JP2720528B2 - Control unit for vehicle air conditioner - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a control device for a vehicle air conditioner using a micro computer.

[Conventional technology]

The vehicle air conditioner includes a compressor that adiabatically compresses the heat medium and a blower that blows the heat-exchanged air, and blows out a necessary amount of air adjusted to a required blowing temperature into a vehicle compartment to achieve air conditioning.

The required outlet temperature TAO is the desired cabin set temperature T _SET ,
Cabin temperature Tr, the outside air temperature Tam, based on the amount of solar radiation S _T, is calculated by the following equation (1).

_{TAO = K SET × T SET -Kr} × Tr-Kam × Tam -Ks × S T + C ... (1) where, K _SET: constant depending preset temperature Kr: constant depending cabin temperature Kam: constant depending outside temperature C: It is a constant.

The amount of air blown into the passenger compartment per unit time, that is, the amount of blown air from the blower is controlled by the voltage applied to the blower.

Conventionally, the voltage V applied to the blower has been controlled to increase when TAO exceeds a certain numerical value. FIG. 6 (a) shows this state, when the TAO exceeds a certain numerical value or when the TAO falls below a certain numerical value, that is,
Generally, when the difference between the set temperature and the cabin temperature is large,
An attempt is made to reduce the difference rapidly by increasing the amount of blown air. The same applies to the opening of the air mix damper provided in the air outlet duct.
Control based on TAO.

Normally, when the difference between the outside air temperature Tam and the set temperature is large, the heat load becomes large, and as a result, the room temperature distribution is likely to occur. As shown in FIG. 6 (b), the blower voltage V becomes the outside air temperature Tam. It is preferable to control so as to increase or decrease according to the following.

FIG. 6 (c) shows the vehicle interior temperature Tr at the warm-up.
And how the temporal change of the blower voltage V is affected by the level of the outside air temperature Tam. The lower the Tam, the longer it takes to increase the vehicle compartment temperature, and the high speed operation of the blower (Hi) The time will be longer. Similar characteristics can be obtained during cool down.

Next, FIG. 6 (d) shows the cabin temperature at the warm-up.
It shows how the temporal changes of Tr and the blower voltage V are affected by the cabin constant Kr. For example, when Kr is set to a small value, the blower high-speed time becomes short, but the blower becomes susceptible to thermal load disturbance. Similar characteristics can be obtained during cool down.

FIG. 6 (e) shows the relationship between the disturbance of the heat load of the passenger compartment and the deviation of the passenger compartment temperature. The deviation is also large.

As described above, it is desirable to set the applied voltage that determines the air volume of the blower based on various factors in order to reduce noise and reduce the deviation of the indoor temperature distribution. The applied voltage was determined centrally from the relationship between the temperature and the cabin temperature.

Such techniques are disclosed, for example, in JP-B-62-58922, JP-B-62-58923, JP-B-62-41128, and JP-B-63-1936.
No. 1 discloses this.

[Problems to be solved by the invention]

In the conventional technology as described above, when trying to reduce the noise by controlling the blower blowing air volume in the transitional period during cool down or warm-up, the blowing air volume in the steady state becomes insufficient. If the room temperature deviation easily occurs due to the generation of the temperature distribution in the room or the disturbance of the heat load, a problem occurs.

SUMMARY OF THE INVENTION The present invention provides a control device for a vehicle air conditioner that reduces noise by suppressing the air volume in a transitional period and increases the air volume in a steady state to achieve a uniform room temperature distribution.

[Means for solving the problem]

In order to solve the above problems, the control device of the present invention detects a set temperature, a vehicle interior temperature, an outside air temperature, and an amount of solar radiation, and based on the detected input information, cools down the air conditioner or transitions to warm-up. Means for calculating a required blow-off temperature to obtain a first blower voltage corresponding to the required blow-out temperature; and calculating a required blow-off temperature corresponding to a steady-state heat load of the air conditioner based on the input information. Means for determining a second blower voltage corresponding to the required blowing temperature.

Then, the comparing means for comparing the first blower voltage and the second blower voltage supplies the larger one of the first and second blower voltages to the blower drive control device as a blower application voltage. is there.

[Action]

Compare the blower voltage required for the transient and steady-state heat loads of the air conditioner, and apply a large voltage to the blower to control the blower air volume, so that the air volume during the transient does not become excessive. As described above, the noise is reduced, and even when the heat load in the steady state fluctuates, a sufficient air volume is secured to achieve a uniform temperature distribution in the vehicle compartment.

〔Example〕

Hereinafter, an embodiment of the present invention will be described with reference to FIGS. 1 to 5.

FIG. 1 is a block diagram showing a control system of an air conditioner of a vehicle to which the present invention is applied. In the control system, in addition to gains G ₁ and G ₂ , a gain corresponding to a vehicle compartment and the like are shown. is inserted in series, when it is set desired set temperature T _sET, performs control while fed back to room temperature Tr.

Heat load Q _L of the vehicle given by Equation (3) described below, the ability of the air conditioner corresponding to the heat load Q _L as Q _L1, performing feedforward control to move this point forward. The disturbance factors include the heat generated by the occupant and the influence of opening and closing the door. During a so-called transitional period at the time of cool-down or warm-up in which the difference between the set temperature T _SET and the vehicle interior temperature Tr is large, the TAO is changed so as to obtain sufficient cooling / heating capacity. The above-mentioned feedback at room temperature Tr performs this function. Assuming that the required blowing temperature at this time is T _D , T _D = K _D × (T _SET −Tr) (2)

Here, K _D is a constant.

Next, even in the steady state after the completion of the cool-down and warm-up, for example, when the temperature difference between the inside and outside of the vehicle is large, the difference between the required blowing temperature TAO and the room temperature Tr becomes large. Is more likely to occur. In such a case, it is desirable to control the applied voltage of the blower according to not only the TAO but also the heat load of the vehicle. Vehicle heat load Q
_L is approximately is represented by _{Q L = A 1 × (Tam} -Tr) + A 2 × S T + C ... (3).

Here, A ₁ , A ₂ , and C are constants.

That is, when the blowout temperature of the air conditioner corresponding to the heat load Q _L of the vehicle and T _S, it is possible to approximately expressed by replacing the Tr of formula (1) described above and T _SET, T _S = represented by _{Ks 1 × T SET -Ks 2 ×} Tam-Ks 3 × S T + Ks 4 ... (4).

Here, Ks ₁ , Ks ₂ and Ks ₄ are constants.

Since T _D expressed by the equation (2) and Ts expressed by the equation (4) express the required blowing temperature at the time of transient and the blowing temperature corresponding to the heat load, respectively, T _S shown in FIG. By selecting the blower applied voltage based on the relationship between the blower applied voltage V _{S and} the relationship between T _D and the blower applied voltage V _D shown in FIG. 3, (1) reduce the air volume during transition to reduce noise thing.

(2) A uniform air temperature distribution is to be achieved by increasing the flow rate in a steady state.

(3) Minimize room temperature deviation against thermal load disturbance.

Control that satisfies the above three requirements can be achieved.

Next, a method of determining the blower application voltage will be described with reference to the flowchart of FIG.

The control means starts the control flow in step 100, and inputs information from various sensors in step 110. The information to be input includes the set temperature T _SET and the outside air temperature Ta
m, cabin temperature Tr, is the amount of solar radiation S _T, and the like.

Next, based on these input information, in step 120, the necessary blow-off temperature T _D at the time of the transition shown in the equations (2) and (4)
Then, the required blowing temperature T _{S corresponding} to the heat load in the steady state is calculated.

In step 130, blower applied voltages V _D and V _S corresponding to the calculated T _D and T _S are obtained. This relationship between T _D and V _D and T _S and V _S
2 and FIG. 3, a pattern is formed in advance, and this is stored in a read-only memory of the control means, and V _D and V _S are obtained from this pattern.

In step 140, it compares the value of V _D and V _S. In other words, the blower applied voltage V _D corresponding to the required blowing temperature during transition
If, compared with the blower applied voltage V _S corresponding to commensurate ivy blowout temperature to the heat load in a steady state, V _D advances to step 160 is greater than V _S, it sets the blower applied voltage V to V _D. V
_S advances to step 150 is greater than V _D, it sets the blower applied voltage V to V _S.

The control means outputs the blower applied voltage V set in step 170 to the blower driving circuit, and drives the blower at a rotation speed corresponding to the applied voltage V. The process returns from step 180 to the start of step 100.

2 and 3, the relationship between T _S and V _S is indicated by a solid line V _S
The pattern shown in, the case where linearly changed to a pattern showing the relationship between T _D and V _D by a solid line V _D, adjust the length of the high-speed operating time of the blower by deforming, for example, as shown by a dotted line It is also possible to pattern the relationship between the required blowing temperature and the blower applied voltage in a curved manner such as curving upward or curving downward. Further, a mathematical expression and a logic circuit may be combined, or an analog electronic circuit or the like may be used.

In short, it suffices to perform patterning so that the blower air volume changes optimally in accordance with the required blowing temperature.

Next, the embodiment shown in FIG. 5 shows a control method for more positively reducing the blower noise at the time of transition by adding a selection switch.

In the flowchart shown in FIG.
After reading the input information from the sensor in step 22,
Check ON / OFF of Mute switch MUTE / SW with 0. Mute switch MUTE / SW is a manual switch attached to the air conditioner, and is used when it is desired to reduce the blowout amount.

In step 230, T _S and T _D are calculated. At step 240, ON / OFF of the Mute switch MUTE / SW is determined. If it is OFF, the process proceeds to step 250, where V _D = V _D2 . Relationship T _D and V _D2 than that shown in FIG. 5 (b), T _D of the curve Figure 3
To match the relationship of V _D.

Step 26 if Mute switch MUTE / SW is ON
Proceed to 0 and set V _D = V _D1 . Pattern V _D1, as shown in FIG. 5 (b), is set to be lower than the curve of V _D2,
The blower voltage also decreases. Accordingly, the blower air volume is reduced, but the noise can be reduced. V at step 270
By comparing the values of _D and V _S, returns to the initial state in step 310 is output to the blower drive circuit at step 300 the value of the larger as blower applied voltage V at step 280 and 290.

〔The invention's effect〕

As described above, the control device of the present invention, when controlling the vehicle air conditioner, achieves the optimum blower shift both in the transient state and in the steady state. _SET, the outside air temperature Tam, the passenger compartment temperature Tr, as well as detecting the amount of solar radiation S _T, blowout temperature T _S that corresponds to the required air temperature T _D and the heat load during transients based on the information
And (2) calculating means for obtaining optimum blower voltages V _D and V _S corresponding to T _D and T _S based on a predetermined pattern, and (3) comparing V _D and V _S And (b) reducing the noise of the blower during the transition, and (b) making the temperature distribution in the vehicle compartment steady during the steady state. c) It has the effect of simultaneously achieving the effect of reducing room temperature deviation with respect to thermal load disturbance.

Further, when a mute switch is provided, the blower applied voltage during transition can be kept low, and the blower noise can be positively reduced.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing a control system of the present invention, FIG. 2 is an explanatory diagram showing a relationship between a required blowing temperature and a blower applied voltage in a transient state, and FIG. 3 is a required blowing corresponding to a heat load in a steady state. Explanatory diagram showing the relationship between temperature and blower applied voltage, FIG. 4 is a flowchart showing a basic control process, FIG. 5 is a flowchart showing another embodiment, and FIG. 6 is necessary for a conventional control method and control. FIG. 4 is an explanatory diagram showing characteristics of various elements. 110: a step of reading a set temperature, an outside air temperature, a vehicle compartment temperature, and an amount of solar radiation as input information; 120: a required blowing temperature T during a transition based on the input information.
_D , a step of calculating the blowout temperature T _S corresponding to the steady-state heat load, 130... A step of obtaining blower voltages V _D , V _S corresponding to T _D and T _S , 140... V _D and V _S comparing the values, 150 and 160 steps to replace large becomes better as the blower voltage applied among ...... V _D and V _S, the step of outputting 170 ...... blower voltage applied to the blower drive circuit.

Claims (1)

(57) [Claims] 1. Means for detecting a set temperature of a cabin, a cabin temperature, an outside air temperature, and an amount of solar radiation as input information, a means for calculating a required blowout temperature of an air conditioner based on the input information, and a necessary blowout temperature And a means for applying an applied voltage to a control device of a blower of the air conditioner based on the control of the vehicle air conditioner. Reading means, calculating means for calculating a required blow-out temperature during a transition of the cool-down or warm-up of the air conditioner based on the input information, and means for obtaining a first blower voltage corresponding to the required blow-out temperature during the transition, Calculating means for calculating a required blowout temperature corresponding to a heat load in a steady state of the air conditioner based on the input information; and a second blower voltage corresponding to the required blowout temperature in a regular state. Means for comparing the first blower voltage and the second blower voltage; and a higher one of the first blower voltage and the second blower voltage as a blower applied voltage to the blower drive control device. Output means; and a control device for a vehicle air conditioner.