actual temperature T _E and the actual amount of solar radiation Ts near the outlet are detected as analog signals by the air temperature sensor 75 and the solar radiation sensor 76, respectively, and these analog signals are sent to the A-D converter 79.
a, each is converted into a digital signal and temporarily stored in the memory of the microcomputer 79. Further, the temperature setting signal from the temperature setting device 77 and the second command signal from the control switch 78 are each temporarily stored in the memory of the microcomputer 79.

When the computer program advances to step 103, the CPU reads the set temperature Tset, internal temperature Tr, and external temperature from the memory of the microcomputer 79.
Tam, solar radiation Ts, constant C and each gain Kset,
Kr, Kam, and Ks are read out, the outlet temperature _TAO is calculated based on equation (1), and the computer program proceeds to step 104. Then, the CPU calculates the optimum opening degree SW of the air mix damper 60 based on equation (2) according to the outlet temperature _TAO calculated in step 103 and the water temperature Tw and air temperature _TE stored in the memory. Then, in step 105, this opening SW is
It generates an output signal representing the difference between the actual opening degree Ar stored in the memory and the actual opening degree Ar stored in the memory. Thereby, the electric pneumatic actuating mechanism 61 appropriately controls the opening degree of the air mix damper 60 according to the value of the output signal from the CPU.

When the computer program proceeds to step 106, the CPU determines "NO" based on the second command signal stored in the memory, and proceeds to step 108 to determine the optimum opening degree of the air mix damper 60.
Determine whether SW is the maximum value. If the optimum opening degree SW is the maximum value, the CPU determines "YES" and the water temperature Tw is changed in step 109.
Determine whether the temperature is below 70℃. As mentioned above, since the internal combustion engine E is in an idling state, if the temperature Tw of the cooling water is lower than 70°C, the CPU determines "YES" and advances the computer program to step 111.

Then, the CPU reads out the water temperature Tw and the air temperature T _E from the memory, and also reads out the stove ratio N, constant pressure specific heat Cp, specific gravity γ, and constants a and b.
A corrected air flow rate Va is calculated based on equation (3), and it is determined in step 112 whether the corrected air flow rate Va is greater than or equal to the minimum value Lo. Then, the CPU
If the corrected air flow rate Va is greater than or equal to the minimum value Lo, it is determined as "YES" and the blowout air flow rate W is determined as the corrected air flow rate Va in step 113, and if the corrected air flow rate Va is smaller than the minimum value Lo. In step 112, the determination is "NO", and in step 114, the blowout air flow rate W is set to the minimum value Lo.
The corrected air flow rate Va or the minimum value Lo is generated as an output signal in step 115 and applied to the drive circuit 31. In this way, the output signal from the CPU is converted and amplified by the drive circuit 31 into an analog signal having a level corresponding to the corrected air flow rate Va, and is applied to the blower 30. As a result, the rotation speed of the blower 30 is controlled based on the level of the analog signal from the drive circuit 31, and the blower 30 controls the evaporator 40 in accordance with the level of the analog signal from the drive circuit 31.
The flow rate of air fed towards the is controlled.

As understood from the above, water temperature
When Tw is 70°C or less, the blowing air flow rate W that defines the rotational speed of the blower 30 is changed to the corrected air flow rate Va or the minimum air flow rate determined in relation to the water temperature Tw while keeping the stove ratio N constant. Since it is determined by the value Lo, even when the internal combustion engine E is in an idling state, substantially the same feeling of heating can be given to the occupants regardless of fluctuations in the water temperature Tw. Note that such effects can be similarly achieved even when the vehicle is in a running state and the load on the internal combustion engine E is low.

While repeatedly executing the above operations,
When the water temperature Tw exceeds 70℃, the CPU goes to step 109.
If the answer is NO, the computer program proceeds to step 110. Then, the CPU determines the blowout air flow rate W based on the characteristic curve (see Figure 2) that defines the relationship between the blowout air flow rate W and the blowout temperature _TAO , depending on the blowout temperature _TAO obtained in step 103.
is calculated and generated as an output signal in step 115 and applied to the drive circuit 31. In this way, this output signal is controlled by the drive circuit 31 to control the blown air flow rate W.
The rotational speed of the blower 30 is changed to an analog signal having a level corresponding to the drive circuit 31.
It is controlled according to the level of the analog signal from. In other words, the flow rate of air fed to the evaporator 40 by the blower 30 is determined by the blowout temperature _TAO , and as a result, the feeling of heating for the occupant can be appropriately controlled.

In this state, if the optimal opening degree SW obtained in step 104 becomes smaller than the maximum value, the CPU determines "NO" in step 108, and
The rotational speed of the blower 30 is controlled in the same manner as described above. Note that when the control switch 78 is operated to generate the first command signal, this first command signal is
The command signal is stored in the memory of the microcomputer 79 in step 102, and based on this,
The CPU determines "YES" in step 106, and in step 107, the blown air flow rate W is determined to be a predetermined value W _M , which is generated as an output in step 115 and applied to the drive circuit 31.

In the above embodiment, a case has been described in which the stove ratio N is kept constant, but instead of this, for example, the blowout temperature _TAO may be kept constant to obtain the same heating feeling. In this case, the temperature efficiency φ is set as (-a・Va+b) as in the above example.
The predetermined program may be changed to calculate the corrected air flow rate based on the following equation.

Va=1/a(b-T _AO -T _E /Tw-T _E )

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment in which the present invention is applied to an air conditioning control system for a large vehicle, and FIG. 2 is a flowchart showing the operation of the computer in FIG. 1. Explanation of symbols, 10... Air duct, 13...
Vehicle interior, 30...Blower, 50...Heater, 60...
...Air mix damper, E...Internal combustion engine.

Claims (1)

[Claims] 1. A blowing means for blowing the airflow into an air passage having an outlet for blowing the airflow into the vehicle interior;
cooling means for cooling the air flow from the blowing means;
and a heating means for heating the cooling air flow from the cooling means, and adjusting the heating ratio of the heating means to the cooling air flow to determine the actual blowing temperature of the air flow from the air outlet into the vehicle interior. In the vehicle air conditioning control device, the vehicle air conditioning control device includes a temperature adjusting means for controlling the temperature of the air to a desired blowing temperature, and an air blowing amount controlling means for controlling the amount of air flow of the blowing means in accordance with a change in the desired blowing temperature. heating capacity detection means for detecting the actual heating capacity of the heating means; and when the heating means is adjusted to maximize its actual heating rate, the detected heating capacity of the heating capacity detection means is below a reference value. and an air blowing amount correcting means that corrects to reduce the amount of the controlled air flow by the air blowing amount control means when the judging means judges that the amount of air flow is equal to or less than the reference value. Features of vehicle air conditioning control equipment.